JPH05315647A - Nitride semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To get favorable property in ultraviolet ray region to orange-colored region by forming the first layer consisting of an orientated polycrystalline nitride semiconductor 5000Angstrom or less in thickness on a substrate, and providing an operating layer consisting of single crystal nitride semiconductor and two electrodes hereon, and connecting at least one electrode to the first layer. CONSTITUTION:An orientated polycrystal (GaN) 24, 5000Angstrom or less in thickness is made on a substrate 23, and a single crystal (n-GaN) 25 and further a single crystal (p-GaN) 26 are made hereon. And, an electrode 27 is connected onto the oriented polycrystal (GaN) 24, and an electrode 28 is made on the single crystal (p-GaN) 26 too. Here, for the substrate, at least one direction of the periodical disposition of atoms on the surface and at least one direction of the crystal axes of the grid face directly in contact with the board of the nitride semiconductor of the first layer are in the same direction, and the divergence between the interval between the atoms in the former direction and an integer times (not less than 1 and not more than 10) the interval between the atoms in the latter direction should be preferably 5% or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a nitride semiconductor device,
In particular, the present invention relates to a semiconductor light emitting device that can be used for a light emitting diode, a laser diode, or the like that emits ultraviolet light to orange light, which is optimal for a light source of a display, optical communication or OA equipment.

[0002]

2. Description of the Related Art Semiconductor devices, particularly visible light emitting diodes (LEDs), are used in a wide variety of fields as display devices and various light sources. However, ultraviolet to blue light emitting diodes have not been put into practical use, and development is urgently needed especially for displays requiring three primary colors. Although a laser diode is expected as a light source for an optical disc or a compact disc because it can increase the recording density 10 times or more, it has not been put into practical use yet. GaN, ZnSe, Z are used as the light emitting diode and the laser diode that generate ultraviolet light to blue light.
It is considered to use a compound semiconductor such as nS or SiC.

However, it is generally difficult to prepare a single crystal thin film of a compound semiconductor having such a wide band gap, and a method of manufacturing a thin film that can be used for a light emitting device has not been established yet. For example, gallium nitride (GaN), which is regarded as a promising blue light-emitting element, has hitherto been formed on the C-plane (0001) of sapphire by the MOCVD method (MetalOr).
ganic Chemical Vapor Depo
position) or VPE method (Vapor Ph
The film is formed by an aseptic epitaxy [Journal of Applied Physics (Journa
l of Applied Physics) 56 (1
984) 2367-2368]. However, according to this method, it was necessary to raise the reaction temperature in order to obtain good crystals, and the production was extremely difficult. Further, since the growth is carried out at a high temperature, nitrogen becomes insufficient and becomes a defect, and the carrier density becomes extremely large, so that good semiconductor characteristics have not been obtained yet. Therefore, in order to overcome it, a buffer layer of aluminum nitride is provided on the sapphire C-plane (0001), and a relatively thick G layer is formed thereon.
An aN thin film is manufactured to manufacture a semiconductor light emitting device.

Further, in an attempt to realize low temperature film formation, a method of irradiating a supplied nitrogen gas with an electron shower to activate it has been carried out [Japanese Journal of Applied Physics (Jap. J. Appl. Phy.
s. ), 20, L545 (1981)]. However, even with this method, a good film quality leading to light emission has not been obtained. Further, it has been attempted to form a film by using a highly active nitrogen source so as not to cause a shortage of nitrogen. In order to obtain highly active nitrogen, a method using plasma has been performed [Journal of Vacuum Science and Technology (J. Vac. Sci. Te.
chnol. ), A7, 701 (1989)] has not been successful at present.

Further, a GaInN mixed crystal thin film has been studied, and most of them are MOVP on a sapphire C plane.
Method E (Metal Organic Vapor Ph
film is formed by the "Asse Epitaxy" [Journal of Applied Physics (Journal)
of Applied Physics) 28 (19)
89) L-1334]. However, in this method, GaN
And InN have very different growth temperatures, and
It is difficult to obtain an InN mixed crystal. For GaAlN mixed crystal, a gas source MBE using ammonia gas is used.
Method (Gas-Source Molecular Be
An example of film formation by am Epitaxy has been reported [Journal of Applied Physics.
cs) 53 (1982) 6844-6848]. However, with this method, although cathode luminescence is observed at the temperature of liquid nitrogen, a thin film of good quality that can be used to fabricate a light emitting device has not yet been obtained.

When using the MOCVD method or MOVPE method, which is a conventional method for forming a nitride-based semiconductor thin film, it is necessary to use a raw material containing carbon and the pressure during film formation is high, so that the thin film There is a drawback that a lot of carbon is taken in as impurities and a nitride-based semiconductor having poor characteristics grows.

On the other hand, In is directly deposited on the insulating single crystal substrate.
A structure has been proposed in which a single crystal thin film of a III-V group compound semiconductor containing and / or Ga is formed (US Pat. No. 4,404,265). However, in this case, there are the following problems. Since the conditions for growing the single crystal thin film of the III-V compound semiconductor directly on the substrate are extremely limited, its implementation is not easy. Further, even when the semiconductor thin film grows directly, a large stress is applied to the semiconductor thin film due to the lattice mismatch between the substrate and the semiconductor, and therefore the durability as an element is low. Furthermore, since the single crystal semiconductor is formed on the substrate,
The conductivity becomes low, and it is difficult to obtain a good ohmic electrode for operating as an element.

Thus, unlike the GaAs-based semiconductor and the Si semiconductor, the nitride-based semiconductor thin film does not have its own single crystal substrate. Therefore, the thin-film growth must be performed by the hetero-epitaxy method. In particular, there is a problem that it is difficult to form a thin film having good crystallinity that can be used as a light emitting device.

[0009]

SUMMARY OF THE INVENTION The present invention is intended to solve this problem and provide a nitride semiconductor device, particularly a semiconductor light emitting device having good characteristics in the ultraviolet to orange region.

[0010]

As a result of intensive studies to solve the above problems, the present inventors have found that the atomic distance of a periodic atomic arrangement in at least one direction on the substrate surface is By approaching an integer multiple of the interatomic distance of the lattice plane of the nitride that constitutes the oriented polycrystalline nitride-based semiconductor that grows directly, a crystal with a very thin film thickness can be obtained on this oriented polycrystalline nitride semiconductor. It was found that a single crystal nitride-based semiconductor thin film having excellent properties was formed, and it was revealed that a semiconductor device having excellent characteristics was obtained by this.

That is, the nitride-based semiconductor device of the present invention has a substrate and a thickness of 50 directly formed on the substrate.
A first layer made of an oriented polycrystalline nitride semiconductor having a thickness of 00 angstroms or less, an operating layer made of a single crystal nitride semiconductor directly formed on the first layer, and connected to a predetermined portion. Two or more electrodes that are connected, and at least one electrode is connected to the first layer.

Further, according to the method for manufacturing a nitride semiconductor device of the present invention, a gas source for supplying a nitrogen-containing compound in a gaseous state, a solid source for supplying a group III element, and n-type and p-type dopants are supplied. Using a crystal growth apparatus using a molecular beam epitaxy method with a source and a pressure of 10 ⁻⁵ T
or less, a substrate temperature of 300 to 1000 ° C., a gaseous nitrogen-containing compound and a Group III element are supplied to the substrate surface,
A first layer of an oriented polycrystalline nitride-based semiconductor was formed on the substrate at a growth rate of 0.1 to 20 Å / sec, and subsequently, the pressure was 10 ⁻⁵ Torr or less and the substrate temperature was 3 or less.
At 00 to 1000 ° C., gaseous nitrogen-containing compounds and III
A group element is supplied to the surface of the first layer, and a 0.
It is characterized in that the single crystal nitride semiconductor layer is formed at a growth rate of 1 to 10 Å / sec.

Here, the oriented polycrystalline nitride semiconductor layer means that crystals are oriented in a substantially constant direction in the vicinity of the interface between the substrate and the nitride semiconductor, and the crystallinity of the oriented polycrystalline nitride semiconductor layer increases as the distance from the substrate increases. It is a thin film that is getting better.

The present invention will be described in more detail below.

In the substrate of the present invention, at least one direction of the periodic arrangement of atoms on the surface and one direction of the crystal axis of the lattice plane of the nitride semiconductor of the first layer which is in direct contact with the substrate are defined. In the same direction, the deviation between the interatomic distance in the former direction and the interatomic distance in the latter direction is preferably within 5% within an integer multiple (1 or more and 10 or less).

The atoms arranged periodically on the surface of the substrate are the atoms that occupy the lattice points of the substrate crystal and are located at the top. The integer multiple of the interatomic distance in at least one direction of the lattice plane of the nitride constituting the oriented polycrystalline nitride-based semiconductor of the first layer is 1 or more and 10 or less. If this is 10 or more, the atomic orbitals of the nitride-based semiconductor and the atoms exposed on the surface of the substrate are less overlapped, and the action of orienting the crystal is reduced, so that a polycrystalline nitride-based semiconductor layer with good orientation is obtained. Becomes difficult. further,
An integer multiple of the interatomic distance in at least one direction of the lattice plane of the nitride constituting the oriented polycrystalline nitride-based semiconductor, and the interatomic distance between atoms arranged periodically in the same direction as the one direction on the surface of the substrate. The deviation from the distance is preferably within 5%,
If the deviation is more than this, it becomes difficult to obtain a nitride-based semiconductor layer having good orientation. The deviation value is more preferably 3% or less, and further preferably 1% or less.

Here, the deviation of the interatomic distance between the substrate and the nitride-based semiconductor means the interatomic distance (a) in one direction of the lattice plane of the nitride-based semiconductor growing on the substrate in contact with the substrate. When the single crystal substrate is cut along a specific plane, it means the deviation from the interatomic distance (b) in one direction which is periodically arranged on the surface, and the magnitude of the deviation is | b−n × a | / b × 1
It is represented by 00 (%) (n = 1 to 10). The interatomic distance can be calculated if the cut surface of the substrate is determined because the lattice constant of each nitride semiconductor or single crystal substrate is known.

In addition, an integer multiple of the interatomic distance in two directions of the lattice plane of the nitride constituting the oriented polycrystalline nitride semiconductor of the first layer, and the number of atoms arranged periodically on the surface of the substrate, It is more preferable that the difference between the two directions and the interatomic distance in the same direction is within 5%. In this case, it is preferable that the shape of the lattice plane of the nitride forming the oriented polycrystalline nitride semiconductor is the same as the shape of the periodic array of atoms on the substrate.

Substrates that can be used in the present invention include single crystal semiconductor substrates such as Si, Ge and SiC, and GaA.
III-V group compound semiconductor substrate such as s, InAs, InP, GaSb, AlN, ZnO, sapphire (Al ₂ 0
₃ ), quartz (SiO ₂ ), TiO ₂ , MgO, MgF
There are single crystal substrates such as ₂ , CaF ₂ and SrTiO ₃ . In order for these substrates to satisfy the above-mentioned conditions, the crystal is grown so that a plane inclined by a desired angle from the predetermined plane of the above-mentioned single crystal substrate is taken as a reference, or the crystal is grown and then cut. A method of polishing is used. Further, these substrates do not normally have perfect lattice planes on the surface, but are generally deviated by about ± 2 degrees, and such substrates can be used. However, it is preferably ± 1 degree or less,
More preferably, it is ± 0.5 degrees or less. Further, a single crystal thin film satisfying the above conditions is grown on a commonly used glass, polycrystalline substrate or single crystal substrate to form a substrate on which a desired oriented polycrystalline nitriding film is formed. A physical semiconductor can be grown. Examples of the single crystal thin film include ZnO and SiC formed on a single crystal Si substrate for GaN. The thickness of this single crystal thin film is not particularly limited as long as it is a single crystal having a flat surface.

Particularly when used as a light emitting element or a light receiving element, it is also preferable to use a transparent single crystal substrate having a transmittance of 80% or more in the wavelength region of 360 to 800 nm, whereby light emission or light reception is performed through the substrate. It becomes possible. As such a transparent single crystal substrate,
Sapphire, single crystal quartz, MgO, TiO ₂ , Mg
There are F ₂ , CaF ₂ , SrTiO _{3 and the} like. Above all, a sapphire substrate is preferable, and as the lattice plane of this sapphire,

[0021]

[Outside 3]

There is a problem, etc., and a desired substrate surface can be obtained by inclining these surfaces by a desired angle. For example,

[0023]

[Outside 4]

Is used, Ga _1-x In _x N
= Ranging from 0 to 0.45, and Ga _1-y Al y N
In the range from y = 0 to 1, the triple length of the c-axis of the nitride-based semiconductor and the R-plane projected axis length of the sapphire c-axis are 5
The deviation is within%, which can be used as the substrate of the present invention. Furthermore, as shown in FIG.

[0025]

[Outside 5]

By using a surface inclined at 9.2 degrees as a substrate surface, the length of the intersection line between the A-plane and the C-plane of the nitride-based semiconductor can be increased by 3 times the c-axis of the nitride-based semiconductor. Quadruple length

[0027]

[Outside 6]

Further, the deviation is within 5% in both directions with respect to the interatomic distance of the atoms arranged periodically on the plane inclined by 9.2 degrees, which is more preferable.

In the present invention, the thickness of the substrate is not particularly limited, but in the case of extracting light through the substrate as a light emitting element, the thinner the thickness, the more preferable. Practically, the mechanical strength of the substrate is required in the process of producing a nitride-based semiconductor thin film and the process of producing an element. Therefore, the thickness is preferably 0.05 to 2.0 mm. .. If the thickness is 0.05 mm or less, it is difficult to handle because the mechanical strength is low, and if the thickness is 2.0 mm or more, it is difficult to cut it into a device, and when it is used as a light emitting device, it is difficult to cut light. It is not preferable because the efficiency of taking out is decreased.

The present invention is characterized in that the nitride-based semiconductor layer directly formed on the substrate is an oriented polycrystalline nitride-based semiconductor layer having a thickness of 5000 angstroms or less. The oriented polycrystalline nitride-based semiconductor layer that is in direct contact with the substrate includes at least one direction of the periodic arrangement of atoms on the surface of the substrate and the lattice plane of the first-layer nitride-based semiconductor that is in direct contact with the substrate. One of the crystal axes of is the same direction, and the difference between the interatomic distance in the former direction and the interatomic distance in the latter direction is an integer multiple (1 or more and 10 or less) of 5
%, The crystal grows two-dimensionally even in the vicinity of the interface between the substrate and the nitride-based semiconductor, and the crystal is oriented in a direction with a small deviation, and the crystal orientation is good as it moves away from the substrate. It is characterized by becoming. As described above, the oriented polycrystalline nitride-based semiconductor layer of the present invention is characterized in that the crystal of the nitride-based semiconductor is oriented in the direction parallel to the substrate surface, and thus the surface flatness is improved. It becomes possible to form an operating layer having good characteristics on this layer. This phenomenon of improving the orientation is caused by RHEED (Refractive High) during the growth of the semiconductor thin film.
Energy Electron Difracti
on) or by performing analysis by a transmission electron microscope or an X-ray diffraction method after the film growth. The thickness of the oriented polycrystalline nitride semiconductor layer is 5000.
Although it is less than or equal to angstrom, this depends on the film growth rate and the degree of deviation.If the film growth rate is large or the deviation is large, the film thickness of the oriented polycrystalline nitride semiconductor layer must be increased, A single crystal nitride semiconductor having a flat surface tends not to grow. When this oriented polycrystalline nitride-based semiconductor layer is produced by the molecular beam epitaxy method (MBE method) of the present invention, a thickness of 5000 angstroms or less has sufficient device characteristics. In that case, there is a problem that it is not realistic because the film growth time is too long. For example, the film growth rate is several angstroms / second, and the deviation in one direction is 1%.
When the thickness is about 100 nm, an oriented polycrystalline nitride semiconductor layer having a flat surface and good crystallinity can be obtained even if the thickness is about 500 to 1000 angstroms. Further, when the deviation is 1% or less in both directions, an oriented polycrystalline nitride semiconductor layer having a flat surface and good crystallinity can be obtained even with a film thickness of several tens of angstroms. Therefore, the thickness of the oriented polycrystalline nitride semiconductor layer is preferably in the range of 10 to 5000 Å.

The oriented polycrystalline nitride semiconductor in the present invention contains at least one group III element selected from Al, Ga or In and nitrogen.

For example, when an oriented polycrystalline nitride-based semiconductor containing Ga as a main component is grown on a sapphire substrate, the direction of the c-axis of the nitride-based semiconductor is the sapphire c-axis on the sapphire R plane. The structure is oriented in the direction of the axis projected onto the surface, and its thickness is usually 300 to 2500 angstroms, although it depends on the film growth rate. Also,

[0033]

[Outside 7]

When a surface inclined at 9.2 degrees (θ ₁ ) is used as the substrate surface, the oriented polycrystalline nitride semiconductor is
With a very thin film thickness of several tens of angstroms or less, for example, 20 angstroms, the surface is flat and the crystallinity is good.

Further, in the present invention, as a second aspect of the oriented polycrystalline nitride-based semiconductor which is in direct contact with the substrate, the composition of the nitride-based semiconductor is sequentially changed from the substrate side to the final state. There is a composition gradient structure that provides the composition of the operating layer required for the above. A compositionally graded structure is Ga _1-xy I
a semiconductor thin film made of _{n x Al y N (0 ≦} x ≦ 1,0 ≦ y ≦ 1) allowed formed on the substrate, and finally in which a composition of the active layer in need. The Ga _1-xy In _x Al
_For the composition of _y N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1), the value of x and / or y may be sequentially changed from the substrate side.
In this case, whether to change the composition in the direction of increasing the lattice constant or in the direction of decreasing the lattice constant,
It can be determined in consideration of the required characteristics of the operation layer. With such a compositionally graded structure, the stress acting on the operating layer can be reduced even in the presence of crystal defects, so that the device characteristics can be improved and the durability can be improved. Will also be possible.

Furthermore, as a third aspect of the oriented nitride-based semiconductor that is in direct contact with the substrate, a plurality of oriented polycrystalline nitrides having different compositions of the nitride-based semiconductor and having a thickness of 100 Å or less are used. A structure in which physical semiconductor layers are alternately stacked can be given. With this structure, the characteristics of the element can be improved and the durability can be improved. In this case, if the thickness of each layer is too large, the effect is reduced. Therefore, the thickness is required to be 100 angstroms or less, preferably 70 angstroms or less, and more preferably 50 angstroms or less. .. In addition, the thickness of the oriented polycrystalline nitride semiconductor layer needs to be 10 angstroms or more, and if the thickness is less than this, the effect is not exhibited.

The flatness of the surface of the oriented polycrystalline nitride-based semiconductor thus obtained has a surface roughness of 10
It is 0 angstrom or less, and it is possible to grow the second layer having good crystallinity thereon. The size of this unevenness can be measured by an atomic force microscope.

In the present invention, the oriented polycrystalline nitride semiconductor layer formed in direct contact with the substrate has good electric conductivity and is connected to the electrode for operating the device, so that the entire operating layer is formed. It is possible to apply an electric field uniformly to the. Further, in order to improve this function, n-type or p-type doping can be performed, and n-type doping is particularly preferable. The n-type dopant includes Si, Ge, C, Sn, Se, Te and the like, and the carrier density can be controlled and the electrical resistance can be lowered by changing the type and doping amount of these dopants. In this case, the carrier density is 10 ¹⁷
cm ^-3 or more, preferably 10 ¹⁸ cm ^-3 or more.

The single crystal nitride semiconductor in the present invention has at least one group III element selected from Al, Ga or In and nitrogen as constituent elements. The bandgap is InN 2.4e.
V, a wide region of 3.4 eV of GaN to 6.2 eV of AlN is included. Bandgap control is A
This can be performed by preparing a mixed crystal semiconductor thin film made of 1, Ga or In. For example, A
lGaN, GaInN or AlGaInN.
Further, it is also possible to dope the semiconductor or the mixed crystal semiconductor with a p-type or n-type dopant.

In the present invention, the operating layer of the single crystal nitride based semiconductor formed on the substrate has at least one type of n-type, i-type or p-type single crystal nitride based semiconductor layer, Depending on the intended element, it is composed of an operating layer composed of two sets of single crystal nitride semiconductor layers. Examples of the n-type dopant include Si, Ge, C, Sn, Se,
Te and the like, and M as a p-type or i-type dopant
g, Ca, Sr, Zn, Be, Cd, Hg, Li and the like. The desired conductivity type and carrier density can be obtained by changing the type and doping amount of these dopants. Further, at this time, a structure in which the doping concentration is changed depending on the film thickness direction or a δ-doping layer for doping only a specific layer can be provided.

In the present invention, the oriented polycrystalline nitride-based semiconductor layer has a streak-like RHEED pattern when an electron beam is incident from the crystal axis direction of the nitride-based semiconductor layer. The patterns when incident from different crystal axis directions are spot-shaped or line-shaped such that they are spread laterally, so that they can be distinguished. In addition, it can be distinguished from the single crystal nitride-based semiconductor layer because both RHEED patterns when the electron beam enters from different crystal axis directions of the nitride-based semiconductor are streaky. It can be distinguished from the polycrystalline nitride-based semiconductor layer because both RHEED patterns when the electron beam enters from different crystal axis directions of the nitride-based semiconductor are spot-shaped. Further, such crystallinity can be distinguished by a multiaxial X-ray diffraction method, a transmission electron microscope method, and an electron beam diffraction method, and the method may be selected depending on the case.

As the nitride semiconductor device, for example, n
-Effect or n-type / p-type / n-type or p-type / n-type / p-type nitride-based semiconductor laminated structure in which majority carriers flowing in a p-type or p-type nitride-based semiconductor layer are controlled by a voltage applied to a gate Such as a bipolar transistor, a light emitting device having a structure having at least one pair of n-type and p-type or i-type nitride semiconductor layers, n
Type / i-type / p-type nitride-based semiconductor laminated structure light receiving element, p ⁺ type / n-type / n ⁺ -type nitride-based semiconductor laminated structure rectifying element, n-type and / or The light emitting device and the electronic device can be made of a structure in which the p-type and the quantum well structure are combined, but the invention is not limited thereto.

As an example of the operation layer used as the light emitting element, the structure shown in FIGS. 2 to 13 can be mentioned.

First, the structure of the operation layer shown in FIG.
Single crystal (n-GaN) 25 / single crystal (p−) formed on the oriented polycrystal (GaN) 24 formed on
GaN) 26. In this element, an electrode 27 is connected on the oriented polycrystal (GaN) 24, and an electrode 28 is also formed on the operating layer 26.

The operation layer structure shown in FIG. 3 has a single crystal (n-Ga _1-x In _x N) 30 formed on the oriented polycrystal (Ga _1-x In _x N) 29 on the substrate 23. / Single crystal (p-
Ga _1-x In _x N) 31. In this element, electrode 2
7 is formed on the oriented polycrystal (Ga _1-x In _x N) 29, and the electrode 28 is formed on the operating layer 31. In addition to this, as an operation layer structure, n-GaN / i-GaN,
n-Ga _1-x Al _x N / p-Ga _1-x Al _x N,
Further, the configurations of FIGS. 4 to 13 can be mentioned.

The operation layer structure shown in FIG. 4 has a single crystal (n-GaN) 25 / single crystal (p-GaN) 26 formed on the oriented polycrystal (n ⁺ -GaN) 32 on the substrate 23. Is. Also in this element, the electrode 27 has an oriented polycrystalline (n ⁺ −
GaN) 32, and an electrode 28 is formed on the operating layer 26.

The operation layer structure shown in FIG. 5 has a single crystal (n-Ga _1-x In _x N) 30 formed on the oriented polycrystal (Ga _1-x In _x N) 29 on the substrate 23. / Single crystal (i-
Ga _1-x In _x N) 33 / single crystal (p-Ga _1-x In _x
N) 31 (0 ≦ x ≦ 1). Also in this element, the electrode 2
7 is formed on the oriented polycrystal (Ga _1-x In _x N) 29, and the electrode 28 is formed on the operating layer 31.

The operating layer structure shown in FIG. 6 has a single crystal (n-Ga _1-x In _x N) 30 formed on the oriented polycrystal (Ga _1-x In _x N) 29 on the substrate 23. / Single crystal (p-
Ga _1-y In _y N) 34 / single crystal (p-Ga _1-x In _x
N) 31 (x≤y, 0≤x≤1, 0≤y≤1).
Also in this element, the electrode 27 has an oriented polycrystalline (Ga _{1 -x} In
_x N) 29 and the electrode 28 is formed on the operating layer 31.

The operation layer structure shown in FIG. 7 has a single crystal (n-Ga _1-a Al _a N) 36 formed on the oriented polycrystal (Ga _1-a Al _a N) 35 on the substrate 23. / Single crystal (p-
Ga _1-b Al _b N) 37 / single crystal (p-Ga _1-a Al _a
N) 38 (a≤b, 0≤a≤1, 0≤b≤1).
Also in this element, the electrode 27 has an oriented polycrystalline (Ga _1-a Al
_a N) 35 and the electrode 28 is formed on the operating layer 38.

The structure of the operating layer shown in FIG. 8 is the single crystal (n-Ga _1-xy In _x Al) formed on the oriented polycrystal (Ga _1-xy In _x Al _y N) 39 on the substrate 23. _y N) 4
0 / monocrystalline _{(i-Ga 1-xy In} x Al y N) 41 / single crystal _{(p-Ga 1-xy In} x Al y N) 42 is (0
≦ x + y ≦ 1). Also in this element, the electrode 27 is formed on the oriented polycrystal 39, and the electrode 28 is formed on the operation layer 42.

The operating layer structure shown in FIG. 9 has a single crystal (n-Ga) formed on the oriented polycrystalline GaN on the substrate 23.
N) 25 / single crystal (p-GaN) 26 / single crystal (p-G)
a _1-x In _x N) 30 / single crystal (p-Ga _1-x In _x
N) 31. In this device, electrodes 27, 2 are formed on the oriented polycrystal 24, the single crystal 26, and the single crystal 30, respectively.
8 and 43 are formed, and an electrode 44 is formed on the single crystal 31 of the operating layer.

The operation layer structure shown in FIG. 10 has a single crystal (n-Ga _1-x In _x N) 30 / single crystal (p) formed on the GaInN composition gradient structure layer 45 formed on the substrate 23. -Ga is _{1-x in x N) 31} . Even with this element,
The electrode 27 is formed on the composition gradient structure layer 45, and the electrode 28
Are formed on the operation layer 31.

The active layer structure shown in FIG. 11 has a single crystal (n-Ga _{1 -x} In _x N) 30 / single crystal (p) formed on the strained superlattice structure layer 49 formed on the substrate 23. -Ga
_1-x In _x N) 31. Also in this element, the electrode 27 is formed on the strained superlattice structure layer 49, and the electrode 28 is formed on the operating layer 3
It is formed on 1.

The operating layer structure shown in FIG. 12 has a single crystal (n-Ga _1-x In _x N) 30 formed on an oriented polycrystal (Ga _1-x In _x N) 29 on a substrate 23. / Quantum well layer 46 / single crystal (p-Ga _1-x In _x N) 31. Also in this element, the electrode 27 is formed on the oriented polycrystal 29, and the electrode 28 is formed on the operation layer 31. Here, the quantum well structure is a structure in which an active layer of a nitride-based semiconductor layer having a quantum effect of several hundred angstroms or less is sandwiched by a cladding layer of a nitride-based semiconductor layer having a band gap larger than that. By using a single quantum well structure having one such structure or a multiple quantum well structure in which such a quantum well structure is laminated with a thin barrier layer interposed therebetween, it is possible to enhance the light emission efficiency or to increase the light emission threshold value. It is possible to reduce the current.

The operation layer structure shown in FIG. 13 has a structure having two light emitting layers, and is a single crystal (Ga _{1 -x} In _x N) 29 formed on the oriented polycrystal (Ga _{1 -x} In _x N) 29 on the substrate 23. n-
Ga _1-x In _x N) 30 / single crystal (p-Ga _1-x In _x
N) 31 / single crystal (n-Ga _1-y In _y N) 47 / single crystal (p-Ga _1-y In _y N) 34. In this element, electrodes 27, 28 and 43 are formed on oriented polycrystal 29, single crystal 31 and single crystal 47, respectively, and electrode 44 is formed on single crystal 34 of the operating layer. In this case, for example, when a voltage is applied between the electrodes 27 and 28, blue light emission can be obtained, and the electrodes 43 and 4 can be emitted.
When a voltage is applied between 4 and 4, green light emission can be obtained, and when a voltage is applied between the electrodes 27 and 44, a yellow emission color can be obtained. By thus selecting the electrodes to which the voltage is applied, it is possible to obtain an element that emits two different emission colors or intermediate colors.

The film thickness of the operating layer made of the single crystal nitride semiconductor in the present invention is preferably thin in order to facilitate the process such as etching.
The film thickness is 5 μm or less, preferably 3 μm or less. In the case of a light emitting element, the thickness of the operating layer needs to be 3 μm or less in order to increase the efficiency of extracting emitted light, and in the case of a light emitting element with a short wavelength, absorption of light occurs. For ease of operation, it is preferable that the operating layer is thin. However, it is necessary that the tunnel current does not flow, and the thickness is 100 angstrom.

When used as a semiconductor light emitting device, for example, MIS (Metal-Insulator) is used.
In a -Semiconductor type element, when an i-type single crystal nitride-based semiconductor is used as an operating layer, it is necessary that the thickness be 5000 angstroms or less. , Can not be used as a light emitting element. In the pn junction element, it is necessary to set the thicknesses of the p-type single crystal nitride semiconductor and the n-type single crystal nitride semiconductor as the operating layers to 3 μm or less. If the thickness is larger than this, it takes too much time to grow the thin film, which is not practical and there is a problem that the extraction efficiency of the emitted light is lowered.

In the case of application as a semiconductor light emitting device, it is necessary to use a p-type or i-type single crystal nitride semiconductor as a surface layer and form an electrode on the surface layer. In order to efficiently take out the light emitted from the operating layer to the outside, the light can be taken out from the substrate side or the surface layer side. In order to extract light from the surface layer side, an electrode formed so that a voltage is uniformly applied to the surface layer is covered within a range not exceeding 50% of the surface, and the electrode is formed without passing through a thick layer called a substrate. It is preferable to extract light from the side. The surface layer has 50 electrodes.
% Or more, it is not preferable because the light extraction efficiency decreases. Here, the patterned electrodes are comb-shaped,
It may have a meander shape, a net shape, or the like.

Materials for the electrodes for applying a voltage to the surface of the nitride semiconductor are Al, In, Cu, Ag, and A.
u, Pt, Ir, Pd, Rh, W, Ti, Ni, Co,
Simple metals such as Sn and Pb, their alloys and P
A silicide of t, W, Mo or the like can be used. Further, tin oxide, indium oxide, tin oxide-indium oxide, zinc oxide, degenerated ZnSe, or the like can be used. Particularly preferably, the electrodes formed on the n-type nitride semiconductor are Al, In, Ti, Cu, Zn, Co,
A simple substance of metal such as Ag, Sn, Pb or an alloy thereof can be used. As the electrode formed on the p-type nitride semiconductor, a simple substance of metal such as Ag, Au, Pt, Ir, Pd, Rh or an alloy thereof can be used. Especially when extracting the emitted light from the electrode side,
It is also preferable that the electrode pattern formed on the p-type or i-type nitride semiconductor has a meandering shape, a net shape, or a comb shape. The width of the electrode and the distance between the electrodes are p
It may be changed according to the electric resistance of the i-type or i-type semiconductor layer or the magnitude of the applied voltage. If the width of the electrodes is narrowed and the distance between the electrodes is reduced, the extraction efficiency when light is extracted through the electrodes can be improved. be able to.

Next, a method for manufacturing the nitride semiconductor device of the present invention will be described.

In the MBE method of the present invention, a crystal growth apparatus having a gas source for supplying a nitrogen-containing compound in a gaseous state and a solid source for supplying a group III element is used, the pressure is 10 ⁻⁵ Torr or less, and the substrate temperature is At 300 to 1000 ° C., a gaseous nitrogen-containing compound and a Group III element are supplied to the surface of the substrate to form the first layer at a growth rate of 0.1 to 20 Å / sec, and then the pressure is set to 10 ^{−. At 5} Torr or less and at a substrate temperature of 300 to 1000 ° C., a gaseous nitrogen-containing compound and a Group III element are firstly added.
Applied to the surface of the layer, 0.1-10 Å / s
A method of manufacturing a nitride-based semiconductor device, comprising forming a single-crystal nitride-based semiconductor layer at a growth rate of ec to obtain a nitride-based semiconductor device.

Here, as the nitrogen-containing compound, ammonia, nitrogen trifluoride, hydrazine or dimethylhydrazine can be used alone, or a mixed gas containing them as a main component can be used. Further, ammonia, nitrogen trifluoride, hydrazine or dimethylhydrazine can be diluted with an inert gas such as nitrogen, argon or helium before use. As a method of supplying these gases, a gas cell having an opening toward the substrate in the crystal growth apparatus may be used, and examples of the shape of the opening include a nozzle shape,
It can be slit-shaped or porous. As a gas supply device, by connecting a valve, a flow rate control device, or a pressure control device in the middle of the pipe leading to the opening, it is possible to control the mixing ratio and supply amount of these gases, and to start and stop the supply. It is preferable to use such a thing. In order to produce a nitride-based semiconductor thin film of higher quality, it is more preferable to heat the gas cell to a predetermined temperature to heat the nitrogen-containing compound and supply it to the substrate surface. In order to efficiently heat the gas cell, alumina, silica, boron nitride,
A material having excellent corrosion resistance, such as silicon carbide, which is made into a fibrous, flake-like, crushed, or granular shape is used to fill the gas cell, or to make it porous and to install it in the gas cell. It is preferable to increase the heating efficiency by increasing the contact area with the gaseous compound. It is necessary to change the heating temperature depending on the kind of the filling material and the supply amount of the nitrogen-containing compound.
It is preferable to set the temperature in the range of 0 to 700 ° C. It is also possible to activate nitrogen or ammonia using a plasma gas cell and supply it to the substrate surface. The supply amount of the gaseous compound to the substrate surface needs to be larger than that of the group III element. When the supply amount of the gaseous compound is smaller than the supply amount of the group III element, the gaseous compound from the nitride-based semiconductor thin film is generated. Since the escape of nitrogen supplied from the compound becomes large, it becomes difficult to obtain a good semiconductor thin film. Therefore, the supply amount of the gaseous compound is 10 times or more, preferably 100 times or more, and more preferably 1000 times or more that of the group III element.

In the present invention, the growth pressure is 10 ⁻⁵ T.
It is required to be not more than orrr, and it is preferable because the gaseous nitrogen-containing compound and metal vapor necessary for growing the nitride-based semiconductor thin film can reach the substrate surface without colliding with each other. When the pressure is 10 ⁻⁵ Torr or more, the amount of impurities in the growth chamber increases and the reaction occurs before reaching the substrate surface, so that a nitride-based semiconductor thin film having good crystallinity cannot be obtained. There is. In particular, it is important to reduce the amount of compounds containing carbon and oxygen as impurities, and among them, by keeping the partial pressure of carbon monoxide and carbon dioxide low, the oxygen taken into the nitride-based semiconductor thin film is reduced. It is preferable to reduce the amount of carbon. Therefore, it is preferable to set the partial pressure of carbon monoxide or carbon dioxide to 10 ⁻⁸ Torr or less,
It is more preferably 10 ^-10 Torr or less. The type and concentration of these impurity gases can be measured by a quadrupole mass spectrometer.

The growth temperature of the nitride semiconductor thin film is 300
The temperature is about 1000 ° C., which can be changed depending on the composition of the nitride-based semiconductor thin film, the type of nitrogen-containing compound used, the material to be doped, and the growth rate.

In the present invention, the growth rate of the nitride semiconductor thin film needs to be 0.1 to 20 Å / sec. When the growth rate is less than 0.1 angstrom / sec, it takes too much time to obtain a required film thickness, and contamination of the film from the growth atmosphere becomes large, so that a good nitride-based semiconductor thin film can be manufactured. If it exceeds 20 angstroms / sec, island-like growth will occur, making it impossible to obtain a good quality nitride-based semiconductor thin film. In order to grow the oriented polycrystalline nitride-based semiconductor thin film, the growth rate may be set to 0.1 to 20 angstroms / sec, and the single crystalline nitride-based semiconductor thin film may be formed into the oriented polycrystalline nitride-based semiconductor layer. 0.1 to 10 Å / sec for growth
You can do this. The growth rate is controlled mainly by changing the supply amount of the group III element to the substrate surface, that is, by adjusting the temperature of the crucible for vaporizing the group III element. In addition, it can be performed by changing the supply amount of the nitrogen-containing compound and the substrate temperature.

As the solid source of the present invention, as the group III element, a simple substance or alloy of a metal of the group III element, or a metal salt can be used. Group III elements are Al, G
At least one element selected from a and In.

When the nitride-based semiconductor thin film of the present invention is manufactured, impurities can be doped to control carrier density and p-type, i-type or n-type conductivity. Examples of impurities doped to obtain a p-type or i-type nitride-based semiconductor thin film include Mg, Ca,
There are Sr, Zn, Be, Cd, Hg, Li and the like, and as impurities to be doped to obtain an n-type nitride semiconductor thin film, there are Si, Ge, C, Sn, S, Se, Te and the like. By changing the type and doping amount of these dopants, the type and carrier density of carriers can be changed. In this case, the doping concentration may be changed depending on the film thickness direction, or a δ-doping method of doping only a specific layer may be used. Further, it is possible to accelerate the control of the conductivity type by irradiating an electron beam or an ultraviolet ray at the time of doping. In addition, the efficiency of p-type conversion can be increased by irradiating an electron beam or performing heat treatment after the laminated structure is manufactured.

In producing the nitride semiconductor thin film by the MBE method in the present invention, the group III element and the nitrogen-containing compound are simultaneously supplied to the substrate surface, or the group III element and the nitrogen-containing compound are alternately deposited on the substrate surface. It is also possible to carry out a method of supplying it or interrupting the growth during the growth of the thin film to promote crystallization of the thin film. In particular, it is preferable to perform film growth while observing the RHEED pattern and confirming that streaks are visible.

A method for manufacturing a semiconductor light emitting device using a nitride-based semiconductor laminated structure manufactured by the MBE method using ammonia gas will be described below as an example.
It is not particularly limited to this.

As an apparatus, an evaporation crucible (Knudsen cell) 2, 3, 3 is provided in a vacuum container 1 as shown in FIG.
A crystal growth apparatus equipped with 4, 5, and 6, a gas cell 7, and a substrate heating holder 8 was used. In the figure, reference numeral 9 is a substrate, 10 is a quadrupole mass spectrometer, 11 is a RHEED electron gun, 12 is a RHEED screen, 13 is a shroud, 14-18 are shutters, 19 is a valve, 20 is a cold trap, Reference numeral 21 is a diffusion pump, and 22 is an oil rotary pump.

Ga metal was placed in the evaporation crucible 2 and heated to a temperature of 10 ¹³ to 10 ¹⁷ / cm ² · sec on the substrate surface. A gas cell 7 is used to introduce ammonia,
The substrate 9 was directly sprayed. The amount introduced was 10 ¹⁶ to 10 ²⁰ / cm ² · sec on the surface of the substrate. In the evaporation crucibles 3 and 4, In, Al, A
s, Sb, etc. are added, and the film formation is performed by controlling the temperature and supply time so that a mixed crystal compound semiconductor having a predetermined composition is obtained. The evaporation crucible 5 contains Mg, Ca, Sr, Zn, B.
e, Cd, Hg, Li, etc. are put in the evaporation crucible 6 and S
Doping is performed by adding i, Ge, C, Sn, S, Se, Te and the like, and controlling the temperature and the supply time so that a predetermined supply amount is obtained.

A sapphire R surface was used as the substrate 9 and was heated to 300 to 900 ° C.

First, the substrate 9 is heated in the vacuum chamber 1 at 900 ° C., set to a predetermined growth temperature, and grown at a growth rate of 0.1 to 20 Å / sec for 10 to 5000.
An oriented polycrystalline nitride semiconductor layer having an angstrom thickness is prepared. An evaporation crucible 6 is formed on the nitride semiconductor layer.
Can also be used to increase conductivity by n-type doping. Further, 0.1-10 is formed on the nitride semiconductor layer.
0.05 to 3μ at a growth rate of Angstrom / sec
An n-type single crystal nitride-based semiconductor layer having a thickness of m was produced. Subsequently, the shutter of the evaporation crucible 5 is opened simultaneously with the Ga shutter of the evaporation crucible 2 on the n-type single crystal nitride based semiconductor layer, and the p of 100 to 10000 angstrom is obtained.
A nitride-based semiconductor layer was formed by doping a type or i-type dopant to form a nitride-based semiconductor laminated structure.

Next, an example in which a semiconductor light emitting device is manufactured using the laminated structure will be described. A lithographic process is performed on the laminated structure to determine the shape of the element and to provide an electrode for injecting a current. The lithography process can be performed by a process using a normal photoresist material, and the etching method is preferably a dry etching method. As the dry etching method, a usual method can be used, and ion milling, ECR etching, reactive ion etching, ion beam assisted etching, or focused ion beam etching can be used. In particular, in the present invention, one of the features is that these dry etching methods can be efficiently applied because the whole film thickness of the nitride-based semiconductor laminated thin film is small. In addition, when the nitride-based semiconductor multilayer thin film is damaged by dry etching, heat treatment in the nitrogen-containing compound of the present invention or an inert gas such as nitrogen, argon, or helium is also effective. It is preferable for obtaining an element. The heat treatment temperature and time may be changed depending on the composition and structure of the nitride semiconductor of the device. For example, in a GaN-based light emitting device, by performing heat treatment in an ammonia flow at 500 ° C. for 30 minutes,
The surface damage caused by etching can be recovered.

The electrodes for uniformly applying the voltage to the surface of the nitride semiconductor are MBE method, CVD method, vacuum deposition method,
It can be manufactured by an electron beam evaporation method or a sputtering method. In particular, when the emitted light is taken out from the electrode side, it is also preferable that the pattern of the electrode formed on the p-type or i-type nitride-based semiconductor is meander-shaped, net-shaped or comb-shaped. The width of the electrodes and the distance between the electrodes may be changed according to the electric resistance of the p-type or i-type semiconductor layer or the magnitude of the applied voltage. If the width of the electrodes is reduced and the distance between the electrodes is reduced, the light When taken out through the electrode, the taking-out efficiency is improved. Also in this case, it is also preferable to perform heat treatment in the nitrogen-containing compound of the present invention or an inert gas such as nitrogen, argon or helium after forming the electrode in order to obtain an element having excellent characteristics. The heat treatment temperature and time may be changed depending on the electrode material and structure. For example, a MIS-type GaN-based light-emitting device using Al for an n-type nitride-based semiconductor and Au for an i-type nitride-based semiconductor is excellent in heat treatment at 400 ° C. for 60 minutes in an argon flow. Metal / semiconductor contacts can be obtained.

The laminated structure processed by this method is cut with a dicing saw or the like to form an element chip, which is then set on a lead frame, and then a wire is formed using an Au wire or an Al wire by a die bonding method and / or a wire bonding method. Then, a light emitting device was produced by packaging with an epoxy resin, a methacrylic resin, a carbonate resin, or the like.

[0077]

The nitride-based semiconductor light-emitting device according to the present invention has excellent surface flatness and crystallinity at a very thin film thickness on a specific substrate, and therefore, the device manufacturing process is easy and highly reliable. There is a feature that An element that emits blue light could be manufactured by current injection. In addition, since the film thickness is small, the process of manufacturing the light emitting device is easy and highly reliable, and the light extraction efficiency can be increased.

[0078]

EXAMPLES The present invention will be described in more detail below with reference to examples.

(Example 1) MBE using ammonia
An example in which a GaN-based semiconductor light emitting device is manufactured by the method will be described.

A crystal growth apparatus having an evaporation crucible 2, 3, 4, 5, 6, a gas cell 7 and a substrate heating holder 8 in a vacuum container 1 as shown in FIG. 14 was used.

Ga metal was put in the evaporation crucible 2 and 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, a sapphire R-plane substrate was used. At this time, the atomic spacing formed by the line of intersection of the A and C planes of GaN is 15.7% that of the sapphire substrate,
Three times the c-axis length of GaN has a deviation of 0.7% from the atomic spacing of the sapphire substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film formation is performed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to form an oriented polycrystalline GaN layer having a film thickness of 1000 angstrom at a film forming rate of 1.2 angstrom / sec. Subsequently, the temperature of the crucible 2 is set to 1010 ° C., and a single crystal n-GaN layer having a film thickness of 3500 angstroms is provided at a film forming rate of 1.0 angstrom / sec. Next, the shutter of the Zn crucible 5 and the shutter of the crucible 2 were simultaneously opened to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure. ..

Then, a lithographic process is applied to the laminated thin film to provide an electrode for injecting a current. The lithographic process can be performed by a process using an ordinary photoresist material. As an etching method, ion milling with Ar is performed to remove the n-GaN layer and the p-GaN layer,
A window was formed to form an electrode pattern for applying a voltage. Then, after removing the resist, a heat treatment was performed at 500 ° C. for 30 minutes in a flow of ammonia gas. Then, a resist pattern for forming an electrode is formed,
A thickness of 3 on the oriented polycrystalline GaN layer by vacuum deposition.
A 000 Å Al electrode and a 3000 Å thick Au electrode were formed on the p-GaN layer, and heat treatment was performed at 400 ° C. for 60 minutes in argon.

The laminated structure obtained by this method was cut with a dicing saw, and wiring was performed using a gold wire with a wire bonder. FIG. 2 shows the device structure of the present invention, FIG. 15 shows the results of measuring the diode characteristics, and FIG. 16 shows the emission spectrum. When a current of 20 mA was injected into this device, blue light emission with an emission wavelength of 470 nm and an emission intensity of 90 mcd was observed.

(Example 2) MBE using ammonia
An example in which a GaN-based semiconductor light emitting device is manufactured by the method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Mg in the evaporation crucible 5 to 28
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, a sapphire R-plane substrate was used.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film was formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 7, and 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 1000 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C., and 1.0 angstrom / se is set.
A single crystal n-GaN layer having a film thickness of 3500 angstroms is provided at a film forming rate of c. Next, simultaneously open the shutter of the crucible 2 and the shutter of the Mg crucible 5,
A nitride-based semiconductor laminated structure was prepared by forming a Mg-doped single crystal i-GaN layer having a film thickness of 500 Å.

Then, a light emitting device was produced by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Purple emission having an emission wavelength of 430 nm and an emission intensity of 5 mcd was observed.

(Example 3) MBE using ammonia
Ga _1-x In _x based semiconductor light emitting device (x = 0.
An example of producing 1) will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was placed in the evaporation crucible 2 to 10
Heat to 20 ° C., put In metal in the evaporation crucible 3 and heat to 820 ° C., and put Mg in 5 to 280 ° C.
Heated to. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, a sapphire R-plane substrate was used. At this time, the atomic spacing formed by the line of intersection of the Ga _0.9 In _0.1 N A-plane and the C-plane is 1 with the atomic spacing of the sapphire substrate.
6.0%, and three times the c-axis length of Ga _0.9 In _0.1 N has a deviation of 1.8 from the atomic spacing of the sapphire substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes and then kept at a temperature of 700 ° C. to form a film. The film formation is performed by simultaneously opening the shutters of the Ga evaporation crucible 2 and the In evaporation crucible 3 while supplying ammonia from the gas cell 9, and at a film formation rate of 1.3 angstrom / sec, a film having a film thickness of 1700 angstroms is aligned. Polycrystal G
a _0.9 In _0.1 N layer is formed. Then, the temperature of the crucible 2 is set to 1010 ° C. and the temperature of the crucible 3 is set to 800 ° C.
Film thickness of 3500 at 0 angstrom / sec deposition rate
An Angstrom single crystal n-Ga _0.9 In _0.1 layer is provided. Next, the shutter for the Mg crucible 5 and the shutter for the crucible 2 were simultaneously opened to simultaneously expose the Mg-doped i-single-crystal Ga _0.9 I having a film thickness of 500 Å.
A nitride semiconductor laminated structure was produced by forming an n _0.1 N layer.

Then, a light emitting device was manufactured by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Blue light emission having an emission wavelength of 480 nm and an emission intensity of 50 mcd was observed.

(Example 4) MBE using ammonia
_1-x In _x based semiconductor light emitting device (x = 0.
An example of producing 3) will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 20 ° C., put In metal in the evaporation crucible 3 and heat to 880 ° C., and put Mg in 5 to 280 ° C.
Heated to. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, a sapphire R-plane substrate was used. At this time, the atomic spacing formed by the intersecting line of the A plane and the C plane of Ga _0.7 In _0.3 N is 1 with that of the sapphire substrate.
6.7%, which is three times the c-axis length of Ga _0.7 In _0.3 N, is displaced by 4.3% from the atomic spacing of the sapphire substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is kept at 680 ° C. to form a film. The film formation is carried out by simultaneously opening the shutters of the Ga evaporation crucible 2 and the In evaporation crucible 3 while supplying ammonia from the gas cell 9, and at a film formation rate of 1.5 angstrom / sec, a 1700 angstrom film thickness orientation property is obtained. Polycrystalline Ga
_{A 0.9} In _0.3 N layer is formed. Subsequently, a single crystal n-Ga _0.7 In _0.3 N layer having a film thickness of 3500 angstroms is provided at a film forming rate of 1.0 angstrom / sec with the temperature of the crucible 2 being 990 ° C. and the temperature of the crucible 3 being 840 ° C. Next, the shutter of the Mg crucible 5 and the shutter of the crucible 2 are simultaneously opened, and the Mg-doped i-single-crystal Ga _0.7 In having a film thickness of 500 Å is opened.
_A nitride-based semiconductor laminated structure was produced by forming a _0.3 N layer.

Then, a light emitting device was produced by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Green emission having an emission wavelength of 540 nm and an emission intensity of 70 mcd was observed.

(Example 5) MBE using ammonia
Ga _1-x Al _x semiconductor light emitting device (x = 0.
An example of producing 3) will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
It was heated to 20 ° C., the evaporation crucible 4 was charged with Al metal and heated to 1070 ° C., and the crucible 5 was charged with Mg and heated to 280 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, a sapphire R-plane substrate was used. At this time, the atomic spacing formed by the line of intersection of the A plane and the C plane of Ga _0.7 Al _0.3 N is 1 with the atomic spacing of the sapphire substrate.
4.5%, which is three times the c-axis length of Ga _0.7 In _0.3 N, is offset by 0.9% from the atomic spacing of the sapphire substrate.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 850 ° C. to form a film. The film formation is performed by simultaneously opening the shutters of the Ga evaporation crucible 2 and the In evaporation crucible 3 while supplying ammonia from the gas cell 9, and at a film formation rate of 1.5 angstrom / sec, a film thickness of 1900 angstrom is obtained. An oriented polycrystalline Ga _0.7 Al _0.3 N layer is prepared. Then, the temperature of the crucible 2 is set to 990 ° C., the temperature of the crucible 3 is set to 1050 ° C., and a film thickness of 35 is obtained at a film forming rate of 1.0 Å / sec.
A 00 Å single crystal n-Ga _0.7 Al _0.3 layer is provided. Next, the shutter of the Mg crucible 5 and the shutter of the crucible 2 are simultaneously opened, and the Mg-doped i-single-crystal Ga having a film thickness of 500 Å is opened.
_A nitride-based semiconductor laminated structure was produced by forming a _0.7 Al _0.3 N layer.

Then, the same method as in Example 1 was applied to the laminated thin film to manufacture a light emitting device.

When a current of 20 mA is injected into this element,
Ultraviolet emission having an emission wavelength of 370 nm and an emission power of 0.5 mW was observed.

(Example 6) MBE using ammonia
An example in which a GaN-based semiconductor light emitting device is manufactured by the method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal is put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, as shown in FIG. 1, a surface obtained by inclining the sapphire R surface by 9.2 degrees in the A surface direction was used. At this time, four times the atomic spacing formed by the line of intersection of the A and C planes of GaN is 1.
0%, which is three times the c-axis length of GaN, has a deviation of 0.7% from the atomic spacing of the sapphire substrate.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 50 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and the film thickness of 4000 angstrom is applied to the single crystal nG with a film forming rate of 1.0 angstrom / sec.
An aN layer is provided. Next, the shutter for the Zn crucible 5 and the shutter for the crucible 2 are simultaneously opened to give a film thickness of 50.
Single crystal p-doped with 0 angstrom Zn
A nitride semiconductor laminated structure was produced by forming a GaN layer.

Then, the same method as in Example 1 was applied to the laminated thin film to fabricate a light emitting device.

When a current of 20 mA is injected into this element,
Blue emission having an emission wavelength of 470 nm and an emission intensity of 110 mcd was observed.

(Example 7) MBE using ammonia
An example in which a GaN-based semiconductor light emitting device is manufactured by the method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Zn into the evaporation crucible 5 to 190
Heated to ° C. Ammonia is used as a gas, a gas cell 7 having alumina fibers filled therein is used to introduce the gas, and the gas is directly heated to 370 ° C.
And was supplied at 5 cc / min.

As the substrate 9,

[0131]

[Outside 8]

The surface inclined by 20.2 degrees was used as the substrate surface. At this time, 1 times the atomic interval formed by the line of intersection of the A and C planes of GaN is 33.2 times the atomic interval of the sapphire substrate.
%, 8 times the c-axis length of GaN is 0.5% off the atomic spacing of the sapphire substrate.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 4600 angstroms is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and 1.0 angstrom / sec.
Single crystal n with a film thickness of 4000 angstrom
-Providing a GaN layer. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, a light emitting device was produced by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Blue emission having an emission wavelength of 470 nm and an emission intensity of 60 mcd was observed.

(Example 8) MBE using ammonia
An example in which a GaN-based semiconductor light emitting device is manufactured by the method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, as shown in FIG.
The gO (001) plane is oriented toward the (100) plane by 11.3 degrees (θ
₂ ) and a surface inclined 11.3 degrees (θ ₃ ) in the (010) plane direction was used as the substrate surface. At this time, twice the atomic spacing formed by the line of intersection of the A and C planes of GaN is 2.7% with the atomic spacing of the MgO substrate, and twice the c-axis length of GaN is the atomic spacing of the MgO substrate. The deviation is 3.9%.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes and then kept at a temperature of 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 2000 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and 1.0 angstrom / sec.
Single crystal n with a film thickness of 4000 angstrom
-Providing a GaN layer. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, a light emitting device was manufactured by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Blue light emission having an emission wavelength of 470 nm and an emission intensity of 45 mcd was observed.

(Example 9) MBE using ammonia
An example in which a GaN-based semiconductor light emitting device is manufactured by the method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal is put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

The substrate 9 is made of SrTi0 ₃ (11
The 0) plane was used as the substrate plane. At this time, one time the atomic spacing formed by the line of intersection of the A and C planes of GaN is the SrTi0 ₃
The atomic spacing of the substrate is 0.2%, and the c-axis length of GaN is twice the atomic spacing of the SrTiO ₃ substrate, which is 32.3%.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 2500 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and 1.0 angstrom / sec.
Single crystal n with a film thickness of 3000 angstrom
-Providing a GaN layer. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, the same method as in Example 1 was applied to the laminated thin film to manufacture a light emitting device.

When a current of 20 mA is injected into this element,
Blue emission having an emission wavelength of 470 nm and an emission intensity of 40 mcd was observed.

(Example 10) MB using ammonia
An example of producing a GaN-based semiconductor light emitting device by the E method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was placed in the evaporation crucible 2 to 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, the (110) plane of TiO ₂ was used as the substrate plane. At this time, the atomic spacing formed by the line of intersection of the A-plane and the C-plane of GaN is 0.9% with the atomic spacing of the TiO ₂ substrate, and 1 times the c-axis length of GaN is the atomic spacing of the TiO ₂ substrate. The gap is 12.3% from the interval.

The pressure in the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 2400 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and 1.0 angstrom / sec.
Single crystal n with a film thickness of 3000 angstrom
-Providing a GaN layer. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, the same method as in Example 1 was applied to the laminated thin film to manufacture a light emitting device.

When a current of 20 mA is injected into this element,
Blue emission having an emission wavelength of 470 nm and an emission intensity of 48 mcd was observed.

(Example 11) MB using ammonia
An example of producing a GaN-based semiconductor light emitting device by the E method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, the (100) surface of CaF ₂ was used as the substrate surface. At this time, the atomic spacing formed by the line of intersection of the A-plane and C-plane of GaN is 0.9% with the atomic spacing of the CaF ₂ substrate, and the 1-fold of the c-axis length of GaN is the atomic spacing of the CaF ₂ substrate. There is a gap of 5.5% from the interval.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 1800 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and 1.0 angstrom / sec.
Single crystal n with a film thickness of 4000 angstrom
-Providing a GaN layer. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, a light emitting device was prepared by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Blue light emission with an emission wavelength of 470 nm and an emission intensity of 52 mcd was observed.

(Example 12) MB using ammonia
An example of producing a GaN-based semiconductor light emitting device by the E method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 20 ° C and put Zn in the evaporation crucible 5 to 19
Heated to 0 ° C. Ammonia was used as a gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so as to be heated to 370 ° C. and directly blow the gas to the substrate 9.

As the substrate 9, as shown in FIG.
A plane obtained by inclining the (110) plane of F ₂ toward the (100) plane by 23.7 degrees (θ ₄ ) was used as the substrate surface. At this time, Ga
One time the atomic spacing formed by the line of intersection of the A and C planes of N is the M
The atomic spacing of the gF ₂ substrate is 0.5%, and the c-axis length of GaN is 3
The difference is 2.2% from the atomic spacing of the MgF ₂ substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes, and then the temperature is maintained at 750 ° C. to form a film. The film is formed by opening the shutter of the Ga crucible while supplying ammonia from the gas cell 9 to 1.2 angstroms /
An oriented polycrystalline GaN layer having a film thickness of 1000 angstrom is formed at a film formation rate of sec. Then, the temperature of the crucible 2 is set to 1010 ° C. and 1.0 angstrom / sec.
Single crystal n with a film thickness of 4000 angstrom
-Providing a GaN layer. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, the same method as in Example 1 was applied to the laminated thin film to manufacture a light emitting device.

When a current of 20 mA is injected into this element,
Blue emission having an emission wavelength of 470 nm and an emission intensity of 75 mcd was observed.

(Example 13) M using nitrogen trifluoride
An example of manufacturing a GaN-based semiconductor light emitting device by the BE method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 00 ° C, put Zn in the evaporation crucible 5 and
Heated to 0 ° C. Nitrogen trifluoride is used as gas,
A gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so that the gas was directly blown onto the substrate 9 by heating to 250 ° C.

The substrate 11 is made of GaAs (001)
The surface inclined by 8.1 degrees in the (010) plane direction was used as the substrate surface. At this time, 1 times the atomic interval formed by the line of intersection of the A and C planes of GaN is 2.5 times the atomic interval of the GaAs substrate.
%, Four times the c-axis length of GaN is displaced by 3.1% from the atomic spacing of the GaAs substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is held at a temperature of 620 ° C. to form a film. The film formation was performed by supplying a nitrogen trifluoride gas from the gas cell 9 and opening the shutter of the Ga crucible.
An oriented polycrystalline GaN layer having a film thickness of 500 angstrom is formed at a film forming rate of angstrom / sec. Then, the temperature of the crucible 2 is set to 980 ° C., and a single crystal n-GaN layer having a film thickness of 4000 angstrom is provided at a film forming rate of 0.4 angstrom / sec. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, a light emitting device was manufactured by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Blue light emission having an emission wavelength of 470 nm and an emission intensity of 25 mcd was observed.

(Example 14) M using nitrogen trifluoride
An example of manufacturing a GaN-based semiconductor light emitting device by the BE method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 00 ° C, put Zn in the evaporation crucible 5 and
Heated to 0 ° C. Nitrogen trifluoride is used as gas,
A gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was supplied at 5 cc / min so that the gas was directly blown onto the substrate 9 by heating to 250 ° C.

As the substrate 11, the (001) plane of GaP was used as the substrate surface. At this time, 1 times the atomic spacing formed by the line of intersection of the A-plane and C-plane of GaN is 0.1% with the atomic spacing of the GaP substrate, and 4 times the c-axis length of GaN is the atomic spacing of the GaP substrate. The deviation is 5.3%.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is held at a temperature of 600 ° C. to form a film. The film formation was performed by supplying a nitrogen trifluoride gas from the gas cell 9 and opening the shutter of the Ga crucible.
An oriented polycrystalline GaN layer having a film thickness of 700 angstrom is formed at a film forming rate of angstrom / sec. Subsequently, the temperature of the crucible 2 is set to 980 ° C., and a single crystal n-GaN layer having a film thickness of 5000 angstrom is provided at a film forming rate of 0.4 angstrom / sec. Next, the shutter of the Zn crucible 5 was simultaneously opened at the same time as the shutter of the crucible 2 to form a Zn-doped single crystal p-GaN layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure.

Then, a light emitting device was manufactured by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Blue light emission with an emission wavelength of 470 nm and an emission intensity of 28 mcd was observed.

(Example 15) M using nitrogen trifluoride
An example in which a Ga _x In _1-x N-based semiconductor light emitting device is manufactured by the BE method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal was put in the evaporation crucible 2 to be 10
Heat to 00 ° C and put In into the evaporation crucible 3 to make 93
Heat to 0 ° C and put Zn in the evaporation crucible 5 to 190
Heated to ° C. Nitrogen trifluoride was used as the gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was directly blown onto the substrate 9 at 200 ° C. at 5 cc / min. Supplied.

As the substrate 9, as shown in FIG. 1, a surface obtained by inclining the sapphire R surface by 9.2 degrees in the A surface direction was used as the substrate surface. At this time, four times the atomic spacing formed by the line of intersection of the A and C planes of GaN is 1.
0%, which is three times the c-axis length of GaN, has a deviation of 0.6% from the atomic spacing of the sapphire substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes and then kept at 700 ° C. to form a film. For film formation, while supplying nitrogen trifluoride from the gas cell 9, first, Ga
Open the crucible shutter only, and then open the Ga and In crucible shutters at the same time, while increasing the temperature of the evaporation crucible 3 from 900 ° C to 960 ° C at a rate of 1.2 ° C / min. In a 1000 angstrom oriented polycrystal, a GaN layer was initially formed, and finally G
A composition gradient layer having a _0.7 In _0.3 N is formed. Then, the temperature of the crucible 2 is set to 980 ° C., and the temperature of the crucible 3 is set to 94
Single crystal n-Ga _0.7 having a film thickness of 4000 angstrom at a film forming rate of 1.0 angstrom / sec at 0 ° C.
An In _0.3 N layer is provided. Next, the shutter of the Zn crucible 5 is simultaneously opened simultaneously with the shutter of the crucible 2 to form a Zn-doped single crystal p-Ga _0.7 In _0.3 N layer having a film thickness of 500 angstroms, thereby forming a nitride semiconductor laminated structure. Was produced.

Then, a light emitting device was produced by applying the same method as in Example 1 to the laminated thin film.

When a current of 20 mA is injected into this element,
Green light emission with an emission wavelength of 535 nm and an emission intensity of 90 mcd was observed.

(Example 16) M using nitrogen trifluoride
An example in which a Ga _x In _1-x N-based semiconductor light receiving element is manufactured by the BE method will be described.

As the apparatus, the same crystal growth apparatus as in Example 1 was used.

Ga metal is put in the evaporation crucible 2 to be 10
Heat to 00 ° C and put In into the evaporation crucible 3 to make 93
Heat to 0 ° C and put Zn in the evaporation crucible 5 to 220
Heated to ° C. Nitrogen trifluoride was used as the gas, a gas cell 7 having alumina fibers filled therein was used to introduce the gas, and the gas was directly blown onto the substrate 9 at 200 ° C. at 5 cc / min. Supplied.

As the substrate 9, as shown in FIG. 1, a surface obtained by inclining the sapphire R surface by 9.2 degrees in the A surface direction was used. At this time, four times the atomic spacing formed by the line of intersection of the A and C planes of GaN is 1.
0%, which is three times the c-axis length of GaN, has a deviation of 0.6% from the atomic spacing of the sapphire substrate.

The pressure inside the vacuum container is 2 × during film formation.
It was 10 ⁻⁶ Torr.

First, the substrate 9 is heated at 900 ° C. for 30 minutes and then kept at a temperature of 700 ° C. to form a film. For film formation, while supplying nitrogen trifluoride from the gas cell 9, first, Ga
Open the crucible shutter only, and then open the Ga and In crucible shutters at the same time, while increasing the temperature of the evaporation crucible 3 from 900 ° C to 960 ° C at a rate of 1.2 ° C / min. In a 1000 angstrom oriented polycrystal, a GaN layer was initially formed, and finally G
A composition gradient layer having a _0.7 In _0.3 N is formed. Then, the temperature of the crucible 2 is set to 980 ° C. and the temperature of the crucible 3 is set to 94 ° C.
Single-crystal n-Ga _0.75 nm thick single crystal with a film forming rate of 1.0 angstrom / sec at 0 ° C.
An In _0.3 N layer is provided. Next, the shutter of the crucible 5 for Zn and the shutter of the crucible 5 for Zn were simultaneously opened to form a single crystal i-Ga _0.7 In _0.3 N layer doped with Zn and having a film thickness of 5000 angstrom. Furthermore, Z
By setting the temperature of the crucible of n to 190 ° C. and setting the temperature to 2000 angstrom, the single crystal p-Ga _0.7 In
_A nitride-based semiconductor laminated structure was produced by laminating _0.3 N layers.

Then, the same method as in Example 1 was applied to the laminated thin film to manufacture a pin type light receiving element as shown in FIG.

[0208] This device has 100 W / at 540 nm.
When light having an irradiance of m ² was irradiated and a bias voltage of 20 V was applied, an output of 6 mA was obtained as a photocurrent.

Comparative Example 1 A GaN semiconductor was prepared by using a quartz reaction tube equipped with a high-frequency induction heating coil and a carbon susceptor, using hydrogen as a carrier gas, and supplying trimethylgallium and ammonia gas into the reaction tube. An example of producing a laminated thin film will be described.

A sapphire R surface is used as the substrate.
Ammonia gas was heated to 0 ° C., trimethylgallium was cooled to −15 ° C., and hydrogen gas was used as a carrier gas at a flow rate of 40 cc / min to give 1000 cc of ammonia gas.
/ Min and hydrogen gas as carrier gas 150
It is supplied to the reaction tube by setting it to 0 cc / min.
N-Ga with a thickness of 10 μm at a growth rate of 2 μm / min
The N semiconductor layer was grown. Subsequently, diethylzinc was heated to 45 ° C. together with the above gas, hydrogen gas was supplied as a carrier gas at a flow rate of 20 cc / min into the reaction tube, and Zn was doped with a thickness of 1 μm. G
A nitride-based semiconductor laminated structure was produced by growing an aN semiconductor thin film.

Then, the same method as in Example 1 was applied to the laminated thin film to manufacture a light emitting device. In this case, Ga having a thickness of 5 μm or more is used to form an electrode.
It is necessary to remove the N semiconductor thin film by etching,
Ion milling with Ar takes 3 hours and is not practical.

When a current of 20 mA is injected into this element,
Although blue light emission with an emission wavelength of 480 nm and an emission intensity of 18 mcd was observed, the emission on the surface of the device was non-uniform, and the durability of the device was low, and the emission intensity decreased to several mcd in a few minutes.

(Comparative Example 2) G was prepared by the same method as in Example 1 except that the sapphire C plane was used as the substrate.
An aN-based semiconductor laminated structure was produced.

In this case, the mismatch between the lattice constant of the GaN C-plane and the lattice constant of the sapphire C-plane is 13.8%.

The GaN semiconductor thin film grown on the C-plane of sapphire was in a polycrystalline state even with a film thickness of 5000 angstroms or more, and had unevenness on the surface and island-shaped growth, so that a light emitting device could not be manufactured.

Comparative Example 3 As a substrate in Example 1

[0217]

[Outside 9]

A GaN-based semiconductor laminated structure was produced by the same method except that was used.

In this case, 1 times the atomic spacing formed by the A-plane and C-plane intersecting lines of GaN is 3 times the atomic spacing of the sapphire substrate.
3.2%, 1 times the C-axis length of GaN is a mismatch of 26.7% with the atomic spacing of the sapphire substrate.

[0220]

[Outside 10]

The GaN semiconductor thin film grown in (1) was in a polycrystalline state even with a film thickness of 5000 angstroms or more, and there was unevenness on the surface and island-shaped growth, so that it was not possible to fabricate a light emitting device.

(Comparative Example 4) In Example 1, as the substrate

[0223]

[Outside 11]

A GaN-based semiconductor laminated structure was produced by the same method except that a substrate inclined by 12.4 degrees was used.

In this case, 1 times the atomic spacing formed by the A-plane and C-plane intersections of GaN is 3 times the atomic spacing of the sapphire substrate.
3.2% and 13 times the C-axis length of GaN are 0.9% mismatch with the atomic spacing of the sapphire substrate.

The first layer had irregularities on the surface, and the film thickness uniformity of n-GaN or i-GaN laminated thereon was poor.

When a current of 20 mA is injected into this element,
Blue light emission with an emission wavelength of 470 nm and an emission intensity of 10 mcd was observed. However, the part that emits light is not uniform,
It turns out that the current is also leaking.

(Comparative Example 5) In Example 1, GaN was used.
A GaN-based semiconductor laminated structure was produced by the same method except that the growth rate of the system-based semiconductor layer was set to 150 Å / sec.

The first layer was in a polycrystalline state even when it had a thickness of 5000 angstroms or more, and had unevenness on the surface and island-shaped growth, so that it was not possible to fabricate a light emitting device.

[0230]

As described above, the nitride-based semiconductor light-emitting device according to the present invention has excellent surface flatness and crystallinity at an extremely thin film thickness on a specific substrate, and therefore the device manufacturing process It is characterized by being easy and highly reliable. An element that emits blue light could be manufactured by current injection. In addition, since the film thickness is small, the process of manufacturing the light emitting device is easy and highly reliable, and the light extraction efficiency can be increased.

[Brief description of drawings]

FIG. 1 In the hexagonal crystal system

[Outside 12] FIG. 3 is a perspective view showing a crystal plane tilted at θ ₁ to.

2 is an oriented polycrystalline GaN / n− produced in Example 1. FIG.
It is a cross-sectional block diagram of the light emitting element which consists of GaN / p-GaN.

FIG. 3 Oriented polycrystalline Ga _1-x In _x N / n-Ga _1-x
Is a sectional view of a light emitting element made of _{In x N / p-Ga 1} -x In x N.

FIG. 4 Oriented polycrystalline n ⁺ -GaN / n-GaN / p-
It is a cross-sectional block diagram of the light emitting element which consists of GaN.

FIG. 5: Oriented polycrystalline Ga _1-x In _x N / n-Ga _1-x
In _x N / i-Ga _1-y In _y N / p-Ga _1-x In _x
FIG. 3 is a cross-sectional configuration diagram of a light emitting element made of N (x ≦ y).

FIG. 6 Oriented polycrystalline Ga _1-x In _x N / n-Ga _1-x
In _x N / p-Ga _1-y In _y N / p-Ga _1-x In _x
FIG. 3 is a cross-sectional configuration diagram of a light emitting element made of N (x ≦ y).

FIG. 7: Oriented polycrystalline Ga _1-a Al _a N / n-Ga _1-a
Al _a N / p-Ga _1-b Al _b N / p-Ga _1-a Al _a N (a
It is a cross-sectional block diagram of the light emitting element which consists of> = b.

FIG. 8: Oriented polycrystalline Ga _1-xy In _x Al _y N / n-
Ga _1-xy In _x Al _y N / i-Ga _1-ab In _a Al
_b is a sectional view of a _{N / p-Ga 1-xy} In x Al y N a light emitting element.

FIG. 9: Oriented polycrystalline GaN / n-GaN / p-GaN
Is a sectional view of a _{/ n-Ga 1-x In} x N / p-Ga 1-x In x N composed of the light emitting element.

FIG. 10: GaInN composition gradient structure / n-Ga _1-x In
is a sectional view of a light emitting element composed of _{x N / p-Ga 1-} x In x N.

FIG. 11: Strained superlattice structure / n-Ga _1-x In _x N / p-
It is a sectional view of a light emitting element composed of Ga _1-x In _x N.

FIG. 12: Oriented polycrystalline Ga _1-x In _x N / n-Ga
It is a sectional view of a light emitting element composed of _1-x In x N / quantum well structure _{/ p-Ga 1-x In} x N.

FIG. 13: Oriented polycrystalline Ga _1-x In _x N / n-Ga
_{1-x In x N / p} -Ga 1-x In x N / n-Ga 1-y I
It is a sectional view of a light emitting element composed of _{n y N / p-Ga 1} -y In y N.

FIG. 14 is a schematic view of a crystal growth apparatus used for forming a thin film.

FIG. 15 is a graph showing diode characteristics of the GaN light emitting device manufactured in Example 1.

16 is a graph showing an emission spectrum of the GaN light emitting device manufactured in Example 1. FIG.

FIG. 17 shows the (001) plane as (1) in a cubic crystal system.
Inclination of θ ₂ toward the (00) plane and θ toward the (010) plane
FIG. 6 is a perspective view showing a crystal plane inclined by ₃ .

FIG. 18 shows the (001) plane in the tetragonal crystal system as (1
FIG. 6 is a perspective view showing a crystal plane inclined by θ _{4 in the (} 00) plane direction.

FIG. 19: Oriented polycrystalline Ga _1-x In _x N / n-Ga
_{1-x In x N / i} -Ga 1-x In x N / p-Ga 1-x I
It is a sectional view of a light-receiving element consisting of n _x N.

[Explanation of symbols]

1 Vacuum Container 2 Evaporating Crucible 3 Evaporating Crucible 4 Evaporating Crucible 5 Evaporating Crucible 6 Evaporating Crucible 7 Gas Cell 8 Substrate Heating Holder 9 Substrate 10 Quadrupole Mass Spectrometer 11 RHEED Electron Gun 12 RHEED Screen 13 Shroud 14 Shutter 15 Shutter 16 Shutter 17 Shutter 18 Shutter 19 Valve 20 Cold trap 21 Diffusion pump 22 Oil rotary pump 23 Substrate 24 Oriented polycrystalline GaN 25 Single crystalline n-GaN 26 Single crystalline p-GaN 27 Electrode 28 Electrode 29 Oriented polycrystalline Ga _{1 -x} In _x n 30 single crystal _{n-Ga 1-x In x} n 31 single crystal _{p-Ga 1-x In x} n 32 oriented polycrystalline n ⁺ -GaN 33 single crystal _{i-Ga 1-x In x} n 34 Single crystal p-Ga _1-y In _y N 35 Oriented polycrystalline Ga _1-a Al _a N 36 Single crystal n-Ga _1-a Al _a N 37 Single crystal p-Ga _1-b Al _b N 38 Single crystal p-Ga _1-a Al _a N 39 Oriented polycrystalline Ga _1-xy In _x Al _y N 40 single crystal _{n-Ga 1-xy In x} Al y n 41 single crystal _{i-Ga 1-xy In x} Al y n 42 single crystal _{p-Ga 1-xy In x} Al y n 43 electrodes 44 electrodes 45 GaInN composition graded structure layer 46 quantum well structure layer 47 single crystal _{n-Ga 1-y In y} n 48 single crystal _{i-Ga 1-x In x} n 49 strained superlattice structure

Claims (25)

[Claims] 1. A substrate, a first layer directly formed on the substrate and made of an oriented polycrystalline nitride semiconductor having a thickness of 5000 angstroms or less, and a first layer directly formed on the first layer. An operating layer made of a single crystal nitride-based semiconductor,
Having two or more electrodes connected to a predetermined site,
A nitride semiconductor device, wherein at least one electrode is connected to the first layer. 2. At least one direction of the periodic arrangement of atoms on the surface of the substrate and one of the crystal axes of the lattice planes of the nitride-based semiconductor of the first layer which are in direct contact with the substrate are the same direction. Yes, there is a 5% difference between the interatomic distance in the former direction and an integer multiple of the interatomic distance in the latter direction (1 or more and 10 or less)
The nitride-based semiconductor device according to claim 1, wherein 3. The nitride-based semiconductor device according to claim 1, wherein the substrate is a transparent single crystal substrate having a transmittance of 80% or more in a wavelength range of 360 to 800 nm. 4. The nitride-based semiconductor device according to claim 3, wherein the transparent single crystal substrate is a sapphire substrate. 5. The surface of the transparent single crystal substrate is The nitride-based semiconductor device according to claim 4, wherein 6. The surface of the sapphire substrate is [2] The nitride-based semiconductor device according to claim 4, wherein the surface is inclined by 9.2 degrees. 7. The single crystal nitride semiconductor is Al, G
The nitride-based semiconductor device according to claim 1, comprising at least one group III element selected from a and In and nitrogen. 8. The nitride-based semiconductor according to claim 1, wherein the c-axis direction of the crystal axis of the oriented polycrystalline nitride-based semiconductor of the first layer is oriented parallel to the substrate surface. element. 9. The composition of the oriented polycrystalline nitride-based semiconductor of the first layer is sequentially changed from the substrate contact portion toward the operation layer contact portion, and finally the required operation layer of the operation layer is formed. The nitride-based semiconductor device according to claim 1, having a compositionally graded structure that provides a composition. 10. The oriented polycrystalline nitride-based semiconductor of the first layer has a structure in which a plurality of nitride-based semiconductor layers different in composition having a thickness of 100 Å or less are alternately laminated. The nitride-based semiconductor device according to claim 1. 11. The nitride-based semiconductor device according to claim 1, wherein the oriented polycrystalline nitride-based semiconductor of the first layer is n-type doped. 12. The operating layer of the single crystal nitride based semiconductor comprises a set of layers made of a combination of two or more selected from p-type, i-type and n-type single crystal nitride-based semiconductors. The nitride-based semiconductor element according to claim 1, wherein 13. The operating layer of the single crystal nitride-based semiconductor comprises at least two sets of layers made of a combination of two or more kinds selected from p-type, i-type and n-type single-crystal nitride-based semiconductors. The nitride-based semiconductor element according to claim 1, wherein 14. The nitride semiconductor device according to claim 12, wherein the operating layer of the single crystal nitride semiconductor has a thickness of 5 μm or less. 15. The operating layer of the single crystal nitride semiconductor comprises at least one pair of p-type, i-type and n-type single crystal nitride semiconductors, and the p-type or i-type single crystal nitride. The nitride-based semiconductor element according to claim 14, wherein an electrode for applying a voltage is connected to the system-based semiconductor layer. 16. A surface layer is formed of the p-type or i-type single crystal nitride-based semiconductor, and an electrode having a pattern for uniformly applying a voltage to the surface layer to extract light is formed on the surface layer. 15. The nitride-based semiconductor element according to claim 14, wherein the nitride-based semiconductor element is formed in a range not exceeding 50%. 17. The operating layer of the single crystal nitride semiconductor comprises an i-type single crystal nitride semiconductor having a thickness of 5000 angstroms or less and an n-type single crystal nitride semiconductor having a thickness of 3 μm or less. 15. The nitride-based semiconductor device according to claim 14, wherein an electrode for applying a voltage is formed on the i-type single crystal nitride-based semiconductor layer. 18. The operating layer of the single crystal nitride-based semiconductor comprises at least one set of a p-type single crystal nitride-based semiconductor having a thickness of 2 μm or less and an n-type single crystal nitride-based semiconductor having a thickness of 3 μm or less. 15. The nitride-based semiconductor device according to claim 14, wherein the p-type single crystal nitride-based semiconductor layer is formed of a semiconductor, and an electrode for applying a voltage is formed on the p-type single-crystal nitride-based semiconductor layer. 19. The single crystal nitride-based semiconductor operating layer comprises at least one set of a p-type single crystal nitride-based semiconductor, an i-type single crystal nitride-based semiconductor, and an n-type single crystal nitride-based semiconductor, The electrode for applying a voltage is formed on the p-type single crystal nitride-based semiconductor layer, and a current is generated in the operating layer upon receiving light irradiation. Nitride semiconductor device. 20. A crystal growth apparatus by a molecular beam epitaxy method, comprising a gas source for supplying a nitrogen-containing compound in a gaseous state, a solid source for supplying a group III element, and a source for supplying n-type and p-type dopants. , Pressure is 1
Substrate temperature of 300 to 1000 ° C at 0 ^-5 Torr or less
Then, a gaseous nitrogen-containing compound and a group III element are supplied to the surface of the substrate, and 0.1 to 20 angstrom / s is applied onto the substrate.
The first layer of the oriented polycrystalline nitride-based semiconductor is formed at a growth rate of ec, and subsequently, the pressure is 10 ⁻⁵ Torr or less, the substrate temperature is 300 to 1000 ° C., and the gaseous nitrogen-containing compound and the group III An element is supplied to the surface of the first layer, and a single crystal nitride based semiconductor layer is formed on the first layer at a growth rate of 0.1 to 10 angstrom / sec. Manufacturing method. 21. The method for producing a nitride semiconductor device according to claim 20, wherein ammonia, nitrogen trifluoride, hydrazine or dimethylhydrazine is used as the nitrogen-containing compound. 22. The method of manufacturing a nitride-based semiconductor device according to claim 20, wherein the gas of the nitrogen-containing compound is heated and supplied to the surface of the substrate. 23. The method for producing a nitride-based semiconductor device according to claim 20, wherein nitrogen or ammonia is used as the nitrogen-containing compound, and these are supplied in a plasma gas state. 24. When growing the nitride-based semiconductor thin film, the partial pressure of the carbon-containing compound in the crystal growth apparatus is set to 10 ^−8.
21. The method for manufacturing a nitride-based semiconductor device according to claim 20, wherein it is set to Torr or less. 25. After dry-etching a required portion of the first layer and the operation layer made of at least one pair of p-type or i-type single crystal nitride-based semiconductor and n-type single crystal nitride-based semiconductor, nitrogen is used. A heat treatment is carried out in a containing compound gas and an inert gas or in each gas at a temperature not higher than the decomposition temperature of the nitride-based semiconductor in the gas, and at least two electrodes are formed at required portions. 21. The method for manufacturing a nitride semiconductor device according to claim 20.