JPH08162720A - Semiconductor laser - Google Patents

Abstract

PURPOSE: To obtain an inexpensive semiconductor laser in which high speed modulation is carried out, especially a semiconductor laser of short wavelength. CONSTITUTION: The semiconductor laser comprises an electron emitting element 21, a stripe semiconductor laser structure 25, and an electronic lens system 23 for focusing electrons emitted from the element 21 to the stripe semiconductor laser structure 25 wherein the element 21 is a surface conduction type electron discharging element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device used as a light source for a laser beam printer, an optical recording device, optical communication, a pointer, a display device and the like, and more particularly to an electron beam emitted from an electron-emitting device. The present invention relates to a semiconductor laser device excited by.

[0002]

2. Description of the Related Art Semiconductor lasers are used as power sources for laser beam printers, optical recording devices, optical communications, pointers, display devices, etc. for the reasons that they are small, inexpensive, convenient to use, and capable of high-speed modulation. There is. Further, for the reason of high density of the optical recording device, the photosensitivity of the laser beam printer, and the purpose of colorization in the display device, a semiconductor having a wide bandgap can be used in order to enable a shorter wavelength, especially blue oscillation. Attempts have been made to make a semiconductor laser. Particularly in recent years, ZnSe / Z, which is a II-VI-based material,
Progress has been made in achieving blue-green pulse oscillation in nMnSe (Applied Physics).
Letters, Vol. 59, p-1272 (199
1)).

However, although the wide bandgap semiconductors that have been studied so far have excellent optical properties, they have high electrical properties, in particular, high resistance because doping cannot be performed freely. The continuous oscillation of the light of room temperature at room temperature has not been achieved yet.

As one method for overcoming the drawbacks of the semiconductor laser using the wide band gap semiconductor, the semiconductor is excited by using an accelerated electron beam,
A method of causing laser oscillation has been proposed. For example, there is a report of a small semiconductor laser configured using a Spindt-type electron-emitting device and a CdTe / CdMnTe-based semiconductor structure (Applied Physics Letter).
rs, Vol. 62, p-796 (1993)).

[0005]

However, the above conventional electron beam excited semiconductors have the following problems, which hinders their practical use.

1) Since the minute electron emission sources are arranged on a plane, the electron emission pattern cannot be narrowed down to a striped elongated pattern required for a semiconductor laser.
The semiconductor laser oscillates in the transverse multi-mode, and the power required for lasing becomes large.

2) Since the device capacity of the electron-emitting device is large and the electron emission amount of the electron-emitting device cannot be modulated at high speed, it is difficult to modulate the light emitted from the semiconductor laser at high speed as a result.

3) The voltage applied to the electron-emitting device is relatively high (about 100 V), and the cost of the electric circuit for modulating and driving the electron-emitting device becomes high.

4) The manufacturing process of the electron-emitting device is complicated, the manufacturing cost of the device is high, and it is difficult to provide a laser device at low cost.

The present invention solves the above-mentioned problems of the prior art and is an inexpensive semiconductor laser device capable of high-speed modulation.
In particular, it is an object to provide a semiconductor laser device having a short wavelength.

[0011]

Means and Actions for Solving the Problems The constitution of the present invention made to achieve the above object is as follows.

That is, according to the present invention, at least an electron-emitting device, a stripe-shaped semiconductor laser structure, and an electron optical system for causing electrons emitted from the electron-emitting device to enter the stripe-shaped semiconductor laser structure. A semiconductor laser device comprising: a semiconductor laser device, wherein the electron-emitting device is a surface conduction electron-emitting device.

The semiconductor laser device of the present invention is further characterized in that, in the above-mentioned striped semiconductor laser structure, a band is formed as the semiconductor layer between the stripe portion on which the electron beam is incident and the active layer is closer to the active layer. In the stripe-shaped semiconductor laser structure, the semiconductor layer between the stripe portion on which the electron beam is incident and the active layer has a diffusion length of carriers generated in the semiconductor layer. The stripe-shaped semiconductor laser structure has a thickness of 10 times or less, a metal thin film having a thickness of 1 to 100 nm is disposed on the stripe portion to cover at least a part of the stripe portion, and
The metal thin film also includes a voltage application unit connected to accelerate the electrons emitted from the electron-emitting device.

As described above, the semiconductor laser device of the present invention uses, in particular, a surface conduction electron-emitting device as an electron beam source for exciting the semiconductor of the stripe semiconductor laser structure. The electron emitting device will be described in detail.

The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is passed through a conductive thin film formed on an insulating substrate in parallel with the film surface.

As a typical example of the structure of the surface conduction electron-emitting device, a conductive thin film such as a metal oxide which connects a pair of device electrodes provided on an insulative substrate is referred to as forming in advance. The thing which formed the electron emission part by the electricity supply process is mentioned. Forming is done at both ends of the conductive thin film.
It is usually done by applying a voltage and energizing, locally destroying, deforming or altering the conductive thin film to change the structure,
This is a process of forming an electron emitting portion having a high electrical resistance. The electron emission is performed from the vicinity of the crack generated in the electron emitting portion by applying a voltage to the conductive thin film in which the electron emitting portion is formed and flowing a current.

As described above, since the surface conduction electron-emitting device has a simple structure and is relatively easy to manufacture, it can be manufactured at a low cost and the cracks having a shape similar to the stripe shape of a semiconductor laser. Since the electrons are emitted from the portion along the line, the emitted electrons can be focused on the stripe portion of the semiconductor laser by a simple electron optical system. Also,
Since the surface conduction electron-emitting device has a very small capacitance and the driving voltage is comparatively small at about ten and several volts, it is possible to easily perform high-speed modulation of the emission current by changing the driving voltage and drive the device. Electric circuits can also be manufactured inexpensively.

FIG. 1 shows a basic configuration example of the surface conduction electron-emitting device according to the present invention. In the figure, 1 is a substrate, 2 is an electron emitting portion, 3 is a conductive thin film including an electron emitting portion, and 4 and 5 are device electrodes.

The substrate 1 is, for example, quartz glass or Na.
And the like, glass having a reduced content of impurities such as, soda lime glass, a laminated body obtained by laminating SiO ₂ on soda lime glass by a sputtering method, and ceramics such as alumina.

The material of the opposing device electrodes 4 and 5 is as follows:
Common conductor materials are used, such as Ni, Cr, Au,
Metal or alloy such as Mo, W, Pt, Ti, Al, Cu and Pd, and printed conductor composed of metal or metal oxide such as Pd, Ag, Au, RuO ₂ , Pd-Ag and glass. , In ₂ O ₃ —SnO _{2 and} other transparent conductors, and polysilicon and other semiconductor conductor materials.

The element electrode spacing L is usually several hundred Å to several hundred μ.
m, which is the basis of the manufacturing method of the device electrode, that is, the photolithography technology, that is, the performance of the exposure device and the etching method,
It is set according to the voltage applied between the device electrodes and the electric field strength capable of emitting electrons, and is preferably several μm to several tens μm
Is.

The element electrode length W1 and the film thickness d are appropriately set in consideration of the resistance value of the electrode, the length W2 of the conductive thin film 3 and the like. Usually, the element electrode length W1 is about several hundreds μm. The film thickness d of the device electrode is several hundred Å to several μm.

The surface conduction electron-emitting device shown in FIG. 1 has the device electrodes 4, 5 and the conductive thin film 3 laminated in this order on the substrate 1. The conductive thin film 3 and the device electrodes 4 and 5 may be laminated in this order. Further, the surface conduction electron-emitting device shown in FIG.
The device is a flat device in which the device electrodes 4 and 5 are formed on the same surface, but the device electrodes are vertically arranged with an insulating layer interposed and a conductive thin film is formed on the side surface of the insulating layer. It may be an element.

In order to obtain good electron emission characteristics, the conductive thin film 3 is particularly preferably a fine particle film composed of fine particles, and the thickness of the conductive thin film 3 depends on the step coverage of the device electrodes 4 and 5 and the device. It is appropriately set depending on the resistance value between the electrodes 4 and 5 and the forming conditions described later. The conductive thin film 3 has a thickness of preferably several Å to several thousand Å, particularly preferably several tens of Å to several hundred Å, and its resistance value is 10 ³
The sheet resistance value is -10 ⁷ Ω / □.

The fine particle film is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state where the fine particles are dispersed and arranged but also in a state where the fine particles are adjacent to each other or overlap each other (island shape). (Including)). In the case of a fine particle film, the particle diameter of the fine particles is preferably several Å to several thousand Å, particularly preferably 10 Å to 200 Å.

The main materials forming the conductive thin film 3 are, for example, Pd, Pt, Ru, Ag, Au, Ti, In, Cu,
Metals such as Cr, Fe, Zn, Sn, Ta, W, Pb, P
dO, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , W
Oxides such as _{O x, HfB 2, ZrB 2} , LaB 6, Ce
Boride such as B ₆ , YB ₄ , GdB ₄ , TiC, ZrC,
Carbides such as HfC, TaC, SiC, WC, TiN, Z
It is made of a nitride such as rN or HfN, a semiconductor such as Si or Ge, or carbon.

A crack is included in the electron emitting portion 2, and the electron is emitted from the vicinity of this crack. The electron emitting portion 2 including the crack and the crack itself are formed depending on the film thickness of the conductive thin film 3, the film quality, the material, the forming conditions described later, and the like.

The crack may have conductive fine particles having a particle diameter of several Å to several hundred Å. The conductive fine particles are the same as some or all of the elements of the material forming the conductive thin film 3. Further, the electron emitting portion 2 including a crack and the conductive thin film 3 in the vicinity thereof may contain carbon and a carbon compound. Further, depending on the manufacturing method, the entire space between the device electrodes 4 and 5 may function as an electron emitting portion.

Various methods are conceivable as a method for manufacturing the surface conduction electron-emitting device according to the present invention. The surface conduction electron emission device having the structure shown in FIG. Based on this, an example of the manufacturing method will be described below.

1) After the insulating substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum deposition method, a sputtering method or the like, and then the insulating substrate 1 is formed by a photolithography technique. On the surface of the device electrode 4,
5 is formed (FIG. 2A).

2) By coating the organic metal solution on the insulating substrate 1 on which the device electrodes 4 and 5 are formed and leaving it to stand,
An organometallic thin film is formed. The organic metal solution is a solution of an organic compound whose main element is a metal that is a constituent material of the conductive thin film 3 described above. Then, the organic metal thin film is heated and baked to form the conductive thin film 3 patterned by lift-off, etching, etc. (FIG. 2B). In addition, although the description has been given here using the coating method of the organic metal solution, the present invention is not limited to this, and may be formed by a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like. is there.

3) Subsequently, an energization process called forming is performed. When a power supply (not shown) is applied between the device electrodes 4 and 5, an electron emitting portion 2 having a changed structure is formed at the portion of the conductive thin film 3 (FIG. 2C). By this energization treatment, the conductive thin film 3 is locally destroyed, deformed or altered, and the electron-emissive portion 2 is a portion whose structure is changed.

An example of the forming voltage waveform is shown in FIG.

The voltage waveform is particularly preferably a pulse waveform,
There are a case where a voltage pulse whose pulse peak value is a constant voltage is continuously applied (FIG. 3A), and a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 3B).

First, the case where the pulse peak value is a constant voltage will be described. T1 and T2 in FIG. 3A are the pulse width and pulse interval of the voltage waveform, for example, T1 is 1 μsec to 10 msec, T2 is 10 μsec to 100 msec,
The peak value of the triangular wave (peak voltage at the time of forming) is appropriately selected according to the form of the surface conduction electron-emitting device described above, and it is several seconds to several tens of minutes under a vacuum atmosphere of an appropriate degree of vacuum. Apply. The voltage waveform to be applied is not limited to the illustrated triangular wave, and a desired waveform such as a rectangular wave can be used.

Next, the case where the voltage pulse is applied while increasing the pulse peak value will be described. T1 and T2 in FIG. 3B are the same as those in FIG. 3A, and the crest value of the triangular wave (peak voltage at the time of forming) is increased by, for example, about 0.1 V step, and then, FIG. It is applied in an appropriate vacuum atmosphere similar to the description of a).

In the pulse interval T2, the conductive thin film 3
(See FIG. 1) The element current is measured at a voltage that does not locally destroy, deform, or alter the properties, for example, a voltage of about 0.1 V to obtain a resistance value. For example, when a resistance of 1 M ohm or more is exhibited, forming is performed. finish.

4) Next, it is preferable to perform an activation process on the element which has completed the forming process.

The activation step is, for example, 10 ⁻⁴ to 10 ⁻⁵ T.
As in the description of the forming step, a process of repeatedly applying a pulse with a constant pulse peak value at a degree of vacuum of about orr is used to remove carbon and carbon compounds from an organic substance existing in a vacuum. 2 (see FIG. 1) is a process in which the states of device current and emission current can be significantly improved. It is effective to perform this activation step while measuring the device current and the emission current, for example, and to end it when the emission current is saturated, because it is effective. The pulse peak value in the activation step is preferably the peak value of the drive voltage applied when driving the element.

The carbon and the carbon compound are graphite (both single crystal and polycrystal), amorphous carbon (amorphous carbon, and a mixture thereof with polycrystal graphite). . The deposited film thickness is preferably 500 Å or less, more preferably 300 Å or less.

5) More preferably, the surface conduction electron-emitting device thus manufactured is operated and driven in a vacuum atmosphere having a vacuum degree higher than the vacuum degree in the forming step and the activation step. In addition, more preferably, operation is performed after heating at 80 ° C. to 150 ° C. in a vacuum atmosphere having a higher degree of vacuum.

By the above step 5), further deposition of carbon and carbon compounds is suppressed, and the device current and the emission current are stabilized.

Next, the basic characteristics of the surface conduction electron-emitting device obtained as described above will be described below.

FIG. 4 is a schematic block diagram showing an example of a measurement / evaluation system for measuring the electron emission characteristics of the surface conduction electron-emitting device. First, the measurement / evaluation system will be described.

4, the same reference numerals as those in FIG. 1 indicate the same members. Further, 51 is a power supply for applying a device voltage Vf to the device, 50 is an ammeter for measuring a device current If flowing through the conductive thin film 3 between the device electrodes 4 and 5, and 54 is an electron emitting portion 2. An anode electrode for trapping the emission current Ie generated, 53 is a high-voltage power supply for applying a voltage to the anode electrode 54, and 52 is a measurement of the emission current Ie emitted from the electron emission portion 5. An ammeter, 55 is a vacuum device, and 56 is an exhaust pump.

The surface conduction electron-emitting device, the anode electrode 54, etc. are installed in a vacuum device 55, and this vacuum device 55 is used.
Is equipped with necessary equipment such as a vacuum gauge (not shown),
The surface conduction electron-emitting device can be measured and evaluated under a desired vacuum.

The exhaust pump 56 is composed of a normal high vacuum system such as a turbo pump and a rotary pump, and an ultra high vacuum system including an ion pump.

The basic characteristics of the surface conduction electron-emitting device described below are that the voltage of the anodic electrode 54 of the measurement and evaluation system is 1 kV to 10 kV and the distance H between the anodic electrode 54 and the surface conduction electron-emitting device is H. Is normally set to 2 mm to 8 mm and the measurement is normally performed.

First, the emission current Ie and the device current If,
A typical example of the relationship of the element voltage Vf is shown in FIG. 5 (solid line in the figure).
Shown in In FIG. 5, the emission current Ie is the device current I
Since it is significantly smaller than f, it is shown in arbitrary units.

As is apparent from FIG. 5, the surface conduction electron-emitting device has the following three characteristic characteristics with respect to the emission current Ie.

First, in the surface conduction electron-emitting device, when a device voltage Vf higher than a certain voltage (called threshold voltage: Vth in FIG. 5) is applied, the emission current Ie rapidly increases, while At the threshold voltage Vth or less, the emission current Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie has the characteristic of monotonically increasing with respect to the element voltage Vf (called MI characteristic), the emission current Ie can be controlled by the element voltage Vf.

Thirdly, the emitted charges captured by the anode electrode 54 (see FIG. 4) depend on the time for applying the device voltage Vf. That is, the amount of charges captured by the anode electrode 54 can be controlled by the time for which the device voltage Vf is applied.

The characteristic shown by the solid line in FIG. 5 is the emission current Ie.
Has an MI characteristic with respect to the element voltage Vf, and at the same time, the element current If also has an MI characteristic with respect to the element voltage Vf. However, as indicated by a broken line in FIG. 5, the element current If changes to the element voltage Vf. On the other hand, it may exhibit a voltage control type negative resistance characteristic (called a VCNR characteristic). Which characteristic is exhibited is
It depends on the manufacturing method of the device and the measurement conditions at the time of measurement. However,
Even if the device current If has a VCNR characteristic with respect to the device voltage Vf, the emission current Ie is M with respect to the device voltage Vf.
It has the I characteristic.

As described above, the surface conduction electron-emitting device according to the present invention has a very simple structure, and the emission current Ie can be modulated at high speed simply by modulating the voltage Vf applied to the device. I have Further, since the electron emission portion 2 (see FIG. 1) is formed in a thin linear stripe shape, it has substantially the same shape as the stripe of the incident portion of the stripe semiconductor laser. Therefore, it is very preferable as an electron beam source for exciting a semiconductor laser.

Next, the stripe-shaped semiconductor laser structure according to the present invention will be described.

FIG. 6 is a diagram showing the basic structure of a stripe-shaped semiconductor laser structure according to the present invention. In FIG. 6, 11 is a semiconductor substrate, 12 and 13 are semiconductor layers forming a clad layer, 14 is a semiconductor layer forming an active layer, 15 is a semiconductor layer forming a cap layer, and 16 is formed on a part of the cap layer 15. Striped ridge, 17 is an insulator,
Reference numeral 18 is a thin film metal layer forming a thin film electrode. Semiconductor layer 12
To 15 are epitaxially sequentially formed on the semiconductor substrate 11,
It is laminated.

As the material of the semiconductor substrate 11, for example, S
Single crystal material such as i, Ge, or GaAs, InP, Z
Any material such as a compound semiconductor material such as nSe that can epitaxially grow the semiconductor layers 12 to 15 may be used.

Regarding the semiconductor material of the active layer 14, basically, it is desirable that the semiconductor has a direct transition type band structure which does not accompany emission or absorption of quantum of lattice vibration upon recombination. It is appropriately selected depending on the required emission wavelength. The cladding layers 12 and 13 are made of a semiconductor whose band gap is larger than that of the active layer 14.

FIG. 7 is a schematic view showing one structural example of the semiconductor laser device of the present invention. In FIG. 7, 21 is the same as in FIG.
, 22 is a driving power source for the surface conduction electron-emitting device 21, 23 is an electron lens system, 24 is a power source for the electron lens system 23, and 25 is a semiconductor as shown in FIG. Laser structure, 26 is an accelerating voltage source, 27
Is a vacuum container having an optical window.

Further, FIG. 8 is a simplified drawing of the band structure in the semiconductor laser structure 25 in FIG.

The principle of operation of the semiconductor laser device of the present invention will be described below with reference to FIGS. 7 and 8.

As described above, when a voltage is applied between the device electrodes 4 and 5 of the surface conduction electron-emitting device 21 by the power supply 22, electrons are emitted into the vacuum. The emitted electrons pass through the electron lens system 23 and the semiconductor laser structure 2
The thin film electrode 18 in the stripe portion of No. 5 is converged into a shape substantially similar to the shape of the ridge 16. Since the thin film electrode 18 is kept at a high voltage with respect to the surface conduction electron-emitting device 21 by the accelerating voltage source 26, the emitted electrons are accelerated and focused on the semiconductor laser structure 25. Since the thin film electrode 18 is formed sufficiently thin on the ridge 16 of the cap layer 15, the accelerated electrons enter the cap layer 15 with almost no energy loss in the thin film electrode 18. The accelerated electrons lose energy while exciting electron-hole pairs in the cap layer 15. The generated electron-hole pairs (in FIG. 8, electrons are shown by black circles, holes are shown by white circles) flow into the active layer 14 from the cladding layer 13 by diffusion, and the energy corresponding to the band gap is generated. The spontaneous emission light of will be emitted. Furthermore, when a sufficient amount of electron-hole pairs are accumulated in the active layer 14 to cause population inversion in the active layer 14, and when an optical resonator is well formed in the semiconductor laser structure 25, finally, a semiconductor is finally formed. Stimulated emission light is emitted from the laser structure 25. That is, laser oscillation occurs.

The semiconductor laser device of the present invention can be used as a light source for laser beam printers, optical recording devices, optical communications, pointers, display devices and the like. Further, from the advantage that laser oscillation is possible without current injection, it is possible to cause laser oscillation of a semiconductor material that has conventionally been poorly controlled in doping, particularly a II-VI group semiconductor material. In general, since the II-VI group semiconductor has a large band gap, a laser beam having a short wavelength can be obtained, and the II-VI group semiconductor can be applied to a high-density optical recording device or a display device.

[0065]

EXAMPLES The present invention will be further described with reference to the following examples.

In this embodiment, an example in which the semiconductor laser device of the present invention having the structure shown in FIG. 7 is manufactured by using the surface conduction electron-emitting device having the same basic structure as in FIG.

First, a method of manufacturing the surface conduction electron-emitting device will be specifically described with reference to FIG.

1) A vacuum-deposited film having a thickness of 0.5 mm on a substrate 1 formed by sputtering a silicon oxide film having a thickness of 0.5 μm on a square quartz glass having a thickness of 1 mm and a side length of about 100 mm. 50ÅCr, 6000Å thick Au
After being sequentially laminated, a photoresist (AZ1370 Hoechst) is spin-coated with a spinner and baked, and then a photomask image is exposed and developed to form a resist pattern, and the Au / Cr deposited film is wet-etched to obtain a desired pattern. The wirings 31 and 32 having the shape of FIG.
(A)).

2) After that, a pattern which should become a gap between the device electrodes 4 and 5 and the device electrodes is formed by a photoresist (RD-2).
000N-41 manufactured by Hitachi Chemical Co., Ltd.) and formed by vacuum vapor deposition to a thickness of 50Å Ti and a thickness of 1000Å Ni.
Were sequentially deposited. The photoresist pattern was dissolved in an organic solvent and the Ni / Ti deposition film was lifted off to form device electrodes 4 and 5 with a device electrode interval L of 3 μm and a device electrode width W1 of 300 μm (FIG. 9B).

3) Using a mask having an element electrode gap L and an opening in the vicinity thereof, a Cr film having a film thickness of 1000 Å is deposited and patterned by vacuum vapor deposition, and organic Pd (ccp-4230 manufactured by Okuno Chemical Industries Co., Ltd.) is formed on the Cr film. Was spin-coated with a spinner and heated and baked at 300 ° C. for 10 minutes. The conductive thin film 3 formed of fine particles mainly made of PdO formed in this way has a thickness of 100 Å,
The sheet resistance value was 5 × 10 ⁴ Ω / □ (Fig. 9)
(C)). Incidentally, the fine particle film described here is a film in which a plurality of fine particles are gathered as described above, and as a fine structure thereof, not only a state in which fine particles are individually dispersed and arranged,
A film in which fine particles are adjacent to each other or overlap each other (including islands).

4) The Cr film and the conductive thin film 3 after firing
Was etched with an acid etchant to form a conductive thin film 3 having a desired pattern shape (FIG. 9).
(D)).

5) Next, the wirings 31, 32, the device electrodes 4,
5 and the substrate 1 on which the conductive thin film 3 is formed are held in a vacuum container, and after reaching a sufficient degree of vacuum by a vacuum pump, a voltage is applied between the device electrodes 4 and 5 to perform a forming process. Then, the electron emitting portion 2 was formed (FIG. 9E). The voltage waveform as shown in FIG. 3A was used for the forming process.

In this embodiment, T1 in FIG.
Seconds, T2 is 10 ms, the peak value of the triangular wave (peak voltage during forming) is 5 V, and about 1 × 10 ⁻⁶ Torr
Forming treatment was performed for 60 seconds in the vacuum atmosphere. In the electron emitting portion 2 thus produced, fine particles containing palladium element as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30Å.

As described above, the surface conduction electron-emitting device used in the semiconductor laser device of this example was obtained.

The stripe-shaped semiconductor laser structure used in the semiconductor laser device of this embodiment is as shown in FIG. 6, and its manufacturing method will be specifically described.

1) After the semi-insulating gallium arsenide substrate 11 was sufficiently washed, the surface was etched with a sulfuric acid-based etching solution to form an oxide film, which was then held in a metal-organic vapor phase epitaxy apparatus.

2) The temperature of the substrate 11 is once raised to 600 ° C. or higher to remove the oxide film on the surface of the substrate 11 and then the substrate 1
While maintaining the temperature of 1 at 550 ° C., (C ₂ H ₅ ) ₂ Zn,
ZnSe / 5 nm-ZnS _0.18 Se _0.82 was obtained by metalorganic vapor phase epitaxy using (C ₂ H ₅ ) ₂ Se and (C ₂ H ₅ ) ₂ S.
100 superlattice buffer layers and 5 clad layers 12
nm-ZnS _0.3 Se _0.7 layer, 100 n as the active layer 14
5 nm-ZnS as m-ZnSe layer and clad layer 13
_0.3 Se _0.7 layer, 400 nm-Zn as cap layer 15
An S _0.09 Se _0.91 layer and a 5 nm-ZnS _0.3 Se _0.7 layer were sequentially stacked.

3) A pattern having a stripe structure is formed on the substrate 11 on which the above semiconductor layers are laminated by a photoresist (R).
D-2000N-41 manufactured by Hitachi Chemical Co., Ltd.,
A ridge 16 having a width of about 5 μm was formed by wet etching using the photoresist pattern as a mask. Furthermore, with the mask remaining, about 30
A 0 nm silicon oxide film was deposited, the resist was dissolved in an organic solvent, the silicon oxide film on the ridge 16 was lifted off, and an insulator 17 was formed on a portion other than the ridge 16.

4) Ridge 1 having a stripe pattern
6 to the photoresist pattern (RD-20
00N-41 manufactured by Hitachi Chemical Co., Ltd.), and Ti of 50 Å thickness and Au of 50 Å thickness were sequentially deposited by a vacuum evaporation method. The photoresist pattern was dissolved in an organic solvent, the Au / Ti deposition film was lifted off, and the thin film electrode 18 was formed on the ridge 16.

5) The substrate 11 having the striped semiconductor laser structure formed as described above is lapped to a thickness of about 100 μm, and then cleaved to form an optical resonator having a length of about 500 μm. Then, a striped semiconductor laser structure of this example was obtained.

Next, the semiconductor laser device shown in FIG. 7 was manufactured by using the surface conduction electron-emitting device and the stripe-shaped semiconductor laser structure obtained as described above.
The manufacturing method thereof will be described below.

1) A semiconductor laser structure 25, a surface conduction electron-emitting device 21, and a vacuum container 27 having an optical window.
And the electrostatic lens 23 was mounted. Since the semiconductor laser structure 25 and the surface conduction electron-emitting device 21 absorb heat generated from these devices, the vacuum container 2 is soldered.
It was fixed in 7 to improve the thermal conductivity. After that, the vacuum container 27 was sealed while keeping the inside of the vacuum container 27 at a high vacuum (1 × 10 ⁻⁵ Torr or less).

2) Finally, a getter process was performed in order to maintain the degree of vacuum after sealing. This is a process of forming a vapor deposition film by heating a getter (not shown) arranged at a predetermined position in the vacuum container 27 by a heating method such as high-frequency heating immediately before sealing. The getter was mainly composed of Ba or the like.

In the semiconductor laser device of the present embodiment completed as described above, electrons are emitted by applying a voltage from the power source 22 between the device electrodes 4 and 5 of the surface conduction electron-emitting device 21, and the semiconductor laser structure. A high voltage of several kV or more is applied from the power supply 26 to the thin film metal 18 of the body 25, the electron beam is accelerated, electron-hole pairs are generated in the semiconductor laser structure 25, and carriers generated in the active layer are accumulated. Then, a population inversion was generated here to obtain laser light emission.

In the semiconductor laser device of this embodiment, the voltage V applied between both device electrodes of the surface conduction electron-emitting device.
The relationship between f and the voltage Va applied to the thin film electrode of the semiconductor laser structure and the laser light output is shown in FIG.

As shown in FIG. 10, the laser light output showed a characteristic of sharply rising above a certain threshold value with respect to the voltage Vf and the voltage Va.

Further, in order to grasp the characteristics of the surface conduction electron-emitting device manufactured in the above-mentioned step, a sample device similar to the above was manufactured, and its electron emission property was measured by using the measurement evaluation system shown in FIG. Was measured.

The measuring conditions were as follows: the distance H between the anode electrode 54 and the electron-emitting device was 4 mm, the potential of the anode electrode 54 was 1 kV, and the degree of vacuum in the vacuum device 55 was 1 × 10 ⁻⁶ Torr.
r.

As a result, the sample element obtained the current-voltage characteristics as shown by the solid line in FIG. In this element,
The emission current Ie sharply increases from the element voltage Vf of about 8V, and when the element voltage Vf is 14V, the element current If is 2.2.
mA, the emission current Ie was 1.1 μA, and the electron emission efficiency η = Ie / If (%) was 0.05%.

In the present embodiment, the semiconductor laser structure used is a laser structure generally called a separate confinement double hetero structure (SCH-DH), but the present invention is not limited to this, and the electron to the active layer is not limited to this. In order to increase the injection efficiency of holes and holes, a graded index separate confinement double hetero (GRIN-S
(CH-DH) structure (see FIG. 8) may be used. Further, the thickness of the ZnS _0.09 Se _0.91 layer directly under the thin film electrode is preferably about the diffusion length of electrons or holes or less, but if it is too thin, the active layer may be damaged by high energy electrons. Therefore, it may be 10 times or less than the diffusion length. Typically this layer has a thickness of 10 nm to 1
It is desirable to set in the range of 000 nm. Further, it is preferable to form this layer into a graded layer (see the band diagram of FIG. 11) whose composition gradually decreases toward the substrate (toward the active layer). Electrons and holes are efficiently captured in the active layer.

In this embodiment, the semiconductor laser structure is made of ZnSe type semiconductor grown on the GaAs substrate. However, the present invention is not limited to this, and GaAs type, InP type, ZnSe system, AlN
Any type of semiconductor may be used as long as it can form a stripe structure such as a GaN-based semiconductor or a GaN-based semiconductor.

Although the ridge structure is selected as the stripe structure in this embodiment, the structure is not limited to this, and any structure may be used as long as it can confine light in the lateral direction and constrict the current. Further, the thickness of the thin film electrode on the stripe is 10 nm as the thickness at which incident electrons do not lose energy, but it can be about 1 nm to 100 nm depending on the metal material used.

[0093]

As described above, the semiconductor laser device of the present invention using the surface conduction electron-emitting device as the excitation electron beam source has the following effects.

1) Since semiconductor laser oscillation is possible without current injection, it is difficult to control the doping of semiconductor materials, especially I.
It is possible to oscillate a semiconductor material of Group I-VI, and it becomes possible to oscillate a visible light and a short wavelength, which has been difficult to continuously oscillate at room temperature. Therefore, it can be applied to high-density optical recording devices and display devices.

2) In the surface conduction electron-emitting device, since electrons are emitted from the electron-emitting portion having the same shape as the stripe portion of the semiconductor laser structure, the electron-emitting pattern is efficiently formed into the stripe pattern required for the semiconductor laser. The semiconductor laser can be squeezed, and the semiconductor laser can be oscillated in the transverse single mode. In addition, the number of ineffective emitted electrons that do not participate in the laser oscillation is reduced, and the power required for the laser oscillation is reduced.

3) Since the surface conduction electron-emitting device has a small device capacity, the electron emission amount can be modulated at high speed,
As a result, the light emitted from the semiconductor laser can be modulated at high speed.

4) The surface conduction electron-emitting device has a relatively low drive voltage (about 10V), and the cost of an electric circuit for driving the device for modulation is low.

5) Since the surface conduction electron-emitting device has a simple manufacturing process, the manufacturing cost of the device is low and the laser can be provided at a low cost.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a surface conduction electron-emitting device according to the present invention.

2 is a cross-sectional view for explaining an example of a method of manufacturing the surface conduction electron-emitting device of FIG.

FIG. 3 is an example of a voltage waveform used for forming processing.

FIG. 4 is a schematic diagram of a measurement evaluation system for measuring electron emission characteristics of a surface conduction electron-emitting device.

FIG. 5 is a diagram showing a typical example of a relationship between an emission current Ie and a device current If and a device voltage Vf of a surface conduction electron-emitting device.

FIG. 6 is a schematic view showing an example of a stripe-shaped semiconductor laser structure according to the present invention.

FIG. 7 is a schematic view of a semiconductor laser device of the present invention.

FIG. 8 is a band diagram of a stripe-shaped semiconductor laser structure according to the present invention.

FIG. 9 is a drawing for explaining the manufacturing process of the surface conduction electron-emitting device shown in Example 1.

10 is a diagram showing applied voltage-light output characteristics of the semiconductor laser device of the present invention shown in Example 1. FIG.

FIG. 11 is an example of a preferable band diagram of the stripe-shaped semiconductor laser structure according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 Electron emission part 3 Conductive thin film 4,5 Element electrode 11 Semi-insulating semiconductor substrate 12, 13 Clad layer 14 Active layer 15 Cap layer 16 Ridge part forming a stripe structure 17 Insulator 18 Thin film electrode consisting of metal thin film Reference Signs List 21 surface conduction electron-emitting device 22 driving power supply for electron-emitting device 23 electron lens system 24 power supply for electron lens system 25 striped semiconductor laser structure 26 accelerating voltage source 27 vacuum container having optical window 31, 32 wiring 50 conductive thin film Ammeter 51 for measuring the device current If flowing through the device 3 Power supply 52 for applying the device voltage Vf to the surface conduction electron-emitting device 52 Ammeter 53 for measuring the emission current Ie emitted from the electron emitting portion 2 High-voltage power supply for applying voltage to the anode electrode 54. Captures electrons emitted from the electron emission unit 2. Because of anode - cathode electrode 55 vacuum device 56 exhaust pump

Claims (4)

[Claims] 1. At least an electron-emitting device, a stripe-shaped semiconductor laser structure, and an electron optical system for causing electrons emitted from the electron-emitting device to enter the stripe-shaped semiconductor laser structure. A semiconductor laser device, wherein the electron-emitting device is a surface conduction electron-emitting device. 2. In the striped semiconductor laser structure, the semiconductor layer between the stripe portion on which the electron beam is incident and the active layer is composed of a semiconductor having a smaller bandgap as it is closer to the active layer. The semiconductor laser device according to claim 1, which is characterized in that. 3. In the stripe-shaped semiconductor laser structure, a semiconductor layer between a stripe portion on which an electron beam is incident and an active layer has a thickness of 10 times or less than a diffusion length of carriers generated in the semiconductor layer. The semiconductor laser device according to claim 1, wherein 4. A metal thin film having a thickness of 1 to 100 nm which covers at least a part of the stripe portion is arranged on the stripe portion in the stripe semiconductor laser structure, and the metal thin film is formed of the metal thin film. 4. The semiconductor laser device according to claim 1, further comprising a voltage applying unit for accelerating electrons emitted from the electron-emitting device.