JP2001345520A - Method of manufacturing semiconductor light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a nitride based III-V compound semiconductor light-emitting element of high quality, in which indium is prevented from being captured into an upper layer of a layer containing indium and crystallinity of the upper layer of the layer containing indium is improved. SOLUTION: This method of manufacturing a semiconductor light-emitting element has a process, in which a III-V compound semiconductor layer containing nitrogen is formed through by crystal growth to take place. A first semiconductor layer (16) as the III-V compound semiconductor containing indium and nitrogen is grown at a first temperature. A second semiconductor layer (18), composed of AlxGa1-xN (where 0<=x<=1), is grown upward of the first semiconductor layer (16) at a second temperature. The second temperature is made higher than the first temperature up to a temperature for preventing indium from being taken into the second semiconductor layer (18).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a group III-V compound semiconductor light emitting device containing nitrogen (hereinafter, also referred to as a nitride), and more particularly, to a method for forming a semiconductor layer containing indium on another semiconductor layer. The present invention relates to a method for manufacturing a semiconductor light emitting device for forming a layer.

[0002]

2. Description of the Related Art A nitride-based III-V compound semiconductor represented by gallium nitride (GaN) (hereinafter also referred to as a "GaN-based semiconductor") emits light that can emit light in a range from green to blue and even ultraviolet rays. It is promising as a material for devices and the like. In particular, since the light-emitting diode (LED) using the GaN-based semiconductor was put to practical use, GaN-based semiconductors have received a great deal of attention. The realization of a semiconductor laser using this GaN-based semiconductor has also been reported,
A device that reads (reproduces) information recorded on an optical recording medium (hereinafter, also referred to as an optical disc) such as a digital versatile disc (hereinafter also referred to as an optical disc) or writes (records) information to or from them. The optical pickup device is also expected to be applied to an optical pickup device incorporated therein.

FIG. 1 shows the above-mentioned Ga having a general structure.
FIG. 3 is a perspective view of an N-based semiconductor light emitting device (laser diode LD). A GaN-based semiconductor layer including an active layer 16 having a multiple quantum well structure is stacked on a sapphire substrate 11 to form a semiconductor stacked body 10. In the semiconductor laminate 10, a p-type electrode 10a and an n-type electrode 10b are formed so as to be connected to the p-type clad layer and the n-type clad layer formed so as to sandwich the active layer 16, respectively. I have. Here, since the sapphire substrate 11 is insulative, the semiconductor layer connected to the n-type cladding layer or n
The lead portion 10c of the mold clad layer itself is formed on the sapphire substrate 11 so as to protrude from the semiconductor laminate 10, and the n-electrode 10b is formed on this upper layer. When a predetermined voltage is applied from the power supply B to the p-electrode 10a and the n-electrode 10b, the laser light L is emitted from the active layer 16 in the semiconductor laminate 10.

FIG. 2A is a cross-sectional view illustrating the above-described semiconductor laminate 10 in more detail. For example, a buffer layer 12 made of GaN or the like is formed on a sapphire substrate 11.
Is formed thereon, and for example, about 5.0 μm
N-type GaN layer (contact layer) 13 having a thickness of
5 μm-thick n-type AlGaN layer (cladding layer) 1
4. An n-type GaN layer (guide layer) having a thickness of about 0.1 μm
15. Multiple quantum well (MQW) made of GaInN or the like
Active layer (light emitting layer) 16 having a structure, p-type AlGaN layer (cap layer) 17 having a thickness of about 0.02 μm, about 0.1 μm
P-type GaN layer (guide layer) 18 having a thickness of about 0.5 μm
m-thick p-type AlGaN layer (cladding layer) 19, about 0.1 μm-thick p-type GaN layer (contact layer) 2
0 are respectively stacked. In the above description, silicon (Si) or the like is used as the n-type impurity (donor impurity) doped into the n-type layer, and magnesium (M) is used as the p-type impurity (acceptor impurity) doped into the p-type layer.
g) or zinc (Zn).

FIG. 2B is a schematic diagram showing the potential of the active layer 16 having the above-described multiple quantum well structure. In the active layer 16, layers having an indium (In) content of 2% and layers having an indium content of 8% are alternately stacked, and the potentials of the respective layers are different, so that a multiple quantum well structure is formed. .

A method for manufacturing the above-mentioned GaN-based semiconductor light emitting device (laser diode LD) will be described. G above
When manufacturing a light emitting element or the like from an aN-based semiconductor,
It is necessary to grow a GaN-based semiconductor in multiple layers on a sapphire substrate, a SiC substrate, or the like. As a method for growing the GaN-based semiconductor, there is known a metal organic chemical vapor deposition (MOCV) method.
There are D) method and molecular beam epitaxy (MBE) method. Of these methods, MOCVD method is practically advantageous because it does not require a high vacuum, and is widely used.

In the above-mentioned MOCVD method, a substrate to be processed is placed in an MOCVD reaction tube made of, for example, quartz glass, and ammonia (N) as a nitrogen raw material is placed in the reaction tube while being heated by an RF coil or the like surrounding the reaction tube.
H ₃ ) and gallium (Ga), aluminum (Al), indium (I
A raw material such as n) is supplied together with a carrier gas, and a GaN-based semiconductor is grown on a substrate to be processed placed in a reaction tube.

Referring to FIG. 3, a description will be given of a manufacturing process of a method for manufacturing a semiconductor light emitting device in which a GaN-based semiconductor having the structure shown in FIG. 2 is grown in multiple layers. First, as shown in FIG. 3A, after the c-plane sapphire substrate 11 is thermally cleaned, a buffer layer 12 made of GaN or the like and an n-type GaN layer (contact layer) having a thickness of about 5.0 μm are formed by MOCVD. Layer) 13, n-type A having a thickness of about 0.5 μm
lGaN layer (cladding layer) 14 and about 0.1 μm
An n-type GaN layer (guide layer) 15 having a thickness of 3 is formed by sequentially growing crystals. In the above description, silicon (S) is used as an n-type impurity (donor impurity) doped into each of the n-type layers.
i) and the like are used.

Next, as shown in FIG. 3B, the MOCV
The active layer (light emitting layer) 16 having a multiple quantum well (MQW) structure made of GaInN is formed on the n-type GaN layer 15 by the D method.
Is formed by crystal growth.

Next, a p-type AlGaN layer (cap layer) 17 having a thickness of about 0.02 μm and a p-type Ga layer having a thickness of about 0.1 μm are formed on the active layer 16 by MOCVD.
N layer (guide layer) 18, p-type A having a thickness of about 0.5 μm
lGaN layer (cladding layer) 19 and about 0.1 μm
A p-type GaN layer (contact layer) 20 having a film thickness of 1 is formed by crystal growth in order, and reaches the structure shown in FIG. In the above, magnesium (Mg) or zinc (Zn) is used as a p-type impurity (acceptor impurity) doped into each p-type layer.
And so on. In the subsequent steps, the extraction portion 10 of the n-type cladding layer itself shown in FIG.
After forming c, the electrodes (10a, 10b) are formed, and the end face of the laser resonator is formed by etching or the like, whereby a desired laser diode can be obtained.

In the above-described method for manufacturing a semiconductor light emitting device, as described in JP-A-10-32349, the decomposition efficiency of ammonia, which is a group V raw material, is low. It is preferable to grow at a high temperature. However, indium contained in the active layer is not taken into the grown layer unless the temperature is as low as about 800 ° C. Further, after the active layer is grown, if the temperature is raised to about 1000 ° C. immediately after the growth of the active layer in order to form a GaN layer, an AlGaN layer, and the like thereon, InN in the active layer is decomposed. Therefore, at least a cap layer above the active layer (specifically, for example, p-type AlG
The temperature was not raised until the growth of the (aN layer) was completed, but was raised again to about 1000 ° C. before or during the growth of a guide layer (specifically, for example, a p-type GaN layer) thereover.

That is, in the conventional method of manufacturing a semiconductor light emitting device, the buffer layer 12 is grown at a growth temperature of, for example, 510 ° C.
Is grown, for example, the temperature is increased to about 1000 ° C., and n
-Type GaN layer (contact layer) 13, n-type AlGaN
A layer (cladding layer) 14 and an n-type GaN layer (guide layer) 15 are grown.
The temperature is lowered to 850 ° C., and the active layer 16 and the p-type AlG
aN layer (cap layer) 17 is grown and then
The temperature is raised to 000 ° C., and the p-type GaN layer (guide layer) 1
8. While growing the p-type AlGaN layer (cladding layer) 19 and the p-type GaN layer (contact layer) 20, or raising the temperature to about 1000 ° C. while growing the p-type GaN layer (guide layer) 18 And then p-type AlGaN
A layer (cladding layer) 19 and a p-type GaN layer (contact layer) 20 were grown. The temperature profile Z in FIG. 4B is an example of the growth temperature profile according to the above, and corresponds to each layer in FIG. 4C (codes respectively correspond to the codes in FIG. 2).

[0013]

However, in the above-mentioned manufacturing method, a semiconductor layer such as a GaN layer grown at 800 ° C. has poor crystallinity and low carrier concentration, resulting in low luminous efficiency. This was a factor in increasing the voltage.

In addition, during the growth of the GaInN layer (active layer), indium adheres around the susceptor, which is the base on which the substrate to be processed is mounted, in the reaction tube of the MOCVD apparatus. It is taken into an AlGaN layer such as a layer or a GaN layer, which causes a decrease in crystallinity.

FIG. 5A shows the results of SIMS (Secondary Ion Mass Spectroscopy) analysis of the semiconductor light emitting device grown by the above-mentioned conventional method. In the figure, the solid line A is indium (In) and the broken line B is, respectively. Indicates the gallium (Ga), and the dashed line C indicates the secondary ion intensity (relative value) of aluminum (Al) measured relative to the distance (relative value) from the surface. As shown in FIG. 5A, a shoulder A ′ is formed in the spectrum of indium indicated by the solid line A, indicating that indium is incorporated in the upper layer of the active layer.

Accordingly, an object of the present invention is to provide a nitride III
In a -V compound semiconductor layer, indium is prevented from being taken into a semiconductor layer above the semiconductor layer containing indium such as an active layer, and the crystallinity of the semiconductor layer above the semiconductor layer containing indium is improved, High quality nitride I
An object of the present invention is to provide a method capable of manufacturing a group II-V compound semiconductor light emitting device.

[0017]

In order to achieve the above object, a method for manufacturing a semiconductor light emitting device according to the present invention comprises a step of forming a group III-V compound semiconductor layer containing nitrogen by crystal growth. A method for manufacturing a light emitting device,
Growing a first semiconductor layer that is a III-V compound semiconductor containing indium and nitrogen at a first temperature;
Above the first semiconductor layer, Al _x Ga at a second temperature
Growing a second semiconductor layer made of _1-xN (where 0 ≦ x ≦ 1), wherein the second temperature is equal to the first temperature.
The temperature is higher than the temperature for preventing indium from being taken into the second semiconductor layer.

In the method of manufacturing a semiconductor light emitting device according to the present invention, preferably, after the step of growing the first semiconductor layer and before the step of growing the second semiconductor layer, A _y
The method further includes the step of growing a third semiconductor layer made of Ga _{1 -yN} (where 0 ≦ y ≦ 1). In the step of growing the second semiconductor layer, the third semiconductor layer is grown on the third semiconductor layer. Then, during the growth of the third semiconductor layer, the temperature is raised from the first temperature to the second temperature.

According to the method for manufacturing a semiconductor light emitting device of the present invention, the temperature of the first semiconductor layer is higher than the first temperature, which is the growth temperature of the first semiconductor layer, above the first semiconductor layer containing indium. A second semiconductor layer made of Al _x Ga ₁ -xN (where 0 ≦ x ≦ 1) is grown at a second temperature that prevents incorporation. The first semiconductor layer may be grown at the first temperature, the temperature may be raised to the second temperature, and then the second semiconductor layer may be grown on the first semiconductor layer. A third semiconductor layer may be formed in between, and the temperature may be raised from the first temperature to the second temperature while forming the third semiconductor layer. As described above, even if the temperature is immediately increased after forming the first semiconductor layer containing indium,
While it is clear that the crystallinity of the first semiconductor layer does not decrease due to the decomposition of InN, indium is taken into the second semiconductor layer by increasing the growth temperature during the growth of the second semiconductor layer. , The crystallinity of the second semiconductor layer can be improved, and a high-quality semiconductor light emitting device can be manufactured.

In the method for manufacturing a semiconductor light emitting device according to the present invention, preferably, the second temperature is 850 ° C. or higher and 110 ° C.
0 ° C. or lower, more preferably 900 ° C. or higher and 1050 ° C. or lower. By raising the temperature to the above temperature, the second
Prevents indium from being taken into the semiconductor layer,
The crystallinity of the second semiconductor layer can be improved.

In the method of manufacturing a semiconductor light emitting device according to the present invention, preferably, the third semiconductor layer is formed in a thickness of 0.01 to 0.5.
μm, more preferably 0.01 to 0.1 μm. By completely raising the temperature before the completion of the growth of the third semiconductor layer, the growth temperature of the second semiconductor layer can be set to a high temperature from the beginning, and the crystallinity of the second semiconductor layer can be improved.

In the method of manufacturing a semiconductor light emitting device according to the present invention, preferably, in the step of growing the second semiconductor layer, the temperature is further increased from the second temperature while growing the second semiconductor layer. Warm and grow. By raising the temperature from the first temperature to the second temperature, a certain degree of crystallinity of the second semiconductor layer can be secured. However, by further raising the temperature, the crystallinity can be further improved.

In the method of the present invention for manufacturing a semiconductor light emitting device, preferably, a laser diode is formed as the semiconductor light emitting device. Although high crystallinity is required to achieve a practical life as a laser diode, crystallinity can be improved by the present invention.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a semiconductor light emitting device and a method of manufacturing the same according to the present invention, and a laser coupler and an optical disk device using the semiconductor light emitting device will be described with reference to the drawings. In all the drawings of the embodiments, the same or corresponding portions are denoted by the same reference numerals.

FIG. 1 shows a nitride III according to this embodiment.
FIG. 2 is a perspective view of a GaN-based semiconductor light-emitting device (laser diode LD) that is a group V compound semiconductor light-emitting device. On a sapphire substrate 11, a GaN-based semiconductor layer, which is a group III-V compound semiconductor including an active layer 16 having a multiple quantum well structure, is laminated to form a semiconductor laminate 10. In the semiconductor laminate 10, a p-type electrode 10a and an n-type electrode 10b are formed so as to be connected to the p-type clad layer and the n-type clad layer formed so as to sandwich the active layer 16, respectively. I have. Here, since the sapphire substrate 11 is insulative, the lead portion 10 of the semiconductor layer connected to the n-type cladding layer or the n-type cladding layer itself is used.
c is formed on the sapphire substrate 11 so as to protrude from the semiconductor laminate 10.
0b is formed. The above-mentioned p electrode 10a and n electrode 1
A laser beam L is emitted from the active layer 16 in the semiconductor laminate 10 by applying a predetermined voltage to the power supply 0b from the power supply B.

FIG. 2A is a cross-sectional view for explaining in more detail the portion of the semiconductor laminate 10 which is the GaN-based compound. For example, a buffer layer 12 made of GaN or the like is formed on a sapphire substrate 11, and
For example, an n-type GaN layer (contact layer) 13 having a thickness of about 5.0 μm, an n-type AlGaN having a thickness of about 0.5 μm
Layer (cladding layer) 14, n-type G having a thickness of about 0.1 μm
aN layer (guide layer) 15, active layer (light emitting layer) 16 having a multiple quantum well (MQW) structure made of GaInN or the like, p-type AlGaN layer (cap layer) 17 having a thickness of about 0.02 μm, A p-type GaN layer (guide layer) 18 having a thickness of 1 μm, a p-type AlGaN layer (cladding layer) 19 having a thickness of about 0.5 μm, and a p-type Ga layer having a thickness of about 0.1 μm.
N layers (contact layers) 20 are respectively laminated.
In the above description, silicon (Si) or the like is used as the n-type impurity (donor impurity) doped into the n-type layer, and magnesium (Mg) or zinc (zinc) is used as the p-type impurity (acceptor impurity) doped into the p-type layer. Zn) or the like.

FIG. 2B is a schematic diagram showing the potential of the active layer 16 having the multiple quantum well structure. In the active layer 16, layers having an indium (In) content of 2% and layers having an indium content of 8% are alternately stacked, and the potentials of the respective layers are different, so that a multiple quantum well structure is formed. .

A method of manufacturing the GaN-based semiconductor light emitting device (laser diode LD) will be described. G above
When manufacturing a light emitting element or the like from an aN-based semiconductor,
It is necessary to grow a GaN-based semiconductor in multiple layers on a sapphire substrate, a SiC substrate, or the like. As a method for growing the GaN-based semiconductor, there is known a metal organic chemical vapor deposition (MOCV) method.
D) method, molecular beam epitaxy (MBE) method, or the like can be used.

In the above MOCVD method, a substrate to be processed is placed in an MOCVD reaction tube made of, for example, quartz glass, and ammonia (N) as a nitrogen raw material is placed in the reaction tube while being heated by an RF coil or the like surrounding the reaction tube.
H ₃ ) and gallium (Ga), aluminum (Al), indium (I
A raw material such as n) is supplied together with a carrier gas, and a GaN-based semiconductor is grown on the substrate to be processed placed in the reaction tube.

A manufacturing process of a method for manufacturing a semiconductor light emitting device in which a GaN-based semiconductor having the structure shown in FIG. 2 is grown in multiple layers will be described with reference to FIG. First, as shown in FIG. 3A, after the c-plane sapphire substrate 11 is thermally cleaned, a buffer layer 12 made of GaN or the like and an n-type GaN layer (contact layer) having a thickness of about 5.0 μm are formed by MOCVD. Layer) 13, n-type A having a thickness of about 0.5 μm
lGaN layer (cladding layer) 14 and about 0.1 μm
An n-type GaN layer (guide layer) 15 having a thickness of 3 is formed by sequentially growing crystals. In the above description, silicon (S) is used as an n-type impurity (donor impurity) doped into each of the n-type layers.
i) and the like are used.

Next, as shown in FIG.
The active layer (light emitting layer) 16 having a multiple quantum well (MQW) structure made of GaInN is formed on the n-type GaN layer 15 by the D method.
Is formed by crystal growth.

Next, a thickness of 0.01 to 0.5 μm, preferably 0.01 to 0.5 μm, is formed on the active layer 16 by MOCVD.
P-type Al having a thickness of 0.1 μm (for example, 0.02 μm)
A GaN layer (cap layer) 17 is crystal-grown, and further thereon, a p-type GaN layer (guide layer) 18 having a thickness of about 0.1 μm and a p-type AlGaN layer (about 0.5 μm) ( Cladding layer) 19 and p of about 0.1 μm thickness.
Formed GaN layers (contact layers) 20 are formed by sequentially growing crystals, resulting in the structure shown in FIG. In the above, magnesium (Mg), zinc (Zn), or the like is used as a p-type impurity (acceptor impurity) to be doped into each p-type layer. In the subsequent steps, the lead portion 10c of the n-type clad layer itself shown in FIG. 1 is formed by etching,
The electrodes (10a, 10b) are formed, and the end faces of the laser resonator are formed by etching or the like, whereby a desired laser diode can be obtained.

In the MOCVD process, for example, 5
After growing the buffer layer 12 at a growth temperature of 10 ° C., the temperature is raised to, for example, about 1000 ° C., and the n-type GaN layer (contact layer) 13 and the n-type AlGaN layer (cladding layer) 1
4 and n-type GaN layers (guide layers) 15 are grown. Next, the active layer 16 is grown by lowering the growth temperature to, for example, 750-850 ° C. (first temperature). next,
As the second temperature, 850 to 1100 ° C., preferably 9
After the temperature was raised to 00 to 1050 ° C. (for example, 1000 ° C.), the p-type AlGaN layer (cap layer) 17 and the p-type G
aN layer (guide layer) 18, p-type AlGaN layer (cladding layer) 19 and p-type GaN layer (contact layer) 20
Can grow.

Also, a p-type AlGaN layer (cap layer)
While growing 17, the temperature is raised to the above-mentioned second temperature,
Thereafter, the p-type GaN layer (guide layer) 18 and the p-type Al
A GaN layer (cladding layer) 19 and a p-type GaN layer (contact layer) 20 may be grown. For example, 0.02
In the case of forming a p-type AlGaN layer (cap layer) 17 having a thickness of μm, a temperature profile in which a portion of 0.01 μm is grown at 800 ° C., and then the temperature is raised to 1000 ° C. during further growth of 0.01 μm is set. it can. FIG.
The temperature profile X in (a) is the above-mentioned growth temperature profile drawn so as to correspond to each layer in FIG. 4 (c) (the symbols respectively correspond to the symbols in FIG. 2). As described above, the thickness of the third semiconductor layer grown while the temperature is raised from the first temperature to the second temperature is, for example, 0.01 to
0.5 μm, preferably 0.01 to 0.1 μm,
By completely raising the temperature before the growth of the third semiconductor layer is completed,
The growth temperature of the second semiconductor layer can be set to a high temperature from the beginning, and the crystallinity of the second semiconductor layer can be improved.

Further, a p-type AlGaN layer (cap layer)
While growing 17, the temperature is raised to the above-mentioned second temperature,
Thereafter, while growing the p-type GaN layer (guide layer) 18, the temperature is further raised from the second temperature, and at that temperature, the p-type AlG
An aN layer (cladding layer) 19 and a p-type GaN layer (contact layer) 20 can also be grown. For example, 0.
In the case of forming a 02 μm p-type AlGaN layer (cap layer) 17, a portion of 0.01 μm is grown at 800 ° C., and then further grown to a second temperature of 900 ° C. while growing by 0.01 μm. Further, it is possible to have a temperature profile in which the temperature is raised from the second temperature (900 ° C.) to 1000 ° C. while growing the p-type GaN layer (guide layer) 18. The temperature profile Y in FIG.
The growth temperature profiles described above correspond to the respective layers in (c) (the symbols respectively correspond to the symbols in FIG. 2).

In the method for manufacturing a semiconductor light emitting device according to this embodiment, the first temperature, which is the growth temperature of the first semiconductor layer, is higher than the nitride-based active layer containing indium (first semiconductor layer). also high, at a second temperature to prevent the indium is incorporated Al _x Ga _1-x N (However, 0 ≦
A second semiconductor layer such as a guide layer composed of x ≦ 1) is grown. The first semiconductor layer may be grown at the first temperature, the temperature may be raised to the second temperature, and then the second semiconductor layer may be grown on the first semiconductor layer. A third semiconductor layer such as a cap layer may be formed therebetween, and the temperature may be raised from the first temperature to the second temperature while forming the third semiconductor layer.

As described above, according to the method for manufacturing a semiconductor light emitting device according to the present embodiment, even if the temperature is immediately increased after forming the first semiconductor layer containing indium,
The crystallinity of the first semiconductor layer does not decrease due to the decomposition of InN, and by increasing the growth temperature during the growth of the second semiconductor layer, indium is prevented from being taken into the second semiconductor layer. (2) The crystallinity of the semiconductor layer can be improved, and a high-quality semiconductor light emitting device can be manufactured.

FIG. 5B shows the results of SIMS (Secondary Ion Mass Spectroscopy) analysis of the semiconductor light emitting device grown by the manufacturing method of the present embodiment. In FIG. 5B, the solid line A indicates indium (In). ), The dashed line B indicates gallium (Ga), and the dashed line C indicates the secondary ion intensity (relative value) of aluminum (Al) measured with respect to the distance (relative value) from the surface. As shown in FIG. 5B, in the spectrum of indium indicated by the solid line A, the shoulder A ′ as seen in FIG. 5A was not observed, indicating that indium was not incorporated into the upper layer of the active layer. ing.

Using the laser diode according to the present embodiment, a laser coupler mounted on an optical pickup device for an optical disk device can be configured. FIG.
(A) is a perspective view of the above laser coupler. The laser coupler 1 is loaded in a concave portion of the first package member 2,
It is sealed by a transparent second package member 3 such as glass.

FIG. 6B is an enlarged perspective view of a main part of the laser coupler 1 described above. For example, a semiconductor block 6 on which a PIN diode 5 as a photodetector for monitoring is formed is disposed on an integrated circuit substrate 4 which is a substrate obtained by cutting a single crystal of silicon.
A laser diode LD having the structure shown in FIG.

On the other hand, for example, a photodiode 7 is formed on the integrated circuit board 4, and a prism 8 is mounted on the photodiode 7 at a predetermined distance from the laser diode LD.

The laser beam L is emitted from the laser beam emitting section (active layer) of the laser diode LD. The laser light L emitted from the laser diode LD is
Is partially reflected by the light-splitting surface 8a, and the traveling direction is bent by approximately 90 °, and is emitted in the emission direction from the emission window formed in the second package member 3, and is transmitted via a reflection mirror (not shown) or an objective lens to the DVD. Irradiation is performed on an irradiation target such as an optical disk. The reflected light from the object to be illuminated travels in the direction opposite to the direction of incidence on the object to be illuminated.
From the exit direction, and enters the spectral surface 8a of the prism 8. While focusing on the upper surface of the prism 8, the light is incident on two photodiodes 7 formed on the integrated circuit substrate 4 which is the lower surface of the prism 8.

The P formed on the semiconductor block 6
The IN diode 5 senses the laser light emitted to the rear side of the laser diode LD, measures the intensity of the laser light, and controls the drive current of the laser diode LD so that the intensity of the laser light becomes constant. (Automatic Power
Control) Control is performed.

FIG. 7 is a structural diagram showing an example when an optical pickup device is constructed using the above laser coupler. Laser light L emitted from a laser diode incorporated in the laser coupler 1 is incident on an optical disc D such as a DVD via a collimator C, a mirror M, an aperture R, an objective lens OL, and the like. The reflected light from the optical disk D follows the same path as the incident light, returns to the laser coupler, and is received by a photodiode built in the laser coupler. As described above, the laser diode manufactured according to the present embodiment can be preferably applied to an optical disk system.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to these embodiments. For example, the light emitting wavelength of the light emitting device according to the present invention is not particularly limited, and may be a wavelength employed in DVD or other next-generation optical disk systems. In the embodiment, a laser diode is described. However, the present invention is not limited to a laser, but can be applied to a light emitting diode (LED). In addition, the present invention provides a method in which a layer containing indium such as a GaInN layer is
The present invention can be applied to a method for manufacturing a semiconductor light emitting device that forms a semiconductor layer containing no indium such as a GaN layer or an AlGaN layer. Further, a semiconductor light emitting device in which a plurality of light emitting elements are monolithically configured can be manufactured by using the manufacturing method of the present invention. In this case, for example, a light-emitting device having a plurality of light-emitting elements such as light-emitting elements with different emission wavelengths, light-emitting elements with different element characteristics such as the same emission wavelength and different emission intensity, and further, a light-emitting element with the same element characteristic. It is possible to apply. Although the current constriction structure of the laser diode is not shown in detail in the embodiment, it can be applied to other lasers having various characteristics such as a gain guide type, an index guide type, and a pulsation laser. is there. In addition, various changes can be made without departing from the spirit of the present invention.

[0046]

According to the method for manufacturing a semiconductor light emitting device of the present invention, in the nitride III-V compound semiconductor layer,
Indium is prevented from being taken into the semiconductor layer above the semiconductor layer containing indium such as an active layer, the crystallinity of the semiconductor layer above the semiconductor layer containing indium is improved, and a high-quality nitride III- A group V compound semiconductor light emitting device can be manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor light emitting device (laser diode) according to the present invention and a conventional example.

2A is a cross-sectional view of a semiconductor laminate portion of the semiconductor light emitting device shown in FIG. 1, and FIG. 2B is a potential diagram of an active layer.

FIG. 3 is a cross-sectional view illustrating a manufacturing process of a method for manufacturing a semiconductor light emitting device according to the present invention and a conventional example.
(A) shows up to the step of forming the lower layer of the active layer, and (b) shows the step up to the step of forming the active layer.

FIG. 4 is a growth temperature profile in a manufacturing process of a method for manufacturing a semiconductor light emitting device according to the present invention and a conventional example.

FIG. 5 is a secondary ion mass spectrum of (a) a conventional example and (b) a semiconductor light emitting device according to the present invention.

FIG. 6A is a perspective view of a laser coupler mounted on an optical pickup device for an optical disc device using a laser diode according to the present invention, and FIG. 6B is a perspective view of the laser coupler. It is a principal part expansion perspective view.

FIG. 7 is a configuration diagram illustrating an example in which an optical pickup device is configured using a laser coupler including a laser diode according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser coupler, 2 ... 1st package member, 3 ... 2nd
Package member, 4 ... integrated circuit board, 5 ... PIN diode, 6 ... semiconductor block, 7 ... photodiode, 8
... Prism, 8a ... Dispersion surface, 10 ... Semiconductor laminate, 1
0a ... p electrode, 10b ... n electrode, 10c ... lead part,
11 sapphire substrate, 12 buffer layer, 13 n-type GaN layer (contact layer), 14 n-type AlGaN layer (cladding layer), 15 n-type GaN layer (guide layer), 1
6 Active layer (light emitting layer), 17 p-type AlGaN layer (cap layer), 18 p-type GaN layer (guide layer), 19 p
Type AlGaN layer (cladding layer), 20: p-type GaN layer (contact layer), B: power supply, C: collimator, D: optical disk, L: laser beam, LD: laser diode, M
… Mirror, OL… Objective lens, R… Aperture.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yuki Asazuma 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5D119 AA38 BA01 FA17 NA04 5F041 AA40 CA04 CA34 CA40 CA46 CA65 5F073 AA45 AA51 AA55 AA74 CA07 CB05 CB07 CB10 DA05 DA35

Claims (10)

[Claims] 1. A method of manufacturing a semiconductor light emitting device, comprising: forming a group III-V compound semiconductor layer containing nitrogen by crystal growth, the group III-V containing indium and nitrogen at a first temperature. Growing a first semiconductor layer that is a compound semiconductor; and forming Al _x Ga over the first semiconductor layer at a second temperature.
Growing a second semiconductor layer made of _1-xN (0 ≦ x ≦ 1), wherein the second temperature is higher than the first temperature, and A method for manufacturing a semiconductor light emitting device having a temperature at which indium is prevented from being taken into the semiconductor light emitting device. 2. The second temperature is 850 ° C. or higher and 1100 ° C.
The method for manufacturing a semiconductor light emitting device according to claim 1, wherein the temperature is lower than or equal to ° C. 3. The method according to claim 1, wherein the second temperature is 900 ° C. or more and 1050 ° C.
The method for manufacturing a semiconductor light emitting device according to claim 1, wherein the temperature is lower than or equal to ° C. 4. After the step of growing the first semiconductor layer,
Before the step of growing the second semiconductor layer, Al _y Ga
_{The method} further includes the step of growing a third semiconductor layer made of _1-yN (where 0 ≦ y ≦ 1). In the step of growing the second semiconductor layer, the third semiconductor layer is grown on the third semiconductor layer. The method according to claim 1, wherein the temperature is raised from the first temperature to the second temperature while growing the third semiconductor layer. 5. The method according to claim 1, wherein the second temperature is 850.degree.
The method for manufacturing a semiconductor light emitting device according to claim 4, wherein the temperature is lower than or equal to 0C. 6. The method according to claim 1, wherein the second temperature is 900 ° C. or more and 1050 ° C.
The method for manufacturing a semiconductor light emitting device according to claim 4, wherein the temperature is lower than or equal to 0C. 7. The semiconductor device according to claim 1, wherein said third semiconductor layer has a thickness of 0.01 to 0.5 μm.
The method for manufacturing a semiconductor light emitting device according to claim 4, wherein the semiconductor light emitting device is formed with a thickness of m. 8. The semiconductor device according to claim 1, wherein said third semiconductor layer has a thickness of 0.01 to 0.1 μm.
The method for manufacturing a semiconductor light emitting device according to claim 7, wherein the semiconductor light emitting device is formed with a thickness of m. 9. The method of manufacturing a semiconductor light emitting device according to claim 1, wherein in the step of growing the second semiconductor layer, the temperature is further increased from the second temperature during the growth of the second semiconductor layer. Method. 10. The method for manufacturing a semiconductor light emitting device according to claim 1, wherein a laser diode is formed as said semiconductor light emitting device.