JP2001352133A - Semiconductor laser, semiconductor device, nitride-family iii-v group compound substrate, and their manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser for obtaining a crystal growth layer with less fluctuation in a crystal axis and for improving the characteristics of a device, a semiconductor device and a nitride-family III-V group compound substrate, and their manufacturing method. SOLUTION: A plurality of seed crystal layers 12 provided separately on one surface side of a substrate 11 for growth, and an n-side contact layer 13 that is grown based on the plurality of seed crystal layers and has a growth region in a crosswise direction, are provided. In the seed crystal layer 12, the product of width w1 (unit: μm) of a boundary surface 12a with the n-side contact layer 13 in its arranged direction A and thickness t1 (unit: μm) in a direction where the n-side contact layer 13 is laminated is set to 15 or less, thus reducing the fluctuation of the crystal axis on the n-side contact layer 13, and hence improving the crystallinity of a semiconductor layer from an n-type clad layer 14 to a p-side contact layer 19 being laminated on the n-side contact layer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, a semiconductor laser, a nitride III-V compound substrate, and a semiconductor device having a seed crystal layer and a crystal growth layer grown on the seed crystal layer. And a method for producing the same.

[0002]

2. Description of the Related Art GaN, AlGaN mixed crystal or GaI
A nitride III-V compound semiconductor such as an nN mixed crystal is
It is a direct transition semiconductor material and has a forbidden band width of 1.9.
It has a feature that it ranges from eV to 6.2 eV. Therefore, these nitride III-V compound semiconductors can emit light in the visible region to the ultraviolet region, and can be used as a semiconductor such as a semiconductor laser (laser diode; LD) or a light emitting diode (light emitting diode; LED). It is attracting attention as a material for forming a light emitting element. Further, nitride-based III-V compound semiconductors have attracted attention as materials for electronic devices because of their high saturation electron velocity and high breakdown electric field.

In general, these semiconductor devices are formed by using a nitride III-V compound on a growth substrate made of sapphire (α-Al ₂ O ₃ ) or silicon carbide (SiC) by using a vapor phase growth method. It is manufactured by growing a semiconductor layer. However, there is a large lattice mismatch between the sapphire or silicon carbide and the nitride III-V compound semiconductor and a large difference in the coefficient of thermal expansion. Had a lattice defect. When such a lattice defect occurs, the defective portion becomes a center of non-radiative recombination that does not emit light even when electrons and holes recombine or a current leak point, and the optical or electrical characteristics of the semiconductor element are reduced. Will be spoiled.

Therefore, in recent years, a method of reducing the threading dislocation density by using, for example, a selective growth technique has been proposed. In this method, for example, a nitride-based III-V compound semiconductor layer grown on a growth substrate is selectively etched to form a seed crystal layer, and a crystal is grown laterally from a side wall surface of the seed crystal layer. It grows a layer.

[0005]

However, in this method, if the crystal axis of the crystal growth layer fluctuates, there is a problem that dislocations generated in the crystal growth layer cause defects to multiply. There is also a problem that dislocations spread in the horizontal direction and are easily propagated. Therefore, in order to improve the device characteristics, it is desired to grow a crystal growth layer with little fluctuation in the crystal axis.

The above-mentioned problem is also a problem in growing a nitride-based III-V compound substrate on a growth substrate, and is also required to obtain a good-quality nitride-based III-V compound substrate. It is indispensable to grow a crystal growth layer with little fluctuation in the crystal axis.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a semiconductor laser and a semiconductor device capable of obtaining a crystal growth layer with little fluctuation in the crystal axis and improving the characteristics of the device. And nitride III-V
It is an object of the present invention to provide a group III compound substrate and a method for producing the same.

[0008]

A semiconductor laser according to the present invention comprises a nitride-based III-V compound semiconductor, a plurality of spaced apart seed crystal layers, and a nitride-based III-V compound semiconductor.
And a crystal growth layer made of a group V compound semiconductor and grown on the seed crystal layer, wherein the seed crystal layer has a boundary surface width (unit) with the crystal growth layer in the arrangement direction. Μm) and the thickness (unit: μm) in the direction in which the crystal growth layers are stacked are 15 or less.

Another semiconductor laser according to the present invention comprises a band-shaped seed crystal layer made of a nitride III-V compound semiconductor and a nitride III-V compound semiconductor grown on the seed crystal layer. A crystal growth layer, wherein the seed crystal layer is formed such that a width of a boundary surface between the seed crystal layer and the crystal growth layer in a direction perpendicular to the extending direction (unit is μ
m) and a thickness (unit: μm) in a direction in which the crystal growth layers are stacked is 15 or less.

A semiconductor device according to the present invention has a nitride type II.
A plurality of seed crystal layers made of an IV group compound semiconductor and provided separately, and a crystal growth layer made of a nitride III-V compound semiconductor and grown on the basis of the seed crystal layer are provided. The product of the width (unit: μm) of the boundary surface between the seed crystal layer and the crystal growth layer in the arrangement direction and the thickness (unit: μm) in the direction in which the crystal growth layers are stacked. 15 or less.

Another semiconductor device according to the present invention is a band-shaped seed crystal layer made of a nitride III-V compound semiconductor;
A crystal growth layer made of a nitride-based III-V compound semiconductor and grown on the basis of a seed crystal layer, wherein the seed crystal layer is formed of a crystal in a direction perpendicular to its extending direction. The width of the interface with the growth layer (unit: μm) and the thickness in the direction in which the crystal growth layers are stacked (unit: μm)
Is 15 or less.

A nitride III-V compound substrate according to the present invention comprises a nitride III-V compound, and comprises a plurality of spaced apart seed crystal layers and a nitride III-V compound. And a crystal growth layer grown on the basis of the seed crystal layer, wherein the width of the boundary surface between the seed crystal layer and the crystal growth layer in the arrangement direction (unit: μm)
And the product of the thickness in the direction in which the crystal growth layers are stacked (unit: μm) is 15 or less.

A method for manufacturing a semiconductor laser according to the present invention comprises:
Growing a seed crystal layer growth layer made of a nitride III-V compound semiconductor on the growth substrate, and selectively removing the seed crystal layer growth layer to form a plurality of seed crystal layers; The width of the upper surface on the growth side in the arrangement direction (unit: μm)
And the thickness in the growth direction (unit: μm) is 15
And a step of growing a crystal growth layer made of a nitride III-V compound semiconductor based on the seed crystal layer.

The method of manufacturing a semiconductor device according to the present invention comprises the steps of: growing a seed crystal layer growth layer made of a nitride III-V compound semiconductor on a growth substrate; Selective removal to form a plurality of seed crystal layers, the width of the upper surface on the growth side in the arrangement direction (unit: μm)
And the thickness in the growth direction (unit: μm) is 15
And a step of growing a crystal growth layer made of a nitride III-V compound semiconductor based on the seed crystal layer.

The method of manufacturing a nitride III-V compound substrate according to the present invention comprises the steps of: growing a seed crystal layer growth layer made of a nitride III-V compound; and selecting the seed crystal layer growth layer. So that the product of the width (unit: μm) of the upper surface on the growth side in the arrangement direction and the thickness (unit: μm) in the growth direction is 15 or less. And a step of growing a crystal growth layer made of a nitride III-V compound based on the seed crystal layer.

In the semiconductor laser, the semiconductor device, or the nitride III-V compound substrate according to the present invention, the width (unit: μm) of the boundary surface between the seed crystal layer and the crystal growth layer in the arrangement direction is determined. The product of the thickness and the thickness (unit: μm) in the direction in which the layers are stacked is set to 15 or less. Therefore, the fluctuation in the crystal axis of the crystal growth layer is reduced.

In another semiconductor laser or another semiconductor device according to the present invention, in the seed crystal layer, the width (unit: μm) of the boundary surface with the crystal growth layer in a direction perpendicular to the direction in which the seed crystal layer extends, and The product with the thickness (unit: μm) in the direction in which the growth layers are stacked is set to 15 or less. Therefore, the fluctuation in the crystal axis of the crystal growth layer is reduced.

In the method for manufacturing a semiconductor laser, the method for manufacturing a semiconductor device, or the method for manufacturing a nitride III-V compound substrate according to the present invention, the width of the upper surface on the growth side in the arrangement direction (unit: μm) A crystal growth layer grows based on a plurality of seed crystal layers provided so that the product of the thickness (unit: μm) is 15 or less. Therefore,
A crystal growth layer with little fluctuation in the crystal axis is obtained.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a sectional structure of a semiconductor laser as a semiconductor device according to a first embodiment of the present invention. This semiconductor laser includes a plurality of seed crystal layers 12 provided on one surface side of a growth substrate 11 and spaced apart from each other, and an n-side contact as a crystal growth layer sequentially grown based on the plurality of seed crystal layers 12. Tier 1
3, n-type cladding layer 14, n-type guide layer 15, active layer 1
6, a p-type guide layer 17, a p-type cladding layer 18, and a p-side contact layer 19 are stacked in this order. Seed crystal layer 12, n-side contact layer 13, n-type cladding layer 14, n
The mold guide layer 15, the active layer 16, the p-type guide layer 17, the p-type cladding layer 18, and the p-side contact layer 19 are each made of a nitride III-V compound semiconductor. Here, the nitride-based III-V compound semiconductor refers to a compound semiconductor containing at least one of the group 3B elements and at least nitrogen of the group 5B element.

The growth substrate 11 is made of, for example, sapphire or silicon carbide having a thickness in the laminating direction (hereinafter, simply referred to as “thickness”) of 80 μm. For example, it is formed on the c-plane. The growth substrate 11 is, for example, a seed crystal layer 1.
It has a concave portion 11a corresponding to the two separated regions. The depth of the recess 11a in the stacking direction is preferably 20 nm or more. This is because, when growing the n-side contact layer 13 based on the seed crystal layer 12, it is possible to effectively prevent the n-side contact layer 13 from coming into contact with the growth substrate 11. The depth of the recess 11a is 3
It is more preferable that the thickness be 00 nm or less. This is because if the etching is performed more than necessary, the manufacturing cost increases.

The seed crystal layer 12 is made of, for example, undope-GaN to which no impurity is added or n-type GaN to which silicon (Si) is added as an n-type impurity.
The seed crystal layer 12 has, for example, a band shape and is arranged in a stripe shape. The seed crystal layer 12 has a width w ₁ (unit: μm) of a boundary surface 12a with the n-side contact layer 13 in the arrangement direction A (for example, a direction perpendicular to the extending direction of the strip) and the n-side. The product of the thickness t ₁ (unit: μm) in the direction in which the contact layers 13 are stacked is 1
5 or less. This is for reducing the fluctuation of the crystal axis in the n-side contact layer 13 and improving the crystallinity of the n-side contact layer 13. Specifically, for example, the fluctuation of the crystal axis in the arrangement direction A of the seed crystal layer 12 is reduced. Width w ₁ (μm) and thickness t in seed crystal layer 12
The product with ₁ (μm) is also preferably larger than 2.25. When the width w ₁ is smaller than 1.5 μm, the seed crystal layer 12 is easily separated from the growth substrate 11 at the time of manufacturing, as described later, and when the thickness is smaller than 1.5 μm, as described later. This is because the crystallinity of the seed crystal layer 12 deteriorates. Width w ₁ (μ) in seed crystal layer 12
The product of m) and the thickness t ₁ (μm) is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. This is because the fluctuation of the crystal axis in the n-side contact layer 13 can be further reduced.

FIG. 2 shows a preferred range of the width w ₁ of the boundary surface 12 a with the n-side contact layer 13 in the arrangement direction A of the seed crystal layer 12 and the separation distance d ₁ of the seed crystal layer 12 in the arrangement direction A. Things. Width w ₁ of seed crystal layer 12
Is preferably in the range indicated by the diagonally downward slanted lines in FIG. 2, that is, 1.5 μm to 6 μm. Further, it is more preferable to be within the range indicated by the solid line, that is, within the range of 2 μm or more and 5 μm or less. If the width w ₁ is small, the n-side contact layer 13 is easily peeled off during manufacturing, and the width w ₁
This is because if the width is large, the crystal axis of the n-side contact layer 13 tends to fluctuate. The separation distance d ₁ of the seed crystal layer 12 is in the range indicated by the diagonally downward slanted line in FIG.
m or more, more preferably the range shown by the solid line, that is, 10 μm or more. Separation distance d ₁
When the length is short, the process margin becomes narrow at the time of mask alignment at the time of manufacturing and the productivity is reduced.

FIG. 3 shows the thickness t ₁ of the seed crystal layer 12 and the X-ray diffraction (XRD) of the seed crystal layer 12 obtained when X-rays are incident from the boundary surface 12a side. The relationship with the half width of the rocking curve is shown.
As described above, as the thickness t ₁ of the seed crystal layer 12 increases, the half-value width decreases, and the fluctuation of the crystal axis decreases.
Note that the half width of the rocking curve by X-ray diffraction becomes narrower as the fluctuation in the crystal axis becomes smaller, and serves as an index of crystallinity.

The crystallinity of the seed crystal layer 12 is as follows.
It is preferable that the fluctuation of the crystal axis is small so that the half width at 2a is, for example, 300 arcsec or less. This is because the higher the crystallinity of the seed crystal layer 12 is, the more the fluctuation of the crystal axis in the n-side contact layer 13 can be reduced. Therefore, the thickness t ₁ of the seed crystal layer 12 is, for example, 1.
It is preferably at least 5 μm. The seed crystal layer 12
Thickness t ₁ is preferably 3μm or less. 3μ
If the thickness is larger than m, the thickness required for growing the n-side contact layer 13 at the time of manufacturing, which will be described later, for example, until the growth surface is flattened, increases the warpage of the growth substrate 11. It is because.

The n-side contact layer 13 has a thickness of, for example, 3 μm, and is doped with silicon as an n-type impurity.
It is composed of type GaN. The n-side contact layer 13 has a laterally grown region grown in the arrangement direction A (lateral direction) based on the side wall surface of the seed crystal layer 12 corresponding to the separated region of the seed crystal layer 12. In this lateral growth region, as shown in FIG. 4, threading dislocations from seed crystal layer 12 do not easily propagate, and the dislocation density is low. Thereby, also in the semiconductor layers from the n-type cladding layer 14 stacked on the n-side contact layer 13 to the p-side contact layer 19, the dislocation density of the portion corresponding to the lateral growth region is, for example, 10 ⁶ cm. ^-2 or less. On the other hand, threading dislocation M ₁ from seed crystal layer 12 is propagated to a region of n-side contact layer 13 corresponding to seed crystal layer 12. The n-side contact layer 13 also has an associated portion B formed by the association of crystals grown laterally at substantially the center of the lateral growth region,
The threading dislocation M ₂ generated by the association is present at the junction B. The threading dislocation M ₂ is often propagated to the semiconductor layers from the n-type cladding layer 14 stacked on the n-side contact layer 13 to the p-side contact layer 19.

The n-type cladding layer 14 has a thickness of, for example, 1
μm, n-type A doped with silicon as an n-type impurity
It is composed of an lGaN mixed crystal. n-type guide layer 15
Is made of, for example, n-type GaN having a thickness of 0.1 μm and adding silicon as an n-type impurity.

The active layer 16 has, for example, a thickness of 30 nm and Ga _x In ₁ -xN (x ≧ 0) having different compositions.
It has a multiple quantum well structure in which mixed crystal layers are stacked. The active layer 16 has an injection region into which current is injected, and the injection region functions as a light emitting region.

The p-type guide layer 17 has, for example, a thickness of 0.1 mm.
1 μm, and magnesium (Mg) as a p-type impurity
Of p-type GaN to which is added. The p-type cladding layer 18 has a thickness of, for example, 0.8 μm, and is made of a p-type AlGaN mixed crystal to which magnesium is added as a p-type impurity. The p-side contact layer 19 has a thickness of, for example, 0.5 μm, and is made of p-type GaN to which magnesium is added as a p-type impurity.
A part of the p-side contact layer 19 and a part of the p-type cladding layer 18 are formed into a narrow band (in FIG. 1, a band extending in a direction perpendicular to the plane of the drawing), and constitute a current confinement portion.

The current confinement portion serves to limit an injection region into which a current is injected into the active layer 16, and a portion of the active layer 16 corresponding to the current confinement portion serves as an injection region and serves as a light emitting region. ing. Therefore, in order to prevent and improve the deterioration of the device characteristics, it is preferable that the injection region (that is, the current confinement portion) is formed corresponding to the lateral growth region having a low dislocation density. However, the meeting part B of the crystal
Since threading dislocations M ₂ (see FIG. 4) are present, it is more preferable that an implantation region is provided corresponding to a region between seed crystal layer 12 and associated portion B.

It should be noted, as the thickness of the semiconductor layer from the n-side contact layer 13 to the p-side contact layer 19 is increased, as shown in FIG. 5, the threading dislocations M ₁ seed crystal layer 12
Of the boundary layer 12a on the side of the active layer 16 on the side of the active layer 16 extends by ΔL _{1 in the} arrangement direction A, and threading dislocations M ₂ propagate from the junction B of the crystal grown in the lateral direction by ΔL _{2 in the} arrangement direction A. Tend to. Therefore, the seed crystal layer 12
In the vicinity of the junction B, threading dislocations M ₁ and M ₂ may propagate. Therefore, in order to further reduce the possibility that threading dislocations M ₁ and M ₂ enter the light emitting region and obtain sufficient device characteristics, it is preferable to provide an implantation region in a region described below.

FIG. 6 shows the relationship between the thickness t of the nitride III-V compound semiconductor layer and the extension ΔL of threading dislocations. Thus, the thickness t and the spread of threading dislocations Δ
L is in a proportional relationship. These relationships are, specifically,
For example, ΔL = t / 20, and the n-side contact layer 13
Is the thickness t ₁ of the seed crystal layer 12 in the direction in which the layers are stacked, and the n-side contact layer 13, the n-type cladding layer 14, the n-type guide layer 15, the active layer 16, and the p-type guide Layer 17, p-type cladding layer 18 and p-type
When the total thickness of the side contact layer 19 and t _2, spread [Delta] L ₁ of threading dislocations M _{1 is, ΔL 1 = (t 2 -t} 1) /
20 can be approximated. In addition, the threading dislocations M ₂ spread ΔL ₂
Is a ΔL ₂ = t _2/20. Therefore, as shown in FIG. 7, ΔL ₁ = (t ₂ −t ₁ ) / 2 in the arrangement direction A from the end C at the boundary surface 12 a on the active layer side of the seed crystal layer 12.
0 (μm) or more, and Δ
_{L 2 = t 2/20 (} μm) may be as compatible providing injection region than distant region. Incidentally, when t ₂ is 7 μm and t ₁ is 2 μm, ΔL ₁ = 0.25 μm
m, and ΔL ₂ = 0.35 μm.

A region where both the distance in the arrangement direction A from the end C and the distance in the arrangement direction A from the associated portion B at the boundary surface 12a of the seed crystal layer 12 on the active layer 16 side are 0.93 μm or more. It is preferable to form the injection region corresponding to the inside, because the device characteristics can be further improved. The diffusion length of the minority carrier in the GaN crystal is 0.93 μm, and it is considered that the diffusion length in the crystal of the nitride III-V compound semiconductor used here is also substantially the same. This is because the dislocation density can be reduced also in the diffusion region in which is diffused. Further, it is at least ΔL ₁ +0.93 (μm) away from the seed crystal layer 12 in the arrangement direction A, and ΔL ₂ +0.93 (μm) in the arrangement direction A from the associated portion B.
It is preferable to provide the light emitting region in the region separated as described above, because the dislocation density in the diffusion region can be further reduced.

In this semiconductor laser, the arrangement direction A
In this case, the width of the n-side contact layer 13 is larger than the widths of the other n-type cladding layers 14, n-type guide layers 15, active layers 16, p-type guide layers 17, p-type clad layers 18 and p-side contact layers 19. The n-side contact layer 13
An n-type clad layer 14, an n-type guide layer 15, an active layer 16, a p-type guide layer 17, a p-type clad layer 18, and a p-side contact layer 19 are laminated on a part of.

An insulating film 20 made of, for example, silicon dioxide (SiO ₂ ) is formed on the surfaces of the n-side contact layer 13 to the p-side contact layer 19. The insulating film 20 is provided with openings corresponding to the n-side contact layer 13 and the p-side contact layer 19, respectively. The openings corresponding to these openings are formed on the n-side contact layer 13 and the p-side contact layer 19. Thus, an n-side electrode 21 and a p-side electrode 22 are formed. The n-side electrode 21 has a structure in which, for example, titanium (Ti) and aluminum (Al) are sequentially laminated and alloyed by heat treatment, and is electrically connected to the n-side contact layer 13. The p-side electrode 22
For example, palladium (Pd), platinum (Pt) and gold (A
u) have a structure in which they are sequentially stacked, and are electrically connected to the p-side contact layer 19.

In this semiconductor laser, for example, a pair of side surfaces facing each other in the length direction of the p-side contact layer 19 are resonator end faces, and a pair of reflecting mirror films (not shown) are provided on the pair of resonator end faces. Each is formed.
The reflectance is adjusted so that one of the pair of reflecting mirror films has a low reflectance and the other has a high reflectance. Thus, the light generated in the active layer 16 reciprocates between the pair of reflecting mirror films and is amplified, and is emitted as a laser beam from the low-reflecting reflecting mirror film.

This semiconductor laser can be manufactured, for example, as follows.

First, as shown in FIG. 8A, a growth substrate 11 made of, for example, sapphire or silicon carbide having a thickness of 400 μm is prepared. Next, on this growth substrate 11 (for example, in the case of the growth substrate 11 made of sapphire, for example, c-plane), for example, MOCVD (Metalo)
An undope-GaN or n-type GaN crystal is grown by a rganic chemical vapor deposition method until the thickness t ₁ in the growth direction reaches a predetermined value of about 1.5 μm to 3 μm, and the seed crystal is grown. A seed crystal layer growth layer 12b for forming the layer 12 is formed. In addition,
When the seed crystal layer growth layer 12b is grown by the MOCVD method, the growth may be performed in any of a normal pressure atmosphere, a reduced pressure atmosphere, and a pressurized atmosphere (for example, 1.33 × 10 ^4).
(Within the range of Pa to 1.62 × 10 ⁵ Pa), but it is preferable to perform the treatment in a pressurized atmosphere in order to obtain a good quality crystal with little fluctuation in the crystal axis.

Next, as shown in FIG. 8B, for example, by CVD (Chemical Vapor Deposition),
An insulating film 31 made of silicon nitride (Si ₃ N ₄ ) or silicon dioxide (SiO ₂ ) having a thickness of 0.3 μm to 1 μm is formed. The insulating film 31 may have a laminated structure of, for example, a silicon nitride film and a silicon dioxide film.

After that, as shown in FIG. 8C, a photoresist film 32 having a thickness of, for example, 2 μm to 5 μm is formed on the insulating film 31 and, for example, the seed crystal layer growth layer 12 b
A number of stripe-shaped patterns extending in the directions shown in FIG. The photoresist film 32 and the insulating film 31 are for selectively etching the seed crystal layer growth layer 12 a to form the seed crystal layer 12.

[0041]

[Outside 1]

When the pattern of the photoresist film 32 is formed, the thickness t ₁ (μm) in the growth direction of the seed crystal layer growth layer 12b and the width w ₂ (in the arrangement direction of the photoresist film 32) are used. μm) is 15 or less, preferably 10 or less, more preferably 8 or less, and still more preferably 6 or less. Thickness t ₁ (μm) and width w ₂ (μm)
Preferably, the product with m) is also greater than 2.25. Further, the separation distance d ₂ in the arrangement direction of the photoresist film 32 is preferably 9 μm or more.

After the pattern formation of the photoresist film 32, as shown in FIG. 9A, for example, RIE (Reactive Ion Etc) is performed using the photoresist film 32 as a mask.
hing; reactive ion etching) to selectively remove portions of the insulating film 31 that are not covered by the photoresist film 32. After that, as shown in FIG.
The photoresist film 32 is removed.

After removing the photoresist film 32, as shown in FIG. 9C, the insulating film 31 is used as a mask and, for example, RI using chlorine gas (Cl ₂ ) as an etching gas is used.
By performing E, portions of the seed crystal layer growth layer 12b that are not covered with the insulating film 31 are selectively removed to form, for example, a plurality of seed crystal layers 12 separated in a stripe shape. Since the seed crystal layer 12 is formed corresponding to the pattern of the photoresist film 32, the width w ₁ (μm) of the upper surface on the growth side in the arrangement direction A of the seed crystal layer 12 and the thickness t of the seed crystal layer 12
The product of ₁ (μm) is 15 or less, preferably 10 or less, more preferably 8 or less, still more preferably 6 μm or less, and desirably a value larger than 2.25. Further, the separation distance d ₁ of the seed crystal layer 12 is preferably 9 μm or more.

After that, for example, RIE is performed using the insulating film 31 as a mask to selectively remove a portion of the growth substrate 11 that is not covered with the insulating film 31. In particular,
For example, a chlorine gas is used as an etching gas, and a substrate temperature of 0 is used.
C. and a pressure of 0.5 Pa. As a result, the removed region of the seed crystal layer growth layer 12b (that is, the seed crystal layer 12
Corresponding to the distance between the recesses 11).
a is formed. The etching of the growth substrate 11 can be performed continuously with the etching of the seed crystal layer growth layer 12b, or can be performed as a separate step.

After the recess 11a is formed in the growth substrate 11, as shown in FIG. 9D, for example, the insulating film 31 is etched by using an aqueous solution containing hydrogen fluoride (HF) as an etching agent. Is removed.

Subsequently, as shown in FIG.
N-type Ga based on seed crystal layer 12 by MOCVD
The n-side contact layer 13 is formed by growing a crystal of N to about 4 μm. At this time, the crystal growth of n-type GaN mainly proceeds from the upper surface and the side wall surface of seed crystal layer 12 and also proceeds in the lateral direction. The growth rate of the seed crystal layer 12 from the side wall surface is higher than the growth rate from the upper surface. After a certain period of time, the n-type GaN crystal grown from the side wall surface spreads and the growth surface becomes substantially flat.

Although the threading dislocation M ₁ (see FIG. 4) is propagated in the region of the n-side contact layer 13 on the seed crystal layer 12, the other portion corresponding to the lateral growth region is not propagated. threading dislocations M ₁ from the seed crystal layer 12 is so bent in the lateral direction, there is little. That is,
By growing the n-side contact layer 13 on the basis of the seed crystal layer 12, the threading dislocation density of the n-side contact layer 13 is reduced.

Here, the width w of the seed crystal layer 12 is
₁(Μm) and thickness t₁(Μm) is 15 or less
The crystal axis in the n-side contact layer 13
Ragi is also reduced. Width w of seed crystal layer 12₁(Μm)
And thickness t₁(Μm) is 10 or less, 8 or less, and furthermore
If the thickness is 6 μm or less, the n-side contact layer 13
The fluctuation of the crystal axis is further reduced. Further, the seed crystal layer 12
Width w₁(Μm) and thickness t ₁(Μm) is 2.25
Larger than the substrate 11 for growing the seed crystal layer 12.
Is prevented from peeling off.

When growing the n-side contact layer 13, the growth rate is preferably set to 6 μm / h or less.
When the growth speed is higher than 6 μm / h, the fluctuation in the crystal axis of the n-side contact layer 13 increases, and the seed crystal layer 1
Crystals grown laterally on the basis of No. 2 meet, and it takes a long time until the growth surface of the n-side contact layer 13 becomes flat, or a problem that a flat growth surface cannot be obtained occurs. is there. In addition, the growth rate is 4 μm / h
It is more preferable to set it as below, and it is more preferable to set it as 2 μm / h or more. When the thickness is 4 μm / h or less, fluctuation of the crystal axis is further reduced, and a good crystal is obtained.
If it is smaller than this, the surface may be roughened.

Here, the recess 1 is formed in the growth substrate 11.
1a, n in the lateral growth region
This prevents the side contact layer 13 from coming into contact with the growth substrate 11 to cause a defect or to cause fluctuation in the crystal axis. When the concave portion 11a is not provided in the growth substrate 11, the crystals grown in the lateral direction do not associate with each other, and a substantially flat surface may not be obtained. Seed crystal layer 12
The lateral growth from the substrate may not proceed directly beside, but may proceed slightly to the growth substrate 11 side.
By setting the depth of the first concave portion 11a to 20 nm to 300 nm, contact between the n-side contact layer 13 and the growth substrate 11 is effectively prevented.

After forming the n-side contact layer 13,
On the side contact layer 13, an n-type clad layer 14 of an n-type AlGaN mixed crystal is formed by MOCVD, for example.
an n-type guide layer 15 of n-type GaN, an active layer 16 of undope-GaInN mixed crystal not doped with impurities, a p-type guide layer 17 of p-type GaN, a p-type cladding layer 18 of p-type AlGaN mixed crystal, and A p-side contact layer 19 made of p-type GaN is sequentially grown.

When MOCVD is performed, the source gas of gallium is, for example, trimethylgallium ((C
H ₃ ) ₃ Ga), a raw material gas of aluminum is, for example, trimethyl aluminum ((CH ₃ ) ₃ Al), a raw material gas of indium is, for example, trimethyl indium ((CH ₃ ) ₃ In), and a raw material gas of nitrogen is, for example, Ammonia (NH ₃ ) is used. For example, monosilane (SiH ₄ ) is used as a silicon source gas, and bis = cyclopentadienyl magnesium ((C ₅ H ₅ ) ₂ Mg) is used as a magnesium source gas.
Is used.

After growing the p-side contact layer 19,
The p-side contact layer 19, the p-type cladding layer 18, the p-type guide layer 17, the active layer 16, the n-type guide layer 15, the n-type cladding layer 14, and a part of the n-side contact layer 13 are sequentially etched to form an n-side contact layer. The contact layer 13 is exposed on the surface. Subsequently, a mask (not shown) is formed on the p-side contact layer 19, and the p-side contact layer 19 and a part of the p-type cladding layer 18 are selectively etched using the mask to form a p-type cladding layer. The upper portion 18 and the p-side contact layer 19 are formed into a narrow band shape having a width of, for example, about 2.5 μm to form a current confinement portion.

At this time, the threading dislocation M ₂ (see FIG. 4) is present at the junction B located at the center of the separation region of the seed crystal layer 12 in the arrangement direction A. More preferably, a current constriction portion is provided corresponding to a region between the centers of the regions in the arrangement direction, and the injection region of the active layer 16 is formed in that region. Further, as described above, the distance in the arrangement direction A from the end C on the upper surface on the growth side of the seed crystal layer 12 is ΔL ₁ = (t ₂ −t ₁ ) /.
20 is a ([mu] m), and seeds internal current confinement portion in the array direction distance in A is _{ΔL 2 = t 2/20 (} μm) region from the center in the arrangement direction A of the separation region of the crystal layer 12, i.e. It is more preferable to provide an injection region for the active layer 16. The distance in the arrangement direction A from the end C on the upper surface on the growth side of the seed crystal layer 12 and the distance in the arrangement direction A from the center in the arrangement direction A of the separated region of the seed crystal layer 12 are both 0.93 μm or more. It is preferable to form a current confinement portion inside a certain region. The distance in the arrangement direction A from the upper surface of the seed crystal layer 12 on the growth side is ΔL ₁ +0.93 (μm). The distance in the arrangement direction A is ΔL ₂ +0.93
(Μm) is particularly preferable.

After forming the current confinement portion, the insulating layer 2 made of silicon dioxide is formed on the entire exposed surface by, for example, a vapor deposition method.
0 is formed, an opening is provided corresponding to the p-side contact layer 19, and the p-side contact layer 19 is exposed on the surface. After exposing the p-side contact layer 19, an opening is formed in a region on the n-side contact layer of the insulating layer 20, and, for example, titanium (Ti), aluminum (Al), platinum, and gold are sequentially deposited in the opening. Then, the n-side electrode 21 is formed by alloying. Also, for example, palladium, platinum and gold are sequentially deposited on the surface of the p-side contact layer 19 and the vicinity thereof,
The side electrode 22 is formed. After that, the growth substrate 11 is ground to a thickness of, for example, about 80 μm. After grinding the growth substrate 11, it is adjusted to a predetermined size, and a not-illustrated reflecting mirror film is formed on a pair of resonator end faces facing each other in the length direction of the p-side contact layer 19. This allows
The semiconductor laser shown in FIG. 1 is completed.

Next, the operation of the semiconductor laser will be described.

In this semiconductor laser, the n-side electrode 21 is
When a predetermined voltage is applied to the side electrode 22, a current is injected into the active layer 16, and light emission occurs due to electron-hole recombination. Here, since the product of the width w ₁ (μm) and the thickness t ₁ (μm) of the seed crystal layer 12 is 15 or less, n
The fluctuation of the crystal axis in the side contact layer 13 is reduced. Therefore, the crystallinity of the semiconductor layers from the n-type cladding layer 14 stacked on the n-side contact layer 13 to the p-side contact layer 19 is improved. Therefore, deterioration of the element hardly occurs, and the life is extended.

As described above, according to the semiconductor laser of the present embodiment, width w ₁ (μm) and thickness t _{1 of} seed crystal layer 12 are obtained.
(Μm), the fluctuation of the crystal axis in the n-side contact layer 13 can be reduced. Therefore, the crystallinity of the semiconductor layers from the n-type cladding layer 14 stacked on the n-side contact layer 13 to the p-side contact layer 19 can be improved. Therefore, deterioration due to application of a voltage hardly occurs, and the life of the semiconductor laser can be extended. In addition, the ratio of non-radiative recombination caused by threading dislocation or the like can be reduced, and luminous efficiency can be improved.

Further, if the injection region of the active layer 16 is provided corresponding to the region between the seed crystal layer 12 and the associated portion B, the luminous efficiency can be further improved. Further, from the seed crystal layer 12, ΔL ₁ = (t ₂ −t ₁ ) / 20 (μm)
Or more apart, and the association portion _{B ΔL 2 = t 2/20} (μ
m) If an implantation region is provided corresponding to a region at least distant or an implantation region is provided corresponding to a region distant from the seed crystal layer 12 and the associated portion B by 0.93 μm or more, respectively. By doing so, a higher effect can be obtained.

In particular, if the half width of the rocking curve of the seed crystal layer 12 by X-ray diffraction is set to 300 arcsec or less, the fluctuation of the crystal axis can be further reduced.

Further, if the separation distance d ₁ of the seed crystal layer 12 in the arrangement direction A is set to 9 μm or more,
The degree of freedom in manufacturing is increased at the time of mask alignment, and the productivity can be improved.

Further, a seed crystal layer 12
The concave portion 11a is provided corresponding to the separated area.
Then, the n-side contact layer 13 is formed based on the seed crystal layer 12.
At the time of growth, the crystal grown laterally from seed crystal layer 12
To prevent the crystal from coming into contact with the growth substrate 11.
it can. Therefore, the n-side contact layer 13 and the
N-type clad layer 14, n-type guide layer 15, active
Layer 16, p-type guide layer 17, p-type cladding layer 18, and
Threading dislocation M in p-side contact layer 19₁, M _TwoDense
Degree and crystal axis fluctuation
Can be reduced.

[Second Embodiment] FIG. 11 shows a sectional structure of a nitride III-V compound substrate according to a second embodiment of the present invention. This nitride III-
The group V compound substrate includes a plurality of seed crystal layers 71 provided separately from each other, and a substrate main body 72 as a crystal growth layer grown on the basis of the plurality of seed crystal layers 71.
The seed crystal layer 71 and the substrate body 72 are made of a nitride III-containing at least one of the group 3B elements in the short period type periodic table and at least nitrogen of the group 5B element in the short period type periodic table. It is composed of a crystal of a group V compound. Here, the nitride III-V compound refers to both a semiconductor and a non-semiconductor.

The seed crystal layer 71 has the same configuration, operation and effect as the seed crystal layer 12 of the first embodiment, for example. The substrate main body 72 has a thickness of, for example, 10 μm to 20 μm.
0 μm, and n added with silicon as an n-type impurity.
It is composed of type GaN. This substrate body 72
Corresponding to the separated regions of the seed crystal layer 71, there is a lateral growth region grown in the lateral direction (arrangement direction A) from the seed crystal layer 71.

This nitride III-V compound substrate is
For example, similar to the case where the seed crystal layer 71 is formed on a growth substrate (not shown) made of sapphire or the like in the same manner as in the first embodiment, and the n-side contact layer 13 of the first embodiment is grown. Then, after growing the substrate body 72 on the basis of the seed crystal layer 71, it can be obtained by removing the growth substrate (not shown).

The nitride III according to the present embodiment
The -V group compound can be used, for example, as a substrate of a semiconductor laser or the like on which an n-type clad layer, an active layer, a p-type clad layer, etc. similar to those of the first embodiment are grown.

[0068]

EXAMPLES Further, specific examples of the present invention will be described in detail.

(Examples 1-1 to 1-10) A plurality of band-shaped seed crystal layers were formed in parallel with GaN on a growth substrate made of sapphire.
To grow a crystal growth layer. At that time, Example 1-1
The thickness t ₁ , width w _1, and separation distance d ₁ of the seed crystal layer were changed as shown in Table 1 in で 1-10. The growth rate of the crystal growth layer is 3 μm / h to 4 μm / h.
And

[0070]

[Table 1]

As Comparative Examples 1-1 and 1-2 with respect to Examples 1-1 to _1-10 , the thickness t ₁ and the width w of the seed crystal layer were set.
₁ and the distance d ₁ except that varied respectively as shown in Table 1, others were grown crystal growth layer in the same manner as in Example 1-1 to 1-10.

Examples 1-1 to 1 thus obtained
The crystal growth layers of -10 and Comparative Examples 1-1 and 1-2 were analyzed by the X-ray diffraction method. The result is shown in FIG.
And FIG.

FIG. 12 shows the half width of a rocking curve measured by irradiating X-rays in the direction of arrangement of the seed crystal layers. FIG. 13 shows the half width of a rocking curve measured by making an X-ray incident in the direction in which the seed crystal layer extends. 12 and 13, the vertical axis indicates the half width (unit: arcsec), and the horizontal axis indicates the width w ₁ (unit;
μm) and the thickness t ₁ (unit: μm).

As can be seen from FIG. 12, the half widths in the arrangement direction of the seed crystal layers are smaller in Examples 1-1 to 1-10 than in Comparative Examples 1-1 and 1-2. As the product of the width w ₁ and the thickness t ₁ of the crystal layer became smaller, the half-width tended to become smaller. That is, the width w ₁ (μ
When the product of m) and the thickness t ₁ (μm) is set to 15 or less, the fluctuation of the crystal axis of the crystal growth layer in the arrangement direction of the seed crystal layers is reduced, and a crystal growth layer having high crystallinity can be obtained. I understood that. The width w ₁ (μm) and the thickness t
It was found that when the product of ₁ (μm) was 10 or less, the fluctuation in the crystal axis was further reduced, and when it was 8 or less, the fluctuation was further reduced. Further, it was found that when the value was set to 6 or less, the number tended to be particularly small.

Particularly, Examples 1-1 and 1-2 and Example 1-
3 and 1-4, Examples 1-6 and 1-7 and Comparative Example 1-1
It was found that when the width w ₁ of the seed crystal layer was the same, the half-width increased as the thickness t ₁ increased, and the crystallinity tended to deteriorate. Similarly, when comparing Examples 1-1,1-5,1-7,1-8,1-10, if the thickness t ₁ is the same, the half value width is widened in accordance with the width w ₁ is wider It was found that the crystallinity tended to deteriorate.

As can be seen from FIG. 13, the half width in the extending direction of the seed crystal layer is largely different between Examples 1-1 to 1-10 and Comparative Examples 1-1 and 1-2. Did not. That is, it has been found that the fluctuation of the crystal axis of the crystal growth layer in the extending direction of the seed crystal layer does not depend on the product of the width w ₁ and the thickness t ₁ of the seed crystal layer.

Example 2 The thickness t ₁ of the seed crystal layer was set to 2 μm.
m, and 3 [mu] m, except that the distance d ₁ was 9μm width w _1, others were grown crystal growth layer in the same manner as in Example 1-1 to 1-10. In this example, when forming the seed crystal layer, X-rays were incident from the upper surface on the growth side, and the half width of the rocking curve of the seed crystal layer by X-ray diffraction was measured. The half width was also measured for the obtained crystal growth layer. 14 and 15 show the results.

FIG. 14 shows the half width of a rocking curve in a crystal growth layer measured by irradiating X-rays in the direction of arrangement of the seed crystal layers. FIG. 15 shows the half width of a rocking curve in the crystal growth layer measured by applying X-rays in the direction in which the seed crystal layer extends. 14 and 15, the vertical axis represents the half-width (unit: arcs) of the crystal growth layer.
ec), and the horizontal axis represents the half-width of the seed crystal layer (unit: arcsec)
Is shown.

As can be seen from FIG. 14, the FWHM in the arrangement direction of the seed crystal layers varied greatly, and no clear dependence on the FWHM of the seed crystal layers could be seen.

On the other hand, as can be seen from FIG. 15, the half width of the seed crystal layer in the extending direction becomes narrower as the half width of the seed crystal layer becomes narrower, and the crystallinity of the crystal growth layer tends to be higher. . In particular, when the half width of the seed crystal layer is 300 arcsec or less, the half width of the crystal growth layer is 180 arcsec.
It turned out that it can be reduced below.

That is, the half width of the rocking curve by X-ray diffraction on the upper surface of the seed crystal layer on the growth side is 300 ar.
It has been found that when the time is csec or less, fluctuation of the crystal axis of the crystal growth layer at least in the extending direction of the seed crystal layer can be reduced.

(Examples 3-1 to 3-6) The thickness t ₁ of the seed crystal layer is 2 μm, the width w ₁ is 3 μm, and the separation distance d ₁ is 9 μm.
A crystal growth layer was grown in the same manner as in Examples 1-1 to 1-10, except that the growth rate of the crystal growth layer was changed as shown in Table 2. Also in this embodiment,
X-rays were incident on the crystal growth layer in the direction in which the seed crystal layers were arranged, and analyzed by X-ray diffraction. Table 2 shows the peak shapes of the obtained rocking curves.

[0083]

[Table 2]

As can be seen from Table 2, Examples 3-3 to 3
At -6, a single peak was obtained, and it was confirmed that the crystal axes of the crystal growth layer were entirely aligned. However, in Example 3-6 in which the growth rate was 1 μm / h, the surface was roughened. This is considered to be because the growth of the portion corresponding to the upper surface of the seed crystal layer 12 was slow, and the surface etching by the carrier gas or the like became dominant.
In Examples 3-1 and 3-2, the peaks were separated. This indicates that the crystal axes are aligned in the minute region, but the axial direction is inclined in two directions. In particular, in Example 3-1, although not specifically shown here, the half width is wide, and the fluctuation in the crystal axis of the crystal growth layer is large.
Moreover, the surface of the crystal growth layer did not become a clean flat surface.

That is, it was found that a crystal growth layer with little fluctuation in the crystal axis can be obtained by growing the crystal growth layer at a rate of 6 μm / h or less. 4 μm
It has been found that a crystal growth layer having a uniform crystal axis can be obtained by growing at a rate of not more than / h. Furthermore, it was found that a crystal growth layer having a clean and flat surface can be obtained by growing at a rate of 2 μm / h or more.

Although not specifically shown here, I
Ga containing at least one of Group II elements and nitrogen
Similar results are obtained when a crystal growth layer made of a group III-V nitride semiconductor other than N is grown.

Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the above-described embodiments and examples, and can be variously modified. For example, in the above-described embodiments and examples, the case where a plurality of band-shaped seed crystal layers 12 and 41 are provided has been described.
Depending on the size of the element, there may be only one in the end. Further, the shape may be a lattice shape or an island shape.

In the above embodiment and examples,
Part of p-type cladding layer 18 and p-side contact layer 19
Is formed as a narrow band extending in the direction shown outside 1 of the seed crystal layer growth layer 12b, but the current may be narrowed as a narrow band extending in another direction. The current may be confined by the structure.

Further, in the above embodiment and examples,
Although the case where the growth substrate 11 is provided has been described, the growth substrate 11 may be removed after growing the crystal. In that case, the n-side electrode and the p-side electrode may be provided separately on the front side and the back side.

In addition, in the above embodiments and examples, the growth substrate 11 is made of sapphire or silicon carbide. However, gallium nitride (GaN),
Spinel (MgAl ₂ O ₄ ) or gallium arsenide (G
It may be made of another material such as aAs).

Further, in the above embodiments and examples, the n-side contact layer 13 is formed after the insulating film 31 is removed, but the insulating film 31 on the seed crystal layer 12 is formed.
May be formed without removing the n-side contact layer 13 (a crystal growth layer in the embodiment). Thereby, threading dislocation M ₁ is blocked by insulating film 31, and propagation of threading dislocation M ₁ from seed crystal layer 12 is prevented. Thus, the n-side contact layer 13 hardly exists crystal defects except threading dislocations M ₂ due to association, it is possible to obtain a group III-V nitride semiconductor having excellent crystallinity on its upper side. However, when the n-side contact layer 13 is grown, the constituent material of the insulating film 31 is used as an impurity in the n-side contact layer 1.
3 may deteriorate the characteristics of the semiconductor laser, and it is preferable to select an appropriate manufacturing method according to the purpose of use.

In each of the above embodiments and examples, the seed crystal layer growth layer 12a and the n-side contact layer 13 are grown by MOCVD.
It may be formed by another vapor phase growth method such as MBE (Molecular Beam Epitaxy), hydride vapor phase epitaxy, or halide vapor phase epitaxy.

Further, in the above embodiment, the semiconductor laser is described as a specific example of the semiconductor device. However, the present invention can be applied to other semiconductor devices such as a light emitting diode or a field effect transistor.

[0094]

As described above, a semiconductor laser according to any one of claims 1 to 10, a semiconductor device according to claim 12, or a nitride III-V compound substrate according to claim 14. According to the formula, the width of the boundary surface with the crystal growth layer in the arrangement direction of the seed crystal layers (unit: μm)
And the product of the thickness and the thickness t ₁ in the direction in which the crystal growth layers are stacked is 15 or less, so that the fluctuation of the crystal axis in the crystal growth layer can be reduced. Therefore,
There is an effect that the characteristics of the element can be improved.

In particular, according to the semiconductor laser of the sixth or seventh aspect, the injection region of the active layer is provided corresponding to the region between the seed crystal layer and the associated portion. Is further improved.

According to the semiconductor laser described in claim 11 or the semiconductor device described in claim 13, the width of the boundary surface with the crystal growth layer in the direction perpendicular to the extending direction of the seed crystal layer (unit is: μm) and the thickness (unit: μm) in the direction in which the crystal growth layers are stacked are 15 or less, so that the fluctuation of the crystal axis in the crystal growth layer can be reduced. Therefore, there is an effect that the characteristics of the element can be improved.

Further, the method for manufacturing a semiconductor laser according to any one of claims 15 to 20, the method for manufacturing a semiconductor device according to claim 21, or the nitride III-V compound according to claim 22 According to the substrate manufacturing method, the seed layer growth layer is formed by multiplying the product of the width (unit: μm) of the upper surface on the growth side in the arrangement direction of the seed crystal layer and the thickness (unit: μm) in the growth direction. Since a plurality of seed crystal layers are selectively removed as described below, the crystal growth layer can be grown with little fluctuation in the crystal axis.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a seed crystal layer shown in FIG.

FIG. 3 is another explanatory diagram for explaining the seed crystal layer shown in FIG.

FIG. 4 is a schematic diagram showing a state of occurrence of threading dislocations in an n-side contact layer shown in FIG.

FIG. 5 is a schematic diagram illustrating another state of occurrence of threading dislocations in the n-side contact layer illustrated in FIG.

FIG. 6 is a characteristic diagram showing a relationship between the thickness of a crystal and the spread of dislocations.

FIG. 7 is another cross-sectional view illustrating a configuration of the semiconductor device according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view for explaining the method for manufacturing the semiconductor device shown in FIG.

FIG. 9 is a cross-sectional view for explaining a manufacturing step following FIG. 8;

FIG. 10 is a cross-sectional view for explaining a manufacturing step following FIG. 9;

FIG. 11 shows a nitride-based I according to a second embodiment of the present invention.
It is sectional drawing showing the structure of a II-V compound substrate.

FIG. 12 is a characteristic diagram illustrating a relationship between a seed crystal layer and a half width in a crystal growth layer according to the first embodiment of the present invention.

FIG. 13 is another characteristic diagram showing a relationship between a seed crystal layer and a half width in a crystal growth layer according to the first embodiment of the present invention.

FIG. 14 is a characteristic diagram illustrating a relationship between a half width in a seed crystal layer and a half width in a crystal growth layer according to a second embodiment of the present invention.

FIG. 15 is another characteristic diagram illustrating a relationship between a half width in the seed crystal layer and a half width in the crystal growth layer according to the second embodiment of the present invention.

[Explanation of symbols]

 11: growth substrate, 11a: recess, 12, 71: seed crystal
Layer, 12a ... interface, 12b ... seed crystal layer growth layer, 1
3, 61 ... insulating film, 20 ... first conductivity type semiconductor layer, 21 ...
n-side contact layer, 22 ... n-type cladding layer, 23 ... n-type
Guide layer, 30 ... active layer, 40 ... second conductivity type semiconductor layer,
41 ... p-type guide layer, 42 ... p-type cladding layer, 43 ... p
Side contact layer, 51 ... n-side electrode, 52 ... p-side electrode, 6
2. Photoresist film, 72: Substrate body, A: Arrangement method
Direction, B: meeting, C: end, M₁, M _Two… Threading dislocation

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takeharu Asano 3-53-3 Shiratori, Shiroishi City, Miyagi Prefecture Inside Sony Shiroishi Semiconductor Co., Ltd. (72) Inventor Osamu Goto 3-53 Shiratori, Shiraishi City, Miyagi Prefecture 2 Inside Sony Shiroishi Semiconductor Co., Ltd. (72) Inventor Masaro Ikeda 3-53-3 Shiratori, Shiroishi City, Miyagi Prefecture Inside 2 Sony Shiroishi Semiconductor Co., Ltd. (72) Inventor Katsuyoshi Shibuya 3-53 Shiratori, Shiroishi City, Miyagi Prefecture 2 Inside Sony Shiroishi Semiconductor Co., Ltd. (72) Inventor Satoshi Hino 3-53-3 Shiratori, Shiraishi-shi, Miyagi Prefecture Inside 2 Sony Shiroishi Semiconductor Co., Ltd. (72) Satoru Kishima 3-53 Shiratori, Shiraishi-shi, Miyagi Prefecture (2) Inventor Masao Ikeda White in Miyagi Prefecture 3 53 Ishiichi Shiratori 3-chome 2 Sony Shiroishi Semiconductor Co., Ltd. F-term (reference) 5F041 AA40 CA04 CA40 CA46 CA65 CA74 CA75 CA77 5F045 AA02 AA04 AA05 AB09 AB14 AC08 AC12 AC19 AF02 AF09 CA12 DA53 DA63 DA64 5F073 AA13 AACA CA CB07 DA05 DA22 DA35 EA29

Claims (22)

[Claims] 1. A seed crystal layer made of a nitride III-V compound semiconductor and provided at a distance, and a nitride group III-V compound semiconductor grown on the seed crystal layer A seed crystal layer, wherein the seed crystal layer has a width (unit: μm) of a boundary surface with the crystal growth layer in the arrangement direction, and the crystal growth layer is stacked. The product of the thickness in the direction (unit: μm) is 15
A semiconductor laser characterized by the following. 2. The semiconductor laser according to claim 1, wherein said product of said seed crystal layer is larger than 2.25. 3. The semiconductor laser according to claim 1, wherein the product of the seed crystal layer is 10 or less. 4. The semiconductor laser according to claim 1, wherein the product of the seed crystal layer is 8 or less. 5. The semiconductor laser according to claim 1, wherein the product of the seed crystal layer is 6 or less. 6. The crystal growth layer has an active layer and includes an associated portion formed by growing the seed crystal layer in an arrangement direction, and the active layer includes the seed crystal layer and the associated portion. 2. The semiconductor laser according to claim 1, further comprising an injection region into which a current is injected corresponding to a region between the first region and the second region. 7. The thickness of the seed crystal layer in the direction in which the crystal growth layers are stacked is defined as t ₁ (unit: μm), and the thickness of the crystal growth layer in the direction in which the crystal growth layers are stacked is defined as t _1. When t ₂ (unit is μm), the injection region in the active layer is shifted from the seed crystal layer in the direction of its arrangement by (t
₂ -t ₁₎ / 20 or more apart, and the semiconductor laser according to claim 6, characterized in that provided in correspondence from the association unit to the region away t _2/20 or more in the arrangement direction of the seed crystal layer . 8. The seed crystal layer according to claim 1, wherein a half width of a rocking curve by X-ray diffraction obtained when X-rays are incident from the boundary surface side is 300 arcsec or less. Semiconductor laser. 9. The semiconductor laser according to claim 1, wherein a separation distance in the arrangement direction of the seed crystal layers is 9 μm or more. 10. The semiconductor device according to claim 1, further comprising a growth substrate for growing the seed crystal layer, wherein the growth substrate has a concave portion corresponding to a separation region between the seed crystal layers. 2. The semiconductor laser according to 1. 11. A strip-shaped seed crystal layer made of a nitride III-V compound semiconductor and a crystal growth layer made of a nitride III-V compound semiconductor and grown on the basis of the seed crystal layer. A semiconductor laser comprising: a width of a boundary surface (unit: μm) between the seed crystal layer and the crystal growth layer in a direction perpendicular to a direction in which the seed crystal layer extends;
A semiconductor laser having a product of a thickness (unit: μm) in a direction in which the crystal growth layers are stacked is 15 or less. 12. A seed crystal layer made of a nitride III-V compound semiconductor and provided separately, and a nitride III-V compound semiconductor, and grown on the seed crystal layer as a base. A seed crystal layer, wherein the seed crystal layer has a width (unit: μm) of a boundary surface with the crystal growth layer in an arrangement direction thereof, and the crystal growth layer is stacked. The product of the thickness in the direction (unit: μm) is 15
A semiconductor element characterized by the following. 13. A band-shaped seed crystal layer made of a nitride III-V compound semiconductor and a crystal growth layer made of a nitride III-V compound semiconductor and grown on the seed crystal layer. A semiconductor element provided, wherein the seed crystal layer has a width (unit: μm) of a boundary surface with the crystal growth layer in a direction perpendicular to an extending direction of the seed crystal layer;
A semiconductor element having a product of a thickness (unit: μm) in a direction in which the crystal growth layers are stacked is 15 or less. 14. A nitride-based III-V compound comprising a plurality of spaced apart seed crystal layers;
A nitride-based group III-V compound substrate comprising a group II-V compound and a crystal growth layer grown on the basis of the seed crystal layer, wherein the seed crystal layer comprises The product of the width (unit: μm) of the boundary surface with the growth layer and the thickness (unit: μm) in the direction in which the crystal growth layers are stacked is 15
A nitride III-V compound substrate characterized by the following. 15. On a growth substrate, a nitride III-
A step of growing a seed crystal layer growth layer composed of a group V compound semiconductor; and selectively removing the seed crystal layer growth layer to form a plurality of seed crystal layers. And the thickness in the growth direction (unit: μm) is adjusted to be 15 or less. A crystal growth layer made of a nitride III-V compound semiconductor based on a seed crystal layer is formed. Growing the semiconductor laser. 16. An active layer is grown at least as a crystal growth layer, and an injection region into which current is injected into the active layer corresponds to a region between the seed crystal layer and the center of the separation region in the arrangement direction. The method for manufacturing a semiconductor laser according to claim 15, further comprising a step of forming the semiconductor laser. 17. The thickness of the seed crystal layer in the growth direction is t
₁ (unit is μm) and the thickness of the crystal growth layer in the growth direction is t ₂ (unit is μm), the injection region of the active layer is shifted from the seed crystal layer in the arrangement direction by (t ₂ −t ₁ ) / 2
0 or more away, and a semiconductor laser manufacturing method according to claim 16, wherein the forming in response to a region apart t _2/20 or more from the center in the arrangement direction of the separation region in the arrangement direction of the seed crystal layer. 18. The method according to claim 15, wherein the crystal growth layer is grown at a rate of 6 μm / h or less. 19. The semiconductor laser according to claim 15, wherein the seed crystal layer growth layer is selectively removed so that a separation distance between the seed crystal layers in the arrangement direction of the seed crystal layers is 9 μm or more. Production method. 20. Prior to the step of growing the crystal growth layer, the growth substrate is further selectively removed corresponding to the removed region of the seed crystal layer growth layer to form a recess in the growth substrate. The method for manufacturing a semiconductor laser according to claim 15, comprising a step. 21. A nitride III-
A step of growing a seed crystal layer growth layer composed of a group V compound semiconductor; and selectively removing the seed crystal layer growth layer to form a plurality of seed crystal layers. And the thickness in the growth direction (unit: μm) is adjusted to be 15 or less. A crystal growth layer made of a nitride III-V compound semiconductor based on a seed crystal layer is formed. Growing the semiconductor device. 22. On a growth substrate, a nitride III-
A step of growing a seed crystal layer growth layer composed of a group V compound; and selectively removing the seed crystal layer growth layer to form a plurality of seed crystal layers. (μm) and the thickness in the growth direction (unit: μm) so that the product is 15 or less; and growing a crystal growth layer made of a nitride III-V compound based on the seed crystal layer And a method of manufacturing a nitride-based III-V compound substrate.