JP2911087B2 - Semiconductor light emitting device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device and a method for manufacturing the same. More specifically, the present invention relates to a short-wavelength semiconductor laser that emits red to orange laser light, a light-emitting diode (LED) in a red to green wavelength band, and a method for manufacturing the same.

2. Description of the Related Art In recent years, 630 using AlGaInP as a material has been developed.
-680 nm red semiconductor laser is used as a light source for POS,
It is attracting attention as a light source for high-definition and high-density magneto-optical disks, and is being actively researched and developed. When used for a disk, the stability of the fundamental mode and optical characteristics such as astigmatism are particularly important. Therefore, a refractive index guide type structure that confine light in the oscillation region is desired.

2. Description of the Related Art As a conventional 680 nm band refractive index guide type semiconductor laser device, there are known an effective refractive index guide type shown in FIG. 11 and a real refractive index guide type shown in FIG. The semiconductor laser element shown in FIG. 11, (100) on the n-GaAs substrate 131 whose principal, n- by MOCVD _{(Al 0. 5 Ga 0.} 5) 0. 5 In 0. 5 P cladding layer (Thickness 1.
And 5 [mu] m) 133, a non-doped Ga _{0. 5} In _0. And ₅ P active layer (thickness _{0.05μm) 134, p- (Al 0} . 5 Ga 0. 5) 0. 5 In 0. 5
A P clad layer (thickness _{1.5μm) 135, p-Ga 0} . 5 In 0.
_A 5P intermediate layer 136 is grown. Next, after the ridge portion 141 is left at the center of the element and the surface of the intermediate layer 136 to the middle of the cladding layer 135 is removed by etching, n-GaAs current confinement layers 132 are grown on both sides of the ridge portion 141. Further, a p-GaAs contact layer (thickness: 2 μm) 137 is grown over the entire area. Finally, the electrodes 13 are provided on the rear surface of the substrate 131 and the surface of the contact layer 137, respectively.
9, 140 are formed. In this semiconductor laser, the current confinement layer 132 restricts the current path to reduce the reactive current, and gives a substantially large mode loss to the higher-order mode of oscillation. Therefore, the higher-order oscillation mode is suppressed, and the fundamental mode oscillation is stably maintained up to a high optical output in the oscillation region 134a.

The semiconductor laser device shown in FIG.
N-GaAs is formed on a p-GaAs substrate 101 having a (100) plane.
A current confinement layer 102 is formed, and a groove 102b extending from the surface of the current confinement layer 102 to the substrate 101 is formed. Next, by _{MOCVD, p- (Al 0. 5 Ga} 0. 5) 0. 5 In 0. 5
P cladding layer (thickness: 1.8 μm) 103 and non-doped Ga
_{0. 5} In _0. And ₅ P active layer (thickness 0.05μm) 104, n- (Al
_{0. 5 Ga 0. 5)} 0. 5 In 0. 5 P clad layer (thickness 1.5 [mu] m) 10
And _{5, n-Ga 0. 5} In 0. 5 P contact layer (thickness 1 [mu] m) 10
6 are formed in order (the thickness of each layer is
This is a value within b. ). Finally, the electrodes 10 are provided on the back surface of the substrate 101 and the surface of the contact layer 106, respectively.
9, 110 are formed. In the growth by the MOCVD method, the growth layer generally grows while reflecting the shape of the underlying layer. I have. As a result, a real refractive index guide structure is formed. As a result, the loss in the fundamental mode is reduced, the oscillation threshold is reduced, and the differential efficiency is increased.

[0004]

However, FIG.
In the semiconductor laser device shown in (1), the stability of the fundamental mode depends on the thickness of the cladding layer left on both sides of the ridge 141.
There is a problem that the fundamental mode becomes unstable when the residual thickness d greatly exceeds 0.3 μm due to a variation in etching (the optimal value of the residual thickness d is 0.3 μm). Exists around 2 μm). The same applies to the case where the remaining thickness d differs between the left and right sides of the ridge 141. Further, at the stage of growing the current confinement layer 132, underlayer comprises Al p- (Al _{0. 5
Ga 0. 5) 0. 5} In 0. 5 for a P layer 135, the quality of the regrowth interface 135a is poor in oxidative influences. As a result, there is a problem that current leakage occurs and the oscillation threshold value becomes high. Typically, it has a non-coated, resonator length of 400 μm, an oscillation threshold of 45 mA, and a kink level of 25 m.
About W.

In the semiconductor laser device shown in FIG. 12, the active layer 104 is bent at the end of the current confinement layer 102 so as to have a real refractive index guide structure. Loss is also reduced. For this reason, there is a problem that the kink level is rather lowered. Typically, it has a non-coating, resonator length of 400 μm, an oscillation threshold of 25 to 30 mA, and a kink level of about 20 mW.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor light emitting device having a current confinement layer and capable of improving characteristics, and a method of manufacturing the same. The semiconductor light emitting device is a semiconductor laser device and a light emitting diode.

[0007]

In order to achieve the above object, a semiconductor light emitting device according to a first aspect of the present invention comprises a p-type or n-type GaAs substrate having a p-type or n-type conductivity. A current confinement layer of GaAs or AlGaAs having a through groove for forming a current path in a direction perpendicular to the substrate surface, having the other conductivity type of the mold, and a double heterostructure formed on the current confinement layer. In a semiconductor light emitting device having a first cladding layer, an active layer, and a second cladding layer having a structure, the through groove has a stripe pattern extending in a direction perpendicular to an end face of the substrate, and the through groove has AlGaA having one of the above conductivity types
s is embedded in the third cladding layer, and the surface of the third cladding layer and the surface of the current confinement layer are flush with each other, and the first cladding layer has the one conductivity type. It is characterized by being composed of AlGaInP.

Further, the third cladding layer has an extended portion covering the surface of the current constriction layer, and the thickness of the extended portion is smaller than the thickness of the portion embedded in the through groove. It is desirable that it is set.

The current confinement layer has a peripheral portion in the through groove, and a current confinement layer extension having the other conductivity type and having a surface flush with the surface of the current confinement layer is buried in the periphery of the current confinement layer. Preferably, the cladding layer of No. 3 is buried inside the extension of the current constriction layer in the through groove.

Preferably, a plurality of the through-grooves of the current constriction layer are provided, and the third cladding layer is embedded in each of the through-grooves.

Further, the current confinement layer has one or more non-penetrating grooves having a depth that stays in the current confinement layer in a line with the through-grooves, and the one conductivity type is provided in the non-penetrating groove. It is preferable that the fourth cladding layer is embedded and the surface of the fourth cladding layer and the surface of the current confinement layer are on the same plane.

Further, the semiconductor light emitting device of the second invention has a p
On the surface of the substrate having one of the conductivity types of
a current confinement layer having the other conductivity type of p-type or n-type and having a through groove for forming a current path in a direction perpendicular to the surface of the substrate, and a double heterostructure on the current confinement layer; In the semiconductor light emitting device provided with the first cladding layer, the active layer, and the second cladding layer, the through groove has a circular pattern, and the third groove having the one conductivity type in the through groove. The present invention is characterized in that the cladding layer is embedded and the surface of the third cladding layer and the surface of the current constriction layer are on the same plane.

It is preferable that the layer forming the double hetero structure is formed in a truncated cone shape.

Further, the substrate has a (111) B surface or a Ga surface having an off surface having (111) B as a main surface.
As, the current confinement layer is made of GaAs or AlGaAs.
And the third cladding layer is preferably made of AlGaAs.

Further, a method of manufacturing a semiconductor light emitting device according to a third aspect of the present invention is a method of manufacturing a semiconductor light emitting device, the method comprising:
On the (111) B surface or the off surface having (111) B as a main surface of the As substrate, a G layer having the other conductivity type of p-type or n-type is provided.
providing a current confinement layer made of aAs or AlGaAs, and forming a through-groove of a predetermined pattern from the surface of the current confinement layer to the substrate in the current confinement layer;
In a state where the substrate is kept at a temperature at which the growth rate of AlGaAs on the (111) B plane becomes substantially zero, the third groove made of AlGaAs having the one conductivity type is placed in the through groove.
Growing the cladding layer so that the surface is flush with the surface of the current confinement layer, and filling the through-groove; and forming the first cladding layer, the active layer and the active layer forming a double heterostructure on the substrate. The method is characterized by having a step of growing the second clad layer over the entire surface.

The method of manufacturing a semiconductor light emitting device according to a fourth aspect of the present invention is a method of manufacturing a semiconductor light emitting device, comprising the steps of:
Providing a current confinement layer made of GaAs or AlGaAs having the other conductivity type of p-type or n-type on the (111) B surface or the off surface having the (111) B surface as a main surface of the As substrate; Forming a through-groove of a predetermined pattern from the surface of the current confinement layer to the substrate in the current confinement layer, and forming the substrate at a temperature at which the growth rate of AlGaAs on the (111) B plane becomes substantially zero. And a current confinement layer extension made of GaAs or AlGaAs having the other conductivity type is grown on the periphery of the through groove so that the surface is flush with the surface of the current confinement layer. A step of narrowing the width of the through groove, and a step of holding the substrate at a predetermined temperature, inside the extending portion of the current confinement layer in the through groove, forming a first conductive layer made of AlGaAs having the one conductivity type. 3 clad layer, the surface is above A step of burying the through-groove by growing the surface so as to be flush with the surface of the current confinement layer, and forming a first clad layer, an active layer and a second clad layer having a double hetero structure on the entire surface of the substrate. It is characterized by having a growing step.

The method of manufacturing a semiconductor light emitting device according to a fifth aspect of the present invention is a method of manufacturing a semiconductor light emitting device, comprising the steps of:
Providing a current confinement layer made of GaAs or AlGaAs having the other conductivity type of p-type or n-type on the (111) B surface or the off surface having the (111) B surface as a main surface of the As substrate; Forming a non-through groove having a predetermined pattern in the current confinement layer in the current confinement layer; and forming a through groove having a predetermined pattern from the surface of the current confinement layer to the substrate in the current confinement layer. And maintaining the substrate at a temperature at which the growth rate of AlGaAs on the (111) B plane becomes substantially zero, and forming the AlGaAs having the one conductivity type in the through-groove and the non-penetrating groove. Growing the third and fourth cladding layers, each having a surface flush with the surface of the current confinement layer, to bury the through-grooves and the non-through-grooves; The first of the structure Rudd layer is characterized by having a step of growing an active layer and a second cladding layer on the entire surface.

[0018]

According to the first aspect of the present invention, a semiconductor light emitting device is a p-type or n-type.
A current confinement layer having the other p-type or n-type conductivity is provided on the surface of a GaAs substrate having one of the conductivity types, and a stripe extending in a direction perpendicular to the end face of the substrate on the current confinement layer; It has a through-groove in a pattern. Therefore, a semiconductor laser device of a refractive index guide type can be configured. In this semiconductor laser device, Ga
On the surface of the As substrate, a third cladding layer made of AlGaAs having one conductivity type is buried in a through groove of a current confinement layer made of GaAs or AlGaAs, and
The surface of the cladding layer and the surface of the current confinement layer are on the same plane. This structure allows the above GaAs substrate to be replaced by (11
1) While maintaining a temperature at which the growth rate of AlGaAs on the B-plane becomes substantially zero, a third cladding layer made of AlGaAs is formed in the through groove by a known growth method, for example, MO.
It is realized by growing by a CVD method. In this case, AlGa is formed on the current confinement layer and the third cladding layer.
The first cladding layer made of InP can be formed by a known growth method without intervening an etching process, for example, MOCVD.
According to the method, it is formed flat with good controllability. In addition, the active layer and the second clad layer are formed flat with good controllability following the growth of the first clad layer so as to form a double hetero structure. Therefore, the thickness of the first cladding layer, the active layer and the second cladding layer hardly varies. Therefore, the fundamental mode of laser oscillation is stabilized. Further, since the etching step is not interposed after the formation of the third cladding layer, the growth interface is not oxidized.
Therefore, current leakage is reduced and the oscillation threshold value is reduced. Further, the thickness of the first cladding layer is usually set to be thin, and at this time, the loss of the higher-order mode does not decrease. Therefore, the kink level is improved. Thus, the characteristics of the semiconductor laser device are improved.

Further, the third cladding layer has an extended portion covering the surface of the current constriction layer, and the thickness of the extended portion is smaller than the thickness of the portion embedded in the through groove. When it is set, for example, when a layer forming a double hetero structure is formed by MOCVD, the active layer is slightly bent at the edge of the through groove. As a result, the waveguide structure has both the characteristics of the effective refractive index guide structure due to the light absorption of the substrate (current constriction layer) and the characteristics of the real refractive index guide structure due to the bending of the active layer. 12 has the advantages of the conventional example shown in FIG. That is, in this semiconductor laser device, the mode loss with respect to the basic mode and the effect of increasing the mode loss with respect to the higher-order mode occur, and the basic mode is further stabilized.

A current confinement layer extension having the other conductivity type, the surface of which is flush with the surface of the current confinement layer, is embedded in the periphery of the current confinement layer in the through groove. When the cladding layer No. 3 is buried inside the current constriction layer extension, the current injection width is reduced by the current constriction layer extension during operation. Therefore, the oscillation threshold value is further reduced, and the astigmatic difference is further reduced.

In the case where a plurality of the through-grooves of the current constriction layer are provided and the third cladding layer is embedded in each of the through-grooves, according to a current path formed by each of the through-grooves during operation. A plurality of oscillation regions occur. Therefore, a semiconductor laser array can be configured.

Further, the current confinement layer has one or more non-penetrating grooves in the current confining layer with a depth that stays in the current confinement layer, and the one conductivity type is provided in the non-penetrating groove. When the fourth cladding layer is embedded and the surface of the fourth cladding layer and the surface of the current confinement layer are on the same plane, the strain applied to the active layer due to the lamination of each layer on the substrate Are distributed on each of the non-through grooves. Therefore, the strain applied to the oscillation region on the through groove is reduced, and as a result, the long-term reliability of the element is improved.

Further, the semiconductor light emitting device of the second invention has a p
On the surface of the substrate having one of the conductivity types of
A current confinement layer having the other conductivity type of p-type or n-type is provided, and a through-groove formed in the current confinement layer has a circular pattern. Therefore, the semiconductor light emitting device of the second invention can constitute a surface emitting type light emitting diode. In this light emitting diode, the third cladding layer having the one conductivity type is embedded in the through groove of the current confinement layer, and the surface of the third cladding layer and the surface of the current confinement layer are flush with each other. Has made. In this case, the first clad layer, the active layer, and the second clad layer having a double hetero structure are formed on the current confining layer and the third clad layer.
Is formed with good controllability and flatness by a known growth method, for example, an MOCVD method without an etching step. Therefore, the first cladding layer,
The thickness of the active layer and the second clad layer hardly varies. Therefore, the emission luminance-applied current characteristics are stabilized. Further, since the etching step is not interposed after the formation of the third cladding layer, the growth interface is not oxidized. Therefore, current leakage is reduced and light emission luminance is increased. Thus, the characteristics of the light emitting diode are improved.

When the layer forming the double hetero structure is formed in a truncated cone shape, the light extraction efficiency on the element surface is increased.

The substrate has a (111) B surface or a G surface having an off surface having the (111) B surface as a main surface.
aAs, and the current confinement layer is made of GaAs or AlGaAs.
When the third cladding layer is made of AlGaAs, as described later, while the substrate is kept at a predetermined temperature, the third cladding layer is formed of A having the one conductivity type in the through groove.
A third cladding layer made of lGaAs can be grown so that the surface thereof is flush with the surface of the current confinement layer to fill the through-groove. Therefore, the first cladding layer, the active layer, and the second cladding layer having a double hetero structure can be grown flat on the substrate with good controllability by a known growth method.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments.

FIG. 1 shows a cross section of a semiconductor laser device according to a first embodiment of the present invention. The semiconductor laser device, the p-GaAs substrate 1 (111) B plane, n-GaAs current confinement layer (thickness _{1μm) 2, p- (Al 0} . 5 Ga 0. 5) 0. 5 In ₀ .
₅ P first cladding layer (0.2 μm thick) 3 and non-doped Ga
_0. And ₅ an In _{0. 5} P active layer (thickness _{0.05μm) 4, n- (Al 0} . 5
_{Ga 0. 5) 0. 5} In 0. 5 P second cladding layer (thickness 1.5 [mu] m) 5
_{When, n-Ga 0. 5 In} 0. 5 P contact layer (thickness 0.5 [mu] m) 6
It has. 4a is an oscillation region (shown by oblique lines), 9.1
0 is an electrode. The center of the current confinement layer 2 is formed a stripe-shaped through-channel 2b extending in the vertical direction in this section is, in this through-channel _{2b, p-Al 0. 7} Ga 0. 3 As third cladding layer (thickness (1.3 μm) 8 is embedded. The surface 8a of the cladding layer 8 and the surface 2a of the current confinement layer 2 are on the same plane.

Here, before explaining the manufacturing process of this element, the underlying phenomena will be described. The inventor of the present invention has proposed, by MOCVD, Ga having (111) B as a main surface.
Al ₀ on the As substrate (conductivity type may be p even _{n). 7 Ga 0. 3} As
_{Layer, Ga 0. 5 In 0.} 5 P layer, the relationship between the _{(Al 0. 5 Ga 0.} 5) 0. 5 In 0. 5 when the P layer is grown, the growth rate and the substrate temperature of the layers I found that it looks like Figure 4. Material during the growth of each layer, TMG (trimethyl gallium), TMA (trimethyl aluminum), TMI (trimethyl indium), and AsH ₃ (arsine), PH ₃ (phosphine).
In this experiment, during the growth of AlGaAs, the supply ratio of the group V element to the group III element (hereinafter referred to as “V / III ratio”) was set to 8.
0, Group III supply (sum of TMG and TMA supply) 1.6
× 10 ⁻⁵ mol / min, while GaInP and AlGaInP
When growing, the V / III ratio was set to 200 and the group III supply amount (TM
G × TMA + TMI) 2.0 × 10 ⁻⁵ mol
/ Min. Note that AlxGa ₁ -xAs and (AlxGa ₁ -x) yIn
_A similar experiment was performed for the Al composition ratio x changed with _1- yP (x = 0 to 1).
Approximately the same results as shown in FIG. 4 were obtained. As is apparent from FIG. 4, when the substrate temperature is 720 ° C. or lower, AlGaA
The s layer does not grow on the (111) B plane of the GaAs substrate at all.
On the other hand, the GaInP layer and the AlGaInP layer grow over a wide growth temperature range (650 to 750 ° C.), and the growth rate is substantially constant without depending on the substrate temperature. The above-described element manufacturing process utilizes this phenomenon.

When actually manufacturing the above-mentioned semiconductor laser device, first, as shown in FIG. 5A, (1) of the p-GaAs substrate 1
11) On the surface B, an n-GaAs current confinement layer 2 is grown to 1 μm by a liquid phase growth method. Next, as shown in FIG.
Etching is performed to remove p− from the surface 2 a of the current confinement layer 2.
The through grooves 2b having a width of 4 μm and a depth of 1.3 μm reaching the GaAs substrate 1 are formed. In this example, the direction of the through groove 2b is

## EQU00001 ## [00] direction. Next, FIG. (C), as shown in (d), on the substrate 1, p-Al ₀ by MOCVD. ₇ Ga _{0. 3}
The As cladding layer 8 is grown. The growth conditions were a substrate temperature of 700 ° C. and a V / III ratio of 80. As described in FIG. 4, under this growth condition, the (111) B
Since the growth rate on the surface is substantially zero, the AlGaAs layer does not grow on the bottom of the through groove 2b and the surface of the n-GaAs current confinement layer 2. Instead, as shown in FIG.
The As layer grows from the side wall of the through groove 2b toward the inside of the groove, and as shown in FIG. 4D, the whole of the through groove 2b is buried when the front of the layer grown from the periphery contacts. As a result, the surface 8a of each cladding layer 8 and the surface 2a of the current confinement layer 2 are on the same plane, and the surface side of the substrate 1 is flat. Subsequently, as shown in FIG.
By the OCVD method, the p-AlGaInP clad layer 3, the non-doped GaInP active layer 4, the n-AlGaInP clad layer 5, and the n-GaInP contact layer 6 are grown. The growth conditions were a substrate temperature of 700 ° C. and a V / III ratio of 200. At this time, the AlGaInP layer and the GaInP layer
Unlike the AlGaAs layer, it also grows on the (111) B plane (according to the above growth conditions, the growth rate is 1.7 μm / hour).
It is. ). Thereafter, electrodes 9 and 10 are formed on the back surface of the substrate 1 and the surface of the contact layer 6, respectively.
The semiconductor laser device shown in FIG. 1 was obtained by dividing into chips along the alternate long and short dash line in (e).

In this case, the p-AlGaInP clad layer 3 is grown with good controllability by the MOCVD method.
Moreover, it is not etched. Therefore, the thickness d of the cladding layer 3 hardly varies. Therefore, the basic mode is stabilized. Further, since the etching step is not interposed, the growth interface is not oxidized. Therefore, current leakage is reduced and the oscillation threshold value is reduced. Further, since the thickness of the cladding layer 3 on the current confinement layer 2 is small, the loss of the higher-order mode does not decrease. Therefore, the kink level is improved. Actually, the manufactured semiconductor laser device oscillated without kink up to 50 mW at an oscillation threshold of 40 mA in a non-coated, resonator length of 400 μm. Oscillation wavelength is 679nm at 50mW output
Met. The conventional semiconductor laser device shown in FIG.
Non-coating, oscillation length of 45m with resonator length 400μm
A, The kink level was doubled compared to the case where the kink level was 25 mW.

FIG. 2 shows a cross section of a semiconductor laser device according to a second embodiment of the present invention. This semiconductor laser device is provided on the p-GaAs substrate 11.

## EQU00002 ## On the (111) B plane turned off by 2.degree. In the [00] direction, n-
A GaAs current confining layer (thickness _{1μm) 12, p- (Al 0} . 7 G
_{a 0. 3) 0. 5} In 0. 5 P first cladding layer (thickness 0.2 [mu] m) 13
When a non-doped _{(Al 0. 1 Ga 0.} 9) 0. 5 In 0. And ₅ P active layer (thickness _{0.05μm) 14, n- (Al 0} . 7 Ga 0. 3) 0. 5 In 0 . ₅
P second cladding layer (thickness _{1.5μm) 15, n-Ga 0} . 5 In
_0. And ₅ P contact layer (thickness 0.5 [mu] m) 16, and a n-GaAs contact layer (thickness 0.1 [mu] m) 17. 14a is an oscillation area, 19 and 20 are electrodes. Current constriction layer 1
2, a stripe-shaped through groove 12b extending in a direction perpendicular to the section is formed.
_{-Al 0. 7 Ga 0. 3} As third cladding layer (thickness 1.3 .mu.m) 18
Is embedded. The surface 18a of the cladding layer 18 and the surface 12a of the current confinement layer 2 are on the same plane.

This semiconductor laser device is different from that of the first embodiment in that the p-GaAs substrate 11

## EQU00003 ## Each layer 1 is placed on the (111) B plane which is turned off by 2 DEG in the [00] direction.
.. Are provided, and an n-GaAs contact layer 17 is further provided on the n-GaInP contact layer 16. Furthermore, constituting the p- double heterostructure _{(Al 0. 7 Ga 0.} 3) 0. 5 In 0. 5 P cladding layer 13, an undoped _{(Al 0. 1 Ga 0.} 9) 0. 5 In 0. 5 P active layer 14, n- (Al
_{0. 7 Ga 0. 3)} 0. 5 In 0. 5 is a P clad layer 15. As a result, an oscillation wavelength of 650 nm is obtained.

In the case of manufacturing this element, up to the contact layer 16 is formed as in the first embodiment. The surface 18a of the cladding layer 18 and the surface 12 of the current confinement layer 12 could be coplanar despite being off by 2 ° from the (111) B plane of the p-GaAs substrate 11. The contact layer 17 is grown on the surface of the contact layer 16 (the (111) B surface of GaAs) with the substrate temperature raised to 740 ° C. so that GaAs also grows on the (111) B surface.

In this semiconductor laser device, as in the first embodiment, the fundamental mode is stabilized, the current leakage is reduced, the oscillation threshold value is reduced, and the kink level is improved. Actually, a chip having a cavity length of 500 μm is formed by Al ₂ O ₃ with a wavelength
Oscillation threshold 50m with 2-λ / 2 coating applied
A, good characteristics with a kink level of 45 mW were exhibited.

FIG. 3 shows a cross section of a semiconductor laser device according to a third embodiment of the present invention. This semiconductor laser device
On the (111) B plane of the p-GaAs substrate 31, an n-GaAs current confinement layer (thickness 1 μm) 32, a p-Al _0.7 Ga _0.3 As third cladding layer (0.02 μm thickness) 38 ′, p- (Al _{0. 5} G
_{a 0. 5) 0. 5} In 0. 5 P first cladding layer (thickness 0.2 [mu] m) 33
When a non-doped _{Ga 0. 38 In 0. 62} P layer (thickness 0.02 [mu] m) 3
And _{4, n- (Al 0. 5} Ga 0. 5) 0. 5 In 0. 5 P layer second cladding layer
Includes a (thickness 1.5 [mu] m) 35, the _{n-Ga 0. 5 In 0} . 5 P contact layer (thickness 0.5 [mu] m) 36. 34a is an oscillation region, and 39 and 40 are electrodes. In the center of the current confinement layer 32, a stripe-shaped through groove 32b extending in a direction perpendicular to the cross section is formed. In the through groove 32b, p-Al ₀ .
₇ Ga _{0. 3} As third cladding layer (thickness 1.3 .mu.m) 38 is embedded. The cladding layer 38 ′ is an extending portion connected to the cladding layer 38 and covers the surface of the current confinement layer 32. The surface 38a of the cladding layer 38 and the surface 32a of the current confinement layer 32 are on the same plane.

[0036] The semiconductor laser device relative to those of the first embodiment, an undoped Ga ₀ the composition of the active layer 4. ₃₈ In _0.
The surface of the current confinement layer 32 (the (111) B surface of GaAs) 3 on both sides of the through groove 32b is set by setting the strained structure as ₆₂ P and setting the substrate temperature to 730 ° C. during the growth of the cladding layer 38.
The difference is that the AlGaAs layer 38 'was slightly grown on 2a. As a result, as shown in FIG.
4 is slightly bent on the edge of the through groove 32b. As a result, the waveguide structure has both the characteristics of the effective refractive index guide structure due to the light absorption of the substrate (current constriction layer) and the characteristics of the real refractive index guide structure due to the bending of the active layer. 12 has the advantages of the conventional example shown in FIG. That is, in this semiconductor laser device, the mode loss with respect to the basic mode and the effect of increasing the mode loss with respect to the higher-order mode occur, and the basic mode can be further stabilized. Further, similarly to the first embodiment, the current leakage is reduced, the oscillation threshold value is reduced, and the kink level is improved.

Actually, under the conditions that the resonator length was 600 μm, the reflectivity of the front surface and the rear surface was 8% and 70%, respectively, the oscillation threshold value was 55 mA and the kink level was 220 mW (oscillation wavelength 690 nm). . This is because the kink level (1) of the conventional example shown in FIG.
(About 20 mW).

FIG. 6 shows a cross section of a semiconductor laser device according to a fourth embodiment of the present invention. This semiconductor laser device
On the (111) B surface of the p-GaAs substrate 41, two layers 42 ',
42 ", a current confinement layer (1 μm thick) 42 and p- (Al
_{0. 5 Ga 0. 5)} 0. 5 In 0. 5 P first cladding layer (thickness 0.2 [mu] m)
43, a non-doped _{Ga 0. 5 In 0. 5} P active layer (thickness 0.05
and _{μm) 44, n- (Al 0} . 5 Ga 0. 5) 0. 5 In 0. and ₅ P layer second cladding layer (thickness _{1.5μm) 45, n-Ga 0} . 5 In 0. 5 A P contact layer (thickness: 0.5 μm) 46 is provided. 44a is an oscillation region, and 49 and 50 are electrodes. The current confinement layer 42
Is formed at the center of the groove with a stripe-shaped through groove 42b extending in a direction perpendicular to the cross section.
_{Al 0. 7 Ga 0. 3} As third cladding layer (thickness 1.3 .mu.m) 48 is embedded. The surface 48a of the cladding layer 48 and the surface 42a of the current confinement layer 42 are flush with each other.

[0039] The semiconductor laser device relative to those of the first embodiment, the current confinement layer _{42 n-Al 0. 1 Ga} 0. 9 As the (thickness 0.9μm) 42 ', n-GaAs ( Thickness 0.1μm) 42 "
And a two-layer structure. When fabricating the semiconductor laser device, an _{n-Al 0. 1 Ga 0} . 9 As ( thickness 0.9μm) 42 ', n-GaAs ( thickness 0.1 [mu] m) 42 "and after providing a device A through groove 42b extending from the surface of the layer 42 "to the substrate 41 is formed at the center. Next, on the substrate 41, M
An AlGaAs layer is grown by OCVD. N-Al ₀ to the end face of the through groove 42b side of the current blocking layer 42. ₁ Ga _{0. 9}
Even when the As layer 42 'is exposed, as in the first embodiment,
At a substrate temperature of 720 ° C. or lower, selective growth occurred to fill only the inside of the through groove 42b. Note that such selective growth was realized until the Al mixed crystal ratio of the AlGaAs current confining layer was reduced from zero to at least 0.3. Thereafter, by growing each of the layers 43,... By MOCVD, an effective refractive index guide structure by light absorption of the current confinement layer 42 and the substrate 1 can be formed with good controllability.

As a result, this semiconductor laser device also
Similarly to the second embodiment, the fundamental mode was stabilized, the current leakage was reduced, the oscillation threshold was lowered, and the kink level was improved.

FIG. 7 shows a cross section of a semiconductor laser device according to a fifth embodiment of the present invention. This semiconductor laser device is formed on an (111) B surface of a p-GaAs substrate 51 by n-GaAs.
The current confinement layer (thickness 1μm) 52,52 ', p- (Al 0. 5 Ga
_{0. 5) 0. 5 In} 0. 5 P first cladding layer (thickness 0.2 [mu] m) 53
When a non-doped _{Ga 0. 5 In 0. 5} P active layer (thickness 0.05 .mu.m)
And _{54, n- (Al 0. 5} Ga 0. 5) 0. 5 In 0. And ₅ P layer second cladding layer (thickness _{1.5μm) 55, n-Ga 0} . 5 In 0. 5 P Contacts A layer (0.5 μm thick) 56 is provided. 54a is an oscillation region, and 59 and 60 are electrodes. At the center of the current confinement layer 52, a stripe-shaped through groove 52b extending in a direction perpendicular to the cross section is formed. The n-GaAs current confinement layer extension 52 inside the periphery of the through groove 52 b 'is embedded, the current confinement layer extension 52' p-Al ₀ inside the. ₇ Ga
_{0. 3} As third cladding layer (thickness 1.3 .mu.m) 58 is embedded. The surface 58a of the cladding layer 58 and the current confinement layer 5
The surfaces 52a, 52a 'of the second and 52' are flush with each other.

In this semiconductor laser device, the through groove (width 4
μm) 52b, and then by MOCVD,
An n-GaAs current confinement layer extension 52 'is grown laterally until the remaining width of the through groove becomes 2.5 .mu.m, followed by AlGaAs.
A buried layer 58 is grown. Thereafter, the layers 53,... Are grown by MOCVD in the same manner as in the first embodiment.

In this semiconductor laser device, as in the first embodiment, the effective refractive index guide structure can be formed with good controllability, the fundamental mode is stabilized, the current leakage decreases, and the oscillation threshold decreases. The kink level improves. Moreover, since the current confinement layer extension 52 'is formed in the through groove 52b to reduce the current injection width, the oscillation threshold value is further reduced as compared with the first embodiment, and the astigmatic difference is reduced. Is reduced.
Actually, the semiconductor laser device of the first embodiment has an oscillation threshold of 40 m in an uncoated, resonator length of 400 μm.
A, while the astigmatism difference was 5 μm (at 3 mW), this semiconductor laser device had an oscillation threshold of 30 m under the same conditions.
A, the astigmatic difference was 0 μm (at 3 mW).

FIG. 8 shows a cross section of a semiconductor laser device according to a sixth embodiment of the present invention. This semiconductor laser device is provided on an (111) B surface of a p-GaAs substrate 61 by n-GaAs.
The current confinement layer (thickness _{1μm) 62, p- (Al 0} . 5 Ga 0. 5) 0. 5
An In _0. And ₅ P first cladding layer (thickness 0.2 [mu] m) 63, a non-doped _{Ga 0. 5 In 0. 5} P active layer (thickness 0.05μm) 64, n
-.... (.. Al 0 5 Ga 0 5) 0 5 In 0 and ₅ P layer second cladding layer (thickness _{1.5μm) 65, n-Ga 0} 5 In 0 5 P contact layer (thickness (0.5 μm) 66. 64a is an oscillation region, 6
9 and 70 are electrodes. Three stripe-shaped through grooves 62b, 62b, 62b (groove width 3.5 μm, groove pitch 5.5 μm) extending in a direction perpendicular to the cross section are formed at the center and both sides of the current constriction layer 62, respectively. Through groove 6
In the _{2b, p-Al 0. 7} Ga 0. 3 As third cladding layer (thickness 1.
3 μm) 68 is embedded. The surface 68a of the cladding layer 68 and the surface 62a of the current confinement layer 62 are flush with each other.

This semiconductor laser device has the same layer configuration as that of the first embodiment, but has a plurality of through-grooves 62b serving as current paths in the current confinement layer 62, and accordingly, a plurality of oscillation regions. This constitutes a semiconductor laser array having 64a. In this semiconductor laser device, the optical output is 350 m
Oscillation in a 180 ° phase mode was observed up to a high output of W.

FIG. 9 shows a cross section of a semiconductor laser device according to a seventh embodiment of the present invention. This semiconductor laser device is provided on an (111) B surface of a p-GaAs substrate 71 by n-GaAs.
The current confinement layer (thickness _{1μm) 72, p- (Al 0} . 5 Ga 0. 5) 0. 5
An In _0. And ₅ P first cladding layer (thickness 0.2 [mu] m) 73, a non-doped _{Ga 0. 5 In 0. 5} P active layer (thickness 0.05μm) 74, n
-.... (.. Al 0 5 Ga 0 5) 0 5 In 0 5 P layer second cladding layer (thickness _{1.5μm) 75, n-Ga 0} 5 In 0 5 P contact layer (thickness 0.5 μm) 76. 74a is an oscillation region, 7
9, 80 are electrodes. In the center of the current confinement layer 72, a stripe-shaped through groove (current path) 72b extending in a direction perpendicular to the cross section is formed. This through groove 7
In the _{2b, p-Al 0. 7} Ga 0. 3 As third cladding layer (thickness 1.
3 μm) 78 are embedded. The current confinement layer 72
On both sides of the non-through groove 72b striped extending perpendicularly to the cross-section 'is formed with a plurality at a predetermined pitch, each non-penetrating grooves 72b' p-Al ₀ in. ₇ Ga _{0. 3} As fourth cladding layer 7
8 'is embedded. The surfaces 78a, 78a 'of the cladding layers 78, 78' and the surface 72a of the current confinement layer 72 are on the same plane.

In manufacturing this semiconductor laser device, after a current confinement layer 72 is provided on a substrate 71, the current confinement layer 72 is formed.
The non-through groove 72 that stays in the current constriction layer 72
b ', ... are formed. Next, a through groove 72b extending from the surface of the current confinement layer 72 to the substrate 71 is formed in the current confinement layer 72. Thereafter, the substrate 1 is maintained at a temperature of 700 ° C. as in the first embodiment. In this state, the cladding layers 78, 78 ',... Are formed in the through groove 72b and the non-through groove 72b'.
Are simultaneously grown so that the respective surfaces are flush with the surface of the current confinement layer 72, and the through groove 72b and the non-through groove 72b 'are buried. Thereafter, as in the first embodiment, a clad layer 73, an active layer 74 and a clad layer 75 are grown on the entire surface of the substrate 71.

This semiconductor laser device has the same layer structure as that of the first embodiment, but has a current confinement layer 72.
Are provided with a plurality of through-grooves 72b, non-through-grooves 72b ',. The central through groove 72b reaches the substrate 71 from the surface of the current confinement layer 72, while the non-through groove 72b 'on both sides thereof.
Remain in the current confinement layer 72. There is only one through groove 72b for forming the oscillation region, and the other non-through grooves 72b ',... Are for eliminating distortion due to the layer structure. That is, in the semiconductor laser device of the first embodiment shown in FIG. 1, all of the strain is applied to the portion of the active layer 4 on the edge of the through groove 2b (boundary of the oscillation region 4a). In this case, the through grooves 72b, the non-through grooves 72b ',.
Since there are a plurality of (s layers), the strain applied to the active layer 74 is dispersed on each of the grooves 72b ',. Therefore, the strain applied to the oscillation region 74a is reduced, and as a result, the long-term reliability of the device is improved.

FIG. 10 shows a surface-emitting type light emitting diode according to an eighth embodiment of the present invention.
(b) shows a view of FIG. (a) viewed from above. ). This light emitting diode is formed on the p-GaAs substrate 81.
On the (111) B plane, an n-GaAs current confinement layer 82 and a p-
_{(Al 0. 7 Ga 0.} 3) 0. 5 In 0. And ₅ P first cladding layer 83, an undoped _{(Al 0.45 Ga 0. 55)} 0.5 In 0. 5 P active layer 84
_{If, n- (Al 0. 7 Ga} 0. 3) 0. 5 In 0. 5 P layer second cladding layer 8
5, and a _{n-Ga 0. 5 In 0} . 5 P contact layer 86. 89 and 90 are electrodes. The center of the current confinement layer 82 through groove 82b of the circular pattern is formed in the through groove _{82b, p-Al 0. 7} Ga 0. 3 As third cladding layer 8
8 is embedded. The surface 88a of the cladding layer 88 and the surface 82a of the current confinement layer 82 are flush with each other. The central portion of the cladding layer 85 is processed into a truncated cone by an ion milling method.

The current constriction layer 82, the through groove 82b, and the cladding layer 88 are formed in exactly the same steps as in the semiconductor laser device of the first embodiment. Therefore, cladding layer 83, active layer 84 and cladding layer 8 having a double hetero structure
5 can be formed with good controllability, and as a result, the emission luminance-applied current characteristics are stabilized. Further, since the etching step is not interposed after the formation of the cladding layer 88, the growth interface is not oxidized. Therefore, current leakage is reduced and light emission luminance is increased. Thus, the characteristics of the light emitting diode can be improved. Further, the contact layer 86 and the upper electrode 90 have a small area circular pattern provided in the truncated cone portion of the cladding layer 85. Thereby, the light extraction efficiency from the element surface can be increased.

Actually, when this light emitting diode was molded into a 5 mmφ package and energized at 20 mA, a luminous intensity of 4 candela at a wavelength of 555 nm (conventionally about 0.3 candela) was obtained.

In each of the above embodiments, the GaAs substrate is p
It was a type, but of course it is not limited to this.
The conductivity type of the GaAs substrate may be either p-type or n-type, and the conductivity type of each growth layer may be determined according to the conductivity type of the GaAs substrate. The laser oscillation wavelength can be selected from a red to orange wavelength band by appropriately selecting the composition of the AlGaInP active layer. The active layer does not necessarily need to be non-doped, and may be p-type or n-type. The structure of the double hetero layer may be a SCH (separate confinement hetero structure) structure in which a guide layer is inserted as necessary, or a multi-quantum well structure or a multi-quantum barrier structure may be employed. . GaInP or G
A contact layer of aAs can also be provided as needed. In addition, the GaAs substrate does not need to be in the just direction as long as (111) B is the main surface,

## EQU00004 ## It may be turned off several times in the [00] or [0] direction. The layer growth after embedding the AlGaAs layer in the current confinement layer is preferably performed by the MOCVD method.
Other vapor phase growth methods such as an E (molecular beam epitaxy) method, an ALE (atomic layer epitaxy) method, and a CBE (chemical beam epitaxy) method may be used.

[0053]

As is apparent from the above description, the semiconductor light emitting device of the first invention has a p-type or n-type conductive film on the surface of a substrate having one of the p-type and n-type conductive types. A first confining layer having a mold, and having a through groove for forming a current path in a direction perpendicular to the surface of the substrate, and forming a double heterostructure on the current confining layer;
In the semiconductor light emitting device having the cladding layer, the active layer, and the second cladding layer, the through-groove has a stripe-shaped pattern extending in a direction perpendicular to the end face of the substrate, and thus has a refractive index guide type. A semiconductor laser device can be configured. In this semiconductor laser device,
On the surface of the GaAs substrate, AlGaA having one conductivity type is formed in the through groove of the current confinement layer made of GaAs or AlGaAs.
s, and the surface of the third cladding layer and the surface of the current confinement layer are flush with each other.
1) While maintaining a temperature at which the growth rate of AlGaAs on the B-plane becomes substantially zero, a third cladding layer made of AlGaAs is formed in the through groove by a known growth method, for example, MO.
It can be realized by growing by a CVD method. In this case, AlGa is formed on the current confinement layer and the third cladding layer.
The first cladding layer made of InP is formed by a known growth method without intervening an etching step, for example, MOCVD.
According to the method, it can be formed flat with good controllability. In addition, the active layer and the second clad layer can be formed to be flat with good controllability following the growth of the first clad layer so as to form a double hetero structure. Therefore, the thickness of the first cladding layer, the active layer and the second cladding layer hardly varies. Therefore, compared to the conventional semiconductor laser device,
The fundamental mode of laser oscillation can be stabilized. Further, since the etching step is not interposed after the formation of the third cladding layer, the growth interface is not oxidized. Therefore, it is possible to reduce the current leakage and lower the oscillation threshold. Further, the thickness of the first cladding layer is usually set to be thin, and at this time, the loss of the higher-order mode does not decrease. Therefore, the kink level can be improved. Thus, the characteristics of the semiconductor laser device can be improved.

Further, the third cladding layer has an extended portion covering the surface of the current constriction layer, and the thickness of the extended portion is smaller than the thickness of the portion embedded in the through groove. When it is set, for example, when a layer forming a double hetero structure is formed by MOCVD, the active layer is slightly bent at the edge of the through groove. As a result, the waveguide structure has the characteristics of the effective refractive index guide structure due to the light absorption of the substrate (current confinement layer) and the characteristics of the real refractive index guide structure due to the bending of the active layer. And an effect of increasing mode loss with respect to the higher-order mode. As a result, the basic mode can be further stabilized.

Further, a current confinement layer extension having the other conductivity type and having a surface flush with the surface of the current confinement layer is buried in a periphery of the current confinement layer in the through groove. In the case where the cladding layer of No. 3 is buried inside the current confinement layer extension in the through groove, the current injection width can be reduced by the current confinement layer extension during operation,
Therefore, the oscillation threshold value can be further reduced. Further, the astigmatic difference can be reduced.

In the case where a plurality of the through-grooves of the current constriction layer are provided and the third cladding layer is embedded in each of the through-grooves, according to a current path formed by each of the through-grooves during operation. A plurality of oscillation regions can be formed. That is,
A semiconductor laser array can be configured.

Further, the current confinement layer has at least one non-penetrating groove having a depth that stays in the current confinement layer, in line with the through-groove, and has the one conductivity type in the non-penetrating groove. When the fourth cladding layer is embedded and the surface of the fourth cladding layer and the surface of the current confinement layer are on the same plane, the strain applied to the active layer due to the lamination of each layer on the substrate Can be dispersed on each of the non-through grooves. Therefore, the strain applied to the oscillation region on the through groove can be reduced, and as a result, the long-term reliability of the device can be improved.

Further, the semiconductor light emitting device of the second invention has
On the surface of the substrate having one of the conductivity types of
a current confinement layer having the other conductivity type of p-type or n-type and having a through groove for forming a current path in a direction perpendicular to the surface of the substrate, and a double heterostructure on the current confinement layer; In the semiconductor light emitting device having the first cladding layer, the active layer, and the second cladding layer, the through groove has a circular pattern.
A surface-emitting type light-emitting diode can be formed.
In this light emitting diode, the third cladding layer having the one conductivity type is embedded in the through groove of the current confinement layer, and the surface of the third cladding layer and the surface of the current confinement layer are flush with each other. Therefore, the first cladding layer, the active layer and the second cladding layer having a double hetero structure are formed on the current confinement layer and the third cladding layer by a known growth method without an etching step. For example, a flat surface can be formed with good controllability by, for example, the MOCVD method. Therefore, the first clad layer, the active layer and the second
Almost no variation in the thickness of the cladding layer occurs. Therefore, the emission luminance-applied current characteristics can be stabilized. . Further, since the etching step is not interposed after the formation of the third cladding layer, the growth interface is not oxidized. Therefore, the light emission luminance can be increased by reducing the current leakage. Thus, the characteristics of the light emitting diode can be improved.

When the layer having the double hetero structure is formed in a truncated cone shape, the light extraction efficiency on the element surface can be increased.

The substrate has a (111) B plane or a G plane having an off plane having the (111) B plane as a main surface.
aAs, and the current confinement layer is made of GaAs or AlGaAs.
In the case where the third cladding layer is made of AlGaAs, the third cladding layer made of AlGaAs having one conductivity type is placed in the through groove while the substrate is kept at a predetermined temperature. The through-groove can be buried by growing the surface so that the surface is flush with the surface of the current confinement layer. Therefore, the first cladding layer, the active layer, and the second cladding layer having the double hetero structure can be grown flat on the third cladding layer and the current confinement layer with good controllability by a known growth method. it can.

According to the method of manufacturing a semiconductor light emitting device of the third invention, the (111) B surface or the (111) B surface of the GaAs substrate having one of p-type and n-type conductivity is used as the main surface. A current confinement layer made of GaAs or AlGaAs having the other conductivity type of p-type or n-type is provided on the off surface, and a predetermined pattern from the surface of the current confinement layer to the substrate is provided on the current confinement layer. After the through-groove is formed, the substrate is kept at a temperature at which the growth rate of AlGaAs on the (111) B plane becomes substantially zero, and the AlGaAs having one conductivity type is formed in the through-groove. Since the third clad layer made of is grown, the surface of the third clad layer can be grown so that the surface of the current constriction layer is flush with the surface of the current confinement layer, and the through-groove can be embedded. Therefore, the first clad layer, the active layer and the second clad layer having a double hetero structure can be formed on the third clad layer and the current confinement layer flatly with good controllability. A semiconductor light emitting device such as a semiconductor laser device or a semiconductor light emitting device with improved characteristics can be manufactured.

Further, according to the method of manufacturing a semiconductor light emitting device of the fourth invention, the current confinement layer has the other conductivity type at the periphery of the current confinement layer in the through-groove, and the surface is in contact with the surface of the current confinement layer. In the case where the current confinement layer extension part forming the same plane is buried, and the third cladding layer is buried inside the current confinement layer extension part, the current injection width is increased by the amount of the current confinement layer extension during operation. Can be narrow. Therefore, the oscillation threshold value of the semiconductor light emitting device, particularly the semiconductor laser device, can be further reduced. Further, the astigmatic difference can be reduced.

Further, according to the method for manufacturing a semiconductor light emitting device of the fifth invention, one or more non-penetrating grooves are provided in the current confinement layer so as to remain in the current confinement layer in a line with the through grooves. The fourth cladding layer having the one conductivity type may be embedded in the non-through groove, and the surface of the fourth cladding layer and the surface of the current confinement layer may be flush with each other. Therefore, the strain applied to the active layer by disposing each layer on the substrate can be dispersed on each of the non-through grooves. Therefore, the strain applied to the oscillation region on the through groove can be reduced, and as a result, the long-term reliability of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of a semiconductor laser device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a cross section of a semiconductor laser device according to a second embodiment of the present invention.

FIG. 3 is a view showing a cross section of a semiconductor laser device according to a third embodiment of the present invention;

FIG. 4 shows Al on a (111) B surface of a GaAs substrate.
FIG. 4 is a diagram showing the relationship between the growth rate of each layer of GaAs, GaInP, and AlGaInP and the substrate temperature.

FIG. 5 is a diagram illustrating a manufacturing process of the semiconductor laser according to the first embodiment.

FIG. 6 is a view showing a cross section of a semiconductor laser device according to a fourth embodiment of the present invention.

FIG. 7 is a view showing a cross section of a semiconductor laser device according to a fifth embodiment of the present invention.

FIG. 8 is a view showing a cross section of a semiconductor laser device according to a sixth embodiment of the present invention.

FIG. 9 is a view showing a cross section of a semiconductor laser device according to a seventh embodiment of the present invention.

FIG. 10 is a diagram showing a cross section and a surface of a light emitting diode according to an eighth embodiment of the present invention.

FIG. 11 is a diagram showing a cross section of a conventional effective refractive index guide type semiconductor laser device.

FIG. 12 is a diagram showing a cross section of a conventional real refractive index guide type semiconductor laser.

[Explanation of symbols]

1,11,21,31,41,51,61,71,81 p-Ga
As substrate 2,12,22,32,42 ", 52,62,72,82 n-
GaAs current confinement layer 2b, 12b, 22b, 32b, 42b, 52b, 62b, 72b, 82
b Through-groove 3,13,23,33,43,53,63,73,83 First cladding layer 4,14,24,34,44,54,64,74,84 Active layer 5,15,25,35 , 45, 55, 65, 75, 85 Second cladding layer 8, 18, 28, 38, 48, 58, 68, 78, 88 p-AlGaAs third cladding layer 38 'p-AlGaAs Third cladding layer extension Part 42 'n-AlGaAs current confinement layer 52' n-GaAs current confinement layer extension 72b 'non-through groove 78' p-AlGaAs fourth cladding layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H01S 3/18 H01L 33/00

Claims (11)

(57) [Claims] A GaAs substrate having one of p-type or n-type conductivity has a p-type or n-type conductivity on the surface thereof, and has a current path perpendicular to the substrate surface. GaAs or AlGaAs having a through groove for forming
s, and a first clad layer, an active layer, and a second clad layer having a double heterostructure on the current confinement layer. A third cladding layer made of AlGaAs having the one conductivity type is buried in the through-groove, and has a stripe-shaped pattern extending in a direction perpendicular to the end face; The surface of the current confinement layer is coplanar with the surface of the current confinement layer, and the first cladding layer is formed of AlGa having the one conductivity type.
A semiconductor light-emitting device comprising InP. 2. A current path is formed on a surface of a substrate having one of p-type or n-type conductivity and having the other conductivity type of p-type or n-type and perpendicular to the substrate surface. A semiconductor light emitting device comprising: a current confinement layer having a through-groove for forming the first cladding layer, an active layer, and a second cladding layer having a double hetero structure on the current confinement layer; A stripe pattern extending in a direction perpendicular to an end face of the substrate, a third cladding layer having the one conductivity type is embedded in the through groove, and a surface of the third cladding layer is formed. And the surface of the current constriction layer are flush with each other, and the third cladding layer has an extended portion that covers the surface of the current constriction layer, and the thickness of the extended portion is within the through groove. Than the thickness of the embedded part A semiconductor light emitting device characterized in that it is also set to be thin. 3. A current path is formed on the surface of a substrate having one of p-type or n-type conductivity and having the other conductivity type of p-type or n-type and perpendicular to the substrate surface. A semiconductor light emitting device comprising: a current confinement layer having a through-groove for forming the first cladding layer, an active layer, and a second cladding layer having a double hetero structure on the current confinement layer; A stripe pattern extending in a direction perpendicular to an end face of the substrate, a third cladding layer having the one conductivity type is embedded in the through groove, and a surface of the third cladding layer is formed. And the surface of the current confinement layer is flush with the surface of the current confinement layer. Filled layer extension Wherein the third cladding layer is embedded in the through hole and inside the current confinement layer extension. 4. The semiconductor light emitting device according to claim 1, wherein a plurality of said through grooves of said current constriction layer are provided, and said third cladding layer is embedded in each of said through grooves. 5. A current path is formed on a surface of a substrate having one of p-type or n-type conductivity and having the other conductivity type of p-type or n-type and perpendicular to the surface of the substrate. A semiconductor light emitting device comprising: a current confinement layer having a through-groove for forming the first cladding layer, an active layer, and a second cladding layer having a double hetero structure on the current confinement layer; A stripe pattern extending in a direction perpendicular to an end face of the substrate, a third cladding layer having the one conductivity type is embedded in the through groove, and a surface of the third cladding layer is formed. And the surface of the current confinement layer are on the same plane, and the current confinement layer has at least one non-through groove having a depth that remains in the current confinement layer, in line with the through groove. Within the above one conductivity type Fourth cladding layer is embedded, and the semiconductor light emitting device characterized by the aforementioned fourth surface of the cladding layer and the surface of the current constriction layer is flush with. 6. A current path is formed on a surface of a substrate having one of p-type or n-type conductivity and having a p-type or n-type conductivity and perpendicular to the substrate surface. A semiconductor light emitting device comprising: a current confinement layer having a through-groove for forming the first cladding layer, an active layer, and a second cladding layer having a double hetero structure on the current confinement layer; Has a circular pattern, the third cladding layer having the one conductivity type is embedded in the through groove, and the surface of the third cladding layer and the surface of the current confinement layer are flush with each other. A semiconductor light emitting device characterized by the following. 7. The semiconductor light emitting device according to claim 6, wherein the layer forming the double hetero structure is formed in a truncated cone shape. 8. The method according to claim 1, wherein the substrate is a (111) B plane or a (11) B plane.
1) The current constriction layer is made of GaAs or AlGaAs, and the third cladding layer is made of AlGaAs, wherein the current constriction layer is made of GaAs and the off-plane whose main surface is the B-plane. 8. The semiconductor light emitting device according to any one of 7. 9. A p-type or n-type GaAs substrate having a (111) B surface or an off-surface having a (111) B surface as a main surface, the other surface of which is p-type or n-type. Providing a current confinement layer made of GaAs or AlGaAs having a conductivity type; forming a through-groove in a predetermined pattern from the surface of the current confinement layer to the substrate in the current confinement layer; 111) While maintaining a temperature at which the growth rate of AlGaAs on the B-plane becomes substantially zero, a third layer of AlGaAs having one of the above conductivity types is formed in the through groove.
Growing the cladding layer so that the surface thereof is flush with the surface of the current confinement layer, and filling the through-groove. The first cladding layer, the active layer and the active layer forming a double hetero structure on the substrate A method for manufacturing a semiconductor light emitting device, comprising a step of growing a second cladding layer over the entire surface. 10. A p-type or n-type GaAs substrate having a (111) B surface or an off-surface having a (111) B surface as a main surface, the other surface of which is p-type or n-type. Providing a current confinement layer made of GaAs or AlGaAs having a conductivity type; forming a through-groove in a predetermined pattern from the surface of the current confinement layer to the substrate in the current confinement layer; 111) While maintaining the temperature at which the growth rate of AlGaAs on the B-plane becomes substantially zero, GaAs or Al having the other conductivity type is formed around the periphery of the through groove.
Growing a current confinement layer extension made of GaAs so that the surface is flush with the surface of the current confinement layer to reduce the width of the through-groove; and maintaining the substrate at a predetermined temperature. A third cladding layer made of AlGaAs having the one conductivity type is grown inside the extension of the current confinement layer in the through groove so that the surface is flush with the surface of the current confinement layer. Filling the through groove, and growing a first clad layer, an active layer, and a second clad layer having a double hetero structure on the entire surface of the substrate. Production method. 11. A p-type or n-type GaAs substrate having a (111) B surface or an off-surface having a (111) B surface as a main surface, the other surface of which is p-type or n-type. A step of providing a current confinement layer made of GaAs or AlGaAs having a conductivity type; a step of forming a predetermined pattern of non-penetrating grooves remaining in the current confinement layer in the current confinement layer; Forming a through-groove having a predetermined pattern from the surface of the current confinement layer to the substrate; and maintaining the substrate at a temperature at which the growth rate of AlGaAs on the (111) B surface becomes substantially zero. AlGaA having the one conductivity type in the through groove and the non-through groove.
a step of growing third and fourth cladding layers made of s so that their surfaces are respectively flush with the surface of the current confinement layer, and embedding the through-grooves and the non-through-grooves; A method for manufacturing a semiconductor light emitting device, comprising a step of growing a first clad layer, an active layer, and a second clad layer forming a hetero structure on the entire surface.