JPH1126884A - Semiconductor laser device and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: A semiconductor laser device and a method for manufacturing the same are provided.
In the S ³ laser, as in the case of the ordinary ridge-type laser, a means for preventing the current path in the p-side cladding layer from being narrowed without changing the composition of the cladding layer is provided. Keep growth lines parallel to ensure near field pattern stability. An n-type AlGaInP cladding in which an n-side cladding layer has a gentle second slope between a lower side of the first slope and a main surface, and the first slope has a first plane azimuth angle. It is characterized in that the layer 203 and the first slope are composed of a combination of an n-type AlGaInP cladding layer 204 having a second plane azimuth that is slower than the first plane azimuth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lateral mode control type semiconductor laser device manufactured using a GaAs substrate and an improvement in a method of manufacturing the same.

A semiconductor laser using a cladding layer made of AlInP or AlGaInP oscillates at a short wavelength in a red region and can narrow a laser spot to a small size, so that a DVD (digital video) is used.
It is suitable for an optical disk device that performs high-density recording / reproduction such as isk).

As this type of semiconductor laser, an S ³ laser (self-aligned) having excellent performance in various aspects is used.
d Stepped Substrate Race
r) is known (if necessary, see Japanese Patent Application Laid-Open No. 6-4570).
No. 8), this S ³ laser requires another improvement in order to stabilize the near-field pattern, and the present invention can meet the demand.

[0004]

2. Description of the Related Art Generally, AlInP or AlGaInP used as a cladding layer of a semiconductor laser is made of G
It has the largest energy band gap as a group III-V material lattice-matched to aAs, and is indispensable especially for realizing a red laser.

FIG. 4 is a cutaway perspective view of a main part showing a standard red laser for explaining the prior art.

In the figure, (A) is a forward mesa ridge laser, (B) is a reverse mesa ridge laser, 801 is an n-type GaAs substrate 802 is an n-type GaAs buffer layer 803 is an n-type The Al _0.35 Ga _0.15 In _0.5 P cladding layer 804 is an active layer made of strained MQW 805 is a p-type Al _0.35 Ga _0.15 In _0.5 P cladding layer 806 is a p-type GaInP etching stop layer 807 is a p-type Al _0.35 Ga _0.15 In _0.5 P cladding The layer 808 is a p-type GaInP intermediate layer 809 is an n-type GaAs current blocking layer 810 is a p-type GaAs contact layer, and the strained MQW active layer 804 is an Al _0.2 Ga _0.3 In _0.5 P guide layer (thickness 100).
[Å]) GaInP well layer (thickness 60 [Å]) Al _0.2 Ga _0.3 In _0.5 P barrier layer (thickness 40)
[Å]) GaInP well layer (thickness 60 [Å]) Al _0.2 Ga _0.3 In _0.5 P barrier layer (thickness 40)
[Å]) GaInP well layer (thickness 60 [Å]) Al _0.2 Ga _0.3 In _0.5 P guide layer (thickness 100)
[Å]).

The feature of the laser shown is p-type AlG
The point that the periphery of the aInP cladding layer 807 is buried with an n-type GaAs current blocking layer 809. The presence of the current blocking layer 809 realizes excellent current confinement and stability of the optical waveguide mode.

Also, in the reverse mesa ridge type laser shown in (B), if the active layer width is the same, that is, the stripe width is the same, the ridge top laser is compared with the forward mesa ridge type laser shown in (A). Since the surface area is large, the current path can be increased, and the element resistance can be reduced.

In order to manufacture the reverse mesa ridge laser with good reproducibility, the direction perpendicular to the stripe direction of the forward mesa ridge laser, ie, the (01-1) direction, ie, the direction perpendicular to the (01-1) direction, ie, It must be in the (011) direction.

A ridge type laser whose stripe direction is the (011) direction generates a natural superlattice, so that the laser characteristics are greatly deteriorated.
Since the current blocking layer 809 absorbs light, luminous efficiency is reduced.

In order to solve the above-mentioned problems in the laser, the group of the present inventors has realized an S ³ laser having a bent active layer as a visible light laser. This is a structure that does not use a buried structure, and can be manufactured regardless of the selective growth of a semiconductor crystal containing Al.

[0012] Figure 5 is a semiconductor laser slope emission type according to our invention, i.e., a main part cut slope diagram representing the S ³ laser (if desired, supra "JP-A 6-45708
No. Gazette).

In the figure, 701 is an n-type GaAs substrate 702 is an n-type GaAs buffer layer 703 is an n-type GaInP intermediate layer 704 is an n-type AlGaInP cladding layer 705 is an active layer made of MQW 706 is a p-type AlGaInP cladding layer 707 Denotes an AlGaInP current confinement layer 707A, an n-type AlGaInP region 707B, a p-type AlGaInP region 708, a p-type AlGaInP cladding layer 709, an n-type GaInP intermediate layer 710, and a p-type GaAs contact layer.

Since the S ³ laser is not a loss guide structure, that is, a complex refractive index waveguide structure based on light loss using a light absorbing material in the current confinement layer, light absorption loss is not considered. Good, low astigmatism, and M
OVPE (metalorganic vapor p
Since the semiconductor layer laminate can be manufactured by a single growth according to the Hase epitaxy method, the production yield is high, and therefore, it can be provided at a low price.

In the case of manufacturing an S ³ laser, in particular, to form a current confinement layer, the plane orientation dependence of impurity doping is used.

FIGS. 6 and 7 are diagrams for explaining the plane orientation dependence of impurity doping. The horizontal axis represents the off-angle of the substrate, and the vertical axis represents the relative incorporation rate of the impurity. Are each taken.

FIG. 6 shows the case of Mg and Zn, and FIG.
e, the compound semiconductor crystal is AlGa
InP.

As is clear from the figures, the incorporation rate of p-type impurities such as Zn shows a dependency of (311) A> (100), whereas the incorporation rate of n-type impurities such as Se is And (100)> (311) A.

Therefore, by simultaneously doping the p-type impurity and the n-type impurity on the surface of the semiconductor layer having different plane orientations, the p-type crystal layer and the n-type crystal layer can be grown simultaneously.

FIG. 8 is a diagram for explaining the plane orientation dependency when p-type impurities and n-type impurities are simultaneously doped. The horizontal axis indicates the tilt angle in the crystal plane of the substrate, that is,
The off angle from the (100) plane to the (111) A plane direction is taken, and the vertical axis is the carrier concentration.

As is apparent from the figure, p depends on the plane orientation.
Since the n-type crystal layer and the n-type crystal layer can be obtained in one growth,
For example, if a groove having a side surface of (311) A is formed on the surface of the semiconductor layer having a main surface of (100) and the co-doped crystal layer is grown there, an n-type crystal layer is formed on the main surface. However, a p-type crystal layer grows on each side surface (usually a slope) in the groove.

The above-described oblique emission type semiconductor laser shown in FIG. 5, that is, the S ³ laser is manufactured by applying the above-described co-doping technique.
The p-type region 70 in the current confinement layer 707 where a current flows
7B is a slope, and although the central portion of the light emitting region in the active layer 705 thereunder is also sloped, it is straight without being curved.

FIG. 9 is a fragmentary front view showing the essential points of a configuration in which a semiconductor layer is grown on a substrate used for an S ³ laser.

In the figure, 101 is an n-type GaAs stepped substrate after a GaAs buffer layer is grown 102 is an n-type GaInP intermediate layer 103 is an n-type AlGaInP cladding layer 104 is an active layer made of strained MQW 105 is a p-type AlGaInP cladding layer 106 is an AlGaInP current confinement layer 106A is an n-type AlGaInP region 106B is a p-type AlGaInP region 107 is a p-type AlGaInP cladding layer 108 is a p-type GaInP intermediate layer 109 is a p-type GaAs contact layer, and 110 is on the first slope Current path,
111 is the first growth line (boundary between the upper flat surface and the first slope), 112 is the second growth line (boundary between the first slope and the second slope), and 113 is the third growth line (the second slope and the lower flat surface). 114, a first slope, 115, a second slope, 116
Indicates an upper flat surface, 117 indicates a lower flat surface, 118 indicates disturbance of the second growth line and the third growth line, and 119 indicates an inclined surface of the step substrate 101 after the growth of the buffer layer.

As is apparent from the figure, when the required semiconductor layers are actually formed on the stepped substrate 101, the remarkable effect is particularly at the growth stage of the n-side cladding layer 103.
14, a second slope 115 that forms a gentle slope and extends in the lower flat surface direction is generated.

In addition, the surface area of the second slope 115 tends to increase as the semiconductor layer grows, and accordingly, the surface area of the first slope 114 decreases as the semiconductor layer grows.

Incidentally, the p-type impurity concentration on the first slope 114 is more than twice as large as the other faces, that is, the second slope 115, the upper flat face 116, the lower flat face 117, and so on. ^{In the case of the three} lasers, the current path 110 is formed between the portions corresponding to the first slopes of the p-side cladding layers 107 and 105 and the p-type region 106B in the current confinement layer 106.

Therefore, the current path 11 in the S ³ laser
0 has a problem that it becomes narrower as the distance from the active layer 104 increases, and the resistivity increases.

In view of this, the group of the present inventor has proposed a means for changing the appearance of the first slope 114 and the second slope 115 by changing the crystal composition of Group II only during the growth of the n-side cladding layer 103. (If necessary, refer to “Japanese Patent Application No. 8-
246543 ").

The means disclosed in Japanese Patent Application No. 8-246543 for changing the appearance of the first slope and the second slope is useful for producing an inverted mesa structure in principle. However, when the composition is changed, the distribution of the light confinement is changed, so that it is difficult to obtain a good beam shape.

Therefore, it is necessary to develop a technique that does not change the group III composition of the crystal and does not cause a situation in which the width of the stripe becomes narrower as the crystal grows, for example, a technique corresponding to forming an inverted mesa. Must.

In either the normal mesa type or the reverse mesa type, the first growth line 111 and the second growth line 112 shown in FIG. Is approaching, but the angle of this growth line affects the polarization angle of the laser beam (see Japanese Patent Application No. 7-159342 if necessary).

Therefore, if the growth lines are not made parallel, a subtle difference occurs between the polarization angle near the first growth line 111 and the polarization angle near the second growth line 112. This affects the near-field pattern of the laser beam, which causes a problem in kink stability.

[0034]

According to the present invention, in the S ³ laser, as in the case of the inverted-mesa ridge type laser shown in FIG. Means to keep the current path in the area narrow, and keep the two growth lines corresponding to the slope parallel to each other.
To ensure the stability of the field pattern.

[0035]

Means for Solving the Problems The present inventor has proposed MOVPE.
When a clad layer is grown on a stepped substrate by applying the method, a clad layer further grown on a clad layer grown by applying a different group III / group III ratio or a different growth temperature may be temporarily used. And found that the angle of the growth line changed.

FIG. 1 is a fragmentary front view showing the structure of a grown semiconductor layer for explaining the principle of the present invention.

In the figure, 1 is a first region layer grown on a semiconductor base having a step, 2 is a second region layer grown on the first region layer, and 3 is a second region layer grown on the second region layer. Third area layer,
1A is a main surface, 1B is a first slope, 1B ₀ is a first slope having a different plane orientation, 1C is a second slope, 4A is a first upper growth line,
B indicates a second upper growth line, 4C indicates a third upper growth line, 5A indicates a first lower growth line, 5B indicates a second lower growth line, and 5C indicates a third lower growth line.

According to the inventor's experiments, the cladding layer was grown at a high V / III ratio or at a low growth temperature on a cladding layer grown at a low growth temperature. It was found that, as shown in FIG. 1, a region in which the lower growth line temporarily parallels the upper growth line appears when is grown.

Therefore, in order to stabilize the near field pattern of the laser beam, a crystal growth layer in which the lower growth line is temporarily parallel to the upper growth line is formed on the cladding layer near the active layer. good.

The inclination angle of the first slope 1B shown in FIG. 1 slightly changes depending on the group V / group III ratio or the growth temperature.

FIG. 2 is a graph showing the change in the inclination angle of the slope depending on the group V / III ratio or the growth temperature, and the horizontal axis indicates the inclination angle ω of the upper growth line (see FIG. 2 (A)). The vertical axis represents the angle θ of the first slope (see FIG. 2A).

The data on the sample shown in FIG. 2A shows that an AlGaInP layer was grown on a (100) 6 ° off substrate and the group V / III ratio in the AlGaInP layer was 1 unit.
30 to 300, and the growth temperature Tg is 7
The temperature was changed from 05 [° C] to 720 [° C].

As can be seen from the figure, even when the inclination angle ω of the upper growth line changes greatly, the inclination angle θ of the slope is relatively stable, but when the inclination angle ω of the upper growth line increases, the inclination of the slope increases. Angle θ is found to be slightly smaller,
It is understood that there is a weak dependency.

For this reason, if the inclination angle ω of the upper growth line changes, the plane orientation of the first slope changes, and during the growth of the crystal, the group V / group III ratio and the growth temperature are changed, and When the first crystal growth layer 1 and the second crystal growth layer 2 having different growth lines are grown, as shown in FIG. 1, the angle of the plane orientation at the first slope 1B gradually changes during growth. And the angle of the lower growth line changes accordingly.

The second area layer 2 in FIG.
When B is a portion that changes the plane orientation, that is, a transition region, and the first slope 1B is completely stable in the plane orientation of the growth condition, as shown by the lower growth line 5C of the third region layer 3 again, You will change the angle.

As described above, even if the crystals have the same composition, if the growth conditions are different, the angle of the growth line changes, and two regions having different growth conditions, for example, the first region in FIG. Although only the layer 1 has different growth conditions, a transition region for maintaining the slope angle properly, for example, the second region layer 2 in FIG. 1 corresponds between the two region layers. However, there is a condition that the lower growth line and the upper growth line are in a state close to parallel in this portion.

If the transition region described above is used, the angle of the lower growth line of the crystal originally determined spontaneously from the group V / III ratio and the growth conditions can be determined when the crystal growth stage is within the transition region. It is only possible to change temporarily.

As described above, in the semiconductor laser device and the method of manufacturing the same according to the present invention, (1) the (100) plane or the (n11) A plane (7 <n n)
Is a real number) and the (n _{1 1 1} ) A surface (2 ≦
n ₁ ≦ 7 n ₁ is a real number) A stepped substrate having an inclined surface (for example, an n-type GaAs stepped substrate 201 in which a GaAs buffer layer is laminated) and formed on the stepped substrate (100)
Surface, or (n11) A plane (7 <n n is a real number) the principal surface and (n ₂ 11) is exposed A surface _{(3 ≦ n 2 ≦ 7 n} 2 is a real number) having a first inclined surface which is exposed to the outside Active layer (eg, strain M
QW active layer 205) and a p-side first cladding layer (for example, p-type AlGaInP cladding layer 206) stacked in contact with the active layer and having a high carrier concentration in a region along the slope and a low carrier concentration in a region along the main surface. ) And a p-type second cladding layer (for example, p-type AlGaI present on the slope) that is stacked in contact with the p-side first cladding layer and is p-type in a region along the slope.
The same semiconductor layer (for example, AlGa) having an nP cladding layer and an n-type current blocking layer (for example, an n-type AlGaInP current blocking layer on a flat surface) in a region along the main surface.
The InP current block and the cladding layer 207), at least the n-side cladding layer has a gentle second slope between the lower side of the first slope and the main surface, and A cladding layer (for example, n-type A) in which one slope is composed of crystals in a crystal growth region having a first plane azimuth angle
1GaInP cladding layer 203) and a cladding layer (for example, n) composed of crystals in a crystal growth region in which the first slope has a second plane azimuth that is slower than the first plane azimuth.
Or a combination of a type AlGaInP cladding layer 204), or

(2) In the above (1), at least n
Side cladding layer (for example, n-type AlGaInP cladding layer 2
03 and 204), the group V / III ratio of the crystal in the crystal growth region having the first plane orientation angle on the stepped substrate side has the second plane orientation angle on the surface side. Characterized by being higher than the group V / III ratio in the crystal in the crystal growth region, or

(3) In the above (1) or (2), a part of the cladding layer near the active layer has a crystal in a crystal growth region having a second plane azimuth angle (for example, the n-type AlGaInP cladding layer 204). Or the average of the upper growth line (for example, upper growth line 211) and the average of the lower growth line (for example, 214) near the active layer are substantially parallel to each other, or

(4) The principal surface expressed by the (100) plane or the (n11) A plane (7 <nn is a real number) and (n ₁₁ 1)
1) A plane _{(2 ≦ n 1 ≦ 7 n} 1 is a real number) second crystal and the surface side of the crystal growth region having a first surface orientation angle of the stepped substrate side a stepped substrate having exposed the slope Crystal growth regions having a plane orientation angle of (for example, n-type AlGaInP cladding layer 203 and n-type AlGaInP cladding layer 204)
Is grown in order to form a one-conductivity-type side cladding layer (eg, n-side cladding layer), and a crystal growth region (eg, n-type AlGaI) having a second plane azimuth angle on the surface side.
a step of increasing the crystal growth temperature of the nP cladding layer 204), and then a (100) plane or (n11) on one conductivity type side cladding layer (for example, n side cladding layer).
The main surface expressed by the A surface (7 <nn is a real number) and (n ₂
11) An active layer (for example, a strained MQW active layer 205) having a first slope exposed on the A side (3 ≦ n ₂ ≦ 7 n ₂ is a real number)
And then forming an opposite conductive type side first cladding layer (for example, p-type AlGaInP cladding layer 206) having a high carrier concentration in the region along the slope and a low carrier concentration in the region along the main surface on the active layer. ), And then on the opposite-conductivity-type first clad layer along the slope in the opposite-conductivity-type second clad layer (for example, p-type AlGaInP clad layer) and the main surface along the opposite conductivity type. A current blocking layer (for example, n-type A
the same semiconductor layer (for example, an AlGaInP current block and a cladding layer 2) composed of a 1GaInP current block layer
07).

By adopting the above-mentioned means, it is possible to change the ratio of group V to group III or to change the growth temperature, etc., and to grow between the two region layers acting as the cladding layer in the S ³ laser. It is possible to control the lower growth line and the upper growth line related to the inclined plane to be in a state of being close to or close to each other by using a region layer which is a transition region interposed therebetween, so that the near field pattern can be controlled. This is effective for stabilization, and can prevent a narrow current path.

[0053]

Figure 3 DETAILED DESCRIPTION OF THE INVENTION is a main part sectional front view showing an S ³ laser is a semiconductor laser device for explaining a form of in practice of this invention.

In the figure, 201: n-type GaAs stepped substrate after growing a GaAs buffer layer 202: n-type GaInP intermediate layer 203: n-type AlGaInP cladding layer (corresponding to the first region layer, high group 5 / group 3) 204: n-type AlGaInP cladding layer (corresponding to a second region layer, ie, a transition region, having a low Group III / III ratio) 205: active layer made of strained MQW 206: p-type AlGaInP cladding layer 207: AlGaInP current block and cladding layer (included in third region layer and have low V / III ratio) 207A: n-type AlGaInP region (main surface or flat surface) 207B: p-type AlGaInP region (slope) 208: p-type AlGaInP cladding layer 209: p-type GaAs contact layer Respectively, 210 the upper growth line located in the first region layer 203, the upper growth line at the second region layer 204 211,
212 is an upper growth line in the third region layer 206, 213 is a lower growth line in the first region layer 203, 214 is a lower growth line in the second region layer 204, 215 is a third region layer 206
Shows the lower growth lines in FIG.

Next, a process of manufacturing the S ³ laser shown in FIG. 3 will be described. All the semiconductor layers on the step substrate 201 are formed by applying the MOVPE method, the growth pressure is 50 [Torr], and the growth efficiency is about 8
00 [μm / mol], the total flow rate is 8 [sim], and the carrier gas is hydrogen.

(1) The principal plane is shifted from the (100) plane to (11)
1) It is turned off by 6 ° in the direction of the A plane, and the Si content is about 4 × 10 ¹⁸ [c
By applying a resist process in lithography technology to an n-type GaAs substrate of about 5 [cm] φ (2 [inch] φ) doped to about m ⁻³ ],
For example, a stripe resist film having a width of 150 [μm] is formed at intervals of 150 [μm].

(2) The n-type GaAs substrate is immersed in a hydrofluoric acid-based solution and etched so that the angle between the main surface and the inclined surface is about 14 °, thereby forming an n-type GaAs stepped substrate 201. In this case, the depth of the mesa is about 0.5 [μ
m], and the plane orientation of the slope is about (411) A plane.

(3) A GaAs buffer layer (not shown) is grown on the step substrate 201 by applying the MOVPE method.

The conditions for the growth in this case are as follows: temperature: 680 ° C. source gas: trimethylgallium (TMGa: Ga)
(CH ₃ ) ₃ ) and arsine (AsH ₃ ) Group V / Group III: 100 Growth rate: 1 [μm / hour] Dopant material: Si ₂ H ₆ n-type carrier concentration: about 5 × 10 ¹⁷ [cm ^-3] ] Layer thickness: 1.5 [μm]

(4) Subsequently, the intermediate layer 202 is grown on the buffer layer. Conditions for the growth in this case are as follows: temperature: 680 [° C.] source gas: triethylgallium (TEGa: Ga
(C ₂ H ₅ ) ₃ ) and trimethylindium (TMI
n: In (CH ₃ ) ₃ ) and phosphine (PH ₃ ) Group V / Group III: 500 Growth rate: 1 [μm / hour] Dopant material: Si ₂ H ₆ n-type carrier concentration: about 1 × 10 ¹⁸ [ cm ^-3 ] Layer thickness: 0.1 [μm]

(5) Subsequently, a cladding layer 203 (first region layer) is grown on the intermediate layer 202. Conditions for growth in this case are as follows: temperature: 680 [° C.] source gas: trimethylaluminum (TMAl: A
l (CH ₃ ) ₃ ) and TEGa and TMIn and PH ₃ group 5 / group ratio: 273 Growth rate: 2.2 [μm / hour] Dopant material: Si ₂ H ₆ n-type carrier concentration: about 5 × 10 ¹⁷ [Cm ^-3 ] Layer thickness: 1.5 [μm] Here, the doping of Si is due to the n
This is because the type impurity concentration is not lower than the n-type impurity concentration of the main surface.

(6) Subsequently, a cladding layer 204 (second region layer) is grown on the cladding layer 203. Conditions for growth in this case are as follows: temperature: 680 [° C.] source gas: trimethylaluminum (TMAl: A
l (CH ₃ ) ₃ ) and TEGa and TMIn and PH ₃ group 5 / group ratio: 110 Growth rate: 2.2 [μm / hour] Dopant material: Si ₂ H ₆ n-type carrier concentration: about 5 × 10 ¹⁷ [Cm ^-3 ] Layer thickness: 0.5 [μm] (0.2 [μm] to 0.3
[Μm] is the best)

According to the actual measurement, the cladding layer 204 was formed on the 6 ° off substrate used here.
When the layer is grown with a layer thickness of about 0.2 [μm] to about 0.3 [μm], the upper growth line 211 and the lower growth line 214 are completely parallel to obtain the best result. It was observed that the parallelism gradually lost when the thickness exceeded the above range.

(7) Subsequently, a strained MQW active layer 205 is grown on the cladding layer 204. Conditions for the growth in this case are as follows: ○ All: Temperature: 680 [° C.] Source gases: TMIn, TEGa, TMAl and PH ₃ ○ Guide layer (Al _0.2 Ga _0.8 As layer) Group V / III ratio: 60 Growth rate: 1 [μm / hour] Layer thickness: 500 [Å] ○ About barrier layer (GaAs layer) Group V / III ratio: 80 Growth rate: 0.8 [μm / hour] Layer thickness: 50 [Å] ○ Well layer (Ga _0.8 In _0.2 As layer) Group V / Group III ratio: 60 Growth rate: 1.2 [μm / hour] Layer thickness: 70 Number of layers: 2

(8) Subsequently, the strained MQW active layer 2
A cladding layer 206 (third region layer) is grown on the substrate 05. Conditions for the growth in this case are as follows: Temperature: 680 [° C.] Source gas: TMAl and TEGa and TMIn and PH ₃ group / group III ratio: 110 Growth rate: 2.2 [μm / hour] Dopant source: diethyl Zinc (DEZn: (C ₂
H _{5) 2} Zn) (Group II / group III ratio of about 0.1) p-type carrier concentration: about 7 × 10 ¹⁷ [cm ^-3] (slope)
About 1.2 × 10 ¹⁷ [cm ^-3 ] (main surface) Layer thickness: 0.35 [μm]

(9) Subsequently, a current block and a cladding layer 207 (supposed to be included in the third region) are grown on the cladding layer 206. Conditions for the growth in this case are as follows: temperature: 680 [° C.] Source gas: TMAl and TEGa and TMIn and PH ₃ group 5 / group 3 ratio: 110 Growth rate: 2.2 [μm / hour] Dopant source: DEZn And H ₂ Se are alternately doped. P-type carrier concentration: about 7 × 10 ¹⁷ [cm ⁻³ ] (slope) n-type carrier concentration: about 6 × 10 ¹⁷ [cm ⁻³ ] (principal surface) Number of cycles: 30 (At a thickness of 50 [Å]) Layer thickness: 0.30 [μm]

In this case, since the p-type impurity diffuses only on the slope and has a uniform carrier concentration, the slope is 1.2 × 1
A p-type doped region of 0 ¹⁸ [cm ^-3 ] penetrates into the n-type region by diffusion and has an average carrier concentration of half.

(10) Subsequently, a cladding layer 208 is grown on the block and cladding layer 207. Conditions for the growth in this case are as follows: temperature: 680 [° C.] Source gas: TMAl and TEGa and TMIn and PH ₃ group 5 / group 3 ratio: 273 Growth rate: 2.2 [μm / hour] Dopant source: DEZn P-type carrier concentration: about 7 × 10 ¹⁷ [cm ^-3 ] (slope)
About 1.2 × 10 ¹⁷ [cm ^-3 ] (main surface) Layer thickness: 1.5 [μm]

(11) Subsequently, a contact layer 209 is grown on the cladding layer 208. Conditions for the growth in this case are as follows: temperature: 680 [° C.] Source gas: TMGa and AsH ₃ group 5 / group 3 ratio: 100 Growth rate: 1 [μm / hour] Dopant source: DEZn p-type carrier concentration: about 2 × 10 ¹⁸ [cm ⁻³ ] (slope) Layer thickness: 1 [μm] (12) After that, it is completed by applying a usual technique.
For example, formation of an element isolation region having a width of 100 [μm], Au
Of n-side electrode made of / Ge / Au, AuZn / Au
Width of 300μ due to formation and cleavage of p-side electrode
m], a chip having a length of 700 [μm], etc., and then bonding the chip to a heat sink with the p-side up.

The present invention is not limited to the above embodiment,
Many other modifications can be realized. For example, although not shown, if the second region layer is used as a part of the p-side cladding layer, it becomes closer to a laser structure of an inverted mesa, so that the resistance is reduced. Is advantageous.

[0071]

According to the semiconductor laser device and the method of manufacturing the same according to the present invention, at least the n-side cladding layer of the manufactured semiconductor laser device has a gentle second surface between the lower side of the first slope and the main surface. A second plane having a slope, wherein the first slope has a first plane orientation angle, and a cladding layer composed of crystals in a crystal growth region having a first plane orientation angle, and the first slope is slower than the first plane orientation angle. It consists of a combination of cladding layers composed of crystals in a crystal growth region having an azimuth angle.

By adopting the above-described structure, the growth is performed by changing the group V / III ratio, or by changing the growth temperature, and between the two region layers acting as the cladding layer in the S ³ laser. It is possible to control the lower growth line and the upper growth line related to the inclined plane to be in a state of being close to or close to each other by using a region layer which is a transition region interposed therebetween, so that the near field pattern can be controlled. This is effective for stabilization, and can prevent a narrow current path.

[Brief description of the drawings]

FIG. 1 is a fragmentary front view showing the structure of a growing semiconductor layer for explaining the principle of the present invention.

FIG. 2 is a diagram showing a change in a slope angle of a slope depending on a group V / group III ratio or a growth temperature.

3 is a main part sectional front view showing an S ³ laser is a semiconductor laser device for explaining the in embodiments of the present invention.

FIG. 4 is a cutaway perspective view of a main part showing a standard red laser for explaining a conventional technique.

[5] The semiconductor laser slope emission type according to our invention, i.e., a main part cut slope diagram representing the S ³ laser.

FIG. 6 is a diagram for explaining plane orientation dependence of impurity doping.

FIG. 7 is a diagram for explaining plane orientation dependence of impurity doping.

FIG. 8 is a diagram for explaining a plane orientation dependency when a p-type impurity and an n-type impurity are simultaneously doped.

FIG. 9 is a cutaway front view of a main part showing in detail a main point of a configuration in which a semiconductor layer is grown on a substrate used for an S ³ laser.

[Explanation of symbols]

Reference Signs List 1 1st region layer grown on semiconductor base with step 2 2nd region layer grown on 1st region layer 3 3rd region layer grown on 2nd region layer 1A Main surface 1B 1st slope 1B ₀ First slope 1C Second slope 4A First upper growth line 4B Second upper growth line 4C Third upper growth line 5A First lower growth line 5B Second lower growth line 5C Third lower growth line having different plane orientations

Claims (4)

[Claims] 1. The (100) plane or the (n11) A plane (7 <
(n n is a real number) a stepped substrate having a main surface exposed and (n ₁ 11) A-plane (2 ≦ n ₁ ≦ 7 n ₁ is a real number) sloped surface formed on the stepped substrate ( 100) face or (n11)
The main surface expressed by the A surface (7 <nn is a real number) and (n ₂
11) An active layer having a first slope exposed on the A side (3 ≦ n ₂ ≦ 7 n ₂ is a real number), and a high carrier concentration in a region along the slope stacked in contact with the active layer and having a high carrier concentration on the main surface. A p-side first cladding layer having a low carrier concentration in a region along the p-side second cladding layer, which is laminated in contact with the p-side first cladding layer and is p-type in a region along the slope and n in a region along the main surface;
A semiconductor laser device comprising the same semiconductor layer comprising a current blocking layer, wherein at least the n-side cladding layer has a gentle second slope between the lower side of the first slope and the main surface, In addition, the first slope has a second plane azimuth angle which is slower than the first plane azimuth angle and the cladding layer composed of the crystal in the crystal growth region having the first plane azimuth angle. A semiconductor laser device comprising a combination of cladding layers made of crystals in a crystal growth region. 2. In at least the n-side cladding layer, the group V / III ratio of the crystal in the crystal growth region having the first plane azimuth angle on the stepped substrate side is the second group on the surface side. 2. The semiconductor laser device according to claim 1, wherein the ratio is higher than the group V / group III ratio in the crystal in the crystal growth region having the plane azimuth angle. 3. A part of the cladding layer near the active layer is a crystal in a crystal growth region having a second plane azimuth angle, and the average of the upper growth line and the average of the lower growth line near the active layer are substantially equal. 3. The semiconductor laser device according to claim 1, wherein the semiconductor laser devices are parallel to each other. 4. The (100) plane or the (n11) A plane (7 <
nn is a real surface) and a (n ₁ 11) A surface (2 ≦ n ₁ ≦ 7 n ₁ is a real number) on a stepped substrate having a sloped surface and a first surface on the stepped substrate side. The second surface which is the front surface side when forming the one conductivity type side clad layer by sequentially growing the crystal of the crystal growth region having the azimuth angle and the crystal of the crystal growth region having the second plane azimuth angle on the front surface side Growing the crystal in a crystal growth region having an azimuth angle at a higher growth temperature, and then forming a (100) plane or a (n11) A plane (7 <nn is a real number) on the one conductivity type side cladding layer. Forming an active layer having a first slope having the exposed main surface and the (n ₂ 11) A surface (3 ≦ n ₂ ≦ 7 n ₂ is a real number); and then forming a slope on the active layer. The first carrier of the opposite conductivity type having a high carrier concentration in the region along the main surface and a low carrier concentration in the region along the main surface. A step of forming a pad layer, then, on the opposite conductive type side first cladding layer, in the region along the slope, the opposite conductive type side second cladding layer, which is the opposite conductive type in the region along the slope, and in the region along the main surface with one conductivity type. Forming a same semiconductor layer comprising a certain current block layer.