JP3468236B2 - Semiconductor laser - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface emitting semiconductor laser which oscillates laser light in a direction perpendicular to a substrate.

[0002]

2. Description of the Related Art As a surface-emitting type semiconductor laser having a resonator in a direction perpendicular to a substrate (hereinafter referred to as "surface-emitting semiconductor laser"), for example, a proceedings of the 50th Japan Society of Applied Physics Academic Lecture Third Volume p. 909 29a-ZG-
7 (published on September 27, 1989) is known.

In such a surface emitting semiconductor laser, the buried layer is composed of a pn junction layer composed of a p-type AlGaAs layer and an n-type AlGaAs layer. This is p-type GaAs
This is to prevent a current from flowing to a portion other than the active layer.

On the other hand, the applicant of the present application has already proposed a surface emitting semiconductor laser in which such a buried layer is formed of only one II-VI group compound semiconductor layer (Japanese Patent Application No. 2-242000). . Such a surface emitting semiconductor laser is
Since the resistance of the buried layer can be increased, sufficient current confinement can be obtained, and it is not necessary to match the interface position with the cylindrical region.

In this surface emitting semiconductor laser, as shown in FIG. 8, first, a (603) n type G substrate is formed on a (602) n type GaAs substrate.
aAs buffer layer, (604) distributed reflection type multilayer mirror,
(605) n-type Al _0.4 Ga _0.6 As clad layer, (606) p
-Type GaAs active layer, (607) p-type Al _0.4 Ga _0.6 As clad layer, and (608) p-type Al _0.1 Ga _0.9 As contact layer are sequentially grown, and then (607) p-type Al _0.4 G
a _0.6 As clad layer and (608) p-type Al _0.1 Ga
_{The 0.9} As contact layer is vertically etched, leaving a columnar region, and (609) Z is formed around the columnar region.
nS _0.06 Se _0.94 was formed and buried, and then (60
8) On the upper surface of the p-type Al _0.1 Ga _0.9 As contact layer, a (611) dielectric multilayer mirror is vapor-deposited on a region slightly smaller than the cylindrical diameter, and finally, (610) p-type ohmic electrode, (601)
It is configured by forming an n-type ohmic electrode.

As described above, the surface-emitting type semiconductor laser differs from the point-end surface-emitting type semiconductor laser in that the contact layer for making contact with the electrode is interposed in the light emitting area.

[0007]

In such a surface emitting semiconductor laser, in order to increase the output, it is desirable that the Al composition ratio of the (608) contact layer be as high as possible. This is because by increasing the Al composition ratio,
(608) This is because light absorption by the contact layer can be reduced.

However, according to the study by the present inventor,
(608) If the Al composition ratio of AlGaAs forming the contact layer is increased, the following problems occur.

If the Al composition ratio is high, it becomes impossible to dope the (608) contact layer with a high concentration. For this reason, the resistance of the (608) contact layer cannot be suppressed to a low level, so that the Joule heat generated at the time of emission increases, which causes a reduction in emission efficiency and a reduction in life.

Since Al is easily oxidized, (608)
The reliability of forming the (610) p-type ohmic electrode on the surface of the contact layer is reduced, and thus the reliability and characteristics of the surface emitting semiconductor laser are reduced.

In the manufacturing process of the above-mentioned surface emitting semiconductor laser, in order to alloy (alloy) the (608) contact layer and the (610) p-type ohmic electrode, a step of heating them is performed. When the composition ratio of is high,
At this time, the heating temperature must be raised. For this reason, atoms are diffused at the crystal interface in the surface-emitting semiconductor laser, which causes deterioration of characteristics and reliability.

In any of these problems, the higher the Al composition ratio of AlGaAs forming the (608) contact layer,
It becomes remarkable.

Therefore, in the surface-emitting semiconductor laser, the composition ratio of Al in the contact layer could not be increased so much that light absorption by the contact layer could not be sufficiently suppressed, and therefore the output intensity could not be increased. There was a limit to improvement.

The present invention solves such a problem, and an object of the present invention is to provide a semiconductor laser which can obtain excellent output intensity, is highly reliable, and has a long life. is there.

[0015]

A surface emitting semiconductor laser according to the present invention comprises a semiconductor substrate, a lower reflecting mirror arranged above the semiconductor substrate, and a lower cladding layer arranged above the lower reflecting mirror. An active layer disposed above the lower clad layer, an upper clad layer disposed above the active layer and having a columnar portion in an upper portion, and a light exit hole disposed above the columnar portion. A contact layer, an upper reflecting mirror disposed above the contact layer, the light emitting hole, and an upper electrode disposed above the contact layer; and a contact layer below the light emitting hole. When the film thickness and x, Ri 0 <x ≦ 0.1μm der, in the columnar portion
Is a plurality of light emitting parts due to the separation groove that does not reach the active layer.
Is formed, the upper reflecting mirror is at least the
It is characterized in that it is formed on the separation groove . In the above surface emitting semiconductor laser, it is preferable that a buried layer is formed around the columnar portion. It is preferable that the embedded layer is made of a material having a higher resistance than that of the material forming the columnar portion.

The periphery of the columnar semiconductor layer is preferably filled with a II-VI group compound semiconductor layer.

Further, it is desirable that the semiconductor contact layer having the light emitting hole is made of GaAs.

[0018]

According to the above structure, since the light emitting hole is provided in the contact layer, a considerable portion of the laser light emitted from the resonator is emitted from the light emitting hole. This allows
Light absorption by the contact layer is sufficiently suppressed. That is, according to the present invention, it is possible to obtain excellent output intensity regardless of the composition of the contact layer, without being influenced by this.

Therefore, when selecting the composition of the contact layer, it is not necessary to consider the light absorptance of the contact layer, so that the degree of freedom in selecting such composition is increased. As a result, in order to suppress the light absorption of the contact layer, the above-mentioned problems such as increase in resistance, easy oxidation, and increase in temperature required for alloying do not occur.

When the periphery of the columnar semiconductor layer is filled with the II-VI group compound semiconductor layer, leakage of the injection current into the high resistance embedded layer does not occur, sufficient current confinement is obtained, and the threshold current is lowered. As a result, continuous oscillation at room temperature becomes possible, and a highly practical surface-emitting type semiconductor laser can be realized in addition to the above-mentioned effect of increasing the optical output.

If the contact layer is made of GaAs (that is, if the contact layer does not contain Al at all), the resistance is very small, it is difficult to oxidize, and the temperature during alloying is very high. A low contact layer can be obtained.

[0022]

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

(Embodiment 1) FIG. 1 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser (100) according to a first embodiment of the present invention, and FIGS. FIG. 5 is a cross-sectional view showing the manufacturing process of the semiconductor laser in the example.

Hereinafter, the semiconductor laser (10
Regarding the structure of (0) and the manufacturing process, FIGS.
Follow the instructions below.

First, on a (102) n-type GaAs substrate,
(103) An n-type GaAs buffer layer is formed, and further 30 pairs of n-type Al _0.7 Ga _0.3 As layer and n-type Al _0.1 Ga _0.9 As layer having a reflectance of 98% or more with respect to light near a wavelength of 870 nm. The (104) distributed reflection type multilayer film mirror is formed. Then, (105) n-type Al _0.4 Ga _0.6 As cladding layer, (106) p-type GaAs active layer, (107) p-type Al
_{A 0.4} Ga _0.6 As clad layer and a (108) p-type GaAs contact layer are sequentially epitaxially grown by MOCVD (FIG. 2A). At this time, in this embodiment, the growth temperature is 700 ° C., the growth pressure is 150 Torr,
The organic metal of TMGa (trimethylgallium) and TMAl (trimethylaluminum) is used as the group III raw material, AsH ₃ is used as the group V raw material, H ₂ Se is used as the n-type dopant, and DEZn (diethyl zinc) is used as the p-type dopant. Are used respectively.

After that, the surface of the surface is subjected to thermal CVD.
(112) A SiO ₂ layer is formed, and further, by a reactive ion beam etching method (hereinafter referred to as “RIBE method”), (113) a columnar light emitting portion covered with a hard bake resist is left, 107) to the middle of the p-type Al _{0. 4} Ga _0.6 As cladding layer are etched (Figure 2 (b)). At this time, in this embodiment, a mixed gas of chlorine and argon is used as the etching gas, and the gas pressure is 1 × 10 5.
^-3 Torr and extraction voltage is 400V. Here, the reason why the (107) p-type Al _0.4 Ga _0.6 As clad layer is only partially etched is that the structure for confining the injected carriers and light in the horizontal direction of the active layer is a rib waveguide type refractive index waveguide. This is to make it a structure.

Next, this (107) p-type Al _0.4 Ga _0.6
A buried layer is formed on the As clad layer. Therefore, in this embodiment, first, (113) the resist is removed,
Next, by (MBE) method or MOCVD method, etc., (109) Z
nS _0.06 Se _0.94 layer is embedded and grown (Fig. 2
(C)).

Thereafter, a (112) SiO ₂ layer and a (108)
Etching is performed on the p-type GaAs contact layer, leaving only a portion in contact with the vicinity of the outer peripheral portion of the above-described cylindrical light emitting portion (FIG. 2D). As a result, a (108) p-type GaAs contact layer having a (114) light emitting hole in the center is formed.

Further, the (112) SiO ₂ layer is removed, and then four pairs of (111) SiO ₂ / α-Si dielectric multilayers are formed inside the (114) light emitting hole and on the surface of the (108) contact layer. The film mirror is formed by electron beam evaporation, and is removed by dry etching using a reactive ion etching method (hereinafter referred to as "RIE method"), leaving a region slightly smaller than the diameter of the light emitting portion (FIG. 2 (e)). ). The reflectance of this dielectric multilayer mirror at a wavelength of 870 nm is 94%.

Thereafter, a (110) p-type ohmic electrode is vapor-deposited on the surface other than the (111) dielectric multilayer mirror, and
A (101) n-type ohmic electrode is deposited on the (102) n-type GaAs substrate side (FIG. 2 (f)). And finally, alloying at 400 ° C. is performed in an N ₂ atmosphere.

Through the above steps, as shown in FIG.
A (100) surface emitting semiconductor laser having a rib waveguide structure can be obtained.

In the surface-emitting semiconductor laser of this example prepared in this manner, the laser light was provided not in the (108) p-type GaAs contact layer but in the (108) p-type GaAs contact layer. The light is output after passing through the light exit hole. Therefore, the laser light is not attenuated by the absorption of the (108) p-type GaAs contact layer,
An extremely high external differential quantum efficiency could be obtained.

Further, since this contact layer is made of GaAs, it is possible to dope at a high concentration, so that a contact layer having a high carrier concentration and a high mobility can be obtained. Further, by this, the resistance of the contact layer can be reduced, so that the generation of Joule heat can be suppressed, and in turn, the heat dissipation of the (106) p-type GaAs active layer can be facilitated. Therefore, the (100) surface-emitting semiconductor laser of this example has an ambient temperature of 70
It became possible to perform DC continuous oscillation up to ℃.

Further, since the contact layer is made of GaAs, the temperature during alloying can be lowered. This makes it possible to suppress the diffusion of atoms at the crystal interface in the element of the surface emitting semiconductor laser, which is very effective in improving the characteristics and reliability of the surface emitting semiconductor laser.

(Embodiment 2) FIG. 3 shows a semiconductor laser (20) according to a second embodiment of the present invention.
FIG. 4A is a perspective view showing a cross section of the light emitting part of FIG.
(F) is a sectional view showing a manufacturing process of the semiconductor laser (200) in the embodiment.

The semiconductor laser (200) of this embodiment is (208)
This is different from Example 1 in that the p-type Al _0.1 Ga _0.9 As contact layer to a part of the (205) n-type Al _0.4 Ga _0.6 As clad layer are formed in a columnar shape.

The structure and manufacturing process of this embodiment will be described below with reference to FIGS.

First, on a (202) n-type GaAs substrate,
(203) An n-type GaAs buffer layer is formed, which is further composed of an n-type AlAs layer and an n-type Al _0.1 Ga _0.9 As layer and has a reflectance of 98% or more for light near a wavelength of 870 nm.
0 pairs of (204) distributed reflection type multilayer mirrors are formed. Then, (205) n-type Al _0.4 Ga _0.6 As clad layer,
(206) p-type GaAs active layer, (207) p-type Al _0.4 Ga _0.6
The As clad layer and the (208) p-type GaAs contact layer are sequentially epitaxially grown by MOCVD (FIG. 4A). In this example, the growth temperature at this time was 700 ° C., the growth pressure was 150 Torr, and TMGa (trimethylgallium) and TMAl (trimethylaluminum) organometals were used as Group III raw materials.
AsH ₃ is used as the group V raw material, H ₂ Se is used as the n-type dopant, and DEZn (diethyl zinc) is used as the p-type dopant.

After that, the surface of the surface is subjected to thermal CVD.
(212) SiO ₂ is formed, and further, by the RIBE method,
Etching is performed up to the middle of the (205) n-type Al _0.4 Ga _0.6 As clad layer, leaving the columnar light emitting portion covered with the (213) hard bake resist (FIG. 4B). At this time, in this embodiment, a mixed gas of chlorine and argon is used as the etching gas, the gas pressure is set to 1 × 10 ⁻³ Torr, and the extraction voltage is set to 400V.

Next, a buried layer is formed on this etching region. Therefore, in this embodiment, first, (21
3) Remove the resist, then MBE or MOCV
A (209) ZnS _0.06 Se _0.94 layer is embedded and grown by the D method or the like (FIG. 4C).

Then, a (212) SiO ₂ layer and a (208)
Etching is performed on the p-type GaAs contact layer, leaving only a portion in contact with the vicinity of the outer peripheral portion of the cylindrical light emitting portion (FIG. 4D). As a result, a (108) p-type GaAs contact layer having a (214) emission hole in the center is formed.

Further, (212) SiO₂ Remove layers and continue
And 4 pairs of (211) SiO on the surface ₂ / Α-Si dielectric
A multilayer film mirror is formed by electron beam vapor deposition, and the RIE method is used.
Slightly smaller than the diameter of the light emitting part by dry etching using
The remaining area is removed (FIG. 4 (e)). Dielectric multilayer film
The reflectance of the mirror at a wavelength of 870 nm is 94%.
It

Then, a (210) p-type ohmic electrode is vapor-deposited on the surface other than the (211) dielectric multilayer mirror, and a (201) n-type ohmic electrode is vapor-deposited on the (202) n-type GaAs substrate side. (FIG.4 (f)). And finally, N ₂
Alloying at 400 ° C. is performed in the atmosphere.

Through the above steps, as shown in FIG.
A (200) surface emitting semiconductor laser having a buried structure can be obtained.

(200) of this embodiment created in this way
Also in the surface emitting semiconductor laser, as in the case of the above-described Example 1, it has an extremely high external differential quantum efficiency and has a very low resistance, so that the (106) p-type GaAs active layer can easily dissipate heat,
Moreover, it was possible to obtain a contact layer having a very low temperature during alloying.

(Embodiment 3) FIG. 5 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser (300) according to a third embodiment of the present invention, and FIG. 6 is a conceptual view of the semiconductor laser (300). It is a top view. Further, FIGS. 7A to 7G are cross-sectional views showing the manufacturing process of the semiconductor laser (300) in this embodiment.

The semiconductor laser (300) of this embodiment is (307)
The p-type Al _0.5 Ga _0.5 As clad layer is different from the above-described first and second embodiments in that a plurality of columnar portions separated from each other by the separation groove are formed.

The structure and manufacturing process of this embodiment will be described below with reference to FIGS.

First, on a (302) n-type GaAs substrate,
(303) An n-type GaAs buffer layer is formed, which is further composed of an n-type Al _0.9 Ga _0.1 As layer and an n-type Al _0.2 Ga _0.8 As layer, and 98% or more reflection of light of ± 30 nm centered at a wavelength of 780 nm Form 25 pairs of (304) semiconductor multilayer mirrors with index. Then, (305) n-type Al _0.5 G
a _0.5 As clad layer, (306) p-type Al _0.13 Ga _0.87 A
The s active layer, (307) p-type Al _0.5 Ga _0.5 As clad layer, and (308) p-type GaAs contact layer are sequentially formed by MOC.
Epitaxial growth is performed by the VD method (FIG. 7A). In this embodiment, the growth condition at this time is that the growth temperature is 720.
C., the growth pressure is set to 150 Torr, and TMGa (trimethylgallium) and T are used as group III raw materials.
The organic metal of MAl (trimethylaluminum) is AsH ₃ as a group V source, H ₂ Se as an n-type dopant, and p.
DEZn (diethyl zinc) is used as the type dopant.

Next, the surface of the surface (31
2) SiO₂ Layer and then photoresist
Apply and bake at high temperature (313) Hard Bake Regis
Form Furthermore, on this hard bake resist
Then, by EB vapor deposition method, SiO ₂ Form the layers.

Next, each layer formed on the substrate is etched by the RIE method as follows.

First, (313) the SiO ₂ layer formed on the hard bake resist is subjected to a photolithography process usually used to form a required resist pattern, and this pattern is used as a mask to form Si by RIE.
Etch the O ₂ layer. This etching, for example,
Using CF ₄ gas, gas pressure is 4.5Pa, input is RF
It can be performed by controlling the power of 150 W and the temperature of the sample holder at 20 ° C.

Next, using this SiO ₂ layer as a mask, R
The (313) hard bake resist is etched by the IE method. This etching can be performed, for example, by using O ₂ gas to control the gas pressure at 4.5 Pa, the input power at 150 W, and the sample holder temperature at 20 ° C. At this time, the resist pattern initially formed on the SiO ₂ layer is also etched.

Next, in order to simultaneously etch the pattern-remaining SiO ₂ layer and the (312) SiO ₂ layer formed on the epitaxial layer, etching is performed again using CF ₄ gas.

As described above, using the thin SiO ₂ layer as a mask, the RIE method, which is one of the dry etching methods, is used.
3) By using a hard bake resist, it is possible to form a (313) hard bake resist which has a required pattern shape and also has a side surface perpendicular to the substrate (FIG. 7 (b)).

Then, holding this vertical side (313)
Using the hard bake resist as a mask, RIBE is used to leave the columnar light emitting portion, and (307) p-type Al _0.5 Ga
Etching is performed halfway through the _0.5 As clad layer (Fig. 7).
(C)). At this time, in this embodiment, a mixed gas of chlorine and argon is used as the etching gas, and the gas pressure is 5 × 1.
The temperature of the sample holder is kept at 20 ° C. at 0 ⁻⁴ Torr, the plasma extraction voltage is 400 V, the ion current density on the etched sample is 400 μA / cm ² .

Here, (307) p-type Al _0.5 Ga _0.5 As
Only the middle of the clad layer is etched because the injected carriers and light confinement in the horizontal direction of the active layer is made into a refractive index waveguide type rib waveguide structure so that a part of the light in the active layer becomes horizontal. This is to enable transmission in the direction.

Further, the resist has a vertical side surface.
(313) By using a hard bake resist, and further by using the RIBE method of performing etching by irradiating ions in a beam shape perpendicularly to an etching sample as an etching method, the (320) light-emitting portions adjacent to each other are It is possible to separate with a (315) separation groove perpendicular to the substrate, and it is possible to fabricate a vertical optical resonator required for improving the characteristics of a surface emitting semiconductor laser.

Next, this (307) p-type Al _0.4 Ga _0.6
A buried layer is formed on the As clad layer. Therefore, in this embodiment, first, the (313) resist is removed,
Next, by (MB) method or MOCVD method, etc., (309) Z
The nS _0.06 Se _0.94 layer is embedded and grown (FIG. 7).
(D)).

Then, (312) SiO ₂ layer and (308)
Etching is performed on the p-type GaAs contact layer, leaving only a portion in contact with the vicinity of the outer peripheral portion of the above-described cylindrical light emitting portion (FIG. 7E). As a result, a (108) p-type GaAs contact layer having a (314) light emitting hole in the center is formed.

Further, (312) SiO₂ Remove layers and continue
And 4 pairs of (311) SiO on the surface ₂ / Α-Si dielectric
A multilayer film mirror is formed by electron beam vapor deposition, and the RIE method is used.
Slightly smaller than the diameter of the light emitting part by dry etching using
The remaining area is removed (FIG. 7 (f)). Dielectric multilayer film
The reflectance of the mirror at a wavelength of 780 nm is 94%.
It

Here, in the (300) semiconductor laser of this example, since the (311) dielectric multilayer mirror was formed also on the (315) isolation groove filled with ZnS _0.06 Se _0.94 , the light emitting portion was formed. A vertical cavity structure is also formed in the sandwiched region. Therefore, the light trapped in the (315) separation groove also contributes to laser oscillation effectively, and the leaked light is used (320).
The light emission is synchronized with the phase of the light emitting unit.

Thereafter, (311) a (310) p-type ohmic electrode is vapor-deposited on the surface other than the dielectric multilayer mirror, and a (301) n-type ohmic electrode is vapor-deposited on the (302) n-type GaAs substrate side. (FIG.7 (g)). Here, (31
The 0) p-type ohmic electrode is formed so as to be electrically connected to each (308) contact layer of each (320) light emitting portion. And finally, alloying is performed at 400 ° C. in an N ₂ atmosphere.

Through the above steps, the (300) surface emitting semiconductor laser as shown in FIGS. 5 and 6 can be obtained.

(300) of this embodiment created in this way
Also in the surface emitting semiconductor laser, as in the above-described first and second embodiments, the external differential quantum efficiency is extremely high, and the resistance is very small, so that the heat dissipation of the (306) p-type GaAs active layer is easy, and It was possible to obtain a contact layer with a very low temperature during alloying.

In each of the embodiments described above, (10
8), (208), (308) The light emitting hole of the p-type GaAs contact layer was made a complete cavity (that is, the p-type GaA was used in the light emitting hole).
Although the s layer is completely removed), the same effect can be obtained by making the film thickness of the portion corresponding to the light emitting hole extremely thin. In this case, according to the study by the present inventor, in order to obtain a sufficient effect, it is desirable that the film thickness of the portion corresponding to the light emitting hole is 0.1 μm or less. In the present application, not only in the case of forming a complete cavity in the contact layer as shown in each of the above-described embodiments, but also in a region formed in a part of the contact layer and having a thinner film thickness than other regions. , "Light emission hole".

Further, the shape of the light exit hole is not limited to that shown in FIG.

In each of the above embodiments, (108), (20
8) and (308) contact layers were formed of GaAs and alloyed at 400 ° C., but by forming such contact layers of other metals and selecting appropriate conditions,
It is also possible to lower the temperature during alloying.

[0069]

As described in detail above, according to the semiconductor laser of the present invention, the laser light is output not through the contact layer but through the light emission hole provided in the contact layer. Therefore, the laser light is not attenuated by the absorption of this contact layer, and therefore an extremely high external differential quantum efficiency can be obtained.

Further, when this contact layer is made of GaAs, it is possible to dope at a high concentration, so that the resistance of the contact layer can be reduced, and therefore, the generation of Joule heat can be suppressed. Therefore, the emission efficiency and life can be improved.

When the periphery of the columnar semiconductor layer is filled with a II-VI group compound semiconductor layer, the threshold current can be lowered by the buried layer having high resistance, so that continuous oscillation at room temperature can be achieved and light absorption in the contact layer can be reduced. In addition, it is possible to realize a highly practical surface emitting semiconductor laser.

Further, when the contact layer is made of GaAs, the temperature at the time of alloying can be lowered, so that the diffusion of atoms at the crystal interface in the element of the semiconductor laser can be suppressed and the surface emission. It is very effective in improving the characteristics and reliability of the semiconductor laser.

As described above, according to the present invention, an excellent output intensity can be obtained, and a highly reliable semiconductor laser having a long life can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser according to a first embodiment.

2A to 2F are cross-sectional views showing a manufacturing process of the semiconductor laser according to the first embodiment.

FIG. 3 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser according to a second embodiment.

FIGS. 4A to 4F are cross-sectional views showing a manufacturing process of a semiconductor laser according to a second embodiment.

FIG. 5 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser according to a third embodiment.

FIG. 6 is a conceptual diagram showing an upper surface of a light emitting portion of a semiconductor laser according to a third embodiment.

7A to 7G are cross-sectional views showing a manufacturing process of a semiconductor laser according to a third embodiment.

FIG. 8 is a perspective view showing a cross section of an example of a light emitting portion of a conventional semiconductor laser.

[Explanation of symbols]

101, 201, 301 n-type ohmic electrodes 102, 202, 302 n-type GaAs substrates 103, 203, 303 n-type GaAs buffer layers 104, 204, 304 distributed reflection multilayer mirrors 105, 205, 305 n-type Al _0.4 Ga _0.6 As
Cladding layer 106, 206, 306 p-type GaAs
Active layer 107, 207, 307 p-type Al _0.4 Ga _0.6 As
Cladding layers 108, 208, 308 p-type GaAs
Contact layers 109, 209, 309 ZnS _0.06 Se _0.94 layers (buried layers) 110, 210, 310 p-type ohmic electrodes 111, 211, 311 SiO ₂ / α-Si dielectric multilayer mirrors 112, 212, 312 SiO ₂ layers 114 , 214, 314 Light exit hole

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-46788 (JP, A) JP-A-1-264285 (JP, A) JP-A-1-289291 (JP, A) JP-A-1- 236671 (JP, A) JP 2-177490 (JP, A) JP 4-340288 (JP, A) JP 64-44083 (JP, A) JP 64-66988 (JP, A) JP-A-64-50431 (JP, A) JP-A-63-7692 (JP, A) JP-A-63-188983 (JP, A) JP-A-60-81888 (JP, A) JP-A-56-36186 (JP, A) Proceedings of the 37th Spring Meeting of the Japan Society for Applied Physics, 1990, 3rd volume 29a-SA-11,933 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01S 5 / 00-5/50

Claims (4)

(57) [Claims] 1. A semiconductor substrate, A lower reflecting mirror arranged above the semiconductor substrate, A lower clad layer disposed above the lower reflector, An active layer disposed above the lower cladding layer, Above the active layer and having a columnar portion on the top
Part clad layer, A contour having a light emitting hole arranged above the columnar portion.
Layer, Located above the contact layer and above the light exit hole.
Upper reflector, An upper electrode disposed above the contact layer,
See When the film thickness of the contact layer below the light emitting hole is x,
0 <x ≦ 0.1 μm, In the columnar portion, due to the separation groove that does not reach the active layer,
A plurality of light emitting parts are formed, The upper reflecting mirror is formed at least on the separation groove.
Has been A surface emitting semiconductor laser characterized by the above. 2. The surface-emitting type semiconductor laser according to claim 1, wherein a buried layer is formed around the columnar portion. 3. The surface-emitting type semiconductor laser according to claim 2 , wherein the buried layer is made of a material having a higher resistance than a material forming the columnar portion. laser. 4. The surface-emitting type semiconductor laser according to claim 3 , wherein the high resistance material is a II-VI group compound semiconductor.