JP3666444B2 - Surface emitting semiconductor laser and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface emitting semiconductor laser that oscillates laser light in a direction perpendicular to a substrate and a method for manufacturing the same.
[0002]
[Background]
In Japanese Patent Application No. 2-242000, the present applicant has proposed a surface emitting semiconductor laser in which an optical resonator is embedded with a II-VI group compound semiconductor.
[0003]
In this surface-emitting type semiconductor laser, as shown in FIG. 13, first, a (702) n-type GaAs substrate has a (703) n-type GaAs buffer layer, (704) a distributed reflection type multilayer mirror, and (705) n. Type Al_0.4Ga_0.6As cladding layer, (706) p-type GaAs active layer, (707) p-type Al_0.4Ga_0.6As cladding layer and (708) p-type Al_0.1Ga_0.9As contact layers are grown sequentially, then (707) p-type Al_0.4Ga_0.6As cladding layer and (708) p-type Al_0.1Ga_0.9The As contact layer is etched vertically leaving a cylindrical region, and (709) ZnS is formed around the cylindrical region._0.06Se_0.94Then, (708) p-type Al is formed._0.1Ga_0.9Constructed by depositing a (711) dielectric multilayer mirror in a region slightly smaller than the cylindrical diameter on the upper surface of the As contact layer, and finally forming a (710) p-type ohmic electrode and (701) an n-type ohmic electrode. Has been. (709) ZnS used for buried layer_0.06Se_0.94Since the layer has a high resistance and a low refractive index, current and light are efficiently confined, resulting in a high-performance surface-emitting semiconductor laser.
[0004]
[Problems to be solved by the invention]
In this prior art, as shown in FIG. 13, a p-type ohmic electrode for injecting current into the active layer is formed on the optical resonator in a ring shape. It has been found that the presence of the ring-shaped (710) p-type ohmic electrode causes the following two problems.
[0005]
First, the reflectance of the (710) p-type ohmic electrode is smaller than the reflectance of the (711) dielectric multilayer mirror on the light emitting side. Therefore, there occurs a situation in which the efficiency of multiple reflection of light is reduced inside the optical resonator under the (710) p-type ohmic electrode. And to solve this situation, (708) p-type Al_{0. 1}Ga_0.9It is necessary to reduce the area of the contact portion between the As contact layer and the (710) p-type ohmic electrode. However, if the contact area of this part is reduced, this time, due to poor contact, etc., (710) p-type ohmic electrode and (708) p-type Al_0.1Ga_0.9The contact resistance with the As contact layer becomes extremely high, and the heat generated by this portion of resistance becomes extremely large. As a result, the supplied power is consumed in this portion, and new problems such as a decrease in efficiency in the optical resonator and a further improvement in the input current vs. optical output characteristics occur. Further, such heat generation is not preferable in terms of reliability.
[0006]
Next, due to the presence of the ring-shaped (710) p-type electrode, there also arises a problem that efficiency is lowered due to generation of a plurality of standing waves as shown in FIG.
[0007]
Usually, a surface emitting semiconductor laser has a small optical resonator length, and therefore can only produce a standing wave of one wavelength. Therefore, the wavelength of the standing wave in the optical resonator needs to be uniform in order for all the element volumes to function effectively as a laser resonator.
[0008]
However, as shown in FIG. 14 (a), the boundary conditions of light differ between (10) the interface between the dielectric and (14) the semiconductor, and (12) the interface between the metal and (14) the semiconductor. This is due to the difference in the phase shift of the reflected light at the boundary surface. When light traveling through a semiconductor is reflected at a dielectric interface with a low refractive index, the phase of the reflected wave at the interface is the same as the phase of the incident wave, so the antinode of the standing wave is formed at the interface It will be. On the other hand, when the light is reflected at the metal interface, the phase of the reflected wave changes (a value between 0 and π), so that it appears that light is reflected in the metal in a pseudo manner (virtual reflection surface). As a result, the antinodes of standing waves cannot be formed at the boundary surface.
[0009]
Therefore, in the structure using the ring-shaped (710) p-type ohmic electrode as in the surface emitting semiconductor laser shown in FIG. 14B, the standing wave generated under the electrode and the (711) dielectric multilayer mirror The standing wave generated below the state is different, so the resonance wavelengths do not match. Therefore, the portion under the ring-shaped (710) p-type ohmic electrode in the volume of the resonator does not serve as a laser resonator as shown in FIG. This generates a large reactive current and also serves as a heat source, causing an increase in threshold current, a decrease in efficiency in the optical resonator, and a deterioration in temperature characteristics.
[0010]
The present invention solves such problems, and an object of the present invention is to provide a highly efficient and highly reliable surface emitting semiconductor laser and a manufacturing method capable of manufacturing the same by a simple process. .
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a surface emitting semiconductor laser that emits light in a direction perpendicular to a substrate.
An optical resonator having a pair of reflecting mirrors and a plurality of semiconductor layers therebetween, wherein at least one of the semiconductor layers is formed in one or more columnar shapes;
An II-VI compound semiconductor epitaxial layer embedded around the columnar semiconductor layer,
Of the reflection mirrors, the light-emitting side reflection mirror includes a first layer made of a III-V group compound semiconductor, and a second layer made of a group III-V compound semiconductor having a refractive index different from that of the first layer. Are stacked alternately to form a metal electrode having a light exit port on the second layer, and a third layer made of a dielectric on the light exit port, and a refractive index of the third layer and the third layer. It is a composite multilayer film reflecting mirror constituted by alternately laminating fourth layers made of different dielectrics.
[0012]
The present invention also relates to a method of manufacturing a surface emitting semiconductor laser that emits light in a direction perpendicular to the substrate.
Forming a pair of reflecting mirrors constituting an optical resonator and at least one semiconductor layer between them on a substrate made of a semiconductor or a dielectric by metal organic chemical vapor deposition or molecular beam epitaxy;
Forming a photoresist mask on the semiconductor layer and etching at least one of the semiconductor layers using the photoresist mask to form one or more pillars;
Forming a buried layer by epitaxially growing a II-VI group compound semiconductor around the columnar semiconductor layer, and
The light emitting side reflection mirror of the reflection mirrors includes a first layer made of a III-V group compound semiconductor continuously from the substrate, and a group III-V compound semiconductor having a refractive index different from that of the first layer. After alternately laminating and growing the second layers, a metal electrode having a light exit opening is formed on the second layer, a third layer made of a dielectric is formed on the light exit opening, and the second layer 3 layers and fourth layers made of dielectrics having different refractive indexes are alternately stacked.
[0013]
In this case, the II-VI group compound semiconductor epitaxial layer is formed by metalorganic chemical vapor deposition using an adduct composed of a group II organic compound and a group VI organic compound and a group VI hydrogen compound as raw materials. It is desirable.
[0014]
The present invention also relates to a surface emitting semiconductor laser that emits light in a direction perpendicular to the substrate.
An optical resonator having a pair of reflecting mirrors and a plurality of semiconductor layers therebetween, wherein at least one of the semiconductor layers is formed in one or more columnar shapes;
A II-VI group compound semiconductor epitaxial layer embedded around the columnar semiconductor layer;
A metal electrode formed on the semiconductor layer and having a light exit;
Including at least a phase shift layer provided in the light exit port,
The material of the phase shift layer is a material having a small absorption coefficient with respect to the oscillation frequency and a refractive index substantially equal to that of the semiconductor layer in contact with the boundary with the phase shift layer.
[0015]
The present invention also relates to a surface emitting semiconductor laser that emits light in a direction perpendicular to the substrate.
An optical resonator having a pair of reflecting mirrors and a plurality of semiconductor layers therebetween, wherein at least one of the semiconductor layers is formed in one or more columnar shapes;
A II-VI group compound semiconductor epitaxial layer embedded around the columnar semiconductor layer;
A metal electrode formed on the semiconductor layer and having a light exit;
Including at least a phase shift layer provided in the light exit port,
The thickness of the phase shift layer is set such that the wavelength of the standing wave generated under the light exit port is substantially equal to the wavelength of the standing wave generated under the metal electrode. Features.
[0016]
In this case, it is preferable that the material of the phase shift layer is a dielectric material capable of continuously forming a reflection mirror on the light emitting side made of a dielectric material on the phase shift layer.
[0017]
Further, the material of the phase shift layer may be the same material as the semiconductor layer that can be formed by continuously re-growing the semiconductor layer.
[0018]
In addition, the material of the phase shift layer may be an organic material that can be applied and formed at least in the light exit port of the surface of the optical resonator.
[0019]
[Action]
According to the surface-emitting type semiconductor laser of the present invention, the reflection mirror on the light emitting side is composed of the semiconductor multilayer film having the same size as the optical resonator diameter, the metal electrode, and the dielectric multilayer film mirror covering the light emitting port. This makes it possible to increase the reflectivity of the optical resonator under the electrode because the semiconductor multilayer mirror exists under the electrode, and this does not reduce the efficiency in the optical resonator. Type semiconductor laser can be provided.
[0020]
Further, in the manufacturing method according to the present invention, the semiconductor multilayer mirror among the reflecting mirrors on the light emitting side can continuously grow crystals from the substrate together with the active layer constituting the optical resonator. This is a manufacturing method that is extremely simple to manufacture, and that can implement the above-described surface-emitting semiconductor laser in a very stable and reproducible manner.
[0021]
Further, according to the surface emitting semiconductor laser according to the present invention, the phase shift layer is provided in the light emitting port of the metal electrode, and thereby, the standing generated under the metal electrode and under the light emitting port. Wave wavelengths can be made approximately equal. Therefore, the standing wave generated in the optical resonator can be made uniform, and all regions in the optical resonator can function as an effective laser resonator, so that a highly efficient surface emitting semiconductor laser is provided. can do.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0023]
(1) Examples 1 to 3
Examples 1 to 3 are examples in which the reflection mirror on the light output side is configured by a semiconductor multilayer film, a metal electrode, and a dielectric multilayer film mirror that covers the light output port. In these embodiments, since the distributed reflection type multilayer mirror is disposed under the p-type ohmic electrode, it becomes possible to increase the reflectance of the optical resonator under the electrode, and a highly efficient surface emitting semiconductor. A laser can be provided.
[0024]
(A) Example 1
FIG. 1 is a perspective view showing a cross section of a light emitting portion of a (100) semiconductor laser in the first embodiment of the present invention, and FIGS. 2A to 2F are semiconductor laser manufacturing steps in the embodiment. FIG.
[0025]
Hereinafter, the configuration and manufacturing process of the (100) semiconductor laser according to the present embodiment will be described with reference to FIGS.
[0026]
(1) First, a (103) n-type GaAs buffer layer is formed on a (102) n-type GaAs substrate._0.7Ga_0.3As layer and n-type Al_0.1Ga_0.930 pairs of (104) distributed reflection type multilayer mirrors which are composed of As layers and have a reflectance of 98% or more with respect to light having a wavelength of about 870 nm are formed.
[0027]
Subsequently, (105) n-type Al_0.4Ga_0.6As cladding layer, (106) p-type GaAs active layer, (107) p-type Al_0.4Ga_0.6As clad layer and p-type Al_0.7Ga_0.3As layer and p-type Al_0.1Ga_0.95 pairs of (114) distributed reflection type multilayer mirrors and (108) p-type Al having a reflectance of 75% or more with respect to light having a wavelength of about 870 nm and comprising an As layer._0.1Ga_0.9The As contact layer is sequentially epitaxially grown by MOCVD (FIG. 2A). At this time, in this example, the growth temperature is set to 700 ° C., the growth pressure is set to 150 Torr, the organic metals of TMGa (trimethylgallium) and TMAI (trimethylaluminum) are used as the group III material, and AsH is used as the group V material._ThreeAs an n-type dopant₂Se and DEZn (diethyl zinc) are used as p-type dopants, respectively.
[0028]
(2) After the above epitaxial growth, (112) SiO 2 is formed on the surface by thermal CVD.₂Then, a reactive ion beam etching method (hereinafter referred to as “RIBE method”) is used to leave (113) a columnar light-emitting portion covered with a resist, and (107) p-type Al._0.4Ga_0.6Etching is performed halfway through the As cladding layer (FIG. 2 (b)) In this example, a mixed gas of chlorine and argon is used as the etching gas, and the gas pressure is 1 × 10.^-3Torr, and the extraction voltage is 400V. Where (107) p-type Al_0.4Ga_0.6The reason for etching only halfway through the As clad layer is that the structure for confining injected carriers and light in the horizontal direction of the active layer is a rib waveguide type refractive index waveguide structure.
[0029]
(3) Next, this (107) p-type Al_0.4Ga_0.6A buried layer is formed on the As cladding layer. Therefore, in this embodiment, first, (113) the resist is removed, and then the MBE region is formed by (109) ZnS by MOCVD method or the like._0.06Se_0.94A layer is embedded and grown (FIG. 2C).
[0030]
For example, an adduct of DMZn-DMSe (an adduct of dimethyl zinc and dimethyl selenium) and H₂Embedded growth was performed by MOCVD using Se (hydrogen selenide) as a raw material at a growth temperature of 275 ° C. and a growth pressure of 70 Torr.
[0031]
(4) Furthermore, (112) SiO₂Subsequently, the layer is removed, and (108) a region slightly smaller than the diameter of the light emitting portion is formed on the surface of the contact layer (113) with a resist (FIG. 2D).
[0032]
(5) Thereafter, a (110) p-type ohmic electrode is vapor-deposited on this surface, and an emission port is opened on the surface of the light emitting portion by using a lift-off method (FIG. 2 (e)).
[0033]
{Circle around (6)} After that, two pairs of (111) SiO so as to cover the light emitting part without the (110) p-type ohmic electrode₂A / a-Si dielectric multilayer mirror is formed by electron beam evaporation, and a (101) n-type ohmic electrode is evaporated on the (102) n-type GaAs substrate side (FIG. 2 (f)). And finally, N₂Alloying is performed at 400 ° C. in an atmosphere.
[0034]
The (100) surface-emitting type semiconductor laser of this example produced in this way is the ZnS used for embedding._0.06Se_0.94Since the layer has a resistance of IGΩ or more and (109) leakage of the injection current into the buried layer does not occur, extremely effective current confinement is achieved. Further, since the (109) buried layer does not need to have a multilayer structure, it can be easily grown, and the reproducibility between batches is high.
[0035]
Since this surface emitting semiconductor laser has a rib waveguide structure, ZnS_0.06Se_0.94The refractive index difference between the active layer below the active layer and the active layer in the resonator portion is increased, and effective optical confinement is achieved at the same time.
[0036]
Further, the II-VI group compound semiconductor as the buried layer is made of an adduct composed of a group II organic compound and a group VI organic compound and a group VI hydride as a raw material, so that the buried layer can be buried at a much lower temperature than before. A layer can be formed. Therefore, it is possible to prevent the crystallinity of each layer forming the resonator from being deteriorated by heat when forming the buried layer, and at the same time, a buried layer having excellent crystallinity and sufficient uniformity can be obtained. When the MOCVD method is performed by a general method using a Group II material and a Group VI material, the temperature at which the buried layer is formed becomes very high (600 ° C. or higher). For this reason, the heat at this time causes dislocations and defects in each layer forming the resonator to deteriorate the crystallinity, interdiffusion occurs at the interface between each of these layers and the buried layer, and There were several problems such as poor crystallinity of the layer itself and inability to obtain sufficient uniformity. However, by using the adduct and the Group VI hydride, the temperature in MOCVD can be lowered to 500 ° C. or lower, preferably 300 ° C. or lower, and these problems can be solved.
[0037]
In this embodiment, as shown in FIG. 2 (f), the reflection mirror on the light emitting side is a (114) distributed reflection type multilayer mirror comprising a semiconductor multilayer film mirror under a (110) p-type ohmic electrode. Is arranged. Therefore, the reflectance of the optical resonator under the electrode can be increased, and a highly efficient surface emitting semiconductor laser can be provided. As a result, the contact area between the (110) p-type ohmic electrode and the semiconductor layer can be increased, and the resistance at this portion can be reduced. As a result, the generation of heat at this portion can be suppressed, and the semiconductor laser can be made highly efficient and reliable.
[0038]
In the manufacturing method according to the present embodiment, among the reflecting mirrors on the light emitting side, the (114) distributed reflection type multilayer mirror is continuously grown from the substrate together with the active layer constituting the optical resonator. Is possible. Accordingly, the surface-emitting type semiconductor laser can be provided with extremely simple fabrication, very stably and with good reproducibility, and reliability, yield, and the like can be improved.
[0039]
In this embodiment, the reflectance of the reflection mirror on the light emitting portion is such that the (114) distributed reflection type multilayer mirror made of a semiconductor multilayer mirror and the (111) dielectric multilayer mirror are combined, resulting in an oscillation wavelength of 870 nm. 96% or more.
[0040]
Further, when the reflection mirror on the exit side is composed of a (114) distributed reflection type multilayer mirror composed of a semiconductor multilayer mirror and a (111) dielectric multilayer mirror, it is 96% or more when all of the semiconductor multilayer mirrors are used. In order to obtain a reflectance of 40 or more, it is necessary to form 40 or more semiconductor layers with good control, and the electrical resistance in the vertical direction of the 40 or more semiconductor layers becomes very large, and the element of the surface emitting semiconductor laser itself This is because the problem of increasing the resistance has occurred.
[0041]
(B) Example 2
FIG. 3 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser (200) in a second embodiment of the present invention, and FIGS. 4 (a) to 4 (f) are semiconductor lasers (200) in the embodiment. It is sectional drawing which shows this manufacturing process.
[0042]
In the semiconductor laser (200) of this example, the light emitting part is (208) p-type Al._0.1Ga_0.9From the As contact layer, (205) n-type Al_0.4Ga_0.6It differs from Example 1 described above in that a part of the As cladding layer is formed in a columnar shape.
[0043]
Hereinafter, the configuration and manufacturing process of the present embodiment will be described with reference to FIGS.
[0044]
(1) First, a (203) n-type GaAs buffer layer is formed on a (202) n-type GaAs substrate, and an n-type AlAs layer and an n-type Al layer are further formed._0.1Ga_0.9Thirty pairs of (204) distributed semiconductor multilayer mirrors having a reflectance of 98% or more with respect to light having a wavelength of about 870 nm are formed of As layers. Subsequently, (205) n-type Al_0.4Ga_0.6As cladding layer, (206) p-type GaAs active layer, (207) p-type Al_0.4Ga_0.6Growing with an As cladding layer, and p-type AlAs layer and p-type Al_0.1Ga_0.95 pairs of (214) distributed reflection type multilayer mirrors composed of an As layer and having a reflectance of 75% or more with respect to light having a wavelength of about 870 nm are formed, and (208) p-type Al is formed thereon._0.1Ga_0.9The As contact layer is sequentially epitaxially grown by MOCVD (FIG. 4A). At this time, in this example, the growth temperature is set to 700 ° C., the growth pressure is set to 150 Torr, the organic metals of TMGa (trimethylgallium) and TMAI (trimethylaluminum) are used as the group III material, and AsH is used as the group V material._ThreeAs an n-type dopant₂Se and DEZn (diethyl zinc) are used as p-type dopants, respectively.
[0045]
In the formation of the (204) and (214) distributed reflection type multilayer mirrors described above, the (204) distributed reflection type multilayer mirror is H during the layer formation.₂The dopant concentration near the interface of the layer is increased by controlling the Se supply amount and (214) the DEZn supply amount in the distributed reflection type multilayer mirror.
[0046]
(2) Next, (205) n-type Al is left by the RIBE method, leaving (213) a columnar light-emitting portion covered with resist._0.4Ga_0.6Etching is performed halfway through the As cladding layer (FIG. 4B). 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.^-3Torr, and the extraction voltage is 400V.
[0047]
(3) Next, a buried layer is formed on the etching region. Therefore, in this embodiment, first, (213) the resist is removed, and then (209) ZnS is formed by MBE method or MOCVD method._0.06Se_0.94A layer is embedded and grown (FIG. 4C).
[0048]
(4) Furthermore, (212) SiO₂Subsequently, the layer is removed, and (208) a region slightly smaller than the diameter of the light emitting portion is formed on the surface of the contact layer with a resist (FIG. 4D).
[0049]
{Circle around (5)} Thereafter, a (210) p-type ohmic electrode is vapor-deposited on this surface, and an emission port is opened on the surface of the light emitting portion by using a lift-off method (FIG. 4E).
[0050]
(6) After that, two pairs of (211) SiO so as to cover the exit port₂/ A-Si dielectric multilayer mirror is formed by electron beam evaporation. Further, a (201) n-type ohmic electrode is deposited on the (202) n-type GaAs substrate side (FIG. 4F). And finally, N₂Alloying is performed at 400 ° C. in an atmosphere.
[0051]
Through the above steps, a (200) surface emitting semiconductor laser having a buried structure as shown in FIG. 3 can be obtained.
[0052]
Also in the (200) surface emitting semiconductor laser of this example produced in this way, ZnS used for embedding was used._0.06Se_0.94Since the layer has a resistance of IGΩ or more and (209) no leakage of the injected current into the buried layer occurs, extremely effective current confinement is achieved. In addition, since the (209) buried layer is not required to have a multilayer structure, it can be easily grown and the reproducibility between batches is high. Furthermore, ZnS whose refractive index is sufficiently smaller than that of GaAs._0.06Se_0.94More effective light confinement is realized by the embedded refractive index waveguide structure using the layer and (206) the active layer embedded therein.
[0053]
In addition, since the carrier concentration in the vicinity of the interface of the layers constituting the (204) and (214) distributed reflection type multilayer mirrors is increased, the barrier of the conduction band becomes thinner, the electrons are easily tunneled, and the valence band. Since the band steepness of the film becomes gentle, holes are also easily conducted, and the electric resistance in the direction perpendicular to the multilayer film is small.
[0054]
Here, the carrier concentration is increased by doping only in the vicinity of the interface of the layers, so that the film quality is not deteriorated by the high concentration doping.
[0055]
(C) Example 3
FIG. 5 is a perspective view showing a cross section of a light emitting portion of a semiconductor laser (300) in a third embodiment of the present invention, and FIGS. 6 (a) to 6 (f) show the manufacture of the semiconductor laser (300) in the embodiment. It is sectional drawing which shows a process.
[0056]
The semiconductor laser (300) of this example is (307) p-type Al._0.5Ga_0.5The As clad layer is different from the above-described Example 1 and Example 2 in that the light emitting part is formed by a plurality of columnar parts separated from each other by separation grooves.
[0057]
Hereinafter, the configuration and manufacturing process of the present embodiment will be described with reference to FIGS.
[0058]
(1) First, a (303) n-type GaAs buffer layer is formed on a (302) n-type GaAs substrate, and n-type Al is further formed._0.9Ga_0.1As layer and n-type Al_0.2Ga_0.825 pairs of (304) semiconductor multilayer mirrors having a reflectance of 98% or more with respect to light of ± 30 nm centered on a wavelength of 780 nm are formed. Subsequently, (305) n-type Al_0.5Ga_0.5As cladding layer, (306) p-type Al_0.13Ga_0.87As active layer, (307) p-type Al_0.5Ga_0.5As clad layer and p-type Al_0.9Ga_0.1As layer and p-type Al_0.2Ga_0.85 pairs of (315) distributed reflective multilayer mirrors and (308) p-type Al that have an As layer and have a reflectance of 75% or more for light in the vicinity of a wavelength of 780 nm._0.15Ga_0.85As contact layers are epitaxially grown sequentially by MOCVD (FIG. 6A). In the present embodiment, the growth conditions at this time are a growth temperature of 720 ° C. and a growth pressure of 150 Torr, and the group III source material is made of TMGa (trimethylgallium) and TMAI (trimethylaluminum) organometallics. Is AsH_Three, TMSi (tetramethylsilane) is used as an n-type dopant, and DEZn (diethyl zinc) is used as a p-type dopant.
[0059]
Also, (304) n-type Al forming a mirror by intermittently irradiating the growth surface with ultraviolet light during semiconductor multilayer mirror growth_0.9Ga_0.1As layer and n-type Al_0.2Ga_0.8The carrier concentration in the vicinity of the interface of the As layer is increased to reduce the resistance of the (304) semiconductor multilayer mirror.
[0060]
(2) Next, the surface is subjected to (312) SiO 2 by atmospheric pressure CVD.₂A layer is formed, a photoresist is further applied thereon, and a photolithography process is performed to produce a necessary pattern. At that time, the resist pattern is subjected to a pattern preparation condition such that the side surface of the resist pattern is perpendicular to the substrate surface. After the preparation, temperature heating that causes the side surface to sag is not performed.
[0061]
(3) Then, using this pattern as a mask,_FourPerform reactive ion etching (RIE) using gas as etching gas (312) SiO₂Remove the layer. As described above, (313) resist and (312) SiO having a side surface perpendicular to the substrate while having a necessary pattern shape.₂A pattern by layers can be created (FIG. 6B).
[0062]
(4) Subsequently, etching is performed using the RIBE method with the resist having the vertical side surface (313) as a mask, leaving the columnar light emitting portion. At this time, the space between the plurality of columnar parts forming the light emitting part is (307) p-type Al._0.5Ga_0.5Etching is performed halfway through the As cladding layer (FIG. 6C). 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 × 10.^-FourTorr, plasma extraction voltage 400 V, ion current density 400 μA / cm on the etching sample²The sample temperature is kept at 20 ° C.
[0063]
Here, the light emitting part is (307) p-type Al._0.5Ga_0.5The etching is performed only halfway through the As cladding layer because the horizontal direction injection carrier and light confinement of the active layer are made into a refractive index waveguide type rib waveguide structure, and a part of the light in the active layer is made active layer This is to enable transmission in the horizontal direction.
[0064]
Further, a (313) resist having a vertical side surface is used as a resist, and further, an etching is performed by using an RIBE method in which etching is performed by irradiating ions perpendicularly to an etching sample. The (320) light emitting portion can be separated by a (314) separation groove perpendicular to the substrate, and a vertical optical oscillator necessary for improving the characteristics of the surface emitting semiconductor laser can be manufactured.
[0065]
(5) Next, this (307) p-type Al_0.5Ga_0.5A buried layer is formed on the As cladding layer. To this end, in this embodiment, (313) the resist is removed first, and then (309) ZnS is obtained by MBE or MOCVD._0.06Se_0.94A layer is embedded and grown (FIG. 6D).
[0066]
(6) In addition, (312) SiO₂The layer and the polycrystalline ZnSSe formed thereon are removed, and (303) a region slightly smaller than the diameter of the light emitting portion is formed on the surface of the contact layer with a resist. A (310) p-type ohmic electrode is vapor-deposited on this surface, and an emission port is opened on the surface of the light emitting part using a lift-off method (FIG. 6E). Here, the (310) p-type ohmic electrode on the emission side is formed to be electrically connected to each (308) contact layer of each (320) light emitting section.
[0067]
(7) After that, two pairs of (311) SiO so as to cover the exit port₂/ A-Si dielectric multilayer mirror is formed by electron beam evaporation. Further, a (301) n-type ohmic electrode is deposited on the (302) n-type GaAs substrate side (FIG. 6F). And finally, N₂Alloying is performed at 400 ° C. in an atmosphere.
[0068]
Here, in the (300) semiconductor laser of this example, ZnS_0.06Se_0.94Since the (311) dielectric multilayer mirror is fabricated also on the (314) separation groove embedded in (3), a vertical resonator structure is formed also in the region sandwiched between the light emitting portions, and therefore (314) the separation groove. The leaked light also contributes to the laser oscillation effectively, and since the leaked light is used, the emitted light is synchronized with the phase of the (320) light emitting unit.
[0069]
As described above, the (300) surface-emitting type semiconductor laser having the (320) light emitting section as shown in FIG. 5 can be obtained.
[0070]
Also in the (300) surface emitting semiconductor laser of this example produced in this way, ZnS used for embedding was used._0.06Se_0.94Since the layer has a resistance equal to or higher than IGΩ and (309) no leakage of injected current into the buried layer occurs, extremely effective current confinement is achieved. In addition, since the (209) buried layer does not need to have a multilayer structure, it can be easily grown and the reproducibility between batches is high. Since this surface emitting semiconductor laser has a rib waveguide structure, ZnS_0.06Se_0.94The refractive index difference between the active layer below the active layer and the active layer in the resonator portion is increased, and effective optical confinement is achieved at the same time.
[0071]
In the (300) surface emitting semiconductor laser of this example, ZnS is used._0.06Se_0.94Since the (311) dielectric multilayer mirror is formed also on the (314) separation groove embedded in (3), a vertical resonator structure is formed also in the region sandwiched between the light emitting portions. Therefore, (314) the separation groove is formed. The light leaked into the light effectively contributes to the laser oscillation, and since the leaked light is used, the light emitted from the light emitting unit is synchronized (320).
[0072]
(2) Examples 4 to 6
In Examples 4 to 6, as shown in FIG. 7A, (431) a light output port is provided with a (430) phase shift layer.
[0073]
Specifically, (431) the light emitting port is provided with a (430) phase shift layer having an appropriate thickness, and (411) a dielectric multilayer mirror is formed thereon, thereby (431) the light emitting port. The effective resonator length of the standing wave generated below is changed, and the reflection surface of the (411) dielectric multilayer film mirror is set to the same position as the (16) virtual reflection surface inside the (410) p-type ohmic electrode. .
[0074]
As a result, as shown in FIG. 7B, (431) the wavelength λ of the standing wave generated below the light exit port.₁And (410) the wavelength λ of the standing wave generated under the p-type ohmic electrode₂Therefore, the standing wave generated in the wave optical resonator can be made uniform in the element, and the entire element volume can be effectively functioned as a laser resonator.
[0075]
As a condition of the material of such a phase shift layer, it is necessary that the phase shift layer is almost transparent with respect to the oscillation wavelength, and the material has a refractive index close to that of a semiconductor. This is because it is desirable to be able to ignore the influence of reflection at the interface with the semiconductor interface.
[0076]
Furthermore, in order to provide a semiconductor laser with better performance and higher reliability, it is preferable to use a (430) formation method that does not damage the semiconductor surface when the phase shift layer is formed. For this purpose, a process capable of forming a phase shift layer at a low temperature of 200 ° C. or lower and using a lift-off method using a resist is desired.
[0077]
(A) Example 4
This embodiment is an embodiment in the case where a dielectric material, for example, amorphous silicon (hereinafter referred to as a-Si) is used as the material of the phase shift layer, and FIGS. Sectional drawing of the manufacturing process of the semiconductor laser concerning a present Example is shown.
[0078]
This embodiment is caused by the presence of a ring-shaped p-type ohmic electrode by providing a phase shift layer instead of providing the (204) distributed reflection type multilayer mirror made of a semiconductor multilayer mirror in the second embodiment. It solves the problem. Therefore, FIG. 8 shows only the process after depositing the p-type ohmic electrode shown in FIG. 4 (e) and opening the light exit port, and the previous process is omitted.
[0079]
Hereinafter, the configuration and manufacturing process of the present embodiment will be described with reference to FIGS.
[0080]
(1) First, (410) after forming a p-type ohmic electrode (431) after opening the light exit (FIG. 8 (a)), (433) with resist, except for forming the phase shift layer, (431) A pattern is formed so that the light exit port is exposed (FIG. 8B).
[0081]
(2) Next, (430) a-Si to be a phase shift layer is vapor-deposited to a predetermined film thickness d using an EB vapor deposition method or the like (FIG. 8C). That is, a (430) phase shift layer having a film thickness is formed so that the reflective surface of the (411) dielectric multilayer mirror to be formed later is in the same position as the virtual reflective surface inside the (410) p-type ohmic electrode. To do. In this case, as shown in the figure, a-Si is deposited not only on the semiconductor layer and the p-type ohmic electrode but also on the (433) resist.
[0082]
(3) Next, as it is, that is, four pairs of (411) SiO in succession in the same furnace.₂A / a-Si dielectric multilayer mirror is deposited (FIG. 8D). As described above, in this embodiment, since the phase shift layer and the dielectric multilayer mirror can be continuously formed in the same furnace, it is possible to improve laser characteristics, process yield, reliability, and the like.
[0083]
(4) Next, this is put into an acetone solution and lifted off by applying ultrasonic vibration. That is, (433) the resist, (430) phase shift layer and (411) dielectric multilayer mirror deposited on the resist are removed by lift-off, and then (402) (401) on the n-type GaAs substrate side. ) An n-type ohmic electrode is deposited (FIG. 8 (e)). Finally, N₂Alloying is performed at 400 ° C. in an atmosphere.
[0084]
Through the above steps, as shown in FIG. 8E, (431) a top reflection having a structure in which (430) a phase shift layer and (411) a dielectric multilayer mirror are sandwiched on the light exit port. A mirror can be formed. In this case, the (430) phase shift layer may be at least in the (431) light emission port, and may have a structure covering the (410) p-type ohmic electrode as shown in FIG. The structure may exist without being covered (431) only in the light exit.
[0085]
In this embodiment, a-Si is used as the material of the (430) phase shift layer. The refractive index of a-Si is (408) p-type Al formed under the (430) phase shift layer._0.15Ga_0.85It is relatively close to the refractive index of the As contact layer. Moreover, although a-Si has a little light absorption in the vicinity of 780 nm, the light absorption coefficient in other regions, for example, around 870 nm is small. Therefore, it is suitable as a material for a phase shift layer used for a semiconductor laser having an oscillation frequency in this region.
[0086]
In addition, by using a dielectric material such as a-Si, as described above, (411) a dielectric multilayer mirror can be formed in the same furnace in succession to the formation of the phase shift layer. The process is not complicated and there are few steps, a simple manufacturing method can be obtained, and reliability and laser characteristics can be improved.
[0087]
Furthermore, since the (430) phase shift layer using a-Si can be formed at room temperature, patterning by a lift-off method using a resist mask becomes possible. Therefore, compared to patterning using a technique such as dry etching, there are advantages such that the surface of the semiconductor laser is less likely to be damaged during etching and the process can be simplified.
[0088]
In addition, as a dielectric material used for the phase shift layer of a present Example, it is not restricted to a-Si, SixNy, TiO₂, CeO₂Various dielectric materials such as ZnSSe, GaAs, and CdS can be used.
[0089]
For example, SixNy, TiO₂, CeO₂Has a small light absorption coefficient in a wide range as in the above-described a-Si, and is formed under the phase shift layer (408) p-type Al._0.15Ga_0.85The refractive index is relatively close to the As contact layer. Therefore, it becomes suitable as the phase shift layer of this embodiment. Further, since it can be grown at a temperature of 200 ° C. or less, it can be patterned using the lift-off method described above, and it has an advantage that the surface of the semiconductor laser is hardly damaged.
[0090]
On the other hand, ZnSSe, GaAs, and CdS are difficult to grow at a temperature of 200 ° C. or lower. Therefore, the resist is deformed during growth (433), and it is difficult to pattern using the lift-off method. However, these dielectric materials have an advantage in that they have a small light absorption coefficient in a wider range than the above-mentioned a-Si, for example, there is almost no light absorption at 780 nm.
[0091]
As described above, for the dielectric material that cannot use the lift-off method when patterning the phase shift layer, a desired patterning is performed using the dry etching method by the manufacturing process shown in FIGS. I do.
[0092]
(1) First, (410) a p-type ohmic electrode is formed, (431) a light exit port is opened (FIG. 9A), and then composed of ZnSSe, GaAs, etc. by using MOCVD method or MBE method (430) ) A phase shift layer is formed on the entire surface of the semiconductor laser so as to have a predetermined thickness d (FIG. 9B).
[0093]
(2) Next, (435) a resist is formed in a region other than the portion to be etched (FIG. 9C).
[0094]
(3) Next, using a dry etching method, (430) the phase shift layer is etched (FIG. 9D).
[0095]
(4) Next, (433) resist is formed, and then 4 pairs of (411) SiO are formed on the entire surface of the semiconductor laser.₂A / a-Si dielectric multilayer mirror is deposited (FIG. 9E).
[0096]
(5) Next, this is put into an acetone solution and lifted off by applying ultrasonic vibration, and then a (401) n-type ohmic electrode is deposited on the (402) n-type GaAs substrate side (FIG. 9 (f)). Finally, N₂Alloying is performed at 400 ° C. in an atmosphere.
[0097]
(B) Example 5
This embodiment is an embodiment in which a phase shift layer is formed by regrowth of a semiconductor layer by using MBE method, MOCVD method or the like. FIGS. 10A to 10C show this embodiment. Sectional drawing of the manufacturing process of the semiconductor laser concerning is shown.
[0098]
As in the fourth embodiment, FIG. 10 shows only the process after depositing the p-type ohmic electrode and opening the light exit port, and the previous process is omitted.
[0099]
Hereinafter, the structure and manufacturing method of the present embodiment will be described.
[0100]
(1) First, in this embodiment, after forming a (510) p-type ohmic electrode and (531) opening a light exit (FIG. 10 (a)), a semiconductor layer is formed using MBE, MOCVD, or the like. Is regrown, and a phase shift layer is formed (530) so as to obtain a desired film thickness d (530). That is, using a crystal method capable of growing a semiconductor layer at a relatively low temperature, for example, 400 ° C. or less, (508) p-type Al is formed on the surface of the optical resonator._0.15Ga_0.85A semiconductor layer having the same composition as that of the As contact layer is formed and used as a (530) phase shift layer.
[0101]
(2) After that, (531) 2 pairs of (511) SiO so as to cover the light exit port₂/ A-Si dielectric multilayer mirror is formed by electron beam evaporation. Further, a (501) n-type ohmic electrode is deposited on the (502) n-type GaAs substrate side (FIG. 10C). And finally, N₂Alloying is performed at 400 ° C. in an atmosphere.
[0102]
According to this example, the (530) phase shift layer is located under (508) p-type Al._0.15Ga_0.85The As contact layer can be formed by regrowth, and these can be formed of the same material. Therefore, (530) phase shift layer and (508) p-type Al_0.15Ga_0.85Light-related problems such as light interface reflection and light absorption at the boundary with the As contact layer can be ignored. As a result, the deterioration of the laser characteristics due to the insertion of the (530) phase shift layer can be almost ignored, and a semiconductor laser with excellent performance can be provided.
[0103]
Further, the step of regrowing the semiconductor layer can be performed by a process similar to that of the underlying semiconductor layer such as the cladding layer and the active layer. In this process, the MBE method and the MOCVD method are usually used. The film thickness d can be controlled in units of several angstroms. Therefore, the wavelengths λ1, λ of standing waves generated under the (531) light exit and under the (510) p-type ohmic electrode.₂It is possible to control the film thickness d so that they are almost equal. As a result, the standing wave generated in the optical resonator can be made uniform in the element, and the laser characteristics can be greatly improved.
[0104]
(C) Example 6
In this example, after forming a p-type ohmic electrode, an organic material such as polyimide or PMMA is formed on the surface of the semiconductor laser by using a coating method such as spin coating, and a phase shift layer is formed. In (a) to (e), sectional views of the manufacturing process of the semiconductor laser according to the present example are shown.
[0105]
In addition, like the said Example 4, 5, only the process after vapor-depositing a p-type ohmic electrode and opening a light-projection opening is shown by FIG. 11, The previous process is abbreviate | omitted. .
[0106]
Hereinafter, the structure and manufacturing method of the present embodiment will be described.
[0107]
(1) First, in this example, after forming a (610) p-type ohmic electrode and (631) opening a light exit port (FIG. 11 (a)), a desired film thickness is applied by a coating method such as spin coating. A phase shift layer (630) made of an organic material such as polyimide or PMMA is formed on the entire surface of the semiconductor laser so as to be d (FIG. 11B).
[0108]
(2) Next, (610) the (630) phase shift layer on the p-type ohmic electrode is etched by wet etching or dry etching, and (630) the phase shift layer is patterned (FIG. 11C). .
[0109]
(3) Next, (633) resist is formed, and then four pairs of (611) SiO are formed on the entire surface of the semiconductor laser.₂A / a-Si dielectric multilayer mirror is deposited (FIG. 11E).
[0110]
(4) Next, this is put into an acetone solution and lifted off by applying ultrasonic vibration, and then (602) an n-type ohmic electrode is deposited on the (602) n-type GaAs substrate side (FIG. 11 (f)). Finally, N₂ Alloying is performed at 400 ° C. in an atmosphere.
[0111]
According to this example, since the (630) phase shift layer can be formed by a coating process such as spin coating, the manufacturing method can be greatly simplified.
[0112]
In addition, organic materials such as polyimide and PMMA listed here have a small light absorption coefficient in a wide range, and hardly absorb light at, for example, 870 nm. Also, the refractive index is relatively close to the underlying semiconductor layer. Therefore, it is suitable as a material for the phase shift layer in this embodiment. However, even organic materials other than the above polyimide and PMMA are at least (1) transparent to the oscillation wavelength, and (2) relatively close to the semiconductor layer having a refractive index below. If one condition is satisfied, it can be used as the material of the phase shift layer in this embodiment.
[0113]
(D) Control of the thickness d of the phase shift layer
The phase change of the reflected wave at the interface between the metal and the semiconductor varies depending on the metal material and film thickness. Accordingly, the film thickness d of the phase shift layer is preferably obtained and controlled by, for example, the method described below. Hereinafter, this method will be described with reference to FIGS. FIG. 12 shows the case where the design wave number is m = 1 (1/2).
[0114]
First, a semiconductor laser without an upper reflective film and a phase shift layer is produced, and its LED spectrum is measured. FIG. 12 (a) shows an example of the measurement result. As shown in FIG. 12, the peak λ of the wavelength of the standing wave generated under the light exit port.₁And the wavelength peak λ of the standing wave under the p-type ohmic electrode₂Can be measured.
[0115]
Next, as shown in FIG. 12 (b), the measured wavenumber m is set to the measured λ.₁Is multiplied by the effective resonator length L₁Is required.
[0116]
L₁= M × λ₁
In addition, as shown in the figure, the measured λ₂The effective resonator length L finally required by multiplying by₂Is required.
[0117]
L₂= M × λ₂
And this L₁And L₂The difference ΔL is a change in the effective resonator length.
[0118]
ΔL = L₂-L₁
Finally, by dividing ΔL by the refractive index n of the material forming the phase shift layer, the film thickness d of the phase shift layer to be formed is obtained.
[0119]
d = ΔL / n
When forming the phase shift layer, the process is controlled so that the film thickness of the phase shift layer becomes the film thickness d obtained as described above.
[0120]
If the thickness d of the phase shift layer cannot be stably controlled, or if it is desired to control the thickness d with higher accuracy, the thickness d is controlled by the following method.
[0121]
That is, a semiconductor laser provided with a phase shift layer having a predetermined film thickness is manufactured, and the wavelength λ is determined by the LED spectrum in the same manner as described above.₁, Λ₂Measure. Then, the difference Δd (λ from the film thickness to be set is calculated by the following formula.₁And λ₂Δd) for equalizing.
[0122]
Δd = m × (λ₂ー λ₁) / N
Then, this Δd is fed back to the sequential process, and the process condition of the film thickness d is changed so that this Δd becomes zero. Thereby, the film thickness d can be stably controlled, and the film thickness d can be controlled with higher accuracy.
[0123]
The phase shift φ of the reflected wave at the metal-semiconductor interface is directly measured by a method such as applying a laser beam from the outside. From this measured value, the change ΔL in the effective resonator length and the phase shift layer It is also possible to control the film thickness d by approximating the film thickness d.
[0124]
In addition, this invention is not limited to the said Example, A various deformation | transformation implementation is possible within the range of the summary of this invention.
[0125]
For example, in each of the above-described embodiments, a GaAlAs surface emitting semiconductor laser has been described. However, the present invention is not limited to this, and can be suitably applied to other III-V group surface emitting semiconductor lasers. The active layer can also change the oscillation wavelength by changing the composition of Al.
[0126]
In addition, the buried layer is not limited to the ZnSSe mixed crystal, but also a ZnS-ZnSe superlattice,
The same effect can be obtained even when a II-VI group compound semiconductor such as ZnSe, ZnS, CdTe and crystals thereof, or a superlattice of these material systems is selected as the buried layer.
[0127]
In Example 1, dimethylzinc-dimethylselenium as an organometallic adduct and H as a hydrogen compound.₂Although the case where S (hydrogen selenide) is used has been described, the present invention is not limited to this. For example, each embedded layer can be formed by a combination shown in Table 1.
[0128]
Further, the phase shift layer may be a mixed crystal as well as a simple substance such as a-Si.
[0129]
Further, the substrate is not limited to GaAs, and a similar effect was obtained even with a semiconductor substrate such as Si or InP or a dielectric substrate such as sapphire.
[0130]
In the fourth to sixth embodiments, the semiconductor laser having a buried refractive index waveguide structure corresponding to the second embodiment has been described as an example. However, the present invention is not limited to this, and for example, a rib waveguide corresponding to the first embodiment is used. Of course, the present invention can also be applied to a semiconductor laser having a waveguide structure and a surface emitting semiconductor laser having a plurality of columnar semiconductor layers corresponding to the third embodiment. When a phase shift layer is formed in a phase-locked laser having a plurality of columnar semiconductor layers as shown in the third embodiment, it faces the surface of the plurality of columnar semiconductor layers and the buried layers between the columnar semiconductor layers. A phase shift layer can be provided over the region.
[0131]
The optical resonator constituting the present invention includes a plurality of semiconductor layers, and the meaning of “multiple layers” herein means that there are a plurality of layers having different polarities. That is, the optical resonator constituting the present invention only needs to have at least a p-type semiconductor layer and an n-type semiconductor layer. For example, the semiconductor layers are all formed of the same material GaAs (different in polarity). A structure is also possible.
[0132]
Further, the pair of reflection mirrors constituting the present invention is not limited to the one in which a single reflection mirror is provided at each position on both sides facing the optical resonator as in the above-described embodiment. For example, the output side mirror provided at the position facing the optical resonator is composed of a plurality of mirrors, the incident side mirror is composed of a plurality of mirrors, and the output side and the incident side mirrors are both plural Also included are those composed of one mirror.
[0133]
Needless to say, the application range of the surface-emitting type semiconductor laser of the present invention has exactly the same effect not only in printing apparatuses such as printers and copiers, but also in facsimiles, displays and communication devices.
[0134]
【The invention's effect】
As described above in detail, according to the surface-emitting type semiconductor laser according to the present invention, the reflection mirror on the light emitting side covers the semiconductor multilayer film having the same size as the resonator diameter, the ring electrode, and the light emitting port. By configuring with a dielectric multilayer mirror, since there is a semiconductor multilayer mirror under the electrode, it is possible to increase the reflectivity of the resonator under the electrode, thereby not reducing the efficiency in the resonator, A highly efficient surface emitting semiconductor laser can be provided.
[0135]
Further, in the manufacturing method according to the present invention, among the reflection mirrors on the light emitting side, the semiconductor multilayer film mirror can be continuously grown from the substrate together with the active layer constituting the resonator, etc. It is a manufacturing method capable of producing a surface emitting semiconductor laser with high reproducibility.
[0136]
Further, according to the surface emitting semiconductor laser of the present invention, the wavelength of the standing wave generated under the metal electrode and under the light exit port can be made substantially equal, and the standing wave generated in the optical resonator can be reduced. Therefore, a highly efficient surface emitting semiconductor laser can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a cross section of a semiconductor laser according to Example 1. FIG.
FIGS. 2A to 2F are cross-sectional views showing the manufacturing steps of the semiconductor laser according to the first embodiment.
FIG. 3 is a perspective view showing a cross section of a semiconductor laser according to a second embodiment of the present invention.
FIGS. 4A to 4F are cross-sectional views showing the manufacturing steps of the semiconductor laser according to the second embodiment.
FIG. 5 is a perspective view showing a cross section of a semiconductor laser according to a third embodiment of the present invention. .
6 (a) to 6 (f) are cross-sectional views showing a manufacturing process of a semiconductor laser according to Example 3;
FIGS. 7A and 7B are schematic explanatory views for explaining the extension of the effective resonator length using the phase shift layer. FIGS.
FIGS. 8A to 8E are cross-sectional views showing a manufacturing process of a semiconductor laser according to Example 4; FIGS.
FIGS. 9A to 9F are cross-sectional views showing a manufacturing process of a semiconductor laser according to Example 4 when dry etching is used for patterning a phase shift layer. FIGS.
FIGS. 10A to 10C are cross-sectional views showing a manufacturing process of a semiconductor laser according to Example 5. FIGS.
FIGS. 11A to 11E are cross-sectional views showing manufacturing steps of a semiconductor laser according to Example 6. FIGS.
FIGS. 12A and 12B are schematic explanatory diagrams for explaining a method of controlling the film thickness of the phase shift layer.
FIG. 13 is a perspective view showing a cross section of a semiconductor laser before improvement.
FIGS. 14A to 14C are schematic explanatory diagrams for explaining the problem of wavelength uniformity of a standing wave generated due to the presence of a ring-shaped p-type ohmic electrode.
[Explanation of symbols]
101, 201, 301, 401, 501, 601, 701 n-type ohmic electrode
102, 202, 302, 402, 502, 602, 702 n-type GaAs substrate
103, 203, 303, 403, 503, 603, 703 n-type GaAs buffer layer
104, 114, 204, 214, 304, 315, 404, 504, 604, 704 Distributed reflection type multilayer mirror
105, 205, 405, 505, 605, 705 n-type Al_0.4Ga_0.6As cladding layer
106, 206, 406, 506, 606, 706 p-type GaAs active layer
107, 207, 407, 507, 607, 707 p-type Al_0.4Ga_0.6As cladding layer
108, 208, 408, 508, 608, 708 p-type Al_0.1Ga_0.9 As contact layer
109, 209, 309, 409, 509, 609, 709 ZnS_0.06Se_0.94Embedded layer
110, 210, 310, 410, 510, 610, 710 p-type ohmic electrode
111, 311, 411, 511, 611, 711 Dielectric multilayer mirror
112, 212, 312 SiO₂layer
113, 213, 313 resist
305 n-type Al_0.5Ga_0.5As cladding layer
306 p-type Al_0.13Ga_0.87As active layer
307 p-type Al_0.5Ga_0.5 As cladding layer
308 p-type Al_0.15Ga_0.85As contact layer
314 Separation groove
430, 530, 630, 730 Phase shift layer
431, 531, 631, 731 Light exit
433, 533, 633, 733 resist
435 resist
120, 220, 320 Light emitting part

Claims (5)

In a surface emitting semiconductor laser that emits light in a direction perpendicular to the substrate,
An optical resonator having a pair of reflecting mirrors and a plurality of semiconductor layers therebetween, wherein at least one of the semiconductor layers is formed in one or more columnar shapes;
Embedded in the periphery of the columnar semiconductor layer,
Of the reflection mirrors, the light emission side reflection mirror is formed by alternately laminating a first layer made of a semiconductor and a second layer made of a semiconductor having a refractive index different from that of the first layer. A metal electrode provided with a light exit on the layer, and a third layer made of a dielectric on the light exit and the metal electrode, and a dielectric having a refractive index different from that of the third layer. A composite type multilayer film reflecting mirror constituted by alternately laminating the fourth layer,
The reflection mirror in which the first layer and the second layer are alternately stacked has the same size as the columnar semiconductor layer when viewed from a direction perpendicular to the substrate.
The light exit port is smaller than the columnar semiconductor layer when viewed from a direction perpendicular to the substrate, and
When viewed from the direction perpendicular to the substrate, the end of the metal electrode on the light exit side overlaps the first layer, the second layer, the third layer, and the fourth layer. A surface-emitting type semiconductor laser characterized by that. In claim 1,
2. The surface emitting semiconductor laser according to claim 1, wherein the buried layer is an II-VI compound semiconductor epitaxial layer. In claim 1 or 2,
In the light emitting side reflecting mirror of the reflecting mirrors, the first layer is a layer made of a III-V group compound semiconductor, and the second layer is a III-V having a refractive index different from that of the first layer. A surface emitting semiconductor laser characterized in that it is a layer made of a group compound semiconductor. In a method of manufacturing a surface emitting semiconductor laser that emits light in a direction perpendicular to a substrate,
Forming a pair of reflecting mirrors constituting an optical resonator and at least one semiconductor layer between them on a substrate made of a semiconductor or a dielectric by metal organic chemical vapor deposition or molecular beam epitaxy;
Forming a photoresist mask on the semiconductor layer and etching at least one of the semiconductor layers using the photoresist mask to form one or more pillars;
Forming a buried layer around the columnar semiconductor layer,
Of the reflecting mirrors, the light emitting side reflecting mirror is formed by alternately laminating a first layer made of a semiconductor and a second layer made of a semiconductor having a refractive index different from that of the first layer, continuously from the substrate. And forming a metal electrode having a light exit on the second layer, a third layer made of a dielectric on the light exit and the metal electrode, and the third layer. And fourth layers made of dielectrics having different refractive indexes are alternately laminated,
The reflection mirror in which the first layer and the second layer are alternately stacked is formed to have the same size as the columnar semiconductor layer when viewed from a direction perpendicular to the substrate.
The light emission port is formed smaller than the columnar semiconductor layer when viewed from a direction perpendicular to the substrate, and
When viewed from the direction perpendicular to the substrate, the end of the metal electrode on the light exit side overlaps the first layer, the second layer, the third layer, and the fourth layer. Formed into,
A method of manufacturing a surface-emitting type semiconductor laser. In claim 4,
In the light emitting side reflecting mirror of the reflecting mirrors, the first layer is a group III-V compound semiconductor, and the second layer is a group III-V compound semiconductor having a refractive index different from that of the first layer. A method of manufacturing a surface emitting semiconductor laser, comprising: a layer comprising:

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