JP2000012981A - Surface type semiconductor optical device and method of manufacturing the same - Google Patents

Abstract

[PROBLEMS] To provide a surface-type semiconductor optical device having a highly versatile multilayer reflective film, high productivity, and high yield, and a method for manufacturing the same. A surface type semiconductor optical device is a semiconductor multilayer film.
7, 18, 21 and the multilayer reflective film 3 provided on at least one side in the stacking direction of the semiconductor multilayer films 17, 18, 21
1 and 63 are provided. One of the multilayer reflective films 63 has a periodic structure of a small number of semiconductor layers and a gas layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a surface type semiconductor optical device having a multilayer reflective film such as a vertical cavity surface emitting semiconductor laser emitting light in a direction perpendicular to a substrate, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In order to realize large-capacity optical communication and optical interconnection, research is being carried out on arranging a plurality of laser elements in an array and transmitting optical information in parallel.
As a light emitting device suitable for arraying, a vertical cavity surface emitting semiconductor laser (Vertical Cavity)
Surface Emitting Laser: VC
SEL) is attracting attention.

A surface emitting semiconductor laser is generally a Fabry-Perot resonator having a resonator length of several μm and comprising two upper and lower reflecting mirrors. In order to reduce the threshold, a reflecting mirror that is transparent at the oscillation wavelength and has as high a reflectivity as possible is required. Usually, two kinds of materials having different refractive indices are alternately formed with a thickness of 1/4 wavelength. Is used in a surface emitting semiconductor laser.

Further, surface emitting semiconductor lasers having various wavelengths can be formed by selecting a semiconductor material.
For example, GaAs having an oscillation wavelength of 0.85 μm or 0.98 μm
An s-based surface emitting semiconductor laser and an oscillation wavelength of 1.3 μm or 1.
A 55 μm InP-based surface emitting semiconductor laser is well known. In the case of a GaAs-based mirror, an AlAs / (Al) GaAs multilayer film that can be epitaxially grown on a GaAs substrate and has a small absorption with respect to an oscillation wavelength is generally used as a mirror. On the other hand, in the case of the InP system, InGaAsP / InP capable of epitaxial growth on an InP substrate
Under the condition that absorption is small relative to the oscillation wavelength, the difference in the refractive index is very small and it is difficult to obtain a high reflectivity. Therefore, other materials such as a SiO ₂ / Si multilayer film and Al ₂ O ₃
/ Si multilayer film or the like is used as a mirror. The AlAs / (Al) Ga grown on the GaAs substrate is formed on the semiconductor layer including the active layer grown on the InP substrate.
There is also known a method in which a high reflectivity mirror is formed by directly bonding As multilayer films.

[0005]

However, in such a surface emitting semiconductor laser, in the case of a GaAs-based semiconductor laser, AlAs having the largest difference in the refractive index is required in order to increase the reflectance with an AlAs / (Al) GaAs multilayer film. And GaAs
However, there is a drawback that the growth time is required and the productivity is poor. Further, depending on the oscillation wavelength, GaAs has a large absorption,
As is required to be AlGaAs with an increased Al composition, and the number of pairs must be further increased.

On the other hand, in the case of the InP system, after an active layer or the like is grown on a substrate, it is processed by etching or the like, and a SiO ₂ / Si multilayer film or Al ₂ O ₃
/ Si multi-layer film must be formed, which has the disadvantage of complicating the process. Also, AlAs / (Al) GaAs
When the s multilayer film is bonded, the method of bonding is used, so that the process is undeniably complicated.
Since the bonded interface exists in the resonator, there is a disadvantage that the state of the interface (cleaning state, bonding strength, etc.) directly affects the laser characteristics.

In a surface emitting semiconductor laser, it is necessary to remove the substrate depending on the relationship between the semiconductor material of the substrate and the oscillation wavelength band. For example, when manufacturing a surface emitting semiconductor laser having an oscillation wavelength of 0.85 μm using a GaAs substrate,
Since the GaAs substrate has a large absorption for this light, it is necessary to remove the substrate in order to extract light from the substrate side. In addition, when manufacturing a surface emitting semiconductor laser having an oscillation wavelength of 1.3 μm or 1.55 μm using an InP substrate, it is necessary to form a multilayer mirror made of a dielectric after removing the InP substrate. Therefore, a semiconductor substrate is etched into a hole shape in accordance with a light emitting region of a surface emitting semiconductor laser. It is difficult to perform this hole-shaped etching with good reproducibility, and it is also difficult to form a multilayer film such as a SiO ₂ / Si multilayer film or an Al ₂ O ₃ / Si multilayer film with good reproducibility in the hole part. This is a factor that lowers the yield.

In view of these problems, an object of the present invention is to
It is an object of the present invention to provide a surface-type semiconductor optical device such as a surface-emitting semiconductor laser having a highly versatile multilayer reflective film, high productivity, and high yield, and a method for manufacturing the same.

[0009]

According to the present invention, there is provided a vertical resonator comprising a semiconductor multilayer film and a multilayer reflective film provided on at least one side in the stacking direction of the semiconductor multilayer film. 2. Description of the Related Art In a surface type semiconductor optical device for handling light propagating in a direction perpendicular to a substrate, such as a surface emitting semiconductor laser, a multilayer reflective film is characterized by comprising a periodic structure of a semiconductor layer and a gas layer. Typically, this surface type semiconductor optical device includes a semiconductor multilayer film including an active layer, first and second multilayer reflective films provided on both sides in the stacking direction of the semiconductor multilayer film, and an active medium of the active layer. A vertical cavity surface emitting semiconductor laser comprising excitation means for exciting,
The first multilayer reflective film is a semiconductor layer and a gas layer (typically an air layer, but may be filled with a gas such as Ar. The pressure state is typically large. Pressure, but may be decompressed or pressurized if necessary), a semiconductor multilayer film including an active layer, and one side in the stacking direction of the semiconductor multilayer film. Or a multi-layered reflective film provided on the surface layer, and a surface-type LED comprising excitation means for exciting the active medium of the active layer.

Since the reflective film is composed of a gas layer such as an air layer and a semiconductor layer having a large difference in refractive index, a high reflectivity can be achieved with a small period, and the growth time can be shortened. In addition, since the refractive index difference between the semiconductor layer and the gas layer is large, the high reflection wavelength range is very wide, and it can be applied to surface-type semiconductor optical devices such as surface-emitting semiconductor lasers of various wavelengths without being limited to wavelengths. Become. In addition, In
In a P-based surface emitting semiconductor laser, a dielectric reflection film on one side is not required.

More specifically, the present invention can take the following forms. The multilayer reflective film composed of the periodic structure of the semiconductor layer and the gas layer selectively selects one semiconductor layer of the periodic structure composed of two different semiconductor layers epitaxially grown on the first substrate to be finally removed. It is constituted by removing. A reflection film having high reflectance can be manufactured by an easy method called selective etching. Further, since there is no problem even if the semiconductor material to be etched absorbs the wavelength to be handled, a wider range of materials can be selected, and a material that can grow more stably can be selected, thereby improving the yield.

A first substrate, a periodic structure including two different semiconductor layers epitaxially grown on the first substrate;
A first substrate including a semiconductor multilayer film including a functional region such as at least one light emitting region having an active layer attached to a second substrate mainly including a second substrate; To expose a periodic structure composed of the two different semiconductor layers, and selectively etch one of the two different semiconductor layers forming the periodic structure in a portion corresponding to a functional region of the periodic structure. Thus, a periodic structure of the semiconductor layer and the gas layer is formed. A first substrate, a first substrate; a periodic structure including two different semiconductor layers epitaxially grown on the first substrate; a semiconductor multilayer film including at least one functional region including an active layer and a spacer layer; A structure including a second multilayer reflective film (dielectric multilayer film or semiconductor multilayer film) formed in accordance with the region may be used as a surface emitting semiconductor laser. Since the second substrate can be used as a holding substrate, the first substrate can be easily removed. Further, since the surface after the removal of the first substrate is flat, the subsequent patterning,
Processing such as etching is easy.

A third multilayer comprising a semiconductor multilayer film having a periodic structure of two or more semiconductor layers epitaxially grown between the first multilayer reflective film and the semiconductor multilayer film including an active layer. Reflective film (composition-modulated layer,
(Which may include a doping-modulated layer). Since the first multilayer reflective film includes a gas layer, current injection needs to be performed by bypassing the first multilayer reflective film, but between the first multilayer reflective film and the semiconductor multilayer film including the active layer. The presence of the third multilayer reflective film allows the current to diffuse, making it possible to effectively inject the current into the active layer. In addition, compared to the case without the third multilayer reflective film,
Since the amount of phase change that occurs when the film thickness (particularly, the gas layer) of each layer in the first multilayer reflective film changes, the change in resonator length can be reduced. Therefore, it is possible to provide a surface emitting semiconductor laser having a lower threshold and a stabilized oscillation wavelength.

The first multilayer reflection film has a periodic structure of a semiconductor layer and a gas layer having at least three periods or more. With this configuration, a reflective multilayer film having a reflectance of 99% or more and a wide reflection wavelength range can be manufactured.

On the outermost surfaces of the first and second substrates, electrodes as excitation means are formed, and the electrodes are attached so as to be electrically connected to each other. Thus, current injection can be performed through the second substrate, and a surface-emitting semiconductor laser or the like that can be easily mounted can be provided.

As means for attaching the first substrate and the second substrate, an anisotropic conductive adhesive containing conductive particles and having conductivity only in a direction perpendicular to the substrate is used. ing. As a result, it is possible to reliably obtain an electrical contact at a necessary portion by an easy method, and it is possible to provide a surface emitting semiconductor laser or the like that is easy to mount.

The second substrate is made of a material having good heat conductivity, such as Si or AlN. As a result, heat radiation can be performed more effectively, and a surface emitting semiconductor laser or the like with further improved heat radiation can be provided.

Further, in the method of manufacturing a surface type semiconductor optical device according to the present invention for achieving the above object, the present invention provides a method for manufacturing a planar semiconductor optical device, comprising: a first substrate; a periodic structure comprising two different semiconductor layers epitaxially grown on the first substrate; At least one with a layer
Attaching a first substrate including a semiconductor multilayer film including a functional region such as one light-emitting region to a second substrate mainly including a second substrate; and removing the first substrate to remove the second substrate. Exposing a periodic structure composed of two semiconductor layers, forming an etching window in the periodic structure at several locations around the functional region so as to substantially penetrate the periodic structure, and injecting an etchant from the etching window. And selectively etching either one of the two different semiconductor layers forming the periodic structure to form a periodic structure of the semiconductor layer and the gas layer in a portion corresponding to the functional region. A first substrate, a first substrate, a periodic structure including two different semiconductor layers epitaxially grown on the first substrate, a semiconductor multilayer film including at least one functional region including an active layer and a spacer layer, A configuration including a second multilayer reflective film formed in accordance with the region may be adopted. Thus, a surface-type semiconductor optical device such as the above-described surface-emitting semiconductor laser can be easily manufactured.

[0019] After the step of forming the periodic structure of the semiconductor layer and the gas layer, the method may further include a step of filling the etching window with a highly viscous filling material. Accordingly, it is possible to prevent a gas layer such as an air layer from being crushed or a film thickness from being deviated from a design during a processing process, and to suppress a change in the film thickness due to a surrounding pressure. Therefore, a surface-type semiconductor optical device having a strong structure can be provided.

The principle of the present invention will be described with reference to specific examples shown in FIGS. In the first base, the first substrate 11 (a portion corresponding to a functional region such as a light emitting region is eventually removed, but is often removed entirely) is, for example, an n-InP substrate. First, on the first substrate 11, as shown in FIG. 4, an n-InGaAs etch stop layer 13, a semiconductor multilayer film 15 in which InGaAs and InP are alternately laminated, an n-InP spacer layer 17,
An nGaAsP bulk active layer 19, a p-InP spacer layer 21, and a p-InGaAsP contact layer 23 are sequentially grown, and the periphery of the light emitting region is etched in a donut shape to embed an insulating material such as polyimide 25. The light emitting region is, for example, a circle having a diameter of 20 μm, and the outer shape etched into a donut shape is a circle having a diameter of 40 μm. Although not shown in the figure, before embedding with the polyimide 25, the active layer portion is adjusted to have an effective diameter of
m may be selectively etched to about m.

Further, after covering a portion other than the light emitting region with a green layer 27 such as SiN _x , an electrode 29 having a window having a diameter of 15 μm is formed, and the contact layer 23 in the window portion is removed. Next, a dielectric multilayer reflective film 31 having a diameter of 100 μm
Is formed by an RF sputtering method or the like, and the reflection film 31 is
Cover with.

The second substrate 51 is mainly composed of, for example, a Si substrate, and in the example of FIG.
Is formed, and then the electrode 55 is formed. Although not shown, the electrode 53 is connected to a wiring provided with a pad.

Next, the first and second substrates are attached so that the electrodes on the outermost surfaces are electrically connected to each other. The bonding method is such that the electrodes 33 and 55 are pressed together and embedded with a thermosetting resin 57 for bonding, or a thermosetting resin containing conductive particles is applied to bond the electrodes 33 and 55 together. There is a method in which the first substrates are bonded together by compression heating.

Further, the first substrate 11 is removed by using a method such as selective wet etching, and the resulting semiconductor multilayer film 15 is substantially removed by a method such as reactive ion beam etching. Several penetrating etching windows 61 are formed around the light emitting region.

Then, an etchant is injected from the etching window 61 to selectively wet-etch one of the two different semiconductor layers forming the periodic structure, for example, InGaAs, to form the semiconductor layer and the air layer in the light emitting region. The periodic structure 63 is formed.

The refractive index of air is 1.0, and a semiconductor such as I
The refractive index of nP is about 3.2. FIG. 2 shows a change in reflectance at a design wavelength when the number of pairs is increased with the two layers as one cycle. As can be seen from FIG. 2, the multilayer reflective film having the two stacked structures has a thickness of 99 for at most three periods.
%, It is possible to shorten the time required for the growth and improve the productivity as compared with the case where the mirror is constituted only by the semiconductor multilayer film.

FIG. 3 shows the wavelength dependence of the reflectance. Since the difference in the refractive index between the semiconductor layer and the air layer is large, the high reflection wavelength range is very wide, and the invention can be applied to surface emitting semiconductor lasers of various wavelengths without being limited to the oscillation wavelength.

Further, since there is no problem even if the semiconductor material to be etched absorbs the oscillation wavelength, a wider range of materials can be selected, and a material that can grow more stably can be selected, thereby improving the yield.

In addition, in the semiconductor optical device of the present invention, since the second substrate can be used as a holding substrate, the semiconductor substrate on the first substrate side can be easily removed without partial hole etching. It is possible to improve the yield.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail below using embodiments.

[0031] First Embodiment FIG. 1, FIG. 4, the semiconductor optical device of the first embodiment according to the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a surface emitting semiconductor laser according to the present embodiment, and FIGS. 4 and 5 are views for explaining a manufacturing process thereof.

First, the first base will be described with reference to FIG. On the n-InP substrate 11, a 0.2 μm thick n
-InGaAs etch stop layer 13, n-InP / n
-InGaAs semiconductor multilayer film 15 (I
nP layer thickness 0.1 μm, InGaAs thickness 0.32
5 μm), 1.9 μm thick n-InP spacer layer 1
7. 0.7 μm thick InGaAsP (bandgap wavelength 1.3 μm) bulk active layer 19, 1.0 μm thickness
P-InP spacer layer 21, 0.2 μm thick p-I
An nGaAsP contact layer 23 is sequentially grown (FIG. 4).
(A)). The growth means is, for example, MOCVD, MBE,
This is performed by a method such as CBE.

Further, the periphery of the light emitting region is etched into a donut shape by the RIBE method or the like, and the etched portion is embedded with polyimide 25 (FIG. 4B). The light emitting region is, for example, a circle having a diameter of 20 μm, and the outer shape etched into a donut shape is a circle having a diameter of 40 μm. Although not shown in FIG. 4, before embedding with the polyimide 25, the active layer 19 has a diameter of 1 according to the effective diameter of a second multilayer reflective film to be manufactured later.
Selective wet etching may be performed with a sulfuric acid-based etchant up to about 5 μm.

Next, after covering a portion other than the light emitting region with SiN _x 27, a p-electrode 29 made of Cr / Au and having a thickness of 0.5 μm and having a 15 μm diameter window is deposited by vapor deposition. Part of the contact layer 23 is removed (FIG.
(C)). Next, a second multilayer reflective film 31 (dielectric multilayer film) made of Al ₂ O ₃ / Si having a thickness of 2.5 μm and a diameter of 100 μm is formed by RF sputtering or the like, and the thickness of the second multilayer reflective film is reduced. Cover with a 0.5 μm Au electrode 33 (FIG. 4)
(D)). This completes the processing of the first base body on the side to which the first base is attached.

Next, the attachment and the back surface processing will be described with reference to FIG. As the first base, the one manufactured in the above process is turned upside down (FIG. 5 (a-1)).
As for the first base, the substrate 11 may be polished in advance to about 100 μm in order to simplify the subsequent removal of the substrate.

In the second substrate, Si having good heat conductivity is used as the second substrate 51, and the second substrate 51
After the thermal oxide film 53 is formed on the surface of
m of an electrode 55 made of Cr / Au (FIG. 5 (a)
-2)). Although not shown in FIG. 5, this electrode is connected to a wiring having a pad.

The two substrates are pressed together so that the electrode portions 33 and 55 of the first substrate and the second substrate thus produced are in contact with each other, and the surroundings are embedded with a thermosetting resin 57 to bond the two substrates together. (FIG. 5B).

Next, the substrate 11 is etched to the etch stop layer 13 with a hydrochloric acid-based etchant, and the etch stop layer 13 is removed by etching with a sulfuric acid-based etchant (FIG. 5C). At this time, since etching can be performed over the entire surface, the process is simpler and the yield is improved as compared with the case of performing hole-shaped etching.

Further, on the semiconductor surface which has appeared after the removal, FIG.
As shown in (d-2)), a resist (not shown in the figure) is formed in which a partially open ring-shaped window is formed, and the semiconductor multilayer film 15 is formed using this resist as a mask.
Is etched by a highly directional etching method such as reactive ion beam etching (RIBE). In this way, an etching window 61 that substantially penetrates the semiconductor multilayer film 15 is formed so as to surround the light emitting region. After that, the resist is removed (FIG. 5D-1).
Since the semiconductor surface appeared by removing the substrate 11 is flat,
Processing such as patterning and etching is simple.

Subsequently, a sulfuric acid-based etchant is injected from the etching window 61 to selectively remove InGaAs, which is one of the materials constituting the semiconductor multilayer film 15, and has a laminated structure of an air layer and an InP layer. A first multilayer reflection film 63 is formed. Finally, an n-electrode 65 of AuGe / Au is formed in a predetermined region.

In this embodiment, the refractive index of air is 1.
0, the refractive index of InP is 3.2, and the first multilayer reflective film 63 is composed of three periods. However, a 99% reflectance sufficient for laser oscillation can be obtained. Therefore, the number of pairs is smaller and the time required for growth can be shortened as compared with the case where the reflection film is constituted only by the semiconductor multilayer film. First
FIG. 3 shows the wavelength dependence of the reflectance of the multilayer reflective film 63 of FIG.
It can be seen that a high reflection region exists near the set wavelength (1.3 μm).

Using such a method, a 4 × 4 surface emitting semiconductor laser array (the first
May be etched to a suitable depth around the multilayer reflective film 63 to electrically separate the n-electrode 65 side, or because the p-electrode 29 side is electrically isolated, the n-electrode 65 side When a current was injected through the electrode, there was slight variation in wavelength but little variation in characteristics such as threshold voltage and power.

In this embodiment, the second substrate 51 may be made of a material other than Si, for example, AlN.
Further, the active layer 19 may have a MQW structure instead of a bulk, and a laser may be manufactured using a p-InP substrate. Further, the n-electrode 65 is formed after forming the air layer, but may be formed beforehand. In addition, the second multilayer reflective film 31 is made of Al ₂
Not limited to O ₃ / Si, for example, SiO ₂ / S
i, MgO / Si or the like.

Second Embodiment A second embodiment according to the present invention will be described with reference to FIG. FIG. 6 is a sectional view of the surface emitting semiconductor laser according to the present embodiment. The structure is almost the same as that of the first embodiment, and a detailed description of overlapping parts will be omitted. 6, the same parts as those in FIG. 1 are given the same numbers. In the present embodiment, the first
An anisotropic conductive adhesive is used as a means for attaching the second base and the second base.

The anisotropic conductive adhesive is made of, for example, a thermosetting resin 103 containing conductive particles 101 at an appropriate density. The conductive particles 101 are, for example, metal particles of Ni coated with gold, and have a particle size of about 4 μm.

This adhesive is applied on a second substrate, and the first
The two substrates are combined so that the electrode portions 33 and 55 of the second substrate and the second substrate coincide with each other, and heated to 200 ° C. while applying a pressure of 3 kgf / cm ² to cure the resin 103. By compression heating, the electrode 33 and the electrode 55
In the portion sandwiched between the conductive particles, the conductive particles are deformed, and the portion is sunk into the electrode, thereby enabling vertical conduction. On the other hand, in other portions, the particles 101 are in a state of floating in the resin 103 and cannot be conducted.

In the present embodiment, as compared with the first embodiment, even if the surface is covered with insulating dust or covered with an oxide film, an electric contact can be reliably obtained. This has the advantage that the yield is improved.

In this embodiment, Ni is used as the conductive particles.
Although a particle coated with gold is used, the present invention is not limited to this. For example, a particle obtained by coating plastic particles with gold may be used. The particle size may be appropriately selected according to the structure. In addition, an ultraviolet curable resin may be used. In this case, the substrate 51 used for the second base is preferably of a type that transmits ultraviolet light. Furthermore, a resin obtained by processing a resin containing conductive particles into a sheet shape in advance may be sandwiched between the first base and the second base, and the two bases may be bonded to each other by heating under pressure.

Third Embodiment A third embodiment according to the present invention will be described with reference to FIG. FIG. 7 is a sectional view of the surface emitting semiconductor laser according to the present embodiment. The structure is almost the same as that of the first embodiment, and a detailed description of overlapping parts will be omitted. 7, the same parts as those in FIG. 1 are given the same numbers.

In this embodiment, a sulfuric acid-based etchant is injected from the etching window 61 to selectively remove InGaAs, which is one of the materials constituting the semiconductor multilayer film 15, to form a laminated structure of an air layer and an InP layer. The difference from the first embodiment is that the etching window 61 is buried with the burying material 201 after forming the first multilayer reflective film 63 made of. In this embodiment, a relatively viscous polyimide is used as the embedding material 201 to suppress penetration into the air layer.

By adding this filling material 201, the state of the air layer can be maintained, so that the air layer is prevented from being crushed or the film thickness from being deviated from the design during the processing process. It has become possible to reduce the variation in the film thickness. As a result, when the laser array was manufactured, variation in the oscillation wavelength could be reduced as compared with the first embodiment.

Fourth Embodiment A fourth embodiment according to the present invention will be described with reference to FIG. FIG. 8 is a sectional view of the surface emitting semiconductor laser according to the present embodiment. The structure is almost the same as that of the first embodiment, and a detailed description of overlapping parts will be omitted. 8, the same parts as those in FIG. 1 are given the same numbers.

In this embodiment, the third layer composed of 6.5 cycles of n-InGaAsP (band gap wavelength: 1.1 μm) / n-InP is provided on the active layer 19 side of the first multilayer reflection film 63.
That the multilayer reflective film 301 is inserted in the epitaxial growth stage and that the thickness of the n-InP spacer layer 317 is 0.98 μm, which is thinner than the spacer layer 17 in the first embodiment. This is a difference from the first embodiment.

The addition of the third multilayer reflective film 301 has the following advantages. (1) Lowering the Threshold Value Since the first multilayer reflective film 63 contains an air layer, current cannot flow through the first multilayer reflective film 63, and current must be injected around the first multilayer reflective film 63. . Therefore, in order to effectively inject current into the active layer 19, it is necessary to diffuse the current in the spacer layer, and it is necessary to increase the thickness of the spacer layer to some extent (specifically, 1 μm).
m, and the thickness of the spacer layer 17 is 1.9 μm in the first embodiment.) In this embodiment, since the third multilayer reflective film 301 can be used for current diffusion,
The thickness of the spacer layer 317 can be reduced. As a result, the length of the resonator can be reduced, so that the threshold can be reduced as compared with the first embodiment.

(2) Reduction of Fluctuation of Oscillation Wavelength Since the first multilayer reflection film 63 includes an air layer, the thickness of the air layer may deviate from the design during the processing process, or may be caused by the surrounding pressure. The film thickness tends to fluctuate. Of course, the error can be reduced by embedding with the embedding material as in the third embodiment, but it is difficult to completely eliminate the error. When the film thickness changes in this way, the phase of the reflected wave at the first multilayer reflective film 63 changes. this is,
It means that the effective resonator length changes, and as a result,
The oscillation wavelength changes. However, when the third multilayer reflective film 301 is provided, the influence when the film thickness of the first multilayer reflective film 63 changes is reduced.

When there is a third multilayer reflective film 301 (InGaAsP / 1nP) when the thickness of the air layer deviates from the design (corresponding to the present embodiment) and when it does not (corresponding to the first embodiment) FIG. 9 shows the calculation result of the phase shift of the reflected wave at. In this calculation, it is assumed that each layer of the air layer deviates uniformly from the design, while the other layers do not change.

As can be seen from FIG. 9, the ratio of the phase shift of the reflected wave to the change in the thickness of the air layer is smaller when the third multilayer reflective film 301 is provided. As a result, in the present embodiment, it was possible to reduce the fluctuation of the oscillation wavelength due to the deviation from the design as compared with the first embodiment. Of course, in addition to the addition of the third multilayer reflective film 301,
As in the third embodiment, reinforcement with an embedding material may be performed.

In this embodiment, the laser is manufactured using the n-InP substrate, but a p-InP substrate may be used. In this case, compared with n-InGaAsP / n-InP, p-InGaAs as the third multilayer reflective film 301 is used.
P / p-InP has a problem in that the resistance becomes high, so that lowering the threshold voltage is slightly inferior, but has the effect of reducing the fluctuation of the oscillation wavelength.

In addition, in the present embodiment, the third multilayer reflective film 301 has a periodic structure of two semiconductor layers.
For example, a periodic structure in which three or more layers including a composition modulation layer and a doping modulation layer are added may be used. This makes it possible to reduce the discontinuity of the band and reduce the resistance.

Fifth Embodiment A fifth embodiment according to the present invention will be described with reference to FIG.
FIG. 10 is a sectional view of the surface emitting semiconductor laser according to the present embodiment.

This embodiment has a structure in which both the p-electrode and the n-electrode can be taken out from the second substrate side. The structure is almost the same as that of the first embodiment, and a detailed description of overlapping parts will be omitted. 10, the same parts as those in FIG. 1 are denoted by the same reference numerals.

In this embodiment, the first base is etched so that the n-InP spacer layer 17 is exposed in a part of the portion other than the light emitting region. Then, an n-electrode 401 is formed so that an n-side contact can be made at this portion. At this time, both the n-electrode 401 and the p-electrode 29 are electrodes capable of handling both polarities, for example, Ti / Pt /
If it is made of Au, it is possible to form a film at the same time. Further, when the second multilayer reflective film 31 is formed, a bump 403 having the same configuration as that of the second multilayer reflective film 31 is formed, and the bump 403 is covered with an electrode 405 made of Au.

With respect to the first substrate thus manufactured,
In the same manner as in the first embodiment, affixing to the second base, removal of the substrate 11 and the etch stop layer 13,
Of the multilayer reflection film 63 is performed.

In this embodiment, both the n-electrode and the p-electrode can be taken out from the second substrate side, as compared with the first embodiment.
When an electronic circuit is provided on the Si substrate 51, which is the main body of the second base, it is easy to mount it on a C package or the like, and the connection between each part of the electronic circuit and the n-electrode and the p-electrode becomes easy. There is an advantage that consistency is good.

Sixth Embodiment In the above embodiment, an example using an InP substrate has been described, but a GaAs substrate can also be used.
A sixth embodiment according to the present invention will be described with reference to FIG.
FIG. 11 is a sectional view of the surface emitting semiconductor laser according to the present embodiment.

First, the first base will be described. n-
On a GaAs substrate (not shown in the figure because it will be removed later), a semiconductor multilayer film 515 (thickness of the AlAs layer of 0.4 mm) consisting of four periods of n-AlAs / n-GaAs is provided.
N-Al _0.6 Ga _0.4 As spacer layer 51 having a thickness of 0.72 μm and a GaAs thickness of 0.212 μm) and a thickness of 1.0 μm.
7. An active layer 519 having a quantum well structure composed of In _0.3 Ga _0.7 As / GaAs (band gap wavelength 0.85 μm).
m), a 0.5 μm-thick p-Al _0.6 Ga _0.4 As spacer layer 521 and a second semiconductor multilayer reflective film 523 made of p-Al _0.1 Ga _0.9 As / p-AlAs are sequentially grown.
The growth means is, for example, MOCVD, MBE, C
It is performed by a method such as BE.

Further, the periphery of the light emitting region is etched in a donut shape by the RIBE method or the like, and the etched portion is embedded with polyimide 525. The light emitting region has a diameter of, for example, 25 μm.
m, donut-shaped outer shape is 50
It is a circle of μm. Although not shown in FIG. 11, before embedding with polyimide 525, the current constriction structure is provided by selectively oxidizing AlAs of the second multilayer reflective film 523 in the light emitting region to further reduce the diameter of AlAs. Is also good.

Next, in order to insulate a portion other than the light emitting region, TiN having a diameter of 80 μm after covering with SiN _x 527 was used.
A circular p-electrode 529 made of Pt / Au is deposited. This completes the processing of the first base body on the side to which the first base is attached.

The second substrate is made of a Si-based Heat on the surface of plate 551
After forming the oxide film 553, for example, a 1 μm thick Cr
/ Au electrode 555 is formed.
The area other than the connection part is etched by about 5 μm.
Here, the step is provided by etching because of adhesion
This is to improve the wraparound of the resin when performing.

The first and second substrates thus manufactured are
After bonding using a thermosetting resin 557 in the same manner as in the first embodiment, the n-GaAs substrate (not shown in the figure) on the first substrate side is removed over the entire surface. Semiconductor multilayer film 51
In order to impart selectivity to AlAs, which is the first layer of No. 5, the wet etching and the dry etching based on ammonia + hydrogen peroxide may be used in combination. Further, AlAs, which is the first layer of the semiconductor multilayer film 515, is removed by dry etching, and an n-electrode 559 made of Ti / Pt / Au is formed on a part other than the GaAs light-emitting region.
Is formed.

Further, in the same manner as in the first embodiment, the etching window 5 almost penetrating through the semiconductor multilayer film 515 is formed.
61 is formed so as to surround the light emitting region. Subsequently, an etchant is injected from the etching window 561,
G which is one of the materials constituting the semiconductor multilayer film 515
aAs is selectively removed to form a first multilayer reflective film 563 having a laminated structure of an air layer and an AlAs layer.

In the surface emitting semiconductor laser of this embodiment,
Since the GaAs substrate is opaque to the oscillation wavelength, it needs to be removed.
Since the n-GaAs substrate (not shown in the figure) can be removed over the entire surface using the second base as a support substrate, the process is simple and the yield is improved.

When a 4 × 4 surface-emitting semiconductor laser array was manufactured using such a method, there was almost no variation in characteristics such as threshold voltage and power. In this embodiment, the active layer may have a bulk structure,
The laser may be manufactured using a p-GaAs substrate.

Seventh Embodiment A seventh embodiment according to the present invention will be described with reference to FIG.
FIG. 12 is a sectional view of the surface emitting semiconductor laser according to the present embodiment. The structure of the second base is the same as that of the sixth embodiment, and is given the same number.

In this embodiment, n-AlAs / n-Al _0.1 Ga _{0.9 is provided} on the active layer 519 side of the first multilayer reflection film 563.
As a third multilayer reflective film 601 having seven periods is inserted in the epitaxial growth stage,
7 is different from the sixth embodiment in that the thickness of the resonator 7 and the active layer 519 are shortened.

The manufacturing method is the same as that described above, and a description thereof will be omitted. The first layer (the layer on the first multilayer reflective film 563 side) of the third multilayer reflective film 601 is made of AlAs in order to secure selectivity in GaAs etching for forming an air layer. In addition, since the magnitude relationship between the refractive indices of the first multilayer reflective film 563 and the third multilayer reflective film 601 is reversed, the thickness of the first layer of the third multilayer reflective film 601 is changed to a normal one. The wavelength is set to 波長 wavelength instead of 位相 wavelength, and is equivalent in phase to the absence of the first layer.

As in the fourth embodiment, the third multilayer reflective film 6
By adding 01, (1) lowering the threshold value,
(2) Variation in oscillation wavelength can be reduced.

In the sixth and seventh embodiments using a GaAs substrate, the first multilayer reflective film is reinforced with a filling material, and both the p and n electrodes are taken out from the second base. Of course.

Eighth Embodiment Although the above embodiments are all surface-emitting semiconductor lasers,
The structure having the multilayer reflective film of the semiconductor layer and the gas layer of the present invention,
The present invention can also be applied to a surface type semiconductor optical device such as an LED and a light receiving element. In the case of an LED, the multilayer reflective film may be only a multilayer reflective film of a semiconductor layer and a gas layer, whereby an LED with good directivity at a specific wavelength defined by the vertical thickness of the multilayer reflective film can be realized. A light receiving element having a multilayer reflective film of a conductor layer and a gas layer is a light receiving element having extremely high selectivity with respect to wavelength. Further, an optically pumped surface emitting semiconductor laser may be used.

[0080]

As described above, according to the present invention,
It is possible to realize a surface-emitting semiconductor optical device such as a surface-emitting semiconductor laser with a highly versatile multilayer reflective film, high productivity, and high yield, and a method for manufacturing such a surface-emitting semiconductor optical device relatively easily. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a surface emitting semiconductor laser according to the present invention.

FIG. 2 is a diagram showing the dependence of the reflectance of a first multilayer reflective film on the number of pairs.

FIG. 3 is a diagram showing the wavelength dependence of the reflectance of a first multilayer reflective film.

FIG. 4 is a view for explaining a manufacturing process of a first base of the first embodiment.

FIG. 5 is a diagram illustrating a manufacturing process of the first embodiment.

FIG. 6 is a sectional view showing a second embodiment of the surface emitting semiconductor laser according to the present invention.

FIG. 7 is a sectional view showing a third embodiment of the surface emitting semiconductor laser according to the present invention.

FIG. 8 is a sectional view showing a fourth embodiment of the surface emitting semiconductor laser according to the present invention.

FIG. 9 is a diagram showing a phase shift of a reflected wave with respect to a change in the film thickness of an air layer, with and without a third multilayer reflective film.

FIG. 10 is a sectional view showing a fifth embodiment of the surface emitting semiconductor laser according to the present invention.

FIG. 11 is a sectional view showing a sixth embodiment of the surface emitting semiconductor laser according to the present invention.

FIG. 12 is a sectional view showing a seventh embodiment of the surface emitting semiconductor laser according to the present invention.

[Explanation of symbols]

11, 51, 551 substrate 13 etch stop layer 15, 515 semiconductor multilayer film 17, 21, 317, 517, 521, 617 spacer layer 19, 519 active layer 23 contact layer 25, 525 polyimide 27, 527 SiN _x 29, 33, 55, 65, 401, 405, 529, 5
55,559 electrode 31,523 second multilayer reflective film 53,553 thermal oxide film 57,103,557 resin 61,561 etching window 63,563 first multilayer reflective film 101 conductive particles 201 filling material 301,601 first 3 multilayer reflective film 403 bump

Claims (30)

[Claims] 1. A surface type semiconductor optical device having a semiconductor multilayer film and a multilayer reflection film provided on at least one side in the stacking direction of the semiconductor multilayer film, wherein the multilayer reflection film has a periodic structure of a semiconductor layer and a gas layer. A surface type semiconductor optical device, comprising: 2. A vertical resonance comprising a semiconductor multilayer film including an active layer, first and second multilayer reflection films provided on both sides of the semiconductor multilayer film in the laminating direction, and excitation means for exciting the active layer. 2. A surface-emitting semiconductor optical device according to claim 1, wherein said first multilayer reflection film has a periodic structure of a semiconductor layer and a gas layer. 3. A planar LED comprising a semiconductor multilayer film including an active layer, a multilayer reflective film provided on one side in the laminating direction of the semiconductor multilayer film, and an excitation means for exciting the active layer. The surface type semiconductor optical device according to claim 1, wherein: 4. A multilayer reflective film comprising a periodic structure of a semiconductor layer and a gas layer, wherein one of the semiconductors of a periodic structure comprising two different semiconductor layers epitaxially grown on a first substrate to be finally removed. 4. The method according to claim 1, wherein the layer is selectively removed.
The planar semiconductor optical device according to the above. 5. A periodic structure comprising a first substrate, two different semiconductor layers epitaxially grown on the first substrate,
A first substrate including a semiconductor multilayer film including a functional region such as at least one light emitting region having an active layer attached to a second substrate mainly including a second substrate; To expose a periodic structure composed of the two different semiconductor layers, and selectively etch one of the two different semiconductor layers forming the periodic structure in a portion of the periodic structure corresponding to the functional region. 5. The planar semiconductor optical device according to claim 1, wherein a periodic structure of a semiconductor layer and a gas layer is formed. 6. The first substrate includes a first substrate, a periodic structure including two different semiconductor layers epitaxially grown on the first substrate, and at least one functional region including an active layer and a spacer layer. 6. The surface type semiconductor optical device according to claim 5, further comprising a semiconductor multilayer film and a second multilayer reflection film formed in accordance with the functional region. 7. The surface type semiconductor optical device according to claim 6, wherein said second multilayer reflection film is a dielectric multilayer film. 8. The surface type semiconductor optical device according to claim 6, wherein both the first and second multilayer reflection films are semiconductor multilayer films. 9. The surface type semiconductor optical device according to claim 8, wherein one semiconductor layer of said second multilayer reflection film is etched in an in-plane direction to form a current confinement structure. 10. A third semiconductor multilayer film comprising a periodic structure of two or more semiconductor layers epitaxially grown between the first multilayer reflective film and a semiconductor multilayer film including an active layer. The surface type semiconductor optical device according to any one of claims 1 to 9, wherein the multilayer reflection film of (1) is present. 11. The surface type semiconductor optical device according to claim 10, wherein said second and third multilayer reflection films include layers whose composition is modulated. 12. The surface type semiconductor optical device according to claim 10, wherein said second and third multilayer reflection films include layers doped and modulated. 13. The surface type semiconductor optical device according to claim 1, wherein said first multilayer reflection film has a periodic structure of a semiconductor layer and a gas layer having at least three periods or more. 14. An electrode for allowing a current to flow into the active layer is formed on the outermost surface of the first and second substrates, and the electrodes are attached so as to be electrically connected to each other. 14. The surface type semiconductor optical device according to claim 1, wherein: 15. An anisotropic conductive adhesive containing conductive particles, said conductive means having a conductivity only in a direction perpendicular to the substrate, as means for attaching said first base and said second base. The surface type semiconductor optical device according to claim 1, wherein the surface type semiconductor optical device is used. 16. The surface type semiconductor optical device according to claim 1, wherein said second substrate is made of a material having good heat conductivity. 17. The surface type semiconductor optical device according to claim 1, wherein said first substrate is an InP substrate. 18. The surface type semiconductor optical device according to claim 1, wherein said first substrate is a GaAs substrate. 19. The surface type semiconductor optical device according to claim 1, wherein said active layer is etched in an in-plane direction to form a current confinement structure. 20. The planar semiconductor light according to claim 1, wherein both the p and n electrodes, which are part of said excitation means, are taken out from the second base. device. 21. The surface type semiconductor optical device according to claim 1, wherein said functional region is etched in a columnar shape, and an insulating material is buried around said functional region. 22. The planar semiconductor light according to claim 1, wherein a portion of the second substrate other than a portion corresponding to a functional region is etched to form a step. device. 23. When selectively etching one of two different semiconductor layers forming the periodic structure,
23. The surface mold according to claim 1, wherein etching windows formed at several locations around the functional region so as to substantially penetrate the periodic structure are filled with a highly viscous filling material. Semiconductor optical device. 24. The surface type semiconductor optical device according to claim 1, wherein said excitation means comprises a current and a current injected into the active layer via an electrode. 25. The surface type semiconductor optical device according to claim 1, wherein said excitation means is light having a wavelength shorter than the band gap wavelength of the active layer injected from the outside. . 26. The surface type semiconductor optical device according to claim 1, wherein said gas layer is an air layer. 27. A semiconductor device according to claim 1, wherein a plurality of sets including at least the semiconductor multilayer film and a multilayer reflection film having a periodic structure of the semiconductor layer and the gas layer are formed.
A surface type semiconductor optical device according to any one of the above. 28. A semiconductor device comprising: a first substrate; a periodic structure including two different semiconductor layers epitaxially grown on the first substrate; and a semiconductor multilayer film including a functional region such as at least one light emitting region having an active layer. Attaching a first substrate to a second substrate mainly including a second substrate; removing the first substrate to expose a periodic structure including the two different semiconductor layers; Forming a plurality of etching windows in the structure around the functional region so as to substantially penetrate the periodic structure; and either of two different semiconductor layers forming the periodic structure by injecting an etchant from the etching window. 28. The surface type semiconductor according to claim 1, further comprising a step of selectively etching one side to form a periodic structure of a semiconductor layer and a gas layer in a portion corresponding to the functional region. A method for manufacturing a device. 29. The first substrate includes a first substrate, a periodic structure including two different semiconductor layers epitaxially grown on the first substrate, and at least one functional region including an active layer and a spacer layer. 29. The method for manufacturing a surface type semiconductor optical device according to claim 28, further comprising a semiconductor multilayer film and a second multilayer reflection film formed in accordance with the functional region. 30. The surface mold according to claim 28, further comprising a step of embedding the etching window with a highly viscous embedding material after the step of forming the periodic structure of the semiconductor layer and the gas layer. Manufacturing method of semiconductor optical device.