JP2000022273A - Semiconductor optical device having electrode in the vicinity of tightly jointed region and fabrication thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fabricate a semiconductor device having electrode arrangement suitable for forming an array with high productivity and yield using solid phase jointing technology. SOLUTION: A first basic body includes at least one protrusion 21 including an active layer 17 and first joint members 25, 27 formed in the vicinity thereof. A second basic body includes a second substrate 51 and second joint members 59, 61 provided at positions corresponding to the first joint members 25, 27. First and second basic bodies are bonded and the uppermost surfaces of the protrusion 21 and the second basic body are jointed tightly to accomplish electrical joint and the first and second joint members 25, 27 and 59, 61 are jointed each other. An electrode 59 connected electrically with the protrusion 21 is provided on the uppermost surface of the second basic body in the vicinity of the tight joint region of the uppermost surfaces of the protrusion 21 and the second basic body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor optical device such as a semiconductor light emitting device, and more particularly to a semiconductor device such as a vertical cavity surface emitting semiconductor laser which emits light in a direction perpendicular to a substrate characterized by the way of providing electrodes. The present invention relates to an optical device and a method for 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.
Vertical cavity surface emitting semiconductor lasers (Vertical Cavity Surface Emitting)
Laser: VCSEL) 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] Such a surface emitting semiconductor laser is generally used.
A structure such as current confinement or light confinement is provided on the side on which the epitaxial growth is performed. In the case of arraying, it is general that electrodes are independently provided on the side on which the epitaxial growth is performed and the substrate side is a common electrode.

[0006]

However, in such a surface emitting semiconductor laser, for example, In
In the case of P system, after an active layer or the like is grown on a substrate, it is processed by etching or the like, and S is formed by a method such as evaporation or sputtering.
It is necessary to form an iO ₂ / Si multilayer film or an Al ₂ O ₃ / Si multilayer film, and there is a disadvantage that the process becomes complicated. In the case where an AlAs / (Al) GaAs multilayer film is directly bonded on an InP substrate, a small area is effective but a large area is difficult.

In a surface emitting semiconductor laser, it is necessary to remove the substrate depending on the semiconductor material and the oscillation wavelength band of the substrate. For example, an oscillating wavelength of 0.
When manufacturing a surface emitting semiconductor laser of 85 μm, GaAs
Since the s-substrate has a large absorption of this light, it is necessary to remove the substrate in order to extract light from the substrate side. In addition, when fabricating a surface emitting semiconductor laser having an oscillation wavelength of 1.3 μm or 1.55 μm using an InP substrate,
After removing the nP substrate, it is necessary to form a multilayer mirror made of a dielectric. 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-like etching with good reproducibility.
It is also difficult to form a multi-layer film such as an iO ₂ / Si multi-layer film or an Al ₂ O ₃ / Si multi-layer film with good reproducibility, which causes a reduction in yield.

Further, when elements are arrayed with the substrate side as a common electrode of each element, there is a problem that the characteristics of the elements are affected by electric crosstalk from surrounding elements. Further, for example, special wiring such as matrix wiring cannot be used, and versatility is poor.

In this respect, for example, as shown in FIG. 17 (JP-A-9-223848), the optical element 100
0 (1000A is a light receiving element, 1000B is a surface emitting semiconductor laser) is attached to a heterogeneous substrate 2000 using a polyimide 3000, and electrodes 1000C and 1000 are independently provided for each element.
D, 2000A, and 4000, and a type that reduces electrical crosstalk by separating each optical element has been proposed. However, in this example,
Since polyimide 3000 is used, the heat dissipation of the optical element is poor, and there is a disadvantage that a special device such as providing a metal or the like for heat diffusion is required. This example assumes a GaAs surface emitting semiconductor laser,
AlAs / (Al) GaAs on InP-based substrate with active layer
It is difficult to apply to a surface emitting semiconductor laser of a type in which an s multilayer film is bonded.

Further, as shown in FIG. 18, a surface emitting semiconductor laser has a three-terminal structure of pnp or npn, a refractive index modulation layer is provided in a resonator, and a current is injected or a voltage is applied to the modulation layer. A surface emitting semiconductor laser that changes the oscillation wavelength or performs high-speed modulation by controlling the refractive index and the loss by controlling the refractive index and the loss has also been proposed (Japanese Patent Laid-Open No. 5-6).
No. 3301).

However, even in such a surface emitting semiconductor laser, for example, in the case of the InP type, there is a problem described above. Further, as described above, there are problems in removing the substrate, etching the substrate into a hole, forming a multilayer film in the hole, and the like. Further, when the substrate side is arrayed as a common electrode of each element, there is a problem that the characteristics of the elements are affected by electric crosstalk from surrounding elements. In addition, when directly modulating the intensity of the oscillating light by turning on / off the injection current, carriers are required to enter and exit, which limits the speedup.

Further, in the wavelength tunable surface emitting semiconductor laser as shown in FIG. 18, it is not considered to form an array, and the electrode 1015 on the substrate 1001 (p substrate in the case of a pnp structure) (in the case of a pnp structure, Both the p-electrode and the central electrode 1014 (the n-electrode in the case of a pnp structure) are common electrodes for each element, and cannot be controlled independently. For example, even if the center electrode 1014 of each element is separated by providing a separation groove, it is inevitable that the characteristics of the element are affected by electric crosstalk from the surrounding elements through the substrate 1001. In addition, in order to operate the element stably, it is preferable that the central electrode, which is a common electrode among the three terminals, be grounded. In this case, the electrode on the substrate 1001 side must be separated. It is structurally difficult. Further, in this example, a GaAs surface emitting semiconductor laser is assumed, and an AlAs / (Al) G
It is difficult to adapt to a surface emitting semiconductor laser of a type in which an aAs multilayer film is bonded.

In view of these problems, an object of the present invention is to
It is an object of the present invention to provide a semiconductor optical device which has good productivity and yield and has an electrode arrangement suitable for arraying using a solid phase bonding technique, and a method for manufacturing the same.

[0014]

In order to achieve the above object, a semiconductor optical device according to the present invention comprises at least one protrusion including an active layer and a first protrusion formed near the protrusion.
And a second substrate including a second substrate and a second bonding member provided at a position corresponding to the first bonding member. The first substrate includes a second substrate and a second bonding member provided at a position corresponding to the first bonding member. The first and second bonding members are tightly bonded to each other using a solid-state bonding technique so as to achieve electrical bonding with the outermost surface of the second substrate, and the first and second bonding members are bonded to each other. And an electrode electrically connected to the protrusion on the outermost surface of the second substrate in the vicinity of a tightly bonded region between the outermost surface of the protrusion and the uppermost surface of the second substrate. It is characterized by having been done. Here, the joining member gives a joining force to the bases by joining the materials having plastic deformability, and thereby, a functional coupling such as an electric coupling and an optical coupling can be achieved in the above-mentioned close coupling region. Something (ie, whether or not it should be a conductive material such as a metal) may be used,
When an electrical connection with the above-mentioned electrodes or the like is required, it is necessary to use a conductive material. As shown in an embodiment described later, if an insulating layer is formed at a necessary portion and all the joining members are formed of a conductive material, the manufacturing process is simplified.

According to the above configuration, since the mechanical joining force is left to the joining member, the area for solid phase joining can be made very small, the stress at this portion is small, and the joining can be made surely and the area can be increased. Become. Furthermore, stronger bonding is enabled by bonding members or metal members arranged around the bonding member, and processing such as removal of the substrate on the back surface can be easily performed. Furthermore, when arrayed, p, n of each element
Wiring can be provided independently. In other words, since there is no need to provide a common electrode on the back side of the second substrate, electrical crosstalk can be suppressed and special wiring such as matrix wiring can be applied. It is.

Under the basic structure characterized by the above-described tightly-bonded region and electrode arrangement, more specifically, the following forms are possible.

(1) The electrode is electrically connected to the projection via the outermost surface of the second substrate and the outermost surface of the projection. In this case, the outermost surface of the second substrate is conductive in the vicinity of the region where the protrusion is closely bonded to the protrusion and the region where the electrode is provided, and is insulative in other regions. May be electrically connected via the conductive region of the second substrate. As a further specific example in this case, a first substrate (often removed later), at least one protrusion including an active layer formed on the first substrate, and a periphery of the protrusion are provided. A first substrate including a first metal (joining member) electrically insulated from the first substrate formed on the first substrate; a second substrate; and a second substrate provided at a position corresponding to the first metal. A second metal (joining member) electrically connected to the second substrate
The first and second bases are formed such that the outermost surface of the projection and the outermost surface of the second substrate are solid-phase bonded, and the first and second metals are bonded to each other. Glued. Further, the outermost surface of the second substrate is conductive in the vicinity of the region bonded to the protrusion and the region where the second metal is provided, and is insulative in other regions. The metal (which is also an electrode) and the outermost surface of the protrusion are electrically connected via a conductive region of the second substrate.

In this case, another electrode is provided on the side of the first substrate opposite to the side on which the projection is formed (on the side of the first substrate), and the first electrode is connected to the other electrode. The current can be injected between the two. At this time, the joining member may be any material that provides a sufficient mechanical joining force,
It need not be formed of a conductor.

(2) The electrode is electrically connected to the protrusion via the first base. In this case, the first joining member is made of a conductor and is electrically connected to the first base, and the second joining member is also made of the conductor and is electrically connected to the electrode. It is electrically insulated from the outermost surface of the second substrate, and is electrically connected to the protrusion via the second joint member and the first joint member. In this case, the other electrode may be connected to a desired portion of the second base and may be on the front surface or on the back surface of the second base (if it is on the back surface, the electric crosstalk may be reduced). There are disadvantages such as a problem occurring or an attempt to prevent this would complicate the processing of the second substrate).

(3) In the first base, a third bonding member, which is a conductor electrically connected to the first base, is formed near the protrusion, separately from the first bonding member. In the second base, a fourth bonding member, which is a conductor electrically insulated from the second substrate, is formed at a position corresponding to the third bonding member separately from the second bonding member. The first and second substrates are bonded so that the third and fourth bonding members are also bonded to each other, and further, the close contact between the outermost surface of the protrusion and the outermost surface of the second substrate is performed. Second near the coupling region
Another electrode is provided on the outermost surface of the substrate, and the electrode is electrically connected to the projection via the outermost surface of the second substrate and the uppermost surface of the projection, but the first electrode The other electrode is electrically insulated from the second substrate, and the other electrode is electrically insulated from the second substrate. They are electrically connected via a joining member. According to this configuration, the wiring on the back surface side of the first base is unnecessary, and both the p and n wirings can be formed in advance on the surface of the second base by patterning or the like before bonding. . It is possible to provide a semiconductor light emitting element or the like in which the characteristics of the element are stabilized, wiring is easy, and the array is suitable.

Here, the outermost surface of the second substrate is electrically conductive in the vicinity of the region where the electrode is provided and the region where the second substrate is in close contact with the projection, and includes the region where the other electrode is provided. Other regions may be insulative.

(4) A structure having an active layer and a refractive index modulation layer in a resonator, capable of injecting current into the active layer, and a refractive index modulation layer independent of current injection into the active layer. And a structure capable of injecting a current or applying a voltage to the first substrate, wherein the first base is formed near the protrusion, at least one protrusion including the refractive index modulation layer, the active layer, and the second base. A first joining member electrically insulated from the first base, and a third joining member formed of a conductor formed near the protrusion and electrically connected to the first base; The second base member is provided at a position corresponding to the second substrate and the first bonding member and at a position corresponding to the second bonding member provided on the electrode and the third bonding member. A fourth joining member made of a conductor electrically insulated from the first joining member; Electrically connected but electrically insulated from the second substrate and provided with another electrode provided on the outermost surface of the second substrate, the first and second joining members, and 3. The first and second substrates are bonded so that the fourth and fourth bonding members are bonded to each other, and further another electrode is formed on the surface of the first substrate opposite to the tightly bonded region. A current is injected into the active layer using the electrode and the other electrode, and a current is injected or a voltage is applied to the refractive index modulation layer using the other electrode and the further electrode.
As a result, using solid-state bonding technology, the characteristics of the device are stabilized, and the productivity and yield are good.
It is possible to provide a semiconductor laser or the like capable of performing wavelength modulation and high-speed modulation.

More specifically, a first substrate (often removed later), a refractive index modulation layer, at least one protrusion including an active layer, and a formation around the protrusion are provided. A first metal electrically insulated from the first substrate, a first base formed around the protrusion, and including a third metal electrically connected to the first substrate; and A second substrate, a second metal provided at a position corresponding to the first metal and electrically connected to the second substrate, and a second substrate provided at a position corresponding to the third metal. A second base including a fourth metal that is electrically insulated; the outermost surface of the projection and the outermost surface of the second substrate are solid-phase bonded to each other; , And the first and second substrates are bonded so that the third and fourth metals are bonded to each other, and the first and second metals are connected to the first electrode ( Serial electrode) as a function, the third, fourth metal functions as the second electrode (the other electrode),
The first substrate has a third electrode (the above-mentioned further electrode) on a surface opposite to the bonding surface, and current is injected into the active layer using the first electrode and the second electrode. Current injection or voltage is applied to the refractive index modulation layer using the second electrode and the third electrode.

With these configurations, when arrayed, three terminal electrodes of each element can be provided independently.
It is not necessary to provide a common electrode on the back side of the second substrate, so that electrical crosstalk can be suppressed. Both p and n wirings for current injection into the active layer are provided on the surface of the second base,
It can be formed beforehand by patterning or the like before joining. In each element, wavelength control and high-speed modulation can be performed by performing current injection or voltage application to the refractive index modulation layer independently of current injection to the active layer.

Here, if there are two multilayer reflective films so as to sandwich the active layer and the refractive index modulation layer, a resonator can be formed in a direction perpendicular to the substrate surface, and oscillation can be performed as a surface emitting semiconductor laser. In the first base, a vertical cavity may be formed by providing a semiconductor multilayer reflective film on the opposite side of the refractive index modulation layer from the side where the protrusion is located. Especially G
It is applicable to an aAs-based surface emitting semiconductor laser. Further, a part of the semiconductor multilayer reflection film may be a refractive index modulation layer. Thereby, the cavity length can be reduced, and a surface emitting semiconductor laser with a lower threshold can be provided. Also,
The other electrode or the second electrode may be electrically grounded. Reduces electrical crosstalk within the device,
The driving of the element becomes easy. Further, the refractive index modulation layer may have a multiple quantum well structure. The refractive index can be easily changed, and wavelength tuning and high-speed modulation can be performed more effectively.

(5) Two multilayer reflective films are formed so as to sandwich the active layer, and can oscillate as a surface emitting semiconductor laser. In this case, if the semiconductor multilayer reflective film is formed on or near the outermost surface of the second substrate, a vertical resonator can be formed at the same time as the current injection structure is formed at the time of bonding. In particular, it is applicable to an InP-based surface emitting semiconductor laser. Even if the semiconductor multilayer reflective film is formed on or near the outermost surface of the projection, a current injection structure can be formed at the time of bonding. In particular, it is applicable to a GaAs surface emitting semiconductor laser. In the first base, a vertical cavity may be formed by providing a semiconductor multilayer reflective film on the side opposite to the side where the protrusion is located across the active layer. In particular, it is applicable to a GaAs surface emitting semiconductor laser.

In the first substrate, a dielectric multilayer reflective film may be formed on the opposite side of the active layer from the side where the protrusion is located. Removing the first substrate from the first substrate;
A vertical resonator is formed by forming a dielectric multilayer reflective film on the semiconductor surface that appears after the removal. In particular, it is applicable to an InP-based surface emitting semiconductor laser.

(6) At least one of the first and second joining members facing each other and at least one of the third and fourth joining members facing each other have comb-shaped irregularities. Thereby, it is possible to provide a semiconductor optical device in which the mechanical bonding strength of the bonding portion is improved. As described above, the joining member is preferably a conductor such as a metal. In this case, if the joining member and the electrodes are all metal, the manufacturing process is simplified.

(7) The semiconductor layer including the active layer and the refractive index modulation layer is usually formed on a first substrate. The first substrate is often eventually completely removed.

(8) In the first base, the portion of the first substrate that does not function as a semiconductor optical device and the semiconductor layer including the active layer and the refractive index modulation layer are removed. As a result, electrical crosstalk between each element can be reduced,
It is possible to provide a semiconductor optical device in which the characteristics of each element in an array are more stabilized.

In this case, if the insulator is buried between the plurality of semiconductor optical devices in the first base, the threshold value is lower, the structure is robust, the wiring is easy, and the first substrate is arrayed. It is possible to provide a semiconductor optical device with high productivity in which the characteristics of each element at the time are more stabilized. Further, it is possible to reduce the electric crosstalk between the elements, to form a three-dimensional wiring, and to increase the effective area when forming a dielectric multilayer reflective film, In order to achieve the above object of eliminating the need for precise alignment and improving the reflectance, the method for manufacturing a semiconductor optical device includes forming a semiconductor layer including an active layer on a first substrate; At least one protrusion including an active layer is formed on the semiconductor layer, a first bonding member is provided near the protrusion to form a first base, an electrode is formed on a second substrate, and a first substrate is formed. A second joining member is provided at a position corresponding to the joining member to form a second base, and the outermost surface of the protrusion and the outermost surface of the second substrate are tightly joined so as to achieve electrical coupling, And the first and second joining members are joined together. Sea urchin, the first, characterized by bonding a second substrate. According to this manufacturing method, a semiconductor optical device having the above structure can be manufactured with good productivity and yield by using the solid phase bonding technique.

In this manufacturing method, the outermost surface of the second substrate is formed so as to have conductivity in the vicinity of the region where the second substrate is in close contact with the projection and the region where the electrode is provided. The outermost surface may be electrically connected via the conductive region of the second substrate.

The first joint member is made of a conductor and is electrically connected to the first base, and the second joint member is made of a conductor and is electrically connected to the electrode. ,
You may make it electrically insulated from the outermost surface of a 2nd board | substrate, and may be electrically connected to a protrusion part via a 2nd joining member and a 1st joining member.

In the manufacture of the first base, a third bonding member, which is a conductor electrically connected to the first base, is formed in the vicinity of the projection separately from the first bonding member. Then, in the manufacture of the second base, separately from the second bonding member, the second surface is formed on the outermost surface of the second substrate in the vicinity of the tightly bonded region between the outermost surface of the projection and the uppermost surface of the second substrate. Another electrode is provided electrically insulated from the second substrate, and a conductor electrically insulated from the second substrate on the other electrode at a position corresponding to the third bonding member. A fourth joining member is formed, the first and second substrates are adhered so that the third and fourth joining members are joined to each other, and the electrode is connected to the outermost surface of the second substrate and the projection. Electrically connected to the projection through the outermost surface of the first base, but is electrically insulated from the first base,
The other electrode is electrically insulated from the second substrate, but is electrically connected to the protrusion via a third and fourth bonding members, which are conductors. You may be.

The principle and features of the present invention will be described in more detail below using two specific examples. 1, 2, 3, and 4
This will be described using the surface emitting laser shown in FIG. In the first base shown in FIG.
2 μm p-InGaAs etch stop layer 13, 2.0 μm thick p-InP spacer layer 15, 0.7 μm thickness
m of InGaAsP (band gap wavelength: 1.3 μm)
Bulk active layer 17 and an n-InP spacer layer 19 having a thickness of 1.0 μm are sequentially grown, and RIBE is formed around the light emitting region.
The columnar semiconductor projection 2 including the active layer 17 is etched by doughnut-shaped etching until the spacer layer 15 is exposed.
1 (this makes the active layer area narrower,
Current can be constricted). The insulating film 23 is buried except for the outermost surface of the semiconductor protrusion 21. Next, a ring-shaped metal layer 25 is formed so as to surround the semiconductor protrusion 21, and further, a metal protrusion 27 having comb-shaped unevenness is formed so as to surround the semiconductor protrusion 21 by using a method such as an electrolytic plating method. . The metal projection 27 is set to have the same height as the semiconductor projection 21.

Next, in the second substrate shown in FIG. 3, a multilayer reflective film 53 made of i-GaAs / i-AlAs and an n-GaAs / n-AlG
A multilayer reflective film 55 made of aAs is epitaxially grown. Further, an insulating region 57 is formed by implanting impurity ions into a predetermined region, and a substrate having conductivity is formed only on the surface, in the vicinity of the surface of a region to be bonded to the first base later. Further, a ring-shaped metal layer 59 is formed in a predetermined region. The metal layer 59 improves the adhesiveness of a metal projection 61 to be formed later, and is used for injecting a current into the semiconductor layer.
It also functions as the side electrode. Although not shown, the metal layer 59 is connected to a wiring having a pad.

Subsequently, using a method such as an electrolytic plating method,
A metal projection 61 having comb-shaped irregularities is formed at a position corresponding to the metal projection 27 on the first base. The metal protrusion 61
The height is set to be equal to the height of the semiconductor protrusion 21 of the first base.

The first and second substrates thus manufactured are attached as follows. First, the metal projections 27 and 61 formed on the first and second substrates are aligned so that the projections and depressions of the metal projections 27 and 61 are engaged with each other.
After the outermost surface of the first substrate and the outermost surface of the second substrate are brought into close contact with each other, they are heated to about 300 ° C. in a hydrogen atmosphere to perform solid-state bonding at this portion. At this time, the metal projections 27 and 61 undergo plastic deformation upon pressurization, and the metals appearing due to the deformation are bonded to each other, so that stronger bonding can be obtained.

Next, the substrate 11 is removed until the etch stop layer 13 is exposed, and the semiconductor layer that does not function as a device is removed by a method such as RIE. Furthermore, the p-side electrode 7
After forming 1, the etch stop layer is removed in accordance with the light emitting region, and a dielectric multilayer reflective film 73 is formed.

In the conventional direct bonding between different kinds of semiconductors, it is difficult to obtain a large-area and strong bonding due to stress caused by a difference in thermal expansion coefficient. However, in the present invention, since the area where the semiconductors are bonded to each other is small, the stress is small. Further, by adding metal bonding, stronger bonding can be obtained, and the area can be increased.
Furthermore, since the bonding state is good, since the entire surface can be etched even when the substrate on the back surface is removed thereafter, compared to the case where hole-shaped etching is performed,
The process is simple and the yield is improved. Further, processes such as etching can be easily performed.

Further, since the semiconductors are joined by solid-phase joining, heat generated from the active layer can be effectively radiated to the second base.

Also, by using the metal projections used for bonding as electrodes, current can be injected into the active layer from the wiring provided on the second substrate side. The p and n wirings of each element can be provided independently without providing a common electrode on the back surface side. further,
By providing a conductive region only on a part of the uppermost surface of the second base and making the other region insulating, it is also possible to suppress electrical crosstalk between the elements.

Next, a surface emitting semiconductor laser having a refractive index modulation layer will be described as an example with reference to FIGS. 10, 11, 12, and 13. FIG. In the first base, an n-InP substrate 5
11, an n-InGaAs etch stop layer 513,
n-InP spacer layer 514, refractive index modulation layer 515 having a multiple quantum well structure, p-InP spacer layer 516, InG
aAsP (band gap wavelength 1.3 μm) bulk active layer 517 and n-InP spacer layer 519 are sequentially grown,
The periphery of the light emitting region is etched into a donut shape by RIBE or the like until the spacer layer 16 is exposed to form a columnar semiconductor projection 521 including an active layer. The insulating film 523 forms the outermost surface of the semiconductor projection 521 and the spacer layer. Embed except part of 516. Next, ring-shaped metal layers 525 and 52 partially cut off so as to surround the semiconductor protrusion 521.
6 is formed. The metal layer 526 also functions as a p-side electrode for injecting current into the semiconductor layer. Further, metal projections 527 and 528 having comb-like irregularities are formed.

On the second substrate, a multilayer reflective film 553 made of i-GaAs / i-AlAs and a multilayer reflective film 555 made of n-GaAs / n-AlGaAs are epitaxially grown on an insulating GaAs substrate 551. Further, impurity ions are implanted into predetermined regions to form insulating regions 557.
Is formed, and a substrate having conductivity is formed only in the vicinity of the surface of a surface to be bonded to the first base later. further,
In a predetermined area, a ring-shaped metal layer 559 partially cut off,
560 is formed. The metal layer 559 also functions as an n-side electrode for injecting current into the active layer.

Subsequently, the metal projection 527 on the first base,
Metal projection 5 having comb-shaped irregularities at positions corresponding to 528
61 and 562 are formed.

The first and second substrates thus manufactured are attached. Next, the substrate 511 is removed until the etch stop layer 513 is exposed, and a semiconductor layer that does not function as a device is removed by a method such as RIE. Further, after forming the n-side electrode 571, the etch stop layer is removed in accordance with the light emitting region, and the dielectric multilayer reflective film 573 is formed.

Laser oscillation can be achieved by injecting current into the active layer using the metal layers 559 and 560. Furthermore, independently of this, the refractive index of this layer can be controlled by applying a voltage or injecting a current to the refractive index modulation layer using the metal layer 560 and the electrode 571. Therefore, the resonance wavelength of the resonator can be controlled, and the oscillation wavelength can be controlled. Further, since the threshold value can be controlled by controlling the resonator loss, it is possible to switch between the oscillation state and the stop state without involving the entrance and exit of carriers, and high-speed modulation can be performed.

The same effect as that of the above-described embodiment can be achieved, and since the three terminals of each element can be controlled independently, arraying is easy, and a conductive region is formed only on a part of the uppermost surface of the second base. By providing and insulating other regions, it is also possible to suppress electrical crosstalk between each element,
There is no problem if the central electrodes of the three terminals of each element in the array are grounded.

[0049]

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

First Embodiment A first embodiment in which the present invention is applied to a surface emitting semiconductor laser will be described with reference to FIGS. 1, 2, 3 and 4. FIG. FIG. 1 is a cross-sectional view of a surface emitting semiconductor laser according to the present invention, and FIGS. 2, 3, and 4 are views for explaining a manufacturing process. In FIGS. is there.

First, the first base will be described with reference to FIG. On a p-InP substrate 11, a 0.2 μm thick p
-InGaAs etch stop layer 13, thickness 2.0 μm
P-InP spacer layer 15, 0.7 μm thick InG
aAsP (1.3 μm band gap wavelength) bulk active layer 17, 1.0 μm thick n-InP spacer layer 19
Are sequentially grown (FIG. 2A). The growth means is, for example, M
This is performed by a method such as OCVD, MBE, and CBE.

Further, the periphery of the light emitting region is etched in a donut shape by RIBE or the like until the spacer layer 15 is exposed, thereby forming a columnar semiconductor projection 21 including the active layer 17 (FIG. 2 (b-1)). ), (B-2)). The light emitting region is, for example, a circle having a diameter of 20 μm. Furthermore, thickness 0.2
The semiconductor projection 21 is buried with an insulating film 23 such as SiN _{x having a} thickness of μm except for the outermost surface (FIG. 2 (c-1), FIG.
2)). Although not shown in FIG. 2, before embedding with the insulating film 23, the active layer 17 may be selectively wet-etched with a sulfuric acid-based etchant to a diameter of about 15 μm in order to effectively confine the current.

Next, a ring-shaped metal layer 25 made of Cr / Au is formed so as to surround the semiconductor protrusion 21 (FIGS. 2 (d-1) and 2 (d-2)). The metal layer 25 is formed to improve the adhesion of the metal projection 27 formed later to the insulating layer 23, and has a thickness of 0.1 μm.
Degree is fine.

Subsequently, A having a comb-like unevenness is formed so as to surround the semiconductor projection 21 by using a method such as an electrolytic plating method.
u (FIG. 2 (e-1)).
(E-2)). The metal projection 27 is set to have the same height as the semiconductor projection 21. This completes the processing of the first base body on the side to which the first base is attached.

The second base will be described with reference to FIG. On the insulating GaAs substrate 51, i-GaAs / i-
The multilayer reflection film 53 composed of 20 cycles of AlAs and n-
A multilayer reflective film 55 having five periods of GaAs / n-AlGaAs is epitaxially grown (FIG. 3A). Further, impurity ions are implanted into predetermined regions to form insulating regions 57 (FIGS. 3B-1 and B-2). As a result,
A conductive substrate can be formed only on the surface, in the vicinity of the surface of a region to be bonded to the first base later.

Next, a ring-shaped metal layer 59 made of AuGe / Au is formed in a predetermined region (FIG. 3C-1).
(C-2)). The metal layer 59 improves the adhesion of a metal projection 61 to be formed later, and also functions as an n-side electrode for injecting a current into the semiconductor layer. FIG.
Although not shown, the metal layer 59 is connected to a wiring having a pad.

Subsequently, using a method such as an electrolytic plating method,
A metal projection 61 made of Au having comb-shaped irregularities is formed at a position corresponding to the metal projection 27 on the first base (FIG. 3).
(D-1), (d-2)). The metal projection 61 is set to have the same height as the semiconductor projection 21 of the first base.

Referring to FIG. 4, the steps of attaching the first and second substrates and processes on the back side of the first substrate will be described.
As the first base, the one manufactured in the above process is turned upside down. 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.

First, the metal projections 27 and 61 formed on the first and second substrates are aligned with each other so as to engage with the projections and depressions (FIG. 4A, left side). After the outermost surface of the substrate 21 and the outermost surface of the second substrate are brought into close contact with each other, they are heated to about 300 ° C. in a hydrogen atmosphere to perform solid-state bonding at this portion (FIG. 4A, right side). Electrical coupling and optical coupling are achieved by this solid-state bonding. Both surfaces need not be flat, and for example, a plurality of grooves may be formed on one surface to reduce the tightly bonded area.

At this time, the metal projections 27 and 61 undergo plastic deformation upon pressurization, and the metals appearing due to the deformation are bonded to each other, so that stronger bonding can be obtained.

Next, the substrate 11 is removed using a hydrochloric acid-based etchant until the etch stop layer 13 is exposed (FIG. 4B).
E or the like (FIG. 4C). 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, a p-side electrode 7 made of Cr / Au
1 is formed, the etch stop layer 13 is removed in accordance with the light emitting region using a sulfuric acid-based etchant, and Al ₂ O ₃
A multilayer reflective film 73 consisting of 8 cycles of / Si is formed (FIG. 4D).

In the conventional direct bonding between different kinds of semiconductors, it is difficult to obtain a large-area and strong bonding due to stress caused by a difference in thermal expansion coefficient. However, in the present embodiment, since the area where the semiconductors are bonded to each other is small, the stress is small, and by adding metal bonding, stronger bonding can be obtained, and the area can be increased. Furthermore, since the bonding state was good, subsequent processes such as removal of the back surface could be easily performed. Further, the heat generated from the active layer 17 was also effectively dissipated to the second base.

Also, by using the metal protrusions 27 and 61 used for bonding as electrodes, it becomes possible to inject current into the active layer 17 from the wiring provided on the side of the second base, and to form an array when forming an array. The p and n wirings of each element could be provided independently without providing a common electrode on the back side of the second substrate 51. Further, by providing a conductive region only on a part of the uppermost surface of the second base and making the other region 57 insulative, electric crosstalk between the elements could be suppressed.

When a 10 × 10 surface emitting semiconductor laser array was manufactured by using such a method, there was almost no variation in characteristics such as threshold voltage, wavelength, and power. Further, in a certain element, even when a plurality of adjacent elements were driven, there was no change in element characteristics.

In the present embodiment, the metal used for improving the adhesion of the metal projection is not limited to the above-mentioned materials, and for example, Ti / Pt / Au may be used. Further, as a material used for the metal projections 27 and 61, A
u, for example, Al, In, Sn, Z
It may be n, Pb or a compound thereof. Further, both the first base and the second base have metal projections 2 having comb-shaped irregularities.
7 and 61 are formed, but any shape may be used as long as bonding strength can be obtained. For example, one may have a comb-shaped unevenness and the other may have a flat plate shape. Is also good.

The bonding was performed in a hydrogen atmosphere.
Not limited to this, argon gas, nitrogen gas,
Alternatively, a mixed gas thereof may be used. Further, as the order of processing the back surface of the first base, (c) and (b) of FIG. 4 may be exchanged. Further, the active layer 17 may have an MQW structure instead of a bulk.
The laser may be manufactured using a P substrate. in addition,
The multilayer reflective film 73 is not limited to Al ₂ O ₃ / Si, but may be, for example, SiO ₂ / Si or MgO / Si.

Second Embodiment A second embodiment in which the present invention is applied to a surface emitting semiconductor laser will be described with reference to FIG. FIG. 5A 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. 5, the same parts as those in FIG. 1 are given the same numbers.

In this embodiment, the space between the elements on the first base is buried with an insulator 101 such as polyimide, and the electrode 171 is formed so as to cover the insulator 101.
It is characterized in that a dielectric multilayer reflective film 173 made of Al ₂ O ₃ / Si is formed so as to cover the electrode 171.

The present embodiment has the following advantages. (1) Wiring can be made versatile. In the first embodiment, since the p-side electrode 71 is at a spatially floating position, wiring must be performed for each element by a method such as wire bonding. However, in this embodiment, by patterning the surface buried with the insulator 101, the electrode 171 can be connected to, for example, a wiring with a lead-out pad, which facilitates wiring and improves productivity. improves. Further, since the n-side electrode 59 and the p-side electrode 171 are separated with the insulator 101 interposed therebetween, a three-dimensional wiring as shown in FIG. 5 is possible. For example, matrix wiring for each device can be easily performed. It can be formed (see FIG. 5B).

(2) The area of the dielectric multilayer reflective film 173 can be increased, thereby improving the productivity and lowering the threshold value. In this embodiment, since the electrode 171 is connected to the wiring, the dielectric multilayer reflective film 173 may be formed so as to extend over the electrode 171 and the insulator 101. Therefore, it is not necessary to precisely position the minute pattern, and the yield and productivity are improved. Further, since the effective area of the dielectric multilayer reflective film 171 is increased, the reflectance can be improved, and the threshold can be reduced.

(3) Since separation between elements can be performed more reliably, electric crosstalk can be reduced.

(4) Since the insulator 101 can function as a reinforcing material, the structure can be made stronger.

The other effects are the same as in the first embodiment. In this embodiment, the multilayer reflective film 173 is made of Al ₂ O ₃
/ Si is not limited to, for example, SiO ₂ / S
i, MgO / Si.

Third Embodiment A third embodiment in which the present invention is applied to a surface emitting semiconductor laser will be described with reference to FIGS. 6, 7 and 8. FIG. 6 is a cross-sectional view of the surface emitting semiconductor laser according to the present embodiment, and FIGS. 7 and 8 are views for explaining the manufacturing process. FIGS. 7 and 8 show the cross-sectional view and the top view together. The same parts as those in the first embodiment are denoted by the same reference numerals.

First, the first base will be described with reference to FIG. The steps of FIGS. 7A and 7B are the same as those of FIGS. 2A and 2B of the first embodiment, and a description thereof will be omitted.

Subsequently, an insulating film 223 such as SiN _x having a thickness of 0.2 μm is buried except for the outermost surface of the semiconductor protrusion 21 and a part of the spacer layer 15 (FIG. 7C-1).
(C-2)).

Next, so as to surround the semiconductor protrusion 21,
The metal layers 225 and 226 made of Ti / Pt / Au having a partly interrupted ring shape are formed (FIGS. 7D-1 and 7D-1).
-2)). The metal layers 225 and 226 are formed to improve the adhesion of metal projections 227 and 228 to be formed later, and may have a thickness of about 0.1 μm.
The metal layer 226 also functions as a p-side electrode for injecting a current into the semiconductor layer.

Subsequently, A having a comb-like unevenness is formed so as to surround the semiconductor protrusion 21 by using a method such as an electrolytic plating method.
The metal projections 227 and 228 made of u are simultaneously formed (FIGS. 7E-1 and 7E-2). This metal projection 22
7 and 228 are set to have the same height as the semiconductor protrusion 21. Although the height differs slightly depending on the presence or absence of the insulating film 223, there is no problem in bonding because the semiconductor protrusion is about 2 μm and the insulating film 223 is thin. FIG.
Among them, metal protrusions 227 and 228 and semiconductor protrusion 21 are provided for convenience.
Are shown at the same height.

The second base will be described with reference to FIG. The process of FIG. 8A is the same as that of FIG. 3A of the first embodiment, and the description is omitted. Subsequently, impurity ions are implanted into predetermined regions to form insulating regions 257 (FIG. 8B
-1), (b-2)). As a result, it is possible to form a substrate having conductivity only in the vicinity of the surface of a region to be bonded to the first base later, and a portion corresponding to the metal projection 228 becomes insulative.

Next, ring-shaped metal layers 259 and 260 made of Ti / Pt / Au are formed in predetermined regions. The metal layers 259 and 260 are formed to improve the adhesion of metal projections 261 and 262 to be formed later. The metal layer 259 also functions as an n-side electrode for injecting a current into the semiconductor layer. Although not shown in FIG. 8, the metal films 259 and 260 are provided with pads (formed on the second base).
It is connected to the.

Subsequently, using a method such as an electrolytic plating method,
At a position corresponding to the metal protrusions 227 and 228 on the first base, a metal protrusion 261 made of Au having comb-shaped unevenness is provided.
262 are formed. The metal protrusions 261 and 262 are set to have the same height as the semiconductor protrusion 21 of the first base.

The steps of sticking and the back side of the first base are the same as in the first embodiment, and a description thereof will be omitted. However, the p-side electrode 226 is not necessary because it has already been formed. In the present embodiment, unlike the first embodiment, the metal protrusion used for bonding is separated into two regions, and one of the regions is connected to a p-electrode (metal layer 226, metal protrusion 228, metal layer 26).
0, metal projection 262) and the other is used as n-electrode 259. Therefore, both the p and n wiring patterns can be formed on the second base in advance, and the wiring is facilitated and the productivity is improved. Furthermore, although not shown in FIG. 6, if a three-dimensional wiring pattern is formed with an appropriate insulating layer interposed therebetween, for example, special wiring such as matrix wiring can be easily applied, and versatility can be improved. Increase.

Other effects and the like are the same as in the first embodiment. As shown in the second embodiment, it is a matter of course that the space between the elements can be buried with an insulator such as polyimide.

Fourth Embodiment In the first, second, and third embodiments described above, an example using an InP substrate has been described, but a GaAs substrate may be used. The fourth embodiment relates to such an example, and a fourth embodiment in which the present invention is applied to a surface emitting semiconductor laser will be described with reference to FIG. FIG. 9 is a sectional view of the surface emitting semiconductor laser according to the present embodiment.

First, the first base will be described below. On a p-GaAs substrate (not shown in FIG. 9 because it will be removed later), p-AlAs / p-Al
Semiconductor multilayer reflective film 3 consisting of 25 periods of _0.1 Ga _0.9 As
01, p-Al _0.6 Ga _0.4 As spacer layer 303, In
Active layer 305 having a quantum well structure of _0.3 Ga _0.7 As / GaAs (bandgap wavelength 0.85 μm), n-A
l _0.6 Ga _0.4 As spacer layer 307, n-Al _0.1 Ga
Semiconductor multilayer reflective film 30 made of _0.9 As / n-AlAs
9 is grown sequentially. The growth is performed by a method such as MOCVD, MBE, CBE, or the like, as described above. Active layer 3
The film thickness of each layer is set so that the optical thickness of one layer taking into account the refractive index of the spacer 05 and the spacer layers 303 and 307 is one wavelength.

Further, the periphery of the light emitting region is etched in a donut shape by the RIBE method or the like until the semiconductor multilayer film 301 is exposed, thereby forming a columnar semiconductor protrusion 321 including the active layer 305. The light emitting region is, for example, a circle having a diameter of 20 μm. Further, the semiconductor projection 321 is buried with an insulating film 323 such as SiN _{x having} a thickness of 0.2 μm except for the outermost surface.

Next, a ring-shaped metal layer 325 made of Tt / Pt / Au is formed so as to surround the semiconductor protrusion 321.
To form The metal layer 325 is formed to improve the adhesion of the metal projection 327 to be formed later, and may have a thickness of about 0.1 μm.

Subsequently, a metal projection 327 made of Au having comb-shaped unevenness is formed so as to surround the semiconductor projection 321 by using a method such as an electrolytic plating method. The metal projection 327 is set to have the same height as the semiconductor projection 321. This completes the processing of the first base body on the side to which the first base is attached.

Next, the second base will be described. An n-polarity conductive region 353 is formed by ion implantation at a predetermined portion on the outermost surface of the insulating Si substrate 351, and a substrate having conductivity only near the surface of a region to be bonded to the first base is formed.

Next, a ring-shaped metal layer 359 made of Ti / Pt / Au is formed in a predetermined region. This metal layer 35
Reference numeral 9 improves the adhesion of a metal projection 361 to be formed later, and also functions as an n-side electrode for injecting current into the semiconductor layer. Although not shown in FIG. 9, the metal layer 359 is a wiring provided with pads (insulating Si substrate 351).
(Formed above).

Subsequently, using a method such as an electroplating method,
At a position corresponding to the metal protrusion 327 on the first base, a metal protrusion 361 made of Au having comb-shaped unevenness is formed. The metal protrusion 361 is the semiconductor protrusion 321 of the first base.
It should be the same height as.

The attaching step is the same as in the first embodiment, and the description is omitted. After the attachment, the GaAs substrate is etched with an ammonia-based etchant, and the AIAs of the first layer of the semiconductor multilayer reflective film 301 is etched with a hydrochloric acid-based etchant.
An n-electrode 371 made of Pt / Au is formed.

In the surface emitting semiconductor laser of this embodiment, the GaAs substrate is opaque to the oscillation wavelength and needs to be removed. However, without performing hole etching, the GaAs substrate (the second substrate is used as a supporting substrate). FIG.
Can be removed over the entire surface, so that the process is simple and the yield is improved.

Further, since the bonding is performed on the Si substrate 351 having good thermal conductivity, the heat generated from the active layer 305 can be effectively radiated to the second base.

As in the first embodiment, by using the metal projection used for bonding as an electrode, a current can be injected from the wiring provided on the second substrate side to the active layer 305, and a plurality of elements can be used. When arrayed, p and n wirings of each element could be provided independently without providing a common electrode on the back side of the second base. Furthermore, by providing the conductive region 353 only on a part of the uppermost surface of the second base and making the other region insulating, it was possible to suppress electrical crosstalk between the elements. Using such a method, 10 × 10
When the surface emitting semiconductor laser array was manufactured, there was almost no variation in characteristics such as threshold value, wavelength, and power.
Further, in a certain element, even when a plurality of adjacent elements were driven, there was no change in element characteristics.

In this embodiment, as the active layer 305,
Bulk structures may be used, and n-G
The laser may be manufactured using an aAs substrate.

Further, the substrate 35 which is the main body of the second base is
1 is not limited to Si, and for example, AlN or the like may be used. Needless to say, good thermal conductivity is desirable. Also, SOI (semiconductor on i
(nsulator) substrate or the like may be used. In this case, since the insulating layer is present, electrical crosstalk between the elements can be more effectively suppressed.

Also in this embodiment using a GaAs substrate, the elements are buried with an insulator as in the second embodiment, or both the p and n electrodes are connected to the second substrate as in the third embodiment. Of course, it may be configured to be taken out from the side.

In the above-described first to fourth embodiments, the surface emitting semiconductor laser has been described. However, the same structure can be applied to a semiconductor optical device such as an edge emitting laser, an LED, and a light receiving element. In this case, referring to the example of FIG. 1, considering FIG. 1 as a cross section perpendicular to the resonator direction, the multilayer reflective films 53 and 73 are omitted, and the electrodes 59 and 71 are not ring-shaped but stripe-shaped in the resonator direction. The structure may be extended. Each layer extends in the resonator direction. For example, a Fabry-Perot type is formed when both end faces in the resonator direction are cleaved surfaces, and a distributed feedback type is formed when a distributed reflector is formed in the resonator direction.

In the case of an LED, only one of the multilayer reflective films may be used as the multilayer reflective film, and thus, an LE having good directivity at a specific wavelength defined by the film thickness in the vertical direction of the multilayer reflective film is obtained.
D can be realized. A light receiving element having a multilayer reflective film is a light receiving element having extremely high selectivity with respect to wavelength.

Fifth Embodiment A fifth embodiment in which the present invention is applied to a three-electrode surface-emitting semiconductor laser having a refractive index modulation layer will be described with reference to FIGS. 10, 11, 12, and 13. FIG. 10 is a cross-sectional view of the surface emitting semiconductor laser according to the present embodiment, and FIGS. 11, 12, and 13 are diagrams for explaining a manufacturing process. In FIGS. It is.

First, the first base will be described with reference to FIG. 0.2 μm thick on n-InP substrate 511
N-InGaAs etch stop layer 513 with a thickness of 0.
4 μm n-InP spacer layer 514, 0.3 μm thickness
InGaAsP / InP multiple quantum well structure (refractive index modulation layer 515 having a band gap wavelength of 1.15 μm, p-InP spacer layer 516 having a thickness of 0.8 μm, thickness of 0.7
μm InGaAsP (bandgap wavelength 1.3 μm)
m) bulk active layer 517, 1.0 μm thick n-In
A P spacer layer 519 is sequentially grown (FIG. 11A).
The growth means may be, for example, MOCVD, MBE,
This is performed by a method such as CBE.

Further, the periphery of the light emitting region is etched in a donut shape by RIBE or the like until the spacer layer 516 is exposed, and the columnar semiconductor protrusion 5 including the active layer 517 is etched.
21 (FIGS. 11 (b-1) and 11 (b-2)). The light emitting region is, for example, a circle having a diameter of 20 μm. Further, an insulating film 523 such as SiN _{x having} a thickness of 0.2 μm is buried except for the outermost surface of the semiconductor protrusion 521 and a part of the spacer layer 516 (FIGS. 11C-1 and 11C-2). FIG.
Although not shown in the figure, the active layer 517 may be selectively wet-etched with a sulfuric acid-based etchant to a diameter of about 15 μm in order to effectively confine the current before embedding with the insulating film 523.

Next, metal layers 525 and 526 made of Ti / Pt / Au are formed so as to partially surround the semiconductor protrusion 521 (FIG. 11 (d-)).
1), (d-2)). The metal layer 525 is formed to improve the adhesion of the metal projection 527 formed later, and may have a thickness of about 0.1 μm. Further, the metal layer 526 also functions as a p-side electrode for injecting current into the semiconductor layer.

Subsequently, metal projections 527 and 528 made of Au having comb-shaped unevenness are simultaneously formed so as to surround the semiconductor projection 521 by using a method such as an electroplating method (FIG. 11E-1). e-2)). This metal projection 52
7 and 528 are set to have the same height as the semiconductor protrusion 521. Although the height slightly differs depending on the presence or absence of the insulating film 523, there is no problem in bonding since the semiconductor protrusion 521 is about 2 μm and the insulating film 523 is thin. In FIG. 11, the height of the metal projection and the height of the semiconductor projection are shown for convenience. This completes the processing of the first base body on the side to which the first base is attached.

Referring to FIG. 12, the second base will be described. The insulating GaAs substrate 551 has i-GaAs / i-
Multilayer reflective film 553 composed of 20 cycles of AlAs and n
-GaAs / n-AIGaAs A multilayer reflective film 555 having five periods is epitaxially grown (FIG. 12).
(A)). Further, an insulating region 557 is formed by implanting impurity ions into a predetermined region (FIGS. 12B-1 and 12B-2).
2)). As a result, a substrate can be formed that has conductivity only in the vicinity of the surface of the surface, which is to be bonded to the first base later, and that has a portion corresponding to the metal projection 528.

Next, ring-shaped metal layers 559 and 560 of Ti / Pt / Au are formed in predetermined regions (FIG. 12 (c-1), (c-2)). The metal layers 559 and 560 are formed on metal projections 561 and 562 to be formed later.
Are formed in order to improve the adhesion.
Further, the metal layer 559 also functions as an n-side electrode for injecting current into the semiconductor layer. Although not shown in FIG. 12, the metal films 559 and 560 are connected to wiring having pads.

Subsequently, using a method such as an electrolytic plating method,
Metal protrusions 561 and 5 made of Au having comb-shaped irregularities at positions corresponding to metal protrusions 527 and 528 on the first base.
62 are formed (FIGS. 12 (d-1) and (d-2)). The metal protrusions 561 and 562 are formed on the semiconductor protrusion 52 of the first base.
It should be the same height as 1.

With reference to FIG. 13, the steps of sticking and the back side of the first base will be described. As the first base, the one manufactured in the above process is turned upside down. For the first substrate, 1 is used to simplify subsequent substrate removal.
The substrate 511 may be polished in advance to about 00 μm.

First, the metal projections 527 and 561 and the metal projections 528 and 562 formed on the first and second substrates are aligned with each other so as to engage with each other (FIG. 13A).
Left), a load is applied from both the upper and lower sides to bring the outermost surface of the semiconductor protrusion 521 into close contact with the outermost surface of the second base, and then heated to about 300 ° C. in a hydrogen atmosphere to perform solid-state bonding at this portion. (FIG. 13A, right). At this time, the metal protrusion 52
7, 561, 528, and 562 undergo plastic deformation at the time of pressurization, and the metals appearing due to the deformation are bonded to each other, so that stronger bonding can be obtained.

Next, the substrate 511 is removed using a hydrochloric acid-based etchant until the etch stop layer 513 is exposed (FIG. 13B), and the semiconductor layer that does not function as a device is removed by a method such as RIE (FIG. 13B). 13 (c)). 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, after forming an n-side electrode 571 made of Ti / Pt / Au, the etch stop layer 513 is removed in accordance with the light emitting region using a sulfuric acid-based etchant, and an Al ₂ O ₃ / Si 8 cycle is formed. Reflective film 573 made of
Is formed (FIG. 13D).

The operation method of this embodiment will be described. p
The metal layer 560 serving as an electrode is grounded, and current is injected into the active layer 517 using the metal layers 559 and 560 on the second base. Independently, the metal layer 5 which is a p-electrode
By applying a reverse voltage between the electrode 60 and the n-electrode 571 to apply an electric field to the refractive index modulation layer 515, the refractive index of this layer 515 is controlled by the quantum confined Stark effect (QCSE effect). As a result, the effective resonator length could be changed, and the oscillation wavelength could be controlled.

Oscillation can be performed at the lowest threshold value by matching the peak wavelength of the gain of the active layer 517 with the resonator wavelength. In this embodiment, the voltage of −2.5 V is applied to the refractive index modulation layer 515. Was applied, the threshold was the lowest.

When a reverse voltage was further applied, the loss of the refractive index modulation layer 515 increased, and the oscillation stopped. Thus, by modulating the voltage applied to the refractive index modulation layer 515 between −2.5 V and −6 V, the electrodes 526 (560),
The active layer 517 is kept in a current injection state through the layer 559
It is possible to switch between the oscillation state and the stop state without involving carrier ingress and egress, and high-speed intensity modulation on the order of GHz has become possible. Even during the modulation, the oscillation wavelength is changed by controlling the value of the reverse voltage to the refractive index modulation layer 515 to be in the oscillation state (the current injection state to the active layer 517 may be controlled if necessary). be able to. In the first to fourth embodiments, it is necessary to perform modulation by turning on / off the current injection into the active layer.

In the conventional direct bonding between different types of semiconductors, it was difficult to obtain a large-area and strong bonding due to stress due to a difference in thermal expansion coefficient, but in this embodiment, the area where the semiconductors are bonded is small. So stress is small,
Further, by adding metal bonding, stronger adhesion can be obtained, and the area can be increased. Furthermore, since the bonding state is good, the entire surface can be etched even when the substrate on the rear surface is removed, and the process is simpler than in the case of hole-shaped etching, and the yield is improved. Further, processes such as multilayer film formation could be easily performed.

Further, since the semiconductors are joined by solid-phase joining, the heat generated from the active layer 517 can be effectively radiated to the second base.

The metal projections 528 and 56 used for bonding
By also using 2 as an electrode, it becomes possible to inject current into the active layer 517 from the p and n wirings provided on the second base, and to form a common electrode on the back side of the second base when arrayed. There is no need to provide them, and the three terminals of each element can be controlled independently. Further, by providing a conductive region only on a part of the uppermost surface of the second base and making the other region insulating, electric crosstalk between the elements could be suppressed. In addition, since the center electrode 526 of the three terminals of each element in the array can be grounded, each element could be operated stably.

Further, the active layer 517 is previously formed on the second substrate.
In this case, both p and n wiring patterns for injecting current into the semiconductor device can be formed, so that wiring is facilitated and productivity is improved. Further, although not shown in FIG. 5, if a three-dimensional wiring pattern is formed with an appropriate insulating layer interposed therebetween, for example, special wiring such as matrix wiring can be easily applied, and versatility can be improved. Increase.

In this example, when a 10 × 10 surface emitting semiconductor laser array was manufactured, there was almost no variation in the characteristics of each element. Further, in a certain element, even when a plurality of adjacent elements were driven, there was no change in element characteristics.

In the present embodiment, the refractive index is controlled by applying a reverse voltage (applying an electric field) to the refractive index modulation layer 517, but it may be performed by current injection. Also,
The refractive index modulation layer 517 is made of InG instead of a multiple quantum well structure.
It may be a bulk structure of an aAsP single layer.

In the present embodiment, the metal layer used for improving the adhesion of the metal projection of the conductor is not limited to the above-mentioned material, but depends on the polarity of the semiconductor, but may be Cr / A.
u or AuGe / Au may be used. Further, the material used for the metal projection is not limited to Au, but may be, for example, Al, In, Sn, Zn, Pb, or a compound thereof. Further, the first base and the second base are each formed with metal projections having comb-shaped irregularities, but any shape may be used as long as the bonding strength can achieve sufficient electrical and optical coupling. For example, one may be comb-shaped unevenness and the other may have a flat plate shape, or unevenness extending in the radial direction may be provided.

Although the bonding was performed in a hydrogen atmosphere,
Not limited to this, argon gas, nitrogen gas,
Alternatively, a mixed gas thereof may be used. Further, as the order of processing the back surface of the first base, (c) and (b) of FIG. 13 may be exchanged.

Further, the active layer 517 may be of an MQW structure instead of a bulk, and may be of p-type instead of n-type.
The laser may be manufactured using an -InP substrate.
In addition, the multilayer reflective film 573 is not limited to Al ₂ O ₃ / Si, but may be, for example, SiO ₂ / Si, MgO / Si
And so on.

Sixth Embodiment A sixth embodiment in which the present invention is applied to a surface emitting semiconductor laser having a refractive index modulation layer will be described with reference to FIG. FIG.
1 is a sectional view of a surface emitting semiconductor laser according to the present embodiment.
The structure is almost the same as that of the fifth embodiment, and a detailed description of overlapping parts will be omitted. 14, the same parts as those in FIG. 10 are given the same numbers.

In this embodiment, the space between the elements on the first base is buried with an insulator 601 such as polyimide, and the electrode 671 is formed so as to cover the insulator 601.
It is characterized in that a dielectric multilayer reflective film 673 made of Al ₂ O ₃ / Si is formed so as to cover the electrode 671.

This embodiment also has the following advantages similar to the second embodiment. (1) Wiring is easy and productivity is improved. (2) The area of the dielectric multilayer reflective film can be increased, thereby improving the productivity and lowering the threshold value. (3) Since separation between elements can be performed more reliably, electrical crosstalk can be reduced. (4) Since the insulator 601 can function as a reinforcing material, the structure can be made stronger.

The other effects are the same as in the fifth embodiment. Also in this embodiment, the multilayer reflective film 673 is made of Al ₂
Not limited to O ₃ / Si, for example, SiO ₂ / S
i, MgO / Si.

Seventh Embodiment In the above fifth and sixth embodiments, an example of a surface emitting semiconductor laser having a refractive index modulation layer using an InP substrate has been described. However, a GaAs substrate can also be used. It is.
This embodiment relates to such an example, and a seventh embodiment will be described with reference to FIG. FIG. 15 is a sectional view of the surface emitting semiconductor laser according to the present embodiment.

First, the first base will be described below. On an n-GaAs substrate (not shown in the figure because it will be removed later), n-AlAs / n-Al
Semiconductor multilayer reflective film 7 consisting of 25 periods of _0.1 Ga _0.9 As
01, n-Al _0.6 Ga _0.4 As spacer layer 702, Al
A refractive index modulation layer 703 having a quantum well structure made of _0.1 Ga _0.9 As / Al _0.6 Ga _0.4 As, a p-Al _0.6 Ga _0.4 As spacer layer 704, and an active layer 705 having a quantum well structure made of In _0.3 Ga _0.7 As / GaAs ( Band gap wavelength 0.85 μm), n-Al _0.6 Ga _0.4 As spacer layer 7
07, a semiconductor multilayer reflective film 709 composed of n-Al _0.1 Ga _0.9 As / n-AlAs is sequentially grown. The means of growth is
Similarly, it is performed by a method such as MOCVD, MBE, CBE or the like. Resonator length (active layer 705, refractive index modulation layer 703
The film thickness of each layer is set so that the optical thickness of the layers (considering the refractive index of the combined spacer layers 702, 704, and 707) is twice the wavelength.

Further, the periphery of the light emitting region is etched in a donut shape by a RIBE method or the like until the spacer layer 704 is exposed, and the columnar semiconductor protrusion 7 including the active layer 705 is etched.
21 are formed. The light emitting region is, for example, a circle having a diameter of 20 μm. Further, an insulating film 723 such as SiN _{x having} a thickness of 0.2 μm is buried except for the outermost surface of the semiconductor protrusion 721 and the spacer layer 704.

Next, ring-shaped metal layers 725 and 726 made of Ti / Pt / Au are formed so as to partially surround the semiconductor protrusions 721. These metal layers 725, 7
Reference numeral 26 is formed to improve the adhesion between the metal projections 727 and 728 to be formed later, and may have a thickness of about 0.1 μm. Further, the metal layer 726 also functions as a p-side electrode for injecting current into the semiconductor layer.

Subsequently, metal projections 727 and 728 having comb-shaped unevenness are formed so as to surround the semiconductor projection 721 by using a method such as an electroplating method. The metal projections 727 and 728 are set to have the same height as the semiconductor projection 721. This completes the processing of the first base body on the side to which the first base is attached.

The second substrate will be described. Insulating Si
An n-polarity conductive region 753 is formed by ion implantation at a predetermined portion on the outermost surface of the substrate 751, and has conductivity only in the vicinity of the surface of a region to be bonded to the first base later, and corresponds to the metal protrusion 728. The part to be formed forms an insulating substrate.

Next, ring-shaped metal layers 759 and 760 of Ti / Pt / Au are formed in predetermined regions. The metal layers 759 and 760 are formed to improve the adhesion of metal projections 761 and 762 to be formed later. Further, the metal layer 759 also functions as an n-side electrode for injecting current into the semiconductor layer. Although not shown in FIG. 15, the metal films 759 and 760
Are connected to wiring having pads.

Subsequently, using a method such as an electroplating method,
Metal protrusions 761, 7 made of Au having comb-shaped irregularities at positions corresponding to metal protrusions 727, 728 on the first base.
62 is formed. The metal projections 761 and 762 are set to have the same height as the semiconductor projection 721 of the first base. The attaching step is the same as in the fifth embodiment, and the description is omitted.

After the attachment, the GaAs substrate is etched with an ammonia-based etchant to form a semiconductor multilayer reflective film 70.
The first layer of AlAs is etched with a hydrochloric acid-based etchant to form an n-electrode 771 made of Ti / Pt / Au on a part other than the light emitting region.

An operation method according to this embodiment will be described. The metal layers 726 and 760 which are common p electrodes are grounded,
Current injection into active layer 705 is performed using metal layers 759 and 760. Independently, by applying a reverse voltage between the metal layers 726 and 760 as the common p-electrode and the electrode 771 to apply an electric field to the refractive index modulation layer 703, the refractive index of this layer 703 is controlled. As a result, the effective resonator length could be changed, and the oscillation wavelength could be controlled.

By matching the beak wavelength of the gain of the active layer 705 with the resonator wavelength, oscillation can be performed at the lowest threshold value. In this embodiment, a voltage of -2.0 V is applied to the refractive index modulation layer 703. , The threshold was the lowest. Further, the voltage applied to the refractive index modulation layer 703 is-
By modulating between 2.0V and -4.5V, the active layer 7
It was possible to switch between the oscillation state and the stop state without involving the ingress and egress of the carrier 05, and high-speed modulation of 10 GHz became possible.

In the surface emitting semiconductor laser of the present embodiment, the GaAs substrate is opaque to the oscillation wavelength and needs to be removed. However, without performing hole etching, the GaAs substrate (second substrate) is used as a supporting substrate. (Not shown in the figure) can be removed over the entire surface, so that the process is simple and the yield is improved.

Further, since the bonding is performed on the Si substrate 751 having good thermal conductivity, the heat generated from the active layer 705 can be effectively radiated to the second base.

As in the fifth embodiment, by using the metal projections used for bonding as electrodes, current can be injected into the active layer 705 from the p and n wirings provided on the second substrate side. When an array is formed, there is no need to provide a common electrode on the back side of the second substrate, and the three terminals of each element can be controlled independently. Furthermore, by providing the conductive region 753 only on a part of the uppermost surface of the second base and making the other regions insulating, electric crosstalk between the respective elements could be suppressed. In addition, 3
Since the center electrodes 726 and 760 of the terminals could be grounded, each element could be operated stably.

Also in this example, when a 10 × 10 surface emitting semiconductor laser array was manufactured, there was almost no variation in the characteristics of each element. Further, in a certain element, even when a plurality of adjacent elements were driven, there was no change in element characteristics.

In this embodiment as well, the refractive index is controlled by applying a reverse voltage (applying an electric field) to the refractive index modulation layer, but it may be performed by current injection. Instead of a multiple quantum well structure, a bulk structure of an AlGaAs single layer may be used. The active layer may have a bulk structure, or a laser may be manufactured using a p-GaAs substrate.

Further, the substrate serving as the main body of the second base is not limited to Si but may be, for example, AlN. It goes without saying that good thermal conductivity is desirable. Further, an SOI substrate or the like may be used. In this case, as described above, since the insulating layer exists, the electric crosstalk between the elements can be more effectively suppressed.

Eighth Embodiment An eighth embodiment in which the present invention is applied to a surface emitting semiconductor laser having a refractive index modulation layer will be described with reference to FIG. FIG. 16 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 seventh embodiment, and a detailed description of overlapping parts will be omitted. 16, the same parts as those in FIG. 15 are given the same numbers.

In this embodiment, n-AlAs / n-Al
Semiconductor multilayer reflective film 7 consisting of 20 periods of _0.1 Ga _0.9 As
A characteristic feature is that a refractive index modulation layer 803 composed of seven periods of AlAs / Al _0.1 Ga _0.9 As is disposed adjacent to the reference numeral 01.

The thickness of each layer of the refractive index modulation layer 803 is 1
The wavelength is set to / 4 wavelength, and it also functions as a multilayer reflection film. Therefore, the resonator length (optical thickness considering the refractive index of the combined spacer layer 704, active layer 705, and spacer layer 707) can be made smaller than in the seventh embodiment, and a lower threshold value can be obtained. I was able to.

In this embodiment, a quantum well structure made of, for example, Al _0.1 Ga _0.9 As / Al _0.6 Ga _0.4 As may be used instead of Al _0.1 Ga _0.9 As which is a high refractive index material of the refractive index modulation layer 803. Good. In this case, since the thickness of the well layer is reduced, the quantum effect can be further enhanced, and wavelength control or high-speed modulation can be performed effectively.

In the seventh and eighth embodiments using a GaAs substrate, the elements may be buried with an insulator as in the sixth embodiment.

In the above fifth to eighth embodiments, surface-emitting semiconductor lasers having a refractive index modulation layer have been described. However, similar structures are also applied to semiconductor optical devices such as edge-emitting lasers. Applicable. Also in this case, if the example of FIG. 10 is used, FIG. 10 is considered to be a cross section perpendicular to the resonator direction, the multilayer reflective films 553 and 573 are omitted, and the electrodes 559 and 571 are not ring-shaped but striped in the resonator direction. The refractive index modulation layer 5
15 may be brought close to the active layer 517 to form a waveguide together. Each layer extends in the resonator direction. For example, a Fabry-Perot type is formed when both end faces in the resonator direction are cleaved surfaces, and a distributed feedback type is formed when a distributed reflector is formed in the resonator direction.

[0153]

As described above, according to the present invention,
Using solid-state bonding technology, semiconductor-emitting devices (surface-emitting semiconductor lasers,
Such as a semiconductor laser capable of tunable wavelength and capable of high-speed modulation).

According to a more specific structure, the following effects can be obtained. 1) A semiconductor optical device having stabilized element characteristics can be provided. 2) It is possible to provide a semiconductor optical device that is easy to wire and suitable for arraying. 3) A surface emitting semiconductor laser can be provided with the above semiconductor optical device. 4) It is possible to provide a semiconductor light emitting device including a multilayer reflective film that enables oscillation of the above-described surface emitting semiconductor laser. 5) It is possible to provide a semiconductor optical device in which the strength of the joint is improved. 6) It is possible to provide a semiconductor optical device in which the characteristics of each element when arrayed are further stabilized. 7) It is possible to provide a semiconductor-producing device having a lower threshold value, being structurally robust, easily wiring, and stabilizing the characteristics of each element when arrayed, and having good productivity. 8) It is possible to provide a semiconductor laser in which element driving is facilitated. 9) It is possible to provide a semiconductor laser capable of performing wavelength tuning and high-speed modulation more effectively.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a surface emitting semiconductor laser having an electrode near a tight coupling region according to the present invention.

FIG. 2 is a view for explaining a manufacturing process of a first base of the first embodiment.

FIG. 3 is a view for explaining a manufacturing process of a second substrate of the first embodiment.

FIG. 4 is a diagram illustrating a manufacturing process of the first embodiment.

FIG. 5 is a diagram showing a second embodiment of the surface emitting semiconductor laser having an electrode near the tightly bonded region according to the present invention.

FIG. 6 is a sectional view showing a third embodiment of the surface emitting semiconductor laser having an electrode near the tightly coupled region according to the present invention.

FIG. 7 is a view for explaining a manufacturing process of a first base of the third embodiment.

FIG. 8 is a view for explaining a manufacturing process of a second substrate of the third embodiment.

FIG. 9 is a sectional view showing a fourth embodiment of the surface emitting semiconductor laser having an electrode near the tightly coupled region according to the present invention.

FIG. 10 is a sectional view showing a fifth embodiment of the surface-emitting semiconductor laser having an electrode and a refractive index modulation layer in the vicinity of the tight coupling region according to the present invention.

FIG. 11 is a view for explaining a manufacturing process of a first base of the fifth embodiment.

FIG. 12 is a diagram illustrating a process for manufacturing a second substrate according to a fifth embodiment.

FIG. 13 is a diagram illustrating a manufacturing process according to a fifth embodiment.

FIG. 14 is a sectional view showing a sixth embodiment of the surface-emitting semiconductor laser having an electrode and a refractive index modulation layer in the vicinity of the tight coupling region according to the present invention.

FIG. 15 is a cross-sectional view showing a seventh embodiment of the surface emitting semiconductor laser having an electrode near the tightly coupled region and having a refractive index modulation layer according to the present invention.

FIG. 16 is a sectional view showing an eighth embodiment of a surface emitting semiconductor laser having an electrode near a tightly bonded region and including a refractive index modulation layer according to the present invention.

FIG. 17 is a sectional view showing a conventional example.

FIG. 18 is a sectional view showing another conventional example.

[Explanation of symbols]

11, 51, 351, 511, 551, 751 Substrate 13, 513 Etch stop layer 15, 19, 303, 307, 514, 516, 51
9, 702, 704, 707 Spacer layer 17, 305, 517, 705 Active layer 21, 321, 521, 721 Semiconductor protrusion 23, 223, 323, 523, 723 Insulating film 25, 59, 225, 226, 259, 260, 32
5,359,525,526,559,560,72
5,726,759,760 Metal layer 27,61,227,228,261,262,32
7,361,527,528,561,562,72
7,728,761,762 Metal projections 53,55,73,173,301,309,553,
555,573,673,701,709 Multilayer reflective film 57,257,557 Insulating region 71,171,371,571,671,771 Electrode 101,601 Insulator 353,753 Conductive region 515,703,803 Refractive index modulation layer

Claims (31)

[Claims] 1. A first base including at least one protrusion including an active layer and a first bonding member formed near the protrusion, and a second substrate and a first bonding member corresponding to the first bonding member. And a second base member including a second bonding member provided at a position where the outermost surface of the protrusion and the outermost surface of the second substrate are tightly bonded so as to achieve electrical connection. The first and second substrates are bonded so that the first and second bonding members are bonded to each other, and the second and second substrates near the tightly bonded region between the outermost surface of the protrusion and the outermost surface of the second substrate are further bonded. A semiconductor optical device, wherein an electrode electrically connected to the protrusion is provided on the outermost surface of the substrate. 2. The semiconductor optical device according to claim 1, wherein said electrode is electrically connected to said projection via an outermost surface of said second substrate and an outermost surface of said projection. 3. An electrode according to claim 1, wherein the outermost surface of the second substrate is electrically conductive in the vicinity of a region where the second substrate is in close contact with the projection and the region where the electrode is provided, and insulative in other regions. 3. The semiconductor optical device according to claim 2, wherein the outermost surface of the protrusion is electrically connected to the second substrate via the conductive region. 4. The semiconductor optical device according to claim 2, wherein another electrode is provided on the first base on a side opposite to a side on which the protrusion is formed. 5. The semiconductor optical device according to claim 1, wherein said electrode is electrically connected to said projection via a first base. 6. The first joining member is made of a conductor and is electrically connected to the first base, and the second joining member is made of a conductor and is electrically connected to the electrode. 6. The semiconductor device according to claim 5, wherein the first substrate is electrically insulated from the outermost surface of the second substrate, and is electrically connected to the protrusion via the second joint member and the first joint member. Semiconductor optical device. 7. A third bonding member, which is a conductor electrically connected to the first base, is formed in the vicinity of the protrusion in the first base, separately from the first bonding member. Yes, second
In the base body, apart from the second bonding member, a fourth bonding member, which is a conductor electrically insulated from the second substrate, is formed at a position corresponding to the third bonding member. 3,
The first and second substrates are bonded so that the fourth bonding members are also bonded to each other, and the second substrate near the tightly bonded region between the outermost surface of the protrusion and the outermost surface of the second substrate is further bonded. Another electrode is provided on the outermost surface of the substrate, and the electrode is electrically connected to the projection via the outermost surface of the second substrate and the uppermost surface of the projection, but the first electrode The other electrode is electrically insulated from the second substrate, and the other electrode is electrically insulated from the second substrate. 2. The semiconductor optical device according to claim 1, wherein the semiconductor optical device is electrically connected via a joining member. 8. The semiconductor device according to claim 1, wherein the outermost surface of the second substrate is electrically conductive in the vicinity of the region where the electrode is provided and the region in which the second substrate is in close contact with the projection, and includes the region where the other electrode is provided. 8. The semiconductor optical device according to claim 7, wherein said semiconductor optical device is insulative in said region. 9. A structure having an active layer and a refractive index modulation layer in a resonator, capable of injecting current into the active layer, and applying a current to the refractive index modulation layer independently of current injection into the active layer. The first base is formed near the protrusion, the first base including the refractive index modulation layer, at least one protrusion including the active layer, and the first substrate. A first joining member electrically insulated from the first base member, and a third joining member formed of a conductor formed near the protrusion and electrically connected to the first base member; The base is provided at a position corresponding to the second substrate, the first bonding member, and the second bonding member provided on the electrode, and at a position corresponding to the third bonding member. A fourth joining member made of a conductor electrically insulated from the substrate, and electrically contacting the fourth joining member. And a second electrode, which is electrically insulated from the second substrate and is provided on the outermost surface of the second substrate. The first and second substrates are bonded so that the fourth bonding members are bonded to each other, and the first substrate further includes another electrode on a surface opposite to the tightly-bonded region. Current injection into the active layer using the electrode and the other electrode, and current injection or voltage application to the refractive index modulation layer using the other electrode and the further electrode. A semiconductor optical device according to claim 7. 10. The semiconductor optical device according to claim 9, wherein two multilayer reflection films are present so as to sandwich the active layer and the refractive index modulation layer, and can oscillate as a surface emitting semiconductor laser. 11. The semiconductor optical device according to claim 10, wherein in the first base, a semiconductor multilayer reflective film is present on a side opposite to a side where the protrusion is located across the refractive index modulation layer. 12. The semiconductor optical device according to claim 11, wherein a part of the semiconductor multilayer reflection film is a refractive index modulation layer. 13. The semiconductor optical device according to claim 9, wherein said another electrode is electrically grounded. 14. The semiconductor optical device according to claim 9, wherein the refractive index modulation layer has a multiple quantum well structure. 15. The semiconductor optical device according to claim 1, wherein two multilayer reflective films are formed so as to sandwich the active layer, and the semiconductor optical device can oscillate as a surface emitting semiconductor laser. . 16. The semiconductor optical device according to claim 10, wherein a semiconductor multilayer reflective film is formed on or near the outermost surface of the second substrate. 17. The semiconductor optical device according to claim 10, wherein a semiconductor multilayer reflective film is formed on or near the outermost surface of the projection. 18. The semiconductor light according to claim 15, wherein a semiconductor multilayer reflection film is formed on the first base on a side opposite to a side where the protrusion is located across the active layer. device. 19. The semiconductor according to claim 15, 16 or 17, wherein a dielectric multilayer reflective film is formed on the first substrate on the side opposite to the side where the protrusion is located across the active layer. Optical device. 20. The semiconductor device according to claim 1, wherein at least one of said first and second joining members and at least one of said third and fourth joining members have comb-shaped irregularities. 20. The semiconductor optical device according to any one of claims 19 to 19. 21. The semiconductor optical device according to claim 1, wherein the bonding member or the conductor is a metal. 22. The semiconductor optical device according to claim 1, wherein said bonding member and said electrode are all made of metal. 23. The semiconductor optical device according to claim 1, wherein the semiconductor layer including the active layer and the refractive index modulation layer is formed on a first substrate. 24. The semiconductor device according to claim 23, wherein a portion of the first substrate which does not function as a semiconductor optical device and a semiconductor layer including an active layer and a refractive index modulation layer are removed from the first base. Semiconductor optical devices. 25. The semiconductor optical device according to claim 23, wherein the first substrate is entirely removed. 26. The semiconductor optical device according to claim 1, wherein an insulator is embedded between the plurality of semiconductor optical devices in the first base. 27. The active layer of the projection portion extends in a stripe shape parallel to the outermost surface of the second substrate to form a resonator in this direction, and can oscillate as an edge emitting semiconductor laser. Item 27. The semiconductor optical device according to any one of Items 1 to 26. 28. A semiconductor device including an active layer on a first substrate, at least one protrusion including the active layer formed on the semiconductor layer, and a first bonding member provided near the protrusion. A first base is formed, an electrode is formed on the second substrate, and a second bonding member is provided at a position corresponding to the first bonding member to form a second base. The substrate 2 is tightly bonded to the outermost surface of the substrate so as to achieve electrical connection, and
The first and second substrates are bonded so that the first and second bonding members are bonded to each other.
The method for manufacturing a semiconductor optical device according to any one of the above. 29. The outermost surface of the second substrate is formed so as to have conductivity in the vicinity of a region where the second substrate is closely bonded to the projection and the region where the electrode is provided. 29. The method for manufacturing a semiconductor optical device according to claim 28, wherein the semiconductor optical device is electrically connected through the conductive region of the second substrate. 30. A first joining member comprising a conductor,
The second bonding member is made of a conductor and is electrically connected to the electrode.
29. The semiconductor optical device according to claim 28, wherein the semiconductor optical device is electrically insulated from the outermost surface of the substrate and electrically connected to the protrusion via the second bonding member and the first bonding member. Method of manufacturing. 31. In the manufacture of the first base, a third bonding member, which is a conductor electrically connected to the first base, is formed in the vicinity of the projection separately from the first bonding member. Then, in the manufacture of the second base, separately from the second bonding member, the second surface is formed on the outermost surface of the second substrate in the vicinity of the tightly bonded region between the outermost surface of the projection and the uppermost surface of the second substrate Another electrode is provided electrically insulated from the second substrate, and a conductor electrically insulated from the second substrate on the other electrode at a position corresponding to the third bonding member. The first and second bases are bonded so that a certain fourth bonding member is formed, and the third and fourth bonding members are also bonded to each other. Electrically connected to the projection through the outermost surface of the first base, but electrically insulated from the first base, and the other electrode is connected to the second base. Although it is electrically insulated from the plate, the protruding portion is a third conductive material.
29. The method of manufacturing a semiconductor optical device according to claim 28, wherein the semiconductor optical device is electrically connected to the bonding member through a fourth bonding member.