JP2001007353A - Optical transmitter-receiver module and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical transmitter-receiver module which can be lessened in size, decreased in manufacturing cost, less hampered by noises, and improved in performance, and a manufacturing method of the same. SOLUTION: An output light 60 is projected from a semiconductor laser 1, in such a manner that it is made to be incident on the optical branching plane 3 of a photodiode 2 at an angle of incidence, and a reflected light 60b from the optical branching plane 3 is coupled to an optical transmission path 4. An input light 61 is projected from the optical transmission path 4 in the direction opposite to the direction, in which the reflected light 60b travels to be incident on the optical branching plane 3 of the photodiode 2, and a refracted light 60a is refracted inwardly through the optical branching plane 3, so as not to make the peak of its light intensity distribution position at a receiving photodetective region 8 which passed through the photodiode 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmitting / receiving module for bidirectional transmission using one optical transmission line and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 54, there is an optical transmission / reception module which performs bidirectional transmission using a single optical fiber. The optical transmission / reception module 128 includes:
The transmitting light is transmitted to the semiconductor laser 1 for generating the transmitting light, the receiving photodiode 2a for detecting the receiving light, the monitoring photodiode 2b for monitoring the light emission amount of the semiconductor laser 1, and the optical fiber 5 for transmitting and receiving light. It comprises a coupling lens 7 to be coupled, and a half mirror 3a for guiding the transmission light from the semiconductor laser 1 to the optical fiber 5 and guiding the reception light from the optical fiber 5 to the receiving photodiode 2a. Optical transmitting / receiving module 12 having the above configuration
In 8, the optical element such as the half mirror 3a must be provided, which is disadvantageous in terms of miniaturization and cost reduction.

Therefore, an optical transceiver module with a reduced number of components has been proposed for miniaturization and cost reduction.
(See JP-A-7-191237). In this optical transmission / reception module, the function of a half mirror is achieved by using the surface of the light receiving element as a transmission light reflecting surface, thereby achieving a reduction in the number of components and a reduction in size. The optical transmission / reception module 129
55, as shown in FIG. 55, the semiconductor laser 1 for emitting transmission light fixed to the sub-mount 14, the photodiode 2 for detecting and monitoring the transmission light, and transmitting to the optical fiber 5 for transmitting and receiving light. And a coupling lens 7 for coupling light. A reflection film 41 for reflecting transmission light is provided on the surface side of the photodiode 2, and the reflection film 41 is set so as to reflect 50% of the transmission light.

Next, the optical transmission / reception module 12 having the above configuration is described.
At 9, part of the transmission light emitted from the semiconductor laser 1 is reflected by the reflection film 41 of the photodiode 2, collected by the coupling lens 7, and then coupled to the optical fiber 5. The received light transmitted by the optical fiber 5 is guided to the photodiode 2 via the coupling lens 7, and a part of the received light transmitted through the reflection film 41 is incident on the photodiode 2, 2, and is output as a signal current.
Further, a part of the transmission light transmitted without being reflected by the reflection film 41 enters the photodiode 2, is photoelectrically converted by the photodiode 2, and is output as a transmission light monitor current.

[0005]

By the way, the optical transmitting / receiving module 128 shown in FIG. 54 requires optical element parts such as the half mirror 3a, and the half mirror 3a can be replaced with other components such as the semiconductor laser 1 and the receiving photodiode 2a. And it is difficult to reduce the size of the half mirror 3a down to the level of the light emitting and receiving elements, making it difficult to reduce the size and cost of the optical transceiver module. There is.

[0006] Further, the optical transceiver module 1 shown in FIG.
29 has the following problem in the case of ping-pong transmission which is generally applied to a one-wire bidirectional optical transceiver module.

FIG. 56 shows a light intensity distribution of transmission light and reception light incident on the surface of the photodiode 2. 56, the vertical axis represents the incident light intensity, the horizontal axis represents the position on the surface of the photodiode 2, 63 represents the light intensity distribution of the received light incident on the photodiode 2, and 6
Reference numeral 4 denotes the light intensity distribution of the transmission light. The transmission light emitted from the semiconductor laser 1 shown in FIG. 55 is directly incident on the photodiode 2, while the reception light transmitted by the optical fiber 5 is transmitted to the semiconductor laser 1 in the optical transceiver module on the communication partner side. Since there is a loss before the light is coupled to the optical fiber, the incident transmitted light intensity 64 is larger than the incident received light intensity 63.

FIG. 57 is a diagram for explaining noise generation in ping-pong transmission in which transmission and reception are performed in a time-division manner.
In FIG. 57, the vertical axis represents a photocurrent generated in the photodiode 2 (shown in FIG. 55), and the horizontal axis represents time. In FIG. 57, “S” corresponds to transmission, “R” corresponds to reception, and “G” corresponds to a guard time for temporally separating a transmission signal and a reception signal. Reference numeral 65 denotes a reception light monitor current by the reception light, and reference numeral 66 denotes a transmission current by the transmission light. The received light monitor current 65,
The photocurrent intensity of the transmission current 66 depends on the incident light intensity ratio in FIG.
Tail current 67, which is the falling part of the photocurrent
Is also large, and is superimposed as noise on the reception current. In addition, since the transmission light having a large light intensity enters the light receiving region for reception and the transmission current is large, a space charge effect occurs, and the tail current 67 is increased.
This also increases the noise.

As described above, in order to reduce the size and cost of the optical transmitting and receiving module, when the light splitting surface serving as a half mirror for reflecting and transmitting the transmitting and receiving light is provided on the surface of the receiving photodiode, Since transmission light having a high light intensity enters the light receiving region, there is a problem that noise at the time of reception increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical transmitting / receiving module which can be reduced in size and cost, and whose performance can be improved by reducing noise, and a method of manufacturing the same.

[0011]

To achieve the above object, an optical transmitting / receiving module according to the present invention is an optical transmitting / receiving module for transmitting light bidirectionally using an optical transmission line. A photodiode having a light splitting surface and a light receiving area for reception that splits light into refracted light; and a light emitting surface that emits transmission light so as to enter the light splitting surface of the photodiode at a predetermined incident angle, and the light splitting surface. A semiconductor laser in which reflected light of the transmission light reflected by the light transmission path is coupled to the optical transmission path, and wherein the light received from the optical transmission path is opposite to the reflected light of the transmission light in the light branch plane of the photodiode. And the refracted light on the reception light side refracted from the light splitting surface to the photodiode side passes through the photodiode and enters the reception light receiving area of the photodiode. On the other hand, the transmission light emitted from the semiconductor laser is incident on the light branch surface of the photodiode, and is refracted from the light branch surface toward the photodiode and transmitted through the photodiode on the transmission light side. It is characterized in that the peak of the light intensity distribution of the refracted light is not located in the receiving light receiving area of the photodiode.

According to the optical transmission / reception module, since the light splitting surface is formed on the semiconductor portion (element substrate or semiconductor layer) of the photodiode, it is not necessary to provide an optical splitting optical element such as a half mirror. In addition, the number of components can be reduced, and highly accurate position adjustment of the light branching surface is not required. Further, since the light branching surface can be formed at the level of a semiconductor laser or a photodiode, the size and cost can be reduced. In addition, since the light splitting surface is formed on the semiconductor portion (element substrate or semiconductor layer) of the photodiode, the light splitting surface can be created by using a photolithography process, and the positional relationship between the light receiving area for reception and the light splitting surface can be accurately determined. Can be set with.
Furthermore, since the peak of the light intensity distribution of the transmission light refracted into the photodiode from the light splitting surface is designed so as not to be located in the reception light receiving area, unnecessary transmission light detected in the reception light receiving area is used. , The transmission current caused by the transmission current superimposed on the reception current can be reduced. Furthermore, in ping-pong transmission in which transmission and reception are alternately performed in a time-division manner, when switching from transmission to reception, the tail current of the transmission current detected in the reception light receiving region can be reduced, so that noise to the reception current can be reduced. .

In one embodiment of the present invention, the optical transmission line is an optical fiber.

According to the above embodiment, by using an optical fiber used as an optical transmission line for many optical communications including public communications, the handling of the connection between the optical transceiver module and the communication line and the like can be improved. Is convenient.

In one embodiment of the present invention, the photodiode has a monitor light receiving area such that the refracted light on the transmission light side refracted on the light branch surface enters. .

According to the optical transmitting / receiving module of the above embodiment, the photodiode is provided with a monitoring light receiving area for monitoring the light emission amount of the transmitting light, so that one photodiode has a receiving light detecting function and a transmitting light monitoring function. Can be used to further reduce the size and cost.

In one embodiment, the optical transmission / reception module is characterized in that the light branch surface is formed on an element substrate of the photodiode.

According to the optical transmitting / receiving module of the embodiment, the semiconductor substrate having good transmission / reception light transmission is used for the element substrate, so that attenuation of transmission / reception light transmitted through the photodiode can be suppressed. According to the optical transmitting and receiving module of the embodiment, since the light branch surface is formed in the semiconductor portion of the photodiode, it is not necessary to provide a light branching optical element such as a half mirror.
Since the number of components can be reduced and the light branch surface can be manufactured during the wafer process for manufacturing the photodiode, batch manufacturing and alignment with the light receiving region can be performed with high accuracy. Also,
Since the light splitting surface is integrated with the photodiode, no alignment is required when assembling the module, and the size and cost can be reduced.

In one embodiment, the optical transmission / reception module is characterized in that the light splitting surface is formed in a semiconductor layer formed by the epitaxial growth method of the photodiode.

Further, according to the optical transmitting and receiving module of the embodiment, since the light branch surface is formed in the semiconductor portion of the photodiode, it is not necessary to provide a light branching optical element such as a half mirror. Since the number of points can be reduced and the light splitting surface can be manufactured during the wafer process of manufacturing the photodiode, batch manufacturing and alignment with the light receiving region can be performed with high accuracy. In addition, since the light splitting surface is integrated with the photodiode, there is no need for alignment at the time of assembling the module, and the size and cost can be reduced.

In one embodiment of the optical transceiver module, the photodiode has a structure in which a second semiconductor substrate is bonded to a semiconductor layer formed on a first semiconductor substrate as an element substrate by an epitaxial growth method. The semiconductor substrate of the second aspect is characterized in that the above-mentioned light splitting surface is formed.

According to the optical transceiver module of the above embodiment, the semiconductor layer having the light receiving region of the photodiode is integrated with the second semiconductor substrate having the light branch surface by bonding, so that the photodiode is constituted. A semiconductor (second semiconductor substrate) different from the semiconductor (first semiconductor substrate) to be used can be used as the light branch surface. It becomes easy to use a semiconductor transparent to the transmission / reception light for the second semiconductor substrate having an optical branch surface.

In one embodiment of the optical transceiver module, the semiconductor layer and the second semiconductor substrate are bonded together by anodic bonding, or Si / Si bonded together by anodic bonding, or by anodic bonding via a SiO ₂ film. It is characterized by being compound semiconductor / Si.

According to the optical transceiver module of the embodiment, the semiconductor layer and the second semiconductor substrate can be easily and accurately bonded.

In one embodiment of the present invention, the semiconductor layer and the second semiconductor substrate are bonded by direct bonding utilizing atomic rearrangement, and the directly bonded semiconductor interfaces are formed of InP / GaAs, InP / InP. Si, InP / InP,
Any one of GaAs / GaAs and GaAs / Si
It is characterized by one.

According to the optical transceiver module of the above embodiment, the bonding by direct bonding utilizing the atomic rearrangement of the semiconductor layer and the second semiconductor substrate can reduce the temperature of the heat treatment by applying pressure between the substrates. And
The first and second semiconductor substrates can be easily and accurately bonded to each other.

In one embodiment, the optical transmission / reception module is characterized in that the light branch surface is a {111} A surface.

According to the optical transmitting and receiving module of the above-described embodiment, by utilizing the plane orientation dependence of the etching rate of the semiconductor for forming the light branching plane, the light branching plane has a (111) A plane orientation having a low etching rate. And a light splitting surface having high angular accuracy and high specularity can be obtained.

In one embodiment, the optical transmission / reception module is characterized in that the light branch surface is a back surface of an element substrate of the photodiode.

According to the optical transceiver module of the above embodiment, the back surface of the photodiode element substrate can be easily mirror-finished by polishing or the like in a wafer state, and a good light branch surface can be obtained.

In one embodiment, the optical transceiver module has a chamfer formed on the semiconductor laser side of the element substrate of the photodiode.

According to the optical transceiver module of the above embodiment, the chamfered portion is provided on the element substrate of the photodiode on the side of the semiconductor laser, so that the emission end face of the semiconductor laser and the light branch surface of the photodiode are separated. It is possible to dispose them close to each other, so that the size of the transmission / reception module can be reduced and the light intensity of the transmission light coupled to the optical communication path can be increased.

In one embodiment, the optical transmission / reception module is characterized in that the light branch surface is a cleavage surface formed in the photodiode.

According to the optical transmitting and receiving module of the above embodiment, the light splitting surface formed on the photodiode is a light splitting surface, so that a light splitting surface with a very high specularity can be obtained.

In one embodiment, a reflection film made of at least one of a metal film and an insulation film is formed on a slope formed on a portion of the element substrate of the photodiode opposite to the cleavage surface. By providing a reflecting surface, the refracted light on the receiving light side refracted from the light splitting surface toward the photodiode is reflected by the reflecting surface, and then guided to the receiving light receiving area of the photodiode. Features.

According to the optical transmitting and receiving module of the above embodiment, the received light that is refracted from the light splitting surface formed of the cleavage surface to the photodiode side and transmitted through the photodiode is reflected by the reflecting surface, and then received. By guiding to the light receiving region, the semiconductor laser and the photodiode can be arranged on the same plane.

In one embodiment of the present invention, the reflecting surface of the photodiode has a curved surface shape for converging the refracted light on the receiving light side to the receiving light receiving area of the photodiode. Features.

According to the optical transmitting and receiving module of the above embodiment, the refracted light of the transmitting and receiving light is condensed on the curved reflecting surface and guided to the receiving light receiving region. The response speed of the photodiode can be increased. Further, the light beam of the reception light guided to the reception light receiving area becomes narrow, and the separation of the transmission and reception light can be easily performed.

In one embodiment, the optical transmission / reception module has a structure in which the light branch surface is a semiconductor layer selectively grown on the front surface or the back surface of the element substrate of the photodiode.
It is characterized in that it is one of the slopes of the 11｝ A plane and the {111｝ B plane.

According to the optical transmitting and receiving module of the above embodiment, the optical branching surface can be formed by the {111} A surface or the {111} B surface by selective growth, so that high specularity and surface accuracy and miniaturization can be achieved. Is obtained.

In one embodiment, the optical transmitting / receiving module is formed on the light splitting surface, and controls the reflectance to the incident light so that the reflected light and the refracted light on the light splitting surface on the transmission light side can be formed. And a reflection film capable of controlling the ratio of the reflected light and the refracted light on the receiving light side on the light splitting surface.

According to the optical transmitting and receiving module of the above embodiment, a reflective film having an arbitrary reflectance is formed on the light branch surface, and the reflectance is controlled, whereby the transmission light side on the light branch surface is formed. The ratio between the reflected light and the refracted light and the ratio between the reflected light and the refracted light on the reception light side at the light branch surface are controlled. By doing so, it is possible to increase the ratio of the reflected light of the transmission light, which is difficult to amplify, to the reception light, whose photocurrent can be amplified by an amplifier or the like.

In one embodiment of the present invention, the reflection film is formed such that the reflection film is formed on the light branch surface at 1 / (2n) of the wavelength λ of the transmission light (where n is the refractive index at the wavelength λ of the transmission light). ).

According to the optical transmitting and receiving module of the above embodiment, the thickness of the reflection film is set to be 1/1 / the wavelength λ of the transmitted and received light.
By setting (2n), the reflectance of transmitted and received light is maximized. Therefore, a high-reflectance reflective film can be obtained by coating a single-layer film that is easy to form, so that the cost can be reduced.

In one embodiment of the present invention, the photodiode is formed by growing a semiconductor layer including a light absorbing layer on the front side and the back side of the element substrate, and at least one of the photodiodes is used for receiving. It is characterized by having a plurality of light receiving regions as regions.

According to the optical transceiver module of the above embodiment, the semiconductor layer including the light absorbing layer is grown on both the front surface and the rear surface of the photodiode, and the light receiving region including the light receiving region for reception is formed in both semiconductor layers. By arranging
It is not necessary to provide a photodiode for monitoring the semiconductor laser separately from the photodiode for receiving light, and the transmission light and the receiving light are absorbed by the opposite semiconductor layers, so that noise due to the mutual photocurrent can be reduced. Further, the arrangement of the light splitting surface, the light receiving area for reception, and the light receiving area for monitoring can be made flexible.

In one embodiment, the photodiode is formed in at least a part of a region other than the light splitting surface on the surface of the photodiode, and absorbs stray light of transmission / reception light in the photodiode. It is characterized by having a stray light absorbing layer.

According to the optical transmitting and receiving module of the above-described embodiment, in order to repeat reflection in the photodiode and prevent stray light which causes noise, the above-mentioned optical transmitting and receiving module formed on at least a part other than the surface of the light splitting surface is used. The noise can be further reduced by absorbing the stray light by the stray light absorbing layer.

In one embodiment of the present invention, the photodiode is formed in at least a part of a region other than the light splitting surface on the surface of the photodiode, and the stray light of the transmission / reception light in the photodiode is reduced by the photodiode. It is characterized by having an anti-reflection film that goes out of the photodiode.

According to the optical transmitting / receiving module of the above embodiment, in order to repeat reflection in the photodiode and prevent stray light which causes noise, the optical transmitting / receiving module is formed on at least a part other than the light branch surface. The noise can be further reduced by facilitating stray light out of the photodiode by the antireflection film.

In one embodiment of the present invention, the light transmitting / receiving module is characterized in that a concave current excluding a diffusion current preventing region or a light absorbing layer is provided around the receiving light receiving region of the photodiode.

According to the optical transceiver module of the above embodiment, by providing the diffusion current preventing region or the concave portion for removing the light absorbing layer, the diffusion current (the cause of the tail current) generated by light incident outside the light receiving region is reduced. Detection as a transmission / reception current can be prevented, and noise can be further reduced.

In one embodiment, the semiconductor laser is a surface emitting laser.

According to the optical transmitting and receiving module of the above embodiment, by using a surface emitting laser as the semiconductor laser, the semiconductor laser and the optical branch surface can be further arranged.

In one embodiment, the optical transmission / reception module guides transmission light from the semiconductor laser to the optical transmission line without passing through a coupling lens.

According to the optical transceiver module of the above embodiment, the number of coupling lens components can be reduced, and the size and price can be further reduced.

In one embodiment of the present invention, the semiconductor region of the element substrate of the photodiode on which the light branch surface is formed is a photonic crystal having a super prism effect.

According to the optical transceiver module of the above embodiment, since the light branch surface is formed by the photonic crystal having the super prism effect, the refraction angles of the received light and the transmitted light incident on the photodiode are increased. Thus, the reception light and the transmission light can be further separated, and the noise can be reduced. In addition, since the traveling method of the received light incident from the light splitting surface can be controlled by the wavelength, only a desired wavelength component of the received light can be guided to the receiving light receiving region. Further, it is possible to guide the wavelength-multiplexed received light to a different light-receiving area for reception for each wavelength.

Further, a method of manufacturing an optical transceiver module according to the present invention is characterized in that the light splitting surface is formed on a semiconductor layer formed on the element substrate of the photodiode by an epitaxial growth method.

According to the method of manufacturing the optical transmission / reception module, since the light splitting surface is formed in the semiconductor portion of the photodiode, it is not necessary to provide an optical splitting optical element such as a half mirror, and the number of components is reduced. Can be reduced,
Since the light splitting surface can be manufactured during the wafer process for manufacturing the photodiode, batch manufacturing and alignment with the light receiving region can be performed with high accuracy. In addition, since the light splitting surface is integrated with the photodiode, there is no need for alignment at the time of assembling the module, and the size and cost can be reduced.

Further, a method of manufacturing an optical transceiver module according to the present invention is characterized in that the semiconductor layer and the second semiconductor substrate are bonded to each other by anodic bonding.

According to the method of manufacturing the optical transceiver module, the semiconductor layer and the second semiconductor substrate can be easily and accurately bonded.

The method for manufacturing an optical transceiver module according to the present invention is a method for manufacturing an optical transceiver module for manufacturing the optical transceiver module, wherein the semiconductor layer and the second semiconductor substrate are atomically rearranged. It is characterized in that it is bonded by direct joining using.

According to the method of manufacturing the optical transceiver module, the bonding of the semiconductor layer and the second semiconductor substrate by the direct bonding utilizing the atomic rearrangement can reduce the temperature of the heat treatment by applying pressure between the substrates. And
The semiconductor layer and the second semiconductor substrate can be easily and accurately bonded to each other.

Further, the method of manufacturing an optical transceiver module according to the present invention is characterized in that the optical branch surface is formed on the second semiconductor substrate before the semiconductor layer and the second semiconductor substrate are bonded to each other. And

According to the method of manufacturing the optical transceiver module, the second semiconductor substrate on which the light branch surface has been formed in advance can be accurately bonded to the photodiode wafer having the semiconductor layer. The semiconductor substrate can be processed with a high degree of freedom, and the photodiode is not damaged during the processing.

The method for manufacturing an optical transceiver module according to the present invention is a method for manufacturing an optical transceiver module for manufacturing the optical transceiver module, wherein the inclined surface serving as the optical branch surface is formed by etching the photodiode. It is characterized by doing.

According to the method of manufacturing the optical transceiver module, a slope is formed in the photodiode by etching, and the slope is used as a light branch surface, so that a light branch surface can be formed by a wafer process. A branch surface can be easily manufactured.

In one embodiment of the present invention, in the method of manufacturing an optical transmitting / receiving module, when the inclined surface serving as the light splitting surface is formed on the photodiode by etching, the inclined surface serving as the light splitting surface is formed on the {111} A surface. It is characterized by doing.

According to the method of manufacturing the optical transmitting and receiving module of the above embodiment, the light branching surface is formed by utilizing the plane direction dependency of the etching rate of the semiconductor for forming the light branching plane. 111) A plane, so that a light splitting surface with high angular accuracy and high mirror surface can be obtained.

In one embodiment of the present invention, the method for manufacturing the optical transceiver module includes the step of forming (100) 9.7 ° off (100) on the element substrate of the photodiode when forming the inclined surface serving as the light branch surface by etching the photodiode. The off-substrate described above is used to form an inclined surface serving as the light splitting surface having an angle of 45 ° with respect to the element substrate plane.

According to the method of manufacturing the optical transceiver module of the above embodiment, the semiconductor forming the optical branch surface is formed by (10
0) By using an off substrate of 9.7 ° off, the angle of the light branch surface formed by etching is set to 45 ° with respect to the element substrate plane, and the semiconductor laser and the photodiode are coplanar. When disposed on the support substrate, the reflected light on the transmission light side is emitted in the direction normal to the plane of the support substrate, thereby facilitating the design and manufacture of the optical transceiver module.

In one embodiment of the present invention, a method of manufacturing an optical transceiver module is characterized in that dry etching is used when forming the inclined surface serving as the light branch surface in the photodiode by etching.

According to the method of manufacturing the optical transceiver module of the above embodiment, the angle of the light splitting surface can be easily set to 45 ° with respect to the substrate plane by adopting dry etching which can form a slope in an arbitrary direction. Can be

In the method for manufacturing an optical transceiver module according to the present invention, the light branch surface of the photodiode is formed at an angle of 45 ° with respect to the element substrate plane of the photodiode by polishing. .

According to the method of manufacturing the optical transceiver module, a light splitting surface can be formed on the photodiode wafer by batch processing such as photolithography, machining, polishing, and the like. An inclined surface can be formed, and the angle of the light splitting surface can be accurately manufactured.

[0077]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical transceiver module and a method of manufacturing the same according to the present invention will be described in detail with reference to the illustrated embodiments. FIGS. 1 to 53 are diagrams relating to the embodiment of the present invention, and the same reference numerals are given to portions common to the embodiments, and redundant description will be omitted.

(First Embodiment) FIG. 1 is a perspective view showing a configuration of an optical transceiver module according to a first embodiment of the present invention. As shown in FIG.
Is a semiconductor laser 1 that emits transmission light 60 (shown in FIG. 2).
2, a photodiode 2 for receiving a received light (refracted light) 61a (shown in FIG. 2), an optical branch surface 3 formed on the photodiode 2, and an optical transmission line 4 for transmitting transmitted / received light.
A coupling lens 7 for coupling the transmission light to the optical disc, a submount 14 for mounting the semiconductor laser 1, and a support substrate 13 for mounting the photodiode 2 and the submount 14 with the semiconductor laser 1. .
Reference numeral 18 denotes a bonding wire, 19 denotes a wiring pattern provided on the support substrate 13 and one end of the bonding wire 18 is connected, and 62 denotes a transmitted / received light beam.

In the optical transmitting / receiving module 101,
A light branching surface 3 is formed on a semiconductor constituting the photodiode 2 so as to be oblique to an optical path of transmission / reception light (in FIG. 1, an angle of 45 ° with respect to a front surface of the support substrate 13 is set). Is shown).

FIG. 2 shows the optical transmission / reception module 10.
FIG. 2 is a cross-sectional view of the semiconductor laser 1. As shown in FIG. 2, the semiconductor laser 1 is fixed on the sub-mount 14 so that transmission light 60 emitted from the semiconductor laser 1 is incident on the light splitting surface 3. The photodiode 2 is fixed on a support substrate 13. The transmission light (reflected light) 60 b reflected by the light branch surface 3 is condensed by the coupling lens 7 and is coupled to the optical transmission path 4 at the position where the support substrate 13, the coupling lens 7 and the optical transmission path 4 are coupled. Are fixed to a module body (not shown). Further, a receiving light receiving area 8 is provided at a position where the receiving light (refracted light) 61a of the photodiode 2 is incident.

An n-type or p-type electrode or a metal bump (not shown) is formed on both the main surfaces of the first semiconductor substrate 10 as the element substrate of the photodiode 2 and the semiconductor layer 12 including the light absorbing layer. The electrode or the metal bump is electrically connected to the wiring pattern on the support substrate 13 by wire bonding or brazing material, and the photocurrent signal of the photodiode 2 is detected. The semiconductor laser 1 is also electrically connected and driven to oscillate similarly.

FIG. 3 shows the optical transceiver module 10.
FIG. 2 is a diagram illustrating a state of reflection and refraction of transmission light and reception light of No. 1; FIG. 3 shows a case where an InP photodiode is used as the photodiode.

As shown in FIG.
Is an n ⁺ -type InP buffer layer 32 and a non-doped InG substrate on an n-type InP substrate 31 (the lower side in FIG. 3) as an element substrate.
After the aAs light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially epitaxially grown, a p-type diffusion region 35 is selectively provided to form the receiving light-receiving region 8 (FIG. 3). This shows a state in which the n-type InP substrate 31 is upside down. Then, an n-type electrode 36 is formed on the back surface (the upper side in FIG. 3) of the n-type InP substrate 31 to electrically connect the n-type electrode 36 to a bonding wire (not shown) and to form a p-type diffusion region. A p-type electrode 37 and a metal bump 38 are formed on the P-type electrode 35 and the wiring pattern 1 between the p-type electrode 37 and the support substrate 13.
9 is electrically connected. In FIG. 3, for simplification of the drawing, only the metal bump 38 electrically connected to the p-type electrode 37 is shown, but a plurality of metal bumps which are not electrically connected to the insulating film 40 are actually shown. And the photodiode 2 is securely mounted on the support substrate 13. Then, an inclined surface serving as the light splitting surface 3 is formed at one corner on the back surface side of the n-type InP substrate 31.

In the optical transmitting / receiving module 101,
1.3 μm light and 1.55 μm used in subscriber systems
In consideration of the incidence of m light on the light splitting surface 3, InP is 1.3.
Since the light of about 1.6 μm is transmitted by 95% or more, the refracted light is transmitted through the n-type InP substrate 31 and is not doped with InGa.
The light reaches the As light absorbing layer 33, is absorbed in the light receiving area 8 for reception, and is converted into a photocurrent.

A part of the transmission light 60 incident on the light splitting surface 3 becomes transmission light (reflected light) 60 b and is condensed by the coupling lens 7, and then coupled to the optical transmission path 4. .
The other part of the transmission light 60 is transmitted light (refracted light) 6.
0a is transmitted through the photodiode 2. Also,
A part of the received light 61 incident on the light splitting surface 3 becomes a received light (refracted light) 61a, passes through the photodiode 2, is absorbed by the receiving light receiving area 8, and is detected as a received signal. You. At this time, the transmission light 60 and the reception light 61 enter the light branch surface 3 symmetrically with respect to the normal line of the light branch surface 3, and the incident angle θ1 is the same.
Are also symmetric with respect to the normal line of the light splitting surface 3, and the refraction angle θ ₂ has the same value. Here, when θ ₁ = 45 ° and the distance L from the incident portion of the light branch surface 3 to the non-doped InGaAs light absorption layer 33, the transmission light 6 reaching the light absorption layer 33
The interval d between 0a and the peak of the light intensity distribution of the received light 61a can be expressed by d = L {tan (45 ° + θ ₂ ) −tan (45 ° −θ ₂ )}, and according to Snell's law, The refractive index of air n ₁ = 1.0, the refractive index of InP n ₂ = 3.2), θ ₂ = sin ^-1 ｛(n ₁ · sin θ ₁ ) / n ₂ ＝ = sin ^-1 ｛(1.0 × sin45 °) /3.2°｝ 12.8 °, so that d = 0.958L. Therefore, (1) When L = 150 μm, the interval d between the light intensity peaks of the transmitted and received light is 144 μm. (2) When L = 300 μm, the interval d between the light intensity peaks of the transmitted and received light is 287 μm. Even in the case of a light receiving area diameter of 100 μmφ and L = 150 μm, the peak of the light intensity distribution of the transmission light (refracted light) 60 a is set in a state where the reception light (refracted light) 61 a is incident on the center of the reception light receiving area. The light can be prevented from being incident on the light receiving area 8 for reception.

FIG. 4 shows the optical transceiver module 10.
1 shows a light intensity distribution of transmission light and reception light incident on the light absorption layer 33 (shown in FIG. 3) of the photodiode 2. FIG. 5 shows a time change of the photocurrent 65 due to the reception light converted in the reception light receiving area and a time change of the photocurrent 66 due to the transmission light when the transmission and reception are performed in a time division manner.

As shown in FIG. 4, the peak of the light intensity distribution 64 due to the transmitted light is separated from the peak of the light intensity 63 due to the received light by a distance d, and the light receiving area for reception has the light intensity of the transmitted light. No peak light is incident. Therefore, FIG.
As shown in (2), in the photocurrent generated in the light receiving area for reception, the photocurrent 66 due to the transmission light generated at the time of transmission “S” is small, and the tail current 68 is also small. Therefore, at the time of reception “R” after the guard time “G”, noise superimposed on the photocurrent 65 due to the received light can be reduced.

(Second Embodiment) FIG. 6 is a sectional view showing the configuration of an optical transceiver module according to a second embodiment of the present invention.

As shown in FIG. 6, an optical transceiver module 102 according to the second embodiment includes a semiconductor laser 1 for emitting a transmission light 60, a photodiode 2 for receiving a reception light (refracted light) 61a, A light splitting surface 3 formed on the diode 2, a coupling lens 7 for coupling transmission light to an optical fiber 5 for transmitting and receiving light, a submount 14 for mounting the semiconductor laser 1, and a photodiode 2 And a support substrate 13 on which a submount 14 on which the semiconductor laser 1 is mounted is mounted.

The use of the optical fiber 5 which is laid as a communication line including a subscriber system as an optical transmission line connected to the optical transmission / reception module 102 having the above-mentioned structure is difficult in handling the connection between the optical transmission / reception module 102 and the communication line. It is convenient.

(Third Embodiment) FIG. 7 is a perspective view showing a configuration of an optical transceiver module according to a third embodiment of the present invention.

As shown in FIG. 7, the optical transceiver module 103 of the third embodiment includes a semiconductor laser 1 for emitting a transmission light 60 (shown in FIG. 8) and a reception light (refracted light) 61a (FIG. 8).
), A light splitting surface 3 formed on the photodiode 2, a coupling lens 7 for coupling transmission light to an optical fiber 5 for transmitting and receiving light, and the semiconductor laser 1. It comprises a mounted submount 14 and a support substrate 13 on which the photodiode 2 and the submount 14 with the semiconductor laser 1 are mounted.

FIG. 8 is a sectional view of the optical transceiver module. As shown in FIG.
The semiconductor laser 1 is fixed on the submount 14, and the photodiode 2 is fixed on the support substrate 13 so that the transmission light 60 emitted from the sub-mount 14 is incident on the light branch surface. Further, transmission light (reflected light) reflected on the light branch surface 3
The support substrate 13, the coupling lens 7 and the optical fiber 5 are fixed to a module main body (not shown) at a position where the light 60b is condensed by the coupling lens 7 and coupled to the optical transmission path. The receiving light receiving region 8 is provided at a position where the receiving light (refracted light) 61a is incident, and the monitoring light receiving region 9 is provided at a position where the transmitting light (refracted light) 60a is incident. ing.

FIG. 9 is a diagram for explaining the state of reflection and refraction of the transmission light and the reception light of the optical transceiver module. FIG. 9 shows a case where an InP-based photodiode is used as the photodiode.

The optical transmission / reception module 10 shown in FIG.
Operation 3 will be described below.

As shown in FIG. 9, the photodiode 2 has an n ⁺ -type InP buffer layer 32 and a non-doped InGa substrate on an n-type InP substrate 31 (the lower side in FIG. 9) as an element substrate.
After the As light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially epitaxially grown, a p-type diffusion region 35 is selectively provided to form the receiving light receiving region 8 and the monitoring light receiving region 9. (In FIG. 9, the element substrate is shown upside down.) An n-type electrode 36 is formed on the back surface (upper side in FIG. 9) of the n-type InP substrate 31 to electrically connect the n-type electrode 36 to a bonding wire (not shown),
P-type electrode 37 and metal bump 3
8 are formed, and the p-type electrode 37 and the wiring pattern 19 (shown in FIG. 7) of the support substrate 13 are electrically connected. The above n-type I
At one corner on the back side of the nP substrate 31, a slope as the light branching surface 3 is formed.

In the optical transmission / reception module 103 having the above-described configuration, the received light (refracted light) 6 incident on the light branch surface 3 and refracted.
1a and the transmitted light (refracted light) 60a are
After passing through the inside, the light reaches the non-doped InGaAs light absorbing layer 33, the received light (refracted light) 61a is absorbed by the receiving light receiving region 8, converted into a photocurrent, and the transmitted light (refracted light) 60a is received for monitoring. It is absorbed in the region 9 and converted into a photocurrent.

In the optical transmitting / receiving module 103, the separate receiving light receiving areas 8, 9 in one photodiode 2
Thus, the received light (refracted light) 61a and the transmitted light (refracted light) 60a can be converted into a photocurrent, so that the mutual photocurrent can be suppressed from becoming noise. Also, the reception current and monitor current can be detected with one photodiode,
The size and the price can be reduced.

(Fourth Embodiment) FIG. 10 shows a fourth embodiment of the present invention.
1 is a cross-sectional view illustrating a configuration of an optical transceiver module according to an embodiment. As shown in FIG. 10, the optical transceiver module 104 includes a semiconductor laser 1 that emits a transmission light 60,
Photodiode 2 receiving received light (refracted light) 61a
And a light splitting surface 3 formed on the photodiode 2
And a coupling lens 7 for coupling transmission light to an optical fiber 5 for transmitting and receiving light, a submount 14 for mounting the semiconductor laser 1, and a submount 14 with the photodiode 2 and the semiconductor laser 1. And a supporting substrate 13.

An n-type electrode and a p-type electrode are provided on both main surfaces on the first semiconductor substrate 10 side, which is the element substrate of the photodiode 2, and on the semiconductor layer 12 side including the light absorbing layer. It is electrically connected to the upper wiring pattern by wire bonding or mounting with a brazing material, and a photocurrent signal of the photodiode 2 is detected. Similarly, the semiconductor laser 1 is electrically connected to the wiring pattern and driven to oscillate.

FIG. 11 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the optical transceiver module of the present invention. Note that FIG. 11 illustrates a case where an InP-based photodiode is used as the photodiode.

As shown in FIG. 11, the photodiode 2
Represents an n ⁺ -type InP substrate 31 on an n-type InP substrate 31 as an element substrate.
P buffer layer 32, non-doped InGaAs light absorbing layer 3
3. After the n ⁻ -type InP window layer 34 is sequentially grown epitaxially, a p-type diffusion region 35 is selectively provided, and the light receiving region 8 for reception and the light receiving region 9 for monitoring are formed. An n-type electrode 36 is formed on the back surface of the n-type InP substrate 31, the n-type electrode 36 is electrically connected to the support substrate 13, and a p-type electrode 37 is formed on the p-type diffusion region 35. The mold electrode 37 is electrically connected to a bonding wire (not shown). Then, the n ^-- type InP window layer 34 is formed.
In addition, an inclined surface is formed as the light splitting surface 3.

In the optical transmitting / receiving module 104,
The reception light (refracted light) 61a and the transmission light (refracted light) 60a are n
^After passing through the -type InP window layer 34 and reaching the non-doped InGaAs light absorption layer 33, the reception light (refracted light) 61a is absorbed by the reception light receiving region 8, converted into a reception current, and transmitted.
(Refracted light) 60a is absorbed by the monitor light receiving region 9 and
Converted to monitor current.

In the light transmitting / receiving module 104, since the light splitting surface is formed in the semiconductor portion of the photodiode, it is not necessary to provide a light splitting optical element such as a half mirror, and the number of parts can be reduced. Since the light splitting surface can be manufactured during the wafer process for manufacturing the photodiode, batch manufacturing and alignment with the light receiving region can be performed with high accuracy. In addition, since the light splitting surface is integrated with the photodiode, there is no need for alignment at the time of assembling the module, and the size and cost can be reduced.

(Fifth Embodiment) FIG. 12 shows a fifth embodiment of the present invention.
It is a perspective view showing the composition of the optical transceiver module of an embodiment. As shown in FIG.
Reference numeral 5 denotes a semiconductor laser 1 for emitting a transmission light 60 (shown in FIG. 13), a photodiode 2 for receiving a reception light (refracted light) 61a (shown in FIG. 13), and a light formed on the photodiode 2 Coupling lens 7 for coupling transmission light to branch surface 3 and optical fiber 5 for transmitting transmission / reception light
And a submount 14 for mounting the semiconductor laser 1, the photodiode 2 and the semiconductor laser 1
And a support substrate 13 on which the attached submount 14 is mounted. Reference numeral 18 denotes a bonding wire, 19 denotes a wiring pattern provided on the support substrate 13 and one end of the bonding wire 18 is connected, and 62 denotes a transmitted / received light beam.

FIG. 13 is a cross-sectional view showing the structure of the optical transceiver module. As shown in FIG.
The semiconductor laser 1 is fixed on the submount 14 so that the transmission light 60 emitted from the semiconductor laser 1 is incident on the light branch surface, and the photodiode 2 is mounted on the support substrate 13.
It is fixed on top. Further, the support substrate 13, the coupling lens 7, and the optical fiber 5 are placed at a position where the transmission light (reflected light) 60b reflected by the light branch surface 3 is condensed by the coupling lens 7 and coupled to the optical transmission path. Each is fixed to a module body (not shown). The receiving light-receiving region 8 is provided at a position where the receiving light (refracted light) 61a is incident, and at a position where the transmitting light (refracted light) 60a is incident.
A monitoring light receiving area 9 is provided.

FIG. 14 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the optical transceiver module.

As shown in FIG. 14, the photodiode 2
Denotes an n-type In as a first semiconductor substrate which is an element substrate
After an n ⁺ -type InP buffer layer 32, a non-doped InGaAs light absorbing layer 33 and an n ⁻ -type InP window layer 34 are sequentially epitaxially grown on a P substrate 31, a p-type diffusion region 35 is selectively provided, and a light receiving region for reception is provided. 8 and monitor light receiving area 9
Was formed, a p-type electrode 37 and an insulating film 40 were formed on the p-type diffusion region 35, and a Si substrate 11a as a second semiconductor substrate on which the light branch surface 3 was formed was bonded via a SiOx film 42. Has a structure. An n-type electrode 36 is formed on the back surface of the n-type InP substrate 31, and the n-type electrode 36 and the support substrate 13 are formed.
And are electrically connected.

In the optical transmitting / receiving module 105,
The reception light (refracted light) 61a and the transmission light (refracted light) 60a are S
The light passes through the i-substrate 11a and the n ⁻ -type InP window layer 34, reaches the non-doped InGaAs light absorption layer 33, and receives the received light (refracted light).
The light 61a is absorbed by the light receiving area 8 for reception and converted into a reception current, and the transmission light (refracted light) 60a is absorbed by the light reception area 9 for monitoring and converted into a monitor current.

FIG. 15 shows a second example of the light branching surface 3.
The top view of the photodiode 2 in which the semiconductor substrate is bonded is shown, and the p-type electrode 37 is connected to the receiving light receiving area 8a and the monitoring light receiving area 9a via a wiring pattern 37a. The p-type electrode 37 and a bonding wire
(Not shown).

FIG. 16 is a process chart for explaining a manufacturing method of bonding a second semiconductor substrate, which has been processed in advance to become a light branch surface, to a photodiode wafer by anodic bonding.

Hereinafter, a method of manufacturing the photodiode 2 having the light branching surface 3 which is a main part of the optical transceiver module 105 will be described with reference to the process chart of FIG.

As shown in FIG. 16A, in the photodiode wafer, a p-type diffusion region 35 is selectively provided in the semiconductor layer 12 grown on the first semiconductor substrate 10, and the first semiconductor substrate 10 An n-type electrode 36 is formed on the back surface, and a p-type electrode 37 is formed on a part of the p-type diffusion region 35 on the semiconductor layer 12 side, and is insulated on a region excluding the p-type electrode 37 on the semiconductor layer 12 side. It is configured by forming a film 40. As the photodiode 2 (shown in FIG. 14), In
When a P-type photodiode is used, the first semiconductor substrate 10, which is an element substrate, is an n-type InP substrate 31, and the semiconductor layer 12 thereon is composed of an n ⁺ -type InP buffer layer 32, a non-doped InGaAs light absorption layer 33. And n ^- type InP window layer 3
No. 4 was sequentially epitaxially grown.

Next, as shown in FIG. 16B, the upper surface of the p-type electrode 37 and the insulating film 40 are formed by sputtering evaporation or CVD.
An SiO ₂ film 42 is formed thereon.

Next, as shown in FIG. 16C, an opening 42a is formed in the SiO ₂ film 42 by a photolithography process to expose a part of the p-type electrode 37, and the photodiode 2 (FIG.
4) so that electrical connection can be made by wire bonding or the like. The state of this exposed part is shown in FIG.
Is shown in the top view.

Next, as shown in FIG. 16D, the Si substrate 11a as the second semiconductor substrate having the V-groove 43 serving as the light branch surface 3 is formed on the photodiode via the SiO ₂ film. It is bonded to the wafer by anodic bonding.

Next, as shown in FIG. 16E, the light is divided into the photodiodes 2 each having the light splitting surface 3 formed thereon.

In the above-described anodic bonding, the bonding temperature can be set to 400 ° C. or lower. Therefore, after the electrode wiring is formed on the photodiode, the second semiconductor substrate having the V-groove serving as a light branch surface is bonded. Can be matched.

In the element substrate and the semiconductor layer when the photodiode 2 is manufactured by epitaxial growth, there are restrictions on the types of semiconductors that can be used, but a photodiode in which different kinds of second semiconductors are bonded and integrated is used. Since a light splitting surface can be formed at the same time, a semiconductor transparent to transmitted and received light can be easily used as the light splitting surface. In addition, after the second semiconductor substrate is subjected to processing such as an optical branch surface in advance, the second semiconductor substrate can be accurately bonded to the photodiode wafer, so that the second semiconductor substrate can be processed with a high degree of freedom. There is an advantage that the photodiode is not damaged during processing.

In the fifth embodiment, the semiconductor layer 1
An n-type InP substrate as the first semiconductor substrate on which the second semiconductor substrate 2 is formed and an Si substrate 11a as the second semiconductor substrate
Although bonding is performed by anodic bonding via the O ₂ film 42, the first and second semiconductor substrates bonded by anodic bonding are not limited thereto, and another compound semiconductor may be used as the first semiconductor substrate. Further, Si / Si as the first and second semiconductor substrates may be bonded by anodic bonding.

(Sixth Embodiment) FIG. 17 shows a sixth embodiment of the present invention.
FIG. 4 is a diagram illustrating a state of reflection and refraction of transmission light and reception light of the optical transceiver module of the embodiment. This optical transceiver module 106 is the fifth
It has the same configuration as the optical transceiver module 105 of the embodiment.

As shown in FIG. 17, the photodiode 2
Denotes an n-type In as a first semiconductor substrate which is an element substrate
After epitaxially growing an n ⁺ -type InP buffer layer 32, a non-doped InGaAs light absorbing layer 33 and an n ⁻ -type InP window layer 34 on a P substrate 31, two p-type diffusion regions 35 are selected at a predetermined interval. And a light receiving region 8 for monitoring and a light receiving region 9 for monitoring are produced, and the second semiconductor substrate having the light branch surface 3 formed on the p-type diffusion region 35 and the n ⁻ -type InP window layer 34 And a Si substrate 11a as a substrate. An n-type electrode 36 is formed on the back surface of the n-type InP substrate 31, and the n-type electrode 36 and the support substrate 13 are electrically connected. A p-type diffusion region 44 is provided on the Si substrate 11a on the two p-type diffusion regions 35, a p-type electrode 37 is formed on the p-type diffusion region 44, and the p-type electrode 37 and a bonding wire (not shown). And are electrically connected.

In the optical transmitting / receiving module 106,
The reception light (refracted light) 61a and the transmission light (refracted light) 60a are S
The light transmitted through the i-substrate 11a, reaches the non-doped InGaAs light absorbing layer 33, and the received light (refracted light) 61a is absorbed by the light receiving region 8 for reception, converted into a reception current, and transmitted (refracted light) 60a. Is absorbed by the monitor light receiving region 9 and is converted into a monitor current.

FIG. 18 shows a second semiconductor substrate bonded to a photodiode wafer by atomic rearrangement.
FIG. 6 is a process chart for explaining a manufacturing method for forming an optical branch surface on the semiconductor substrate of FIG. Hereinafter, a method of manufacturing the photodiode 2 having the light branch surface 3 as a main part of the optical transceiver module 106 will be described with reference to the process chart of FIG.

As shown in FIG. 18A, the photodiode wafer is obtained by selectively providing a p-type diffusion region 35 in a semiconductor layer 12 grown on a first semiconductor substrate 10. When an InP-based photodiode is used as 2, the first semiconductor substrate 10 as an element substrate is used.
Is an n-type InP substrate 31, as shown in FIG.
The semiconductor layer 12 thereon includes an n ⁺ -type InP buffer layer 32,
The non-doped InGaAs light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially grown by epitaxial growth.

Next, as shown in FIG. 18B, on the surface of the semiconductor layer 12, a Si substrate 11a having a p-type diffusion region selectively provided thereon is bonded as a second semiconductor substrate. Here, they are bonded by direct bonding utilizing atomic rearrangement. Heat treatment temperature for direct bonding is 450-700 ° C
By applying pressure between the substrates before the heat treatment, the temperature of the heat treatment can be lowered, and bonding can be performed by treatment at 450 ° C. (Jpn. J. Appl.
Phys. 33, 4878, 1994).

At the time of the bonding, the p-type diffusion region 35 forming the light-receiving region and the p-type diffusion region 40 formed on the Si substrate 11a are aligned, and the light is received via the p-type electrode 37 on the surface of the Si substrate 11a. A photocurrent signal from a region is obtained.

Next, as shown in FIG. 18C, the Si substrate 1
A V-groove 43 for forming a light splitting surface is formed in 1a. As a method for forming the V-shaped groove 43, a stripe-shaped opening 4 is formed in the etching mask 45 by a photolithography process.
5a, and can be manufactured by etching the Si substrate 11a with a KOH-based etchant.

Next, as shown in FIG. 18D, after removing the etching mask 45, an n-type electrode 36 is formed on the back surface of the first semiconductor substrate 10, which is an n-type InP substrate, and the S-type electrode 36 is formed.
The p-type electrode 37 is formed on the p-type diffusion region 44 of the i-substrate 11a.

Next, as shown in FIG. 18E, the light is divided into a plurality of photodiodes 2 each having a light splitting surface 3 formed thereon.

In the element substrate and the semiconductor layer when the photodiode 2 is manufactured by epitaxial growth, there are restrictions on the types of semiconductors that can be used. However, light is applied to a photodiode integrated by bonding different kinds of second semiconductors. Since the branch surface can be formed, there is an advantage that a semiconductor transparent to transmission / reception light can be easily used as the light branch surface.

In the sixth embodiment, the semiconductor layer 1
Although the n-type InP substrate 31 as the first semiconductor substrate on which the substrate 2 is formed and the Si substrate 11a as the second semiconductor substrate are bonded by direct bonding utilizing atomic rearrangement,
The first and second semiconductor substrates bonded by direct bonding are not limited to this, and the first and second semiconductor substrates may be InP / second semiconductor substrates.
GaAs, InP / InP, GaAs / GaAs and GaAs / S
i may be bonded by direct bonding.

(Seventh Embodiment) FIG. 19 shows a seventh embodiment of the present invention.
It is a sectional view showing the composition of the optical transceiver module of an embodiment. As shown in FIG.
Reference numeral 7 denotes the semiconductor laser 1 which emits the transmission light 60, and the reception light
A photodiode 2 for receiving (refracted light) 61a, a light splitting surface 3 formed on the photodiode 2, a coupling lens 7 for coupling transmission light to an optical fiber 5 for transmitting and receiving light, and the semiconductor laser And a support substrate 1 on which the photodiode 2 and the submount 14 with the semiconductor laser 1 are mounted.
3a.

The light branch surface 3 formed on the photodiode 2 is a {111} A surface, and the first semiconductor substrate 10
Since the inclination angle with respect to the plane is 54.7 °, the support substrate 13a is mounted on the plane on which the semiconductor laser 1 is mounted in order to set the light branching surface 3 at 45 ° on the optical path of the transmission / reception light. The surface on which the photodiode 2 is mounted has an inclination of 9.7 °. By setting the light splitting surface 3 at 45 ° on the optical path, the coupling lens 7 and the optical fiber 5 can be arranged in the normal direction to the mounting surface of the semiconductor laser 1, and the arrangement and position of each component Easy to match.

FIG. 20 is a diagram for explaining the state of reflection and refraction of the transmission light and the reception light of the optical transmission / reception module 107. FIG. 20 shows a case where an InP photodiode is used as the photodiode.

As shown in FIG. 20, the photodiode 2 has an n ⁺ -type InP buffer layer 32 and a non-doped InP buffer layer 32 on an n-type InP substrate 31 (the lower side in FIG. 20) as an element substrate.
After the GaAs light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially epitaxially grown, a p-type diffusion region 35 is selectively provided to form the light receiving region 8 for reception and the light receiving region 9 for monitoring. (In FIG. 20, the element substrate is shown upside down.) The back surface of the n-type InP substrate 31 (FIG. 2)
(0, Kamikawa), an n-type electrode 36 is formed, the n-type electrode 36 is electrically connected to a bonding wire (not shown), and a p-type electrode 37 and a metal bump 38 are formed on the p-type diffusion region 35. The p-type electrode 37 is electrically connected to the wiring pattern 19 of the support substrate 13. The above n-type I
An inclined surface of {111} A surface is formed on the nP substrate 31 by etching to form a light splitting surface 3.

In the optical transmitting / receiving module 107,
The refracted light passes through the n-type InP substrate 31 and is undoped.
The light reaches the GaAs light absorbing layer 33 and is received (refracted light) 51a.
Is absorbed by the receiving light-receiving region 8 and converted into a photocurrent, and the transmission light (refracted light) 50a is absorbed by the monitoring light-receiving region 9 and converted into a photocurrent.

The method of forming the slope to be the light splitting surface 3 is as follows.
Resist or Si on the photodiode in wafer state
After a plurality of V-grooves are formed by chemical etching using Ox, SiNx or the like as an etching mask, an inclined surface is formed by dividing the device into elements, thereby forming a light splitting surface 3.

FIG. 21 shows a manufacturing process diagram in which the light branch surface 3 is formed by etching, and the inclined surface which becomes the light branch surface 3 is a {111} A plane. Hereinafter, a method of manufacturing a photodiode having a light branch surface, which is a main part of the optical transceiver module, will be described with reference to the process chart of FIG.

First, as shown in FIG.
The semiconductor layer 12 including the light absorbing layer is epitaxially grown on the first semiconductor substrate 10 on the (00) plane (the lower side in FIG. 21), a p-type diffusion region 35 is selectively provided, and an insulating film is formed on the surface of the semiconductor layer 12. A film 40 is formed (in FIG. 21A, the first semiconductor substrate 10 is shown upside down). Here, to show an example of an InP-based photodiode, an n-type InP substrate is shown as the first semiconductor substrate.

Next, as shown in FIG. 21B, a SiNx film is formed on the (1-00) plane, which is the surface of the first semiconductor substrate 10 (the back side of the photodiode wafer), by the plasma CVD method. To form an etching mask 45.
Note that "1-" in the crystal direction represents minus 1 in Miller index.

Next, as shown in FIG. 21C, an opening is provided in the insulating film 40 by a photolithography step and an electrode lift-off step, and a p-type electrode 37 is provided in the opening to establish electrical connection. To get it.

Next, as shown in FIG. 21D, after a resist 46 is applied on the etching mask 45, a stripe in the <011-> direction is formed on the etching mask 45 by a photolithography process and a buffered hydrofluoric acid etching process. The first semiconductor substrate 10 is etched by providing an opening 45a in a shape of a circle. Here, HBr: H ₂ is used as an etchant.
Using O ₂ , depending on the plane orientation dependence of the etching rate,
The {111} A plane with a slow etching rate is
A V-groove 43 is formed as shown in FIG.

Next, as shown in FIG. 21 (e), the n-type electrode 3 is formed on the back surface of the first semiconductor substrate 10 in a region excluding the V groove 43.
6 is selectively formed.

Next, as shown in FIG. 21F, by dividing the photodiode wafer, {111}
Optical transmission / reception module 107 having A-side slope as light splitting surface 3
A plurality of photodiodes 2 having a light splitting surface 3 as a main part of are formed.

In the light transmitting / receiving module 107, an optical branch surface can be formed on the photodiode wafer by performing a batch process of a photolithography process and an etching process. In addition, since the light splitting surface is a {111} A crystal plane, a light splitting surface having high specularity and high angular accuracy can be manufactured.

(Eighth Embodiment) FIG. 22 shows an eighth embodiment of the present invention.
FIG. 23 is a cross-sectional view illustrating a configuration of the optical transceiver module according to the embodiment. As shown in FIG. 22, the semiconductor laser 1 is sub-mounted so that transmission light 60 emitted from the semiconductor laser 1 is incident on the light splitting surface 3. While fixed on the mount 14,
The photodiode 2 is fixed on a support substrate 13.
Further, the transmission light (reflected light) 60b reflected by the light branch surface 3
Is condensed by a coupling lens 7 and is fixed to a module main body (not shown) at a position where it is coupled to the optical fiber 5 as an optical transmission path. In addition, the receiving light receiving region 8 is provided at a position where the receiving light (refracted light) 61a is incident, and the monitoring light receiving region 9 is provided at a position where the transmitting light (refracted light) 60a is incident.

FIG. 22 shows a case where the semiconductor laser 1 and the photodiode 2 are mounted on the support substrate 1 in the case of the photodiode 2 having the light branch surface 3 formed at an angle of 45 ° with respect to the element substrate plane.
3 shows that a 45-degree light splitting surface 3 can be installed on the path of transmission / reception light by mounting on the same plane.

FIG. 23 shows the optical transmission / reception module 1
08 is a diagram for explaining the state of reflection and refraction of transmission light and reception light 08. Note that FIG. 23 illustrates a case where an InP-based photodiode is used as the photodiode. Hereinafter, the optical transceiver module 108 shown in FIG.
Will be described.

As shown in FIG. 23, the photodiode 2 is provided on an n-type InP substrate 31a as an element substrate (FIG. 23).
In the lower part), the n ⁺ -type InP buffer layer 32 and the non-doped I
After the nGaAs light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially epitaxially grown, a p-type diffusion region 35 is selectively provided to form the light receiving region 8 for reception and the light receiving region 9 for monitoring. (FIG. 23 shows a state in which the n-type InP substrate 31a is upside down.) The n-type InP substrate 3
An n-type electrode 36 is formed on the back surface of 1a (the upper side in FIG. 23),
The n-type electrode 36 is electrically connected to a bonding wire (not shown), and the p-type electrode 3
7 and metal bumps 38 are formed, and the p-type electrode 37 and the wiring pattern 19 of the support substrate 13 are electrically connected.
At one corner on the back surface side of the n-type InP substrate 31a, a slope serving as the light branching surface 3 is formed. Refracted light is n-type In
The light transmitted through the P substrate 31a reaches the non-doped InGaAs light absorbing layer 33, and the received light (refracted light) 61a is absorbed by the receiving light receiving region of the light absorbing layer 33, converted into a photocurrent, and transmitted light (refracted light). The light 60a is absorbed by the monitor light receiving region of the light absorbing layer 33 and is converted into a photocurrent.

FIG. 24 is a process chart for fabricating a photodiode having a 45 ° light branch surface by anisotropically etching a photodiode wafer using a (100) 9.7 ° off substrate. Is shown. Hereinafter, according to the process diagram of FIG. 24, the photodiode 2 having the light branching surface 3 which is a main part of the optical transceiver module 108 is formed.
The method for fabricating will be described.

As shown in FIG. 24A, (100) 9.7
The semiconductor substrate 12 including the light absorbing layer is epitaxially grown on the first semiconductor substrate 10 (the lower side in FIG. 24) by selectively turning off the off substrate, and the p-type diffusion region 35 is selectively provided on the surface of the semiconductor layer 12. An insulating film 40 is formed (FIG. 21A shows a state where the first semiconductor substrate 10 is upside down).

Next, as shown in FIGS. 24 (b) to (f), FIG.
A V-shaped groove 43a of {111} A plane is formed by anisotropic etching in the same manner as in 1. At this time, both slopes of the V-shaped groove 43a are at 45 ° and 6 ° with respect to the plane of the first semiconductor substrate 10, respectively.
It is 4.4 °, and after being divided into elements, the 45 ° inclined surface side is defined as a light splitting surface 3.

In the light transmitting / receiving module 108 using the photodiode 2 having the 45 ° light splitting surface 3 formed thereon, the semiconductor laser 1 and the photodiode 2 are mounted on the same plane of the supporting substrate 13 so as to transmit and receive the light. A 45 ° light splitting surface can be formed on the path. Therefore, the mounting of the optical device at the time of assembling the optical transceiver module can be facilitated, and the coupling lens 7 and the optical fiber 5 can be arranged in the normal direction to the mounting surface of the semiconductor laser 1. Arrangement and positioning are easy.

(Ninth Embodiment) FIG. 25 shows a ninth embodiment of the present invention.
It is a flowchart explaining the manufacturing method of the optical branch surface by dry etching of the optical transceiver module of an embodiment. In the ninth embodiment, only a method of processing a first semiconductor substrate, which is an element substrate of a photodiode wafer, will be described for the sake of simplification of a manufacturing method for forming a 45 ° light splitting surface on a photodiode.

First, as shown in FIG. 25A, an etching mask 45 having an opening 45a is formed on a first semiconductor substrate 10.

Next, as shown in FIG.
(Reactive Ion Beam Etchin
g) Etching is performed from a 45 ° oblique direction by dry etching to form a 45 ° slope.

Then, as shown in FIG. 25 (c), after the etching mask 45 is removed and the device is divided, the inclined surface at an angle of 45 ° with respect to the plane of the first semiconductor substrate 10 is formed as the light splitting surface 3. I do.

In the method for manufacturing the optical transceiver module,
An optical branch surface can be formed on the photodiode wafer by batch processing such as a photolithography process and dry etching. Further, the angle of the light branch surface can be manufactured with high accuracy. Further, since the light branch surface can be formed at 45 °, the semiconductor laser and the photodiode can be mounted on the same plane of the support substrate.

(Tenth Embodiment) FIG. 26 is a process chart illustrating a method of manufacturing an optical branch surface of an optical transceiver module according to a tenth embodiment of the present invention. In the tenth embodiment, the photodiode has V
For the sake of simplicity, only a method for processing a first semiconductor substrate, which is an element substrate of a photodiode wafer, will be described for a manufacturing method for forming a 45 ° light branch surface by polishing after forming a groove.

First, as shown in FIG. 26A, an etching mask 45 having an opening 45a is formed on the first semiconductor substrate 10.

Next, as shown in FIG. 26B, the first semiconductor substrate 10 is subjected to {111} A
A V-shaped groove 43 having a slope of 54.7 ° is formed.

Next, as shown in FIG. 26 (c), after removing the etching mask 45, the slope of the V-shaped groove 43 is polished by mechanochemical polishing in which a minute mechanical action is combined. In this case, the movement of the policy material 22 in the working fluid 23 by the polisher 21 is greater at the shoulder of the V-groove 43 than at the bottom of the V-groove 43, and polishing proceeds at the shoulder of the V-groove 43. The slope of the slope of 43 gradually decreases. Then, when the angle of the slope of the V-shaped groove 43 becomes 45 °, the polishing is finished, and after dividing into elements, the 45 ° slope is defined as the light branch surface 3.

FIG. 27 is a process chart for explaining a manufacturing method for forming a 45 ° light splitting surface by polishing after forming a V-groove having a 45 ° inclined surface with a blade.

First, as shown in FIGS. 27 (a) to 27 (c), the first
V groove 43b having a slope of 45 ° or more in the semiconductor substrate of
It is produced by machining a blade 24 such as a diamond cutter.

Next, as shown in FIG. 27D, the slope of the V-shaped groove 43b is polished by mechanochemical polishing.
That is, the policy agent 22 in the working fluid 23 is
Then, the slope of the V-shaped groove 43b is polished and mirror-finished.

Then, as shown in FIG. 27 (e), by the above-mentioned polishing, it is possible to remove a film generated by machining on the slope of the V-shaped groove 43b and to mirror-finish the surface roughness, thereby achieving high specularity. Make a 45 ° slope. Then, it is divided into elements and 4
The 5 ° slope is defined as the light splitting surface 3.

In the method for manufacturing the optical transceiver module,
An optical branch surface can be formed on the photodiode wafer by batch processing such as photolithography, machining, polishing, and the like, and a highly mirror-finished slope can be formed by polishing. Further, the angle of the light branch surface can be manufactured with high accuracy. Furthermore, the light splitting surface is set at 45 °
Therefore, the semiconductor laser and the photodiode can be mounted on the same plane of the supporting substrate.

(Eleventh Embodiment) FIG. 28 is a sectional view showing a configuration of an optical transceiver module according to an eleventh embodiment of the present invention. As shown in FIG. 28, the optical transceiver module 111 includes a semiconductor laser 1 that emits a transmission light 60, a photodiode 2 that receives a reception light (refracted light) 61a,
Light splitting surface 3 using the back surface of photodiode 2
And a coupling lens 7 for coupling transmission light to an optical fiber 5 for transmitting and receiving light, a submount 14 for mounting the semiconductor laser 1, and a submount 14 with the photodiode 2 and the semiconductor laser 1. And a supporting substrate 13b. In the optical transmission / reception module 111, the support substrate 13b is disposed on a plane on which the photodiode 2 is mounted with respect to a plane on which the semiconductor laser 1 is mounted in order to set the light branch surface 3 at 45 ° on the optical path of the transmission / reception light. It has a 45 ° inclination. In addition, the light branch surface 3 of the photodiode 2 is formed by mirror-polishing the back surface of the photodiode 2, that is, the surface of the first semiconductor substrate 10 by polishing or etching.

FIG. 29 shows the optical transmission / reception module 1
11 is a diagram illustrating a state of reflection and refraction of transmission light and reception light of No. 11. FIG. FIG. 29 shows a case where an InP-based photodiode is used as the photodiode.

As shown in FIG. 29, the photodiode 2
Represents an n ⁺ -type InP buffer layer 32 and a non-doped InGa on an n-type InP substrate 31 (the lower left side in FIG.
After the As light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially epitaxially grown, a p-type diffusion region 35 is selectively provided to form the light receiving region 8 for reception and the light receiving region 9 for monitoring. (In FIG. 29, the element substrate is shown upside down.) The back surface of the n-type InP substrate 31 (FIG. 29)
The upper right side is formed with an n-type electrode 36, and the n-type electrode 36 is connected to a bonding wire (not shown).
P-type electrode 37 and metal bump 3
8 are formed, and the p-type electrode 37 and the wiring pattern 19 of the support substrate 13 are electrically connected.

In the optical transmitting / receiving module 111,
The received light (refracted light) 61a and the transmitted light (refracted light) 60a that have entered the light splitting surface 3 pass through the n-type InP substrate 31, reach the non-doped InGaAs light absorption layer 33, and receive the received light (refracted light). The light 61a is absorbed by the receiving light-receiving region 8 and converted into a photocurrent, and the transmission light (refracted light) 60a is absorbed by the monitoring light-receiving region 9 and converted into a photocurrent.

In the optical transmission / reception module 111, transmission / reception light (refracted light) can be separated and converted into a photocurrent in a separate light receiving region, so that it is possible to suppress mutual photocurrent from becoming noise.

Mirroring the back surface of the photodiode 2 can be easily performed by polishing or the like in a wafer state, and a good light branch surface can be obtained.

(Twelfth Embodiment) FIG. 30 is a sectional view showing the structure of an optical transceiver module according to a twelfth embodiment of the present invention. As shown in FIG. 30, the optical transceiver module 112 has the same configuration as that of the optical transceiver module 111 of the eleventh embodiment except for a part. Diode 2
Only the arrangement is different from the eleventh embodiment.

The formation of the chamfered portion 15 of the photodiode 2 allows the photodiode 2 to be disposed closer to the emission end of the semiconductor laser 1, thereby reducing the size of the optical transceiver module. The light intensity of the transmission light (reflected light) 60b to be coupled to the optical fiber 5 can be increased.

In the light transmitting / receiving module 112, the chamfered portion 15 can be manufactured by forming a V-groove by chemical etching or the like.

(Thirteenth Embodiment) FIG. 31 is a sectional view showing a configuration of an optical transceiver module according to a thirteenth embodiment of the present invention. As shown in FIG. 31, the optical transceiver module 113 includes a semiconductor laser 1 that emits a transmission light 60, a photodiode 2 that receives a reception light (refracted light) 61a,
A light splitting surface 3 using a cleavage end face 25 of the photodiode 2; a coupling lens 7 for coupling transmission light to an optical fiber 5 for transmitting and receiving light; and a submount 14 with the photodiode 2 and the semiconductor laser 1 And a supporting substrate 13c on which the substrate is mounted. In order to set the light splitting surface 3 at 45 ° on the optical path of the transmission / reception light,
The support substrate 13c has a 45 ° inclination with respect to the plane on which the photodiode 2 is mounted with respect to the plane on which the semiconductor laser 1 is mounted.

The light branch surface 3 of the photodiode 2 is
The chip end surface of the photodiode 2 is used, and the chip end surface is a cleavage surface 25 formed by cleavage when the wafer is divided into chips (bar).

FIG. 32 shows the optical transmission / reception module 1
FIG. 33 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the thirteenth embodiment.

In the optical transmitting / receiving module 113,
The transmission light (refraction light) 60a and the reception light (refraction light) 61a that have entered the light branch surface 3 and refracted pass through the n-type InP substrate 31, reach the non-doped InGaAs light absorption layer 33, and receive the reception light (refraction light). The refracted light 61a is absorbed by the receiving light-receiving region 8 and converted into a photocurrent, and the transmitted light (refracted light) 60a is directed toward the opposite surface of the n-type InP substrate 31.

As described above, since the transmitted / received light (refracted light) can be separated and the received light (refracted light) 61a can be converted into a photocurrent in the receiving light receiving area 8, noise due to the transmitted light (refracted light) 60a is suppressed. can do.

In the optical transmission / reception module 113, by forming the light branch surface 3 by cleavage, it is possible to manufacture a light branch surface having extremely excellent mirror finish. Also, the light splitting surface 3 can be manufactured by cleavage at the time of chip division, and there is no need to add special processing for manufacturing the light splitting surface.

(Fourteenth Embodiment) FIG. 33 is a perspective view showing a configuration of an optical transceiver module according to a fourteenth embodiment of the present invention, and FIG. 34 is a top view of the optical transceiver module. As shown in FIGS. 33 and 34, the optical transceiver module 114 includes a semiconductor laser 1 that emits a transmission light 60, a photodiode 2 that receives a reception light (refracted light) 61a, and a cleavage surface of the photodiode 2. The light splitting surface 3 using the end surface, the reflecting surface 16 for guiding the receiving light (refracted light) 61a to the receiving light receiving region 8, and the coupling lens 7 for coupling the transmitting light to the optical fiber 5 for transmitting and receiving light.
And a support substrate 13 on which the photodiode 2 and the semiconductor laser 1 are mounted on the same plane.
The reflection surface 16 is formed by forming a slope on a first semiconductor substrate, which is an element substrate of the photodiode 2, by anisotropic etching, and forming a metal film on the slope to increase the reflectance. The photodiode 2 is mounted so that the light branch surface 3 has a 45 ° inclination with respect to the emitted light of the semiconductor laser 1.

The light branch surface 3 utilizes the chip end surface of the photodiode 2, and this chip end surface is
A cleavage surface 25 formed by cleavage when the wafer is divided into chips (bar).

FIG. 35 shows the optical transmission / reception module 1
14 is a diagram for explaining the state of reflection and refraction of the 14 transmission light and the reception light.

In the optical transmitting / receiving module 114,
The reception light (refraction light) 61a and the transmission light (refraction light) 60a that have entered the light branch surface 3 and have been refracted pass through the n-type InP substrate 31 and are reflected by the reflection surface 16 before being non-doped InGaAs.
The light (refracted light) 61a that reaches the light absorbing layer 33 is absorbed by the light receiving area 8 for reception and converted into a photocurrent. On the other hand, as shown in FIG. 34, the transmitted light (refracted light) 60a travels in a direction in which it is separated from the received light (refracted light) 61a.
Noise due to the transmission light 60a to the photocurrent of the reception light (refracted light) 61a can be suppressed.

In the optical transmission / reception module 114, the light splitting surface is formed by cleavage, so that a light splitting surface with extremely excellent mirror finish can be manufactured. Further, the semiconductor laser 1 and the photodiode 2 can be mounted on the same plane of the support substrate 13, and the assembly of the optical transceiver module is facilitated.

(Fifteenth Embodiment) FIG. 36 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of an optical transceiver module according to a fifteenth embodiment of the present invention. This optical transceiver module 115 has the same configuration as the optical transceiver module 114 of the fourteenth embodiment except for the reflection surface.
As shown in FIG.
Is a modification of the fourteenth embodiment, in which the planar reflecting surface 16 in the fourteenth embodiment is replaced by a curved reflecting surface 17 having a condensing function.

In the optical transmitting / receiving module 115,
The transmission / reception light (refracted light) is reflected and condensed on the reflection surface 17 having a light condensing function, and becomes a sharp light beam.
It is led to. Therefore, the area of the light receiving region can be reduced, and the response speed of the photodiode 2 can be increased. Further, since the light beam of the transmitted / received light guided to the receiving light receiving area 8 becomes smaller, separation of the transmitted / received light becomes easier.

(Sixteenth Embodiment) FIGS. 37 and 38 are sectional views showing the structure of an optical transceiver module according to a sixteenth embodiment of the present invention.

As shown in FIG. 37, the photodiode 2
The first semiconductor substrate 10, which is the element substrate on the back side of
An iNx film or the like is formed, and the selective growth mask 47 is patterned. Next, a semiconductor layer 48 transparent to the wavelength of the transmitted / received light is grown by a selective vapor deposition method. At this time,
On the selective growth mask 47, the source atoms re-evaporate,
The semiconductor layer 48 having a triangular cross section is formed at the opening of the selective growth mask 47 by performing the growth under the condition that the surface diffusion length becomes long. The selective growth mask is <01
In the case of the stripe pattern in the 1> direction, the triangular slope of the semiconductor layer 48 is formed by the {111} A plane.

On the other hand, as shown in FIG. 38, when the selective growth mask is a stripe pattern in the <01-1> direction, the triangular slope of the semiconductor layer 48 is formed by the {111} B plane.

As described above, the light splitting surface 3 of the photodiode 2 is replaced with the {111} A surface which is the slope of the semiconductor layer 48.
(Shown in FIG. 37) or {111} B plane (shown in FIG. 38).

Further, in the optical transmitting / receiving module 116, the light branching surface 3 is formed by the {111} A surface or the {111} B surface by selective growth, thereby forming an optical branching surface with high mirror surface and high surface accuracy. be able to. Further, the size of the light branch surface can be easily reduced.

(Seventeenth Embodiment) FIGS. 39 and 40 show a configuration of an optical transceiver module according to a seventeenth embodiment of the present invention.

As shown in FIG. 39, the photodiode 2
A SiNx film or the like is formed on the semiconductor layer 12 on the front surface side of the substrate, and a selective growth mask 47 is formed by patterning. Next, a semiconductor layer 48 transparent to the wavelength of the transmitted / received light is grown by a selective vapor deposition method. At this time, similarly to the seventeenth embodiment, the {111} A plane which is the slope of the semiconductor layer 48 is used.
(Shown in FIG. 39) or {111} B plane (shown in FIG. 40)
Thus, the light splitting surface 3 is formed.

On the other hand, as shown in FIG. 40, when the selective growth mask is a stripe pattern in the <01-1> direction, the triangular slope of the semiconductor layer 48 is formed by the {111} B plane.

In the optical transmitting / receiving module 116, the light branching surface 3 is formed by the {111} A surface or the {111} B surface by selective growth, thereby forming an optical branching surface having high mirror surface and high surface accuracy. be able to. Further, the size of the light branch surface can be easily reduced.

(Eighteenth Embodiment) FIG. 41 is a sectional view showing the structure of an optical transceiver module according to an eighteenth embodiment of the present invention. The optical transceiver module 118 has the same configuration as the optical transceiver module 102 of the second embodiment except for the reflectance control thin film 26.

As shown in FIG. 41, by forming the reflectance control thin film 26 on the light branch surface 3, the transmission light (reflected light) 60b at the light branch surface 3 formed on the photodiode 2 is formed.
And the ratio of transmitted light (refracted light) 60a and received light (reflected light)
The ratio between the received light 61b and the received light (refracted light) 61a is controlled.

In the optical transmission / reception module 118, the light intensity of the transmission light (reflected light) 60b coupled to the optical fiber 5 can be increased by increasing the reflectance of the reflectance control thin film 26.

(Nineteenth Embodiment) FIG. 42 is a sectional view showing the configuration of an optical transceiver module according to a nineteenth embodiment of the present invention. Note that this optical transceiver module 119 has a λ /
Except for the two-coat film 27, it has the same configuration as the optical transceiver module 102 of the second embodiment.

As shown in FIG. 42, λ /
By forming the two-coat film 27, the transmission light (reflected light) 60b on the light branch surface 3 formed on the photodiode 2
Can be maximized in a single-layer film that is easy to form. Further, since it is difficult to amplify the transmission light (reflected light) 60b to be coupled to the optical fiber 5 with respect to a general reception signal which is amplified by an amplifier, the light intensity of the transmission light (reflected light) 60b is reduced. Need to be raised.

In such a case, the use of the λ / 2 coat film 27 which can obtain a high reflectance with a single-layer film which can be easily formed can reduce the price of the optical transceiver module 119.

(Twentieth Embodiment) FIG. 43 is a sectional view showing a configuration of an optical transceiver module according to a twentieth embodiment of the present invention. This optical transceiver module 120 has the same configuration as the optical transceiver module 113 of the thirteenth embodiment except for the photodiode 2.

As shown in FIG. 43, semiconductor layers 12, 12 each including a light absorbing layer are formed on both surfaces of a first semiconductor substrate 10, which is an element substrate of a photodiode wafer, by epitaxial growth. The light receiving region 8 for reception is formed in the layer 12 and the semiconductor layer 1 on the upper right side in FIG.
2, a monitor light receiving area 9 is formed.

FIG. 44 is a diagram for explaining the state of reflection and refraction of the transmission light and the reception light of the optical transceiver module.

In the optical transmitting / receiving module 120,
The transmission light (refraction light) 60a and the reception light (refraction light) 61a that have entered the light branch surface 3 and refracted pass through the n-type InP substrate 31, reach the non-doped InGaAs light absorption layer 33, and receive the reception light (refraction light). The refracted light 61a is absorbed by the receiving light-receiving region 8 and converted into a photocurrent, and the transmitted light (refracted light) 60a is absorbed by the monitoring light-receiving region 9 on the surface of the n-type InP substrate 31 on the opposite side. And converted to photocurrent. Thus, the thirteenth
By using the photodiode 2 in the optical transmitting / receiving module 113 of the embodiment, the receiving light (refracted light) 61a is detected by the receiving light receiving area 8, and the transmitting light (refracted light) 60a is detected by the monitoring light receiving area 9 installed on the opposite side. Can be detected.

In the optical transmission / reception module 120, it is not necessary to separately provide a photodiode for the monitor of the semiconductor laser 1, and the transmission light and the reception light are transmitted to the semiconductor layers 1 on the opposite sides.
2, there is an advantage that noise due to mutual photocurrent does not occur.

(Twenty-First Embodiment) FIG. 45 is a sectional view showing the structure of an optical transceiver module according to a twenty-first embodiment of the present invention.

As shown in FIG. 45, the transmission light 60 emitted from the semiconductor laser 1 is
The semiconductor laser 1 is fixed on a submount 14 and the photodiode 2 is fixed on a support substrate 13. Further, the transmission light (reflected light) 60 b reflected on the light branch surface 3.
The support substrate 13 and the coupling lens 7 are condensed by the coupling lens 7 and are coupled to the optical fiber 5.
The optical fiber 5 is fixed to a module body (not shown). Also, the light received by the photodiode 2
At the position where (refracted light) 61a is incident, the light receiving area 8 for reception is arranged. Then, the first of the photodiodes 2
A stray light absorbing layer 28 is formed on a portion of the semiconductor substrate 10 other than the light branch surface 3.

As shown in FIG. 45, light entering the photodiode 2 (transmission light 60a
) Repeats reflection in the photodiode 2,
When such stray light enters the light receiving area 8 for reception, noise may be generated. In the optical transmitting / receiving module 121, the photodiode 2
Absorbs stray light inside and suppresses noise generation due to stray light.

In the optical transmission / reception module 121, 1.
In the case of an InP photodiode that detects 3 μm light,
As the stray light absorbing layer 28, a Ge film or an InGaAs epitaxially grown film can be used.

(Twenty-second Embodiment) FIG. 46 is a sectional view showing the structure of an optical transceiver module according to a twenty-second embodiment of the present invention. The optical transceiver module 123 has the same configuration as the optical transceiver module 121 of the twenty-first embodiment except for the photodiode 2.

As shown in FIG. 46, the transmission light 60 emitted from the semiconductor laser 1 is
The semiconductor laser 1 is fixed on a submount 14 and the photodiode 2 is fixed on a support substrate 13. Further, the transmission light (reflected light) 60 b reflected on the light branch surface 3.
The support substrate 13 and the coupling lens 7 are condensed by the coupling lens 7 and are coupled to the optical fiber 5.
The optical fiber 5 is fixed to a module body (not shown). Also, the light received by the photodiode 2
At the position where (refracted light) 61a is incident, the light receiving area 8 for reception is arranged. Then, the first of the photodiodes 2
The end face of the semiconductor substrate 10 opposite to the light splitting surface 3 has an AR
(Anti-reflection) coat film 29 is formed.

As in the case of stray light 68a, 68b shown in FIG.
When light (such as the transmission light 60 a) entering the photodiode 2 is repeatedly reflected in the photodiode 2, noise may be generated due to such stray light entering the light receiving area 8 for reception. In the light transmitting / receiving module 123, the AR coat film 29 formed on the end face of the photodiode 2 allows the light to be emitted to the outside of the photodiode 2 as stray light 68d, thereby suppressing generation of noise due to stray light.

(Twenty-third Embodiment) FIG. 47 is a sectional view showing the structure of an optical transceiver module according to a twenty-third embodiment of the present invention. The optical transceiver module 123 has the same configuration as the optical transceiver module 121 of the twenty-first embodiment except for the photodiode 2.

As shown in FIG. 47, the transmission light 60 emitted from the semiconductor laser 1 is
The semiconductor laser 1 is fixed on a submount 14 and the photodiode 2 is fixed on a support substrate 13. Further, the transmission light (reflected light) 60 b reflected on the light branch surface 3.
Is condensed by the coupling lens 7 and is coupled to the optical fiber 5 by the support substrate 13 and the coupling lens 7.
The optical fiber 5 is fixed to a module body (not shown). Also, the light received by the photodiode 2
At the position where (refracted light) 61a is incident, the light receiving area 8 for reception is arranged. Then, the first of the photodiodes 2
An AR coat film 29 is formed on the surface of the semiconductor substrate 10 excluding the light branch surface 3 and on the slope.

As in the case of stray light 68a, 68b shown in FIG.
When light (such as the transmission light 60 a) entering the photodiode 2 is repeatedly reflected in the photodiode 2, noise may be generated due to such stray light entering the light receiving area 8 for reception. In the optical transmission / reception module 123, the AR coat film 29 formed on the surface and the slope of the photodiode 2 allows the light to be emitted to the outside of the photodiode 2 as stray light 68d, thereby suppressing generation of noise due to the stray light.

(Twenty-fourth Embodiment) FIG. 48 is a sectional view showing the structure of an optical transceiver module according to a twenty-fourth embodiment of the present invention. Note that this optical transmitting / receiving module 124
Has the same configuration as the optical transceiver module 102 of the second embodiment except for the photodiode 2.

As shown in FIG. 48, in the photodiode 2 having the light branching surface 3 which is a main part of the optical transceiver module 124, a diffusion current preventing region 50 is provided around the light receiving region 8 for reception. .

FIG. 49 shows the optical transmission / reception module 1
FIG. 37 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the twenty-fourth embodiment of the present invention. FIG. 49 shows a case where an InP photodiode is used as the photodiode.

[0224] As shown in FIG.
Represents an n ⁺ -type InP buffer layer 32 and a non-doped InGaA on an n-type InP substrate 31 (the lower side in FIG. 49) as an element substrate.
After the s light absorbing layer 33 and the n ⁻ -type InP window layer 34 are sequentially epitaxially grown, a p-type diffusion region 35 is selectively provided to form the light receiving region 8 for reception (a depletion layer in the light absorbing layer).
A p-type diffusion region 51 is selectively provided around the p-type diffusion region 35, and a diffusion current prevention region 5 is provided around the p-type diffusion region 51.
0 (FIG. 49 shows the n-type InP substrate 31 upside down). The diffusion current preventing region 50 is formed by the p-type diffusion region 51 itself and a depletion layer formed by the p-type diffusion region 51. An n-type electrode 36 is provided on the back surface (the upper side in FIG. 49) of the n-type InP substrate 31, and a p-type electrode 37 and a metal bump 38 are provided on the p-type diffusion region 35.
Make electrical connections.

In the light receiving area 8 for reception, the light such as the received light (refracted light) 61a is absorbed, so that an electron-hole pair is generated and detected as a photocurrent. The electron and hole pairs generated in the receiving light-receiving region 8 formed by the depletion layer contribute to the photocurrent as a drift current, and thus have a high speed. The electron-hole pairs generated by the transmission light (refracted light) 60c absorbed by the absorption layer 33 contribute to the photocurrent as a diffusion current component. In particular, the diffusion current component 5 of holes with a slow diffusion rate
When 2 reaches the light receiving area 8 for reception and is detected, the response speed of the photocurrent becomes slow. In order to prevent such a slow diffusion current component 52 from being detected as a photocurrent, the diffusion current prevention region 50 employs the photodiode 2 formed around the light receiving region 8 for reception. Speed can be increased.

In the optical transmission / reception module 124, the diffusion current component is reduced by providing the diffusion current prevention region around the reception light receiving region 8, but the light absorption layer 33 around the reception light reception region 8 is reduced. The response speed may be increased by providing a concave portion other than the above to prevent the diffusion current component 52 from diffusing into the light receiving region 8 for reception.

(Twenty-Fifth Embodiment) FIG. 50 is a sectional view showing the structure of an optical transceiver module according to a twenty-fifth embodiment of the present invention, and FIG. 51 is a top view of the optical transceiver module. The photodiode 2 in the top view shows only the outer shape for indicating the mounting position.

As shown in FIG. 50, in this optical transmitting / receiving module 125, the coupling lens 7 and the optical fiber 5 are arranged on the support substrate 14a. For simplification of the drawing, the optical fiber 5 and the coupling lens 7 are
4a, the support substrate 14a has V
A groove may be formed, and the coupling lens 7 and the optical fiber 9 may be positioned and fixed on the slope of the V-groove.

In the light transmitting / receiving module 125, since the surface emitting laser 1a is used as the semiconductor laser, the surface emitting laser 1a and the light splitting surface 3 can be easily installed close to each other. Further, the photodiode 2, the surface emitting laser 1, the coupling lens 7, and the optical fiber 5 can be mounted on the support substrate along the same direction, and the mass productivity of the optical transceiver module 125 can be improved.

(Twenty-Sixth Embodiment) FIG. 52 is a sectional view showing the structure of an optical transceiver module according to a twenty-sixth embodiment of the present invention.

As shown in FIG. 52, the photodiode 2 is mounted on the submount 1 so that the transmission light 60 emitted from the surface emitting laser (semiconductor laser) 1a is incident on the light splitting surface 3.
4A, the semiconductor laser 1a is fixed on the concave portion 70 of the submount 14a and at a position where the transmission light (reflected light) 60b reflected on the light branch surface 3 is incident on the optical fiber 5. In addition, the receiving light receiving region 8 is disposed at a position where the receiving light (refracted light) 61a of the photodiode 2 is incident, and the transmitting light (refracted light) of the photodiode 2 is provided.
The monitor light receiving region 9 is disposed at a position where the light 60a enters.

As described above, the light emitting surface of the surface emitting laser 1a, the light splitting surface 3 of the photodiode 2 and the end surface of the optical fiber 5 are brought close to each other, so that the transmission light and the reception light do not spread so much. To the optical fiber 5 or the optical fiber 5 so that the light intensity required for the optical transceiver module is coupled. This forms the optical transceiver module 126 that does not require a lens.

In addition to bringing the above optical components close to each other, when the optical fiber has a small optical coupling loss such as a multimode fiber, or when the light intensity of the semiconductor laser is sufficiently strong, the optical transmission / reception without the coupling lens is performed. Module fabrication is possible.

In the optical transmission / reception module 126, by removing the lens, the number of components can be reduced to reduce the cost and simplify the alignment of the optical components.

(Twenty-Seventh Embodiment) FIG. 53 is a sectional view showing the structure of an optical transceiver module according to a twenty-seventh embodiment of the present invention.

As shown in FIG. 53, this optical transmission / reception module 127 includes a semiconductor laser 1 for emitting transmission light 60.
A photodiode 2 for receiving the received light (refracted light) 61a; an optical branch surface 3 using the back surface of the photodiode 2; and a coupling lens 7 for coupling the transmitted light to the optical fiber 5 for transmitting and receiving light. And a sub-mount 14 for mounting the semiconductor laser 1 and a support substrate 13b on which the photodiode 2 and the sub-mount 14 with the semiconductor laser 1 are mounted. The support substrate 13b has a 45 ° inclination with respect to the plane on which the photodiode 2 is mounted with respect to the plane on which the semiconductor laser 1 is mounted in order to set the light branch surface 3 at 45 ° on the optical path of the transmission / reception light. I'm making it. Further, a photonic crystal 53 having a super prism effect is formed on a semiconductor portion forming the light branch surface 3 of the photodiode 2.

In the light transmitting / receiving module 127 having the above-described configuration, the received light (refracted light) 61a and the transmitted light (refracted light) 60a incident on the photonic crystal 53 formed on the semiconductor portion of the photodiode 2 on the light branch surface 3 side. Can be controlled to a large refraction angle by the super prism effect. Therefore, even when the optical path length from the light branch surface 3 to the light receiving area 8 for reception or the light receiving area 9 for monitoring is short, the light intensity peak of the transmission light is The light intensity peak of the received light can be separated,
Noise generation due to mutual light can be avoided.

An example of the photonic crystal is disclosed in JP-A-10-335758.
The structure is formed by growing a silicon dioxide buffer layer on a silicon substrate and forming a three-dimensional periodic structure of amorphous silicon and silicon dioxide. As a method for manufacturing the photodiode with a light branch surface shown in FIG.
First semiconductor substrate 1 which is an element substrate of a photodiode
It can be manufactured by anodically bonding a silicon substrate of 0 and a photonic crystal via an SiO ₂ film.

As described above, the optical transmission / reception module 12
According to 7, since the light splitting surface 3 is formed by the photonic crystal 53 having the super prism effect, the reception light and the transmission light entering the photodiode 2 can be further separated, and the noise can be reduced. . Further, the light splitting surface 3
Since the traveling method of the received light incident from the light source can be controlled by the wavelength, only the desired wavelength component of the received light can be guided to the light receiving area for reception. Further, a plurality of receiving light receiving regions may be provided in the photodiode, and wavelength-multiplexed received light may be guided to each receiving light receiving region for each wavelength.

[0240]

As is clear from the above, according to the optical transceiver module of the present invention, by forming an optical branch surface on the semiconductor portion (element substrate or semiconductor layer) of the photodiode, an optical component such as a half mirror can be obtained. Parts can be reduced. Further, since the light splitting surface is formed in the semiconductor portion, it can be manufactured by a batch process such as miniaturization and a photolithography process, and can be mass-produced. Also,
Transmit light and receive light are separated in the light receiving area by the difference in the incident direction of the transmitted light and the received light entering the light splitting surface formed on the photodiode and the optical path length from the light splitting surface to the light receiving area of the photodiode. And noise due to the transmission light with respect to the reception light current can be suppressed. Further, a light splitting surface with high mirror surface and high surface precision can be formed on the photodiode, and the performance can be improved.

Further, according to the method for manufacturing an optical transmitting / receiving module of the present invention, it is possible to provide an optical transmitting / receiving module that can be reduced in size and cost, and that can improve performance by reducing noise.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an optical transceiver module according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the optical transceiver module.

FIG. 3 is a diagram illustrating a state of reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 4 is a diagram showing a relationship between incident positions of transmitted and received light and incident light intensity in a light absorption layer of a photodiode of the optical transmitting and receiving module.

FIG. 5 is a diagram illustrating noise generation when transmission and reception of the optical transmission and reception module are performed in a time division manner.

FIG. 6 is a sectional view showing a configuration of an optical transceiver module according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of an optical transceiver module according to a third embodiment of the present invention.

FIG. 8 is a sectional view of the optical transceiver module.

FIG. 9 is a diagram for explaining reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 10 is a sectional view showing a configuration of an optical transceiver module according to a fourth embodiment of the present invention.

FIG. 11 is a diagram illustrating the reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 12 is a perspective view showing a configuration of an optical transceiver module according to a fifth embodiment of the present invention.

FIG. 13 is a sectional view of the optical transceiver module.

FIG. 14 is a diagram illustrating a state of reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 15 is a top view of a photodiode showing a structure in which a second semiconductor substrate forming a light branch surface is bonded.

FIGS. 16A to 16E are process diagrams illustrating a manufacturing method of bonding a second semiconductor substrate, which has been processed in advance to become a light branch surface, to a photodiode by anodic bonding. is there.

FIG. 17 is a diagram illustrating a state of reflection and refraction of transmission light and reception light of the optical transceiver module according to the sixth embodiment of the present invention.

FIGS. 18 (a) to (e) show a manufacturing method of bonding the second semiconductor substrate of the optical transceiver module to a photodiode wafer by atomic rearrangement and forming an optical branch surface on the second semiconductor substrate. FIG.

FIG. 19 is a sectional view showing a configuration of an optical transceiver module according to a seventh embodiment of the present invention.

FIG. 20 is a diagram for explaining reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 21 is a process chart illustrating a manufacturing method in which a light branch surface is formed by etching and the slope is a {111} A surface.

FIG. 22 is a sectional view showing a configuration of an optical transceiver module according to an eighth embodiment of the present invention.

FIG. 23 is a diagram for explaining reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 24 is a process for explaining the fabrication of a photodiode in which a 45 ° light branch surface is formed by anisotropically etching a photodiode wafer using a (100) 9.7 ° off substrate. FIG.

FIGS. 25A to 25C are process diagrams illustrating a method for manufacturing an optical branch surface of an optical transceiver module according to a ninth embodiment of the present invention.

FIGS. 26A to 26D are process diagrams illustrating a method for manufacturing an optical branch surface of an optical transceiver module according to a tenth embodiment of the present invention.

FIGS. 27 (a) to 27 (e) are process diagrams illustrating a process of forming a 45 ° light branch surface by machining and polishing of the optical transceiver module using blades.

FIG. 28 is a sectional view showing a configuration of an optical transceiver module according to an eleventh embodiment of the present invention.

FIG. 29 is a diagram for explaining reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 30 is a sectional view showing a configuration of an optical transceiver module according to a twelfth embodiment of the present invention.

FIG. 31 is a sectional view showing a configuration of an optical transceiver module according to a thirteenth embodiment of the present invention.

FIG. 32 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 33 is a perspective view showing a configuration of an optical transceiver module according to a fourteenth embodiment of the present invention.

FIG. 34 is a sectional view of the optical transceiver module.

FIG. 35 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 36 is a diagram for explaining reflection and refraction of transmission light and reception light of the optical transceiver module according to the fifteenth embodiment of the present invention.

FIG. 37 is a diagram showing a configuration of an optical transceiver module according to a sixteenth embodiment of the present invention.

FIG. 38 is a sectional view showing a configuration of the optical transceiver module.

FIG. 39 is a diagram showing a configuration of an optical transceiver module according to a seventeenth embodiment of the present invention.

FIG. 40 is a sectional view showing the configuration of the optical transceiver module.

FIG. 41 is a sectional view showing a configuration of an optical transceiver module according to an eighteenth embodiment of the present invention.

FIG. 42 is a sectional view showing a configuration of an optical transceiver module according to a nineteenth embodiment of the present invention.

FIG. 43 is a sectional view showing a configuration of an optical transceiver module according to a twentieth embodiment of the present invention.

FIG. 44 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 45 is a sectional view showing a configuration of an optical transceiver module according to a twenty-first embodiment of the present invention.

FIG. 46 is a sectional view showing a configuration of an optical transceiver module according to a twenty-second embodiment of the present invention.

FIG. 47 is a sectional view showing a configuration of an optical transceiver module according to a twenty-third embodiment of the present invention.

FIG. 48 is a sectional view showing a configuration of an optical transceiver module according to a twenty-fourth embodiment of the present invention.

FIG. 49 is a diagram for explaining the state of reflection and refraction of transmission light and reception light of the optical transceiver module.

FIG. 50 is a sectional view showing a configuration of an optical transceiver module according to a twenty-fifth embodiment of the present invention.

FIG. 51 is a top view showing the configuration of the optical transceiver module.

FIG. 52 is a cross-sectional view showing a configuration of an optical transceiver module according to a twenty-sixth embodiment of the present invention.

FIG. 53 is a cross-sectional view showing a configuration of an optical transceiver module according to a twenty-seventh embodiment of the present invention.

FIG. 54 is a schematic diagram showing a basic configuration of a conventional optical transceiver module.

FIG. 55 is a cross-sectional view showing the configuration of another conventional optical transceiver module.

FIG. 56 is a view for explaining the relationship between the incident position of transmitted / received light and the incident light intensity in the light absorption layer of the photodiode of the optical transmission / reception module.

FIG. 57 is a diagram illustrating noise generation when transmission and reception of the optical transmission and reception module are performed in a time-division manner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser, 1a ... Surface emitting semiconductor laser, 2 ... Photodiode, 2a ... Receiving photodiode, 2b ... Monitor photodiode, 3 ... Light branch surface, 3a ... Half mirror, 4 ... Optical transmission line, 5 ... Optical fiber, 6: optical waveguide, 7: coupling lens, 8: light receiving area for reception, 9: light receiving area for monitoring, 10, 10a: first semiconductor substrate (photodiode element substrate), 11: second semiconductor Substrate, 12: semiconductor layer, 13, 13a, 13b, 13c: support substrate, 14, 14a: submount, 15: chamfered part, 16: reflective surface, 17: reflective surface (spherical processing), 18: bonding wire, 19 ... Wiring pattern, 20 ... RIBE, 21 ... Polisher, 22 ... Abrasive grain, 23 ... Working fluid, 24 ... Blade, 25 ... Cleaved surface, 26 ... Reflectance control thin film, 27 ... λ / 2 coat Film, 28 ... stray light absorbing layer, 29 ... AR coat film, 30 ... active layer, 31, 31a ... n-type InP substrate, 32 ... n ⁺ -type InP buffer layer, 33 ... undoped InGaAs light-absorbing layer, 34 ... n ^- -type InP window layer, 35: p-type diffusion region, 36: n-type electrode, 37, 37a: p-type electrode, 38: metal bump, 39: brazing material, 40: insulating film, 41: reflective film, 42: SiOx film, 43, 43a, 43b V-groove, 44 p-type diffusion region, 45 etching mask, 46 resist, 47 selective growth mask, 48 semiconductor layer, 49 light absorption layer, 50 diffusion current prevention region, 51 ... p-type diffusion region, 52 ... diffusion current component, 53 ... photonic crystal, 60 ... transmission light, 60a ... transmission light (reflection light), 60b ... transmission light (reflection light), 60c ... transmission light (reflection light), 61: Received light, 61a: Received light (refracted light), 6 ... light flux of transmission / reception light, 63: light intensity distribution of incident reception light, 64: light intensity distribution of incident transmission light, 65: photocurrent by reception light, 66: photocurrent by transmission light, 67: tail current by transmission light, 68a , 68b, 68c, 68d: stray light, 101 to 129: optical transceiver module.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/02 F term (Reference) 2H037 AA01 BA02 BA11 BA35 CA38 DA03 5F073 AB16 BA01 FA02 FA07 FA30 5F088 AB02 AB07 BA15 BB01 CB01 CB14 CB20 DA17 DA20 EA01 EA09 EA20 HA09 JA14 5F089 AA01 AC05 AC06 AC17 CA20 EA01 EA10 GA10 5K002 AA05 AA07 BA02 BA04 BA07 BA13 BA21 CA02 EA05 FA01

Claims (33)

[Claims] An optical transmitting and receiving module for transmitting light bidirectionally using an optical transmission line, comprising: a photodiode having a light splitting surface for splitting incident light into reflected light and refracted light; A semiconductor laser that emits transmission light so as to be incident on the light splitting surface of the photodiode at a predetermined incident angle, and that the reflected light of the transmission light reflected on the light splitting surface is coupled to the optical transmission path. Wherein the reception light from the optical transmission path is incident on the light branch surface of the photodiode in a direction opposite to the reflected light of the transmission light, and the reception light refracted from the light branch surface toward the photodiode. The refracted light on the side passes through the photodiode and enters the receiving light receiving area of the photodiode, while the transmission light emitted from the semiconductor laser emits the photodiode. Is incident on the light splitting surface, and the peak of the light intensity distribution of the refracted light on the transmission light side which is refracted from the light splitting surface to the photodiode side and transmitted through the photodiode has a peak for the reception of the photodiode. An optical transmission / reception module, which is not located in a light receiving area. 2. The optical transceiver module according to claim 1, wherein said optical transmission line is an optical fiber. 3. The optical transmission / reception module according to claim 1, wherein the photodiode is a monitor light such that refracted light on the transmission light side refracted on the light branch surface is incident. An optical transceiver module having a light receiving area. 4. The optical transmitting / receiving module according to claim 1, wherein the light splitting surface is formed on an element substrate of the photodiode. 5. The optical transmission / reception module according to claim 1, wherein the light splitting surface is formed in a semiconductor layer formed by an epitaxial growth method of the photodiode. module. 6. The optical transceiver module according to claim 1, wherein the photodiode is formed on a semiconductor layer formed by an epitaxial growth method on a first semiconductor substrate that is an element substrate. An optical transmission / reception module, wherein the semiconductor substrate is bonded, and the optical branch surface is formed on the second semiconductor substrate. 7. The optical transceiver module according to claim 6, said semiconductor layer, a second semiconductor substrate, or veneered Si / Si by anodic bonding, or Hariawa by anodic bonding via the SiO ₂ film An optical transceiver module comprising: a compound semiconductor / Si. 8. The optical transceiver module according to claim 6, wherein the semiconductor layer and the second semiconductor substrate are bonded by direct bonding utilizing atomic rearrangement, and the directly bonded semiconductor interface is formed of InP / GaAs, InP / Si, InP / InP, Ga
An optical transmission / reception module, which is one of As / GaAs and GaAs / Si. 9. The optical transmitting and receiving module according to claim 1, wherein the light splitting surface is a {111} A surface. 10. The optical transceiver module according to claim 1, wherein the light branch surface is a back surface of an element substrate of the photodiode. 11. The optical transceiver module according to claim 10, further comprising a chamfer formed on the semiconductor laser side of an element substrate of the photodiode. 12. The optical transmitting and receiving module according to claim 1, wherein the light splitting surface is a cleavage surface formed in the photodiode. 13. The optical transmitting and receiving module according to claim 12, wherein a reflection film made of at least one of a metal film and an insulating film is provided on a slope formed on a portion of the element substrate of the photodiode that faces the cleavage surface. A reflection surface is provided by forming the light, and the refraction light on the reception light side refracted from the light branch surface toward the photodiode is reflected by the reflection surface, and then guided to the reception light receiving area of the photodiode. An optical transmitting and receiving module, comprising: 14. The optical transmitting and receiving module according to claim 13, wherein the reflection surface of the photodiode has a curved surface shape for converging the refracted light on the reception light side to the reception light receiving area of the photodiode. An optical transmitting and receiving module, comprising: 15. The optical transmitting and receiving module according to claim 1, wherein the light branch surface is formed of a semiconductor layer selectively grown on a front side or a back side of an element substrate of the photodiode. 11
An optical transmitting / receiving module, wherein the optical transmission / reception module has a slope of any one of the 1A plane and the {111} B plane. 16. The optical transmission / reception module according to claim 1, wherein a film is formed on the light splitting surface, and the transmission on the light splitting surface is controlled by controlling a reflectance with respect to incident light. An optical transmitting and receiving module, comprising: a reflection film capable of controlling a ratio between reflected light and refracted light on the light side and a ratio between reflected light and refracted light on the receiving light side on the light branch surface. 17. The optical transmitting and receiving module according to claim 16, wherein the reflection film is provided on the optical branch surface at 1 / (2n) of the wavelength λ of the transmission light (where n is the wavelength λ of the transmission light). An optical transceiver module, which is formed to a thickness of (refractive index). 18. The optical transceiver module according to claim 1, wherein the photodiode is formed by growing a semiconductor layer including a light absorbing layer on a front surface and a back surface of an element substrate. An optical transmission / reception module, wherein at least one of the plurality of light reception areas is the reception light reception area. 19. The optical transceiver module according to claim 1, wherein the photodiode is formed on at least a part of a surface of the photodiode other than the light splitting surface,
An optical transmission / reception module comprising a stray light absorbing layer for absorbing stray light of transmission / reception light in the photodiode. 20. The optical transceiver module according to claim 1, wherein the photodiode is formed on at least a part of a region other than the light branch surface on the surface of the photodiode,
An optical transmission / reception module, comprising an antireflection film for emitting stray light of transmission / reception light in the photodiode to the outside of the photodiode. 21. The optical transmitting and receiving module according to claim 1, wherein the light receiving area of the photodiode is surrounded by the light receiving area for reception.
An optical transmitting and receiving module, wherein a concave portion excluding a diffusion current preventing region or a light absorbing layer is provided. 22. The optical transceiver module according to claim 1, wherein the semiconductor laser is a surface emitting laser. 23. The optical transmission / reception module according to claim 1, wherein the transmission light from the semiconductor laser is guided to the optical transmission line without passing through a coupling lens. An optical transmitting and receiving module, comprising: 24. The optical transceiver module according to claim 1, wherein the semiconductor region of the photodiode on which the light branch surface is formed is a photonic crystal having a super prism effect. An optical transceiver module characterized by the above-mentioned. 25. A method for manufacturing an optical transceiver module according to claim 1, wherein the optical transceiver module is formed on an element substrate of the photodiode by an epitaxial growth method. A method for manufacturing an optical transceiver module, comprising forming the optical branch surface on a semiconductor layer. 26. A method of manufacturing an optical transceiver module according to claim 6, wherein the semiconductor layer and the second semiconductor substrate are bonded by anodic bonding. Manufacturing method of an optical transceiver module. 27. A method of manufacturing an optical transmission / reception module according to claim 6, wherein the semiconductor layer and the second semiconductor substrate are directly bonded by using atomic rearrangement. A method for manufacturing an optical transceiver module, comprising laminating. 28. A method of manufacturing an optical transmission / reception module according to claim 6, wherein said second transmission / reception module includes a step of bonding said second semiconductor substrate to said second semiconductor substrate. A method for manufacturing an optical transceiver module, comprising forming the optical branch surface on a semiconductor substrate. 29. A method of manufacturing an optical transmitting / receiving module according to claim 1, wherein the inclined surface serving as the light branch surface is etched by etching the photodiode. A method for manufacturing an optical transceiver module, comprising: 30. The method for manufacturing an optical transceiver module according to claim 29, wherein when forming the slope to be the light branch surface by etching in the photodiode, the slope to be the light branch surface is {111}. A method for manufacturing an optical transceiver module, wherein the method is formed on the A-side. 31. The method for manufacturing an optical transceiver module according to claim 29, wherein (100) 9 is formed on the element substrate of the photodiode when forming the slope serving as the light branch surface by etching the photodiode. A method for manufacturing an optical transmitting and receiving module, comprising using an off-substrate of 0.7 ° off and forming an inclined surface serving as the light splitting surface having an angle of 45 ° with respect to the element substrate plane. 32. The method for manufacturing an optical transmission / reception module according to claim 29, wherein dry etching is used when forming the slope serving as the light branch surface by etching in the photodiode. Module manufacturing method. 33. A method of manufacturing an optical transceiver module according to claim 1, wherein the optical branch surface of the photodiode is polished by polishing the optical branching surface of the photodiode. A method for manufacturing an optical transmitting / receiving module, wherein the optical transmitting / receiving module is formed at an angle of 45 ° with respect to a plane of an element substrate of a diode.