JP2002299680A - Semiconductor photodetector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor photodetector which prevents troubles due to excessive adhesives for mounting the photodetector on a mounting substrate. SOLUTION: The photodetector comprises a filter layer 3, a light absorptive layer 4 and a buffer layer 5 formed on a first main surface 2 of a semiconductor substrate 1. The buffer layer has a p-type diffused region 6 on which a p-side electrode layer 8 is formed and with which this layer 8 is electrically connected through a contact layer. On a second main surface 9 of the substrate 1 a ring- like n-side electrode layer 10 is formed and has a ring-like protrusion 11 protrudent in section. The protrusion 11 of the n-side electrode layer 10 for connecting to a wiring electrode on a mounting board prevents the trouble caused by adhesives flowing to a light receiving part 12 or the mounting board, after extruding between the wiring electrode or the protrusion 11 and turning around to sides of the protrusion 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light receiving element and a light receiving module for receiving light having a specific wavelength.

[0002]

2. Description of the Related Art In the field of optical communication, signal light having a wavelength of 1.3 μm band and 1.55 μm band is used. As a semiconductor light receiving element for receiving these signal lights, In
GaAs and InP-based compound semiconductor pin
Photodiodes are common. This pin photodiode uses, for example, an InP layer as a window layer and an InGaAs layer.
It has a structure in which the s layer is a light absorbing layer.

[0003] In the case of transmitting signal lights of 1.3 μm band and 1.55 μm band simultaneously through the same fiber, a semiconductor light receiving element for selectively receiving only the signal lights of each wavelength is required.

Here, a semiconductor light receiving element that receives signal light having a wavelength in the 1.3 μm band but not signal light in the 1.55 μm band has a composition wavelength of 1.4 μm as a light absorbing layer.
It can be obtained by using a certain amount of InGaAsP layer.

On the other hand, in order to obtain a semiconductor light receiving element which receives the signal light in the 1.55 μm band but does not receive the signal light in the 1.3 μm band, the light absorption layer must be formed of an InGaAs layer having a composition wavelength of about 1.6 μm. At the same time, it is necessary to provide a filter for blocking the signal light in the 1.3 μm band between the window layer and the light absorbing layer. This is because the wavelength absorption characteristics of the semiconductor layer are
This is because signal light having a composition wavelength or less is absorbed, but signal light having a composition wavelength or more is transmitted.

Hereinafter, the latter semiconductor light receiving element, that is, a semiconductor light receiving element which receives signal light in the 1.55 μm band but does not receive signal light in the 1.3 μm band (hereinafter referred to as “1.5.
A conventional example of “5 μm passband semiconductor light receiving element”) will be described with reference to FIG. FIG. 6 is a sectional view of a conventional 1.55 μm pass band semiconductor light receiving element.

As shown in FIG. 6, a conventional 1.55 μm passband semiconductor light receiving element has a filter layer 102 on which an n-type InP semiconductor substrate 101 is formed.
A light absorption layer 103 of 6 μm n-type InGaAs and a buffer layer 104 of n-type InP are sequentially formed. The buffer layer 104 has a Z
A p-type diffusion region 105 in which n is diffused is formed.

On the buffer layer 104, an insulating layer 106 and a p-side electrode layer 107 are formed. p-side electrode layer 10
7 is electrically connected to the diffusion region 105.

On the back surface of the semiconductor substrate 101, a ring-shaped and flat n-side electrode layer 108 is formed. Semiconductor substrate 1 on which n-side electrode layer 108 is not formed
The back surface of the light receiving portion 01 is a light receiving portion 109 for receiving the signal light.

In the conventional 1.55 μm pass band semiconductor light receiving element, when the 1.3 μm band signal light and the 1.55 μm band signal light enter from the light receiving section 109, 1.3 μm
Only the signal light in the band is absorbed by the filter layer 102,
Only the signal light in the 1.55 μm band reaches the light absorbing layer 103 and is absorbed and converted into an electric signal.

[0011]

As shown in FIG. 7, a conventional semiconductor light receiving element 110 having a pass band of 1.55 μm is mounted on a mounting substrate 111 having optical transmission lines such as optical fibers as components. , Semiconductor light receiving element 11
The n-side electrode layer 108 is bonded to the electrode wiring 113 of the mounting substrate 111 by flip chip bonding with an adhesive 112 such as solder. Further, the p-side electrode layer 107 is connected to the electrode wiring 114 of the mounting substrate 111 by wire bonding with a gold wire 115.

However, in this case, the n-side electrode layer 10
Extra adhesive 112 between electrode 8 and electrode wiring 113
However, there is a problem that the signal light protrudes from the mounting substrate 111 and covers the light receiving unit 109, thereby blocking the received signal light. This is particularly true for the semiconductor light receiving element 110 and the mounting substrate 11.
This often occurs when the alignment before bonding 1 is not performed accurately.

Further, if the positioning of the semiconductor light receiving element 110 and the mounting substrate 111 is not performed accurately,
There is also a problem in that the p-side electrode layer 107 and the electrode wiring 114 of the mounting substrate 111 are not properly wire-bonded and a connection failure occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a semiconductor light receiving element and a light receiving module which prevent problems caused by excessive adhesive when mounting the semiconductor light receiving element on a mounting board. And

[0015]

A semiconductor light receiving element according to the present invention is a semiconductor light receiving element having a light absorbing layer located on a first principal surface side of a semiconductor substrate and a light receiving section, wherein the light receiving section is provided. The first electrode formed in the vicinity has a convex portion having a convex cross section.

A light receiving module according to the present invention includes a substrate having an optical transmission path for transmitting output signal light and input signal light therein, a semiconductor light emitting element for emitting output signal light to one end of the optical waveguide, An optical spectroscope provided in the optical transmission path, transmitting at least a part of the output signal light and guiding at least a part of the input signal light to the outside of the optical transmission path,
A light receiving module provided on the substrate and including a semiconductor light receiving element to which input signal light is incident by the optical spectroscope, wherein the semiconductor light receiving element includes an electrode having a convex section having a convex cross section. It is characterized by being electrically connected to a wiring electrode on a substrate.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a semiconductor light receiving element and a light receiving module according to an embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

(First Embodiment) Hereinafter, a semiconductor light receiving element according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a sectional view of the semiconductor light receiving element according to the first embodiment, and FIG. 1B is a back view of the semiconductor light receiving element according to the first embodiment. FIG. 1A is a cross-sectional view taken along line XX in FIG. 1B.

As shown in FIG. 1A, on a first main surface 2 of an n-InP semiconductor substrate 1, a filter layer 3 made of n-InGaAsP, a light absorption layer 4 made of n-InGaAs, and n-InGaAs are formed. A buffer layer 5 made of InP is sequentially formed. In the buffer layer 5, a diffusion region 6 in which Zn is diffused and turned into a p-type is formed, and the diffusion region 6 reaches the light absorption layer 4. The composition wavelength of the filter layer 3 is 1.4.
μm, and the composition wavelength of the light absorbing layer 4 is 1.6 μm.

On the buffer layer 5, an insulating layer 7 is formed. A p-side electrode layer 8 is formed on diffusion region 6, and p-side electrode layer 8 is electrically connected to diffusion region 6 via a contact layer. The p-side electrode layer 8 is
It extends to a part on the insulating layer 7.

On the second main surface 9 of the semiconductor substrate 1, a ring-shaped n-side electrode layer 10 is formed. n-side electrode layer 10
Has a ring-shaped convex portion 11 having a convex cross section. The convex portion 11 is formed at the center of the n-side electrode layer 10 as shown in the cross-sectional view of FIG.

The region of the second main surface 9 of the semiconductor substrate 1 below the diffusion region 6 where the n-side electrode 10 is not formed is a light receiving section 12 for receiving signal light from the outside.

According to the semiconductor light receiving element according to the first embodiment, the n-side electrode layer 10 for connecting to the wiring electrode of the mounting substrate has the convex portion 11 having a convex cross section. When an adhesive such as solder is inserted between the electrode and the convex portion 11 to mount the semiconductor light receiving element on the mounting board, the adhesive protruding between the n-side electrode layer 10 and the electrode wiring is on the side of the convex portion 11. It is possible to prevent the adhesive from entering the portion and flowing to the light receiving portion 12 and the mounting substrate.

Also, since the n-side electrode layer 10 has the convex portion 11, when the n-side electrode layer 10 and the electrode wiring of the mounting board are fixed with an adhesive such as solder, the convex shape and the adhesive Accurate positioning between the semiconductor light receiving element and the mounting substrate can be easily performed by the bonding action. Thereby, it is also possible to prevent a defect such as a connection failure due to wire bonding caused by a displacement of the light receiving element.

Although the projection 11 is formed at the center of the n-side electrode layer 10 when viewed from the cross section, it may be formed along the inside or outside of the ring.

(Modification of First Embodiment) Next, a semiconductor light receiving element according to a modification of the first embodiment will be described with reference to FIG.
This will be described with reference to FIG. FIG. 2A is a cross-sectional view of a semiconductor light receiving element according to a modification of the first embodiment.
FIG. 2B is a rear view of a semiconductor light receiving element according to a modification of the first embodiment. Further, FIG.
It is sectional drawing which follows the XX line in (b).

As shown in FIG. 2B, in the semiconductor light receiving device according to the modification of the first embodiment, the n-side electrode layer 13 has
It has four convex portions 14 having a circular cross section with a convex shape.
The convex portion 14 is formed so as to be located in a cross shape in the ring-shaped n-side electrode layer 13.

The same components as those of the semiconductor light receiving element according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted here.

According to the semiconductor light-receiving element according to the modification of the first embodiment, the n-side electrode layer 13 has four circular convex portions 1.
4 are formed at an interval, and when an adhesive such as solder is inserted between the wiring electrode and the convex portion 14 to mount the semiconductor light receiving element on the mounting substrate, the n-side electrode layer 13 and the wiring electrode Can be prevented from entering the vicinity of the side of the convex portion 14 and flowing to the light receiving portion 12 and the mounting board.

The number of the convex portions 14 is not limited to four.
For example, the number may be 4 to 20, or more.

(Second Embodiment) Hereinafter, a semiconductor light receiving element according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3A is a cross-sectional view of the semiconductor light receiving element according to the second embodiment, and FIG. 3B is a plan view of the semiconductor light receiving element according to the second embodiment. FIG. 3A is a cross-sectional view taken along line XX in FIG. 3B.

As shown in FIG. 3A, a buffer layer 17 made of InP, a light absorption layer 18 made of n-InGaAs,
Filter layers 19 made of n-InGaAsP are sequentially formed. In the filter layer 19, Zn is diffused and p
A patterned diffusion region 20 is formed, and the diffusion region 20 extends to a part of the light absorption layer 18. The filter layer 1
The composition wavelength of No. 9 is 1.4 μm, and the composition wavelength of the light absorbing layer 18 is 1.6 μm.

On the filter layer 19, a p-side electrode layer 22 is formed via an insulating layer 21, and the p-side electrode layer 22 is electrically connected to the diffusion region 20 via a contact layer. The n-side electrode layer 2 is directly provided on the filter layer 19.
3 are formed. p-side electrode layer 22 and n-side electrode layer 2
3 has convex portions 24 and 25 each having a convex cross section.

Here, as shown in FIG. 3B, the p-side electrode layer 22 has a rectangular shape and has three circular convex portions 24. Further, the n-side electrode layer 23 also has a rectangular shape,
It has three circular projections 25. The projections 24, 25
Is not limited to three, but may be one, two, or four or more. Furthermore, the shape of the convex portions 24 and 25 is not limited to a circular shape, but may be one rectangular shape.

An adhesive layer 26 made of a resin is formed on the diffusion region 20, and a glass substrate having a first multilayer film 27 and a second multilayer film 28 on both surfaces on the adhesive layer 26, respectively. 29 are provided.

The adhesive layer 26 contains a powdery wavelength-selective material made of a mineral-based material. here,
The wavelength selection material is, for example, a material having such a property that signal light in the 1.55 μm band is transmitted but signal light in the 1.3 μm band is not transmitted. In addition, both the first multilayer film 27 and the second multilayer film 28 have a wavelength selecting property such that the signal light in the 1.55 μm band is transmitted, but the signal light in the 1.3 μm band is not transmitted. It is a body multilayer filter.

The light receiving portion 30 in the semiconductor light receiving element according to the second embodiment refers to the adhesive layer 26 and the glass substrate 29 formed on the diffusion region 20.

When the semiconductor light receiving element according to the second embodiment is mounted on a mounting substrate, it is performed by flip chip bonding in which the p-side electrode layer 22 and the n-side electrode layer 23 face the mounting substrate. According to the semiconductor light receiving element according to the embodiment, each of the p-side electrode layer 22 and the n-side electrode layer 23 for connecting to the wiring electrode of the mounting substrate has the convex portions 24 and 25 having a convex cross section. Therefore, when an adhesive such as solder is inserted between the wiring electrode and the convex portions 24 and 25,
Between the p-side electrode layer 22 and the wiring electrode or the n-side electrode layer 2
The adhesive which has protruded between the wiring electrode 3 and the wiring electrode 3
5 to prevent the adhesive from flowing into the light receiving section 30 and the mounting substrate.

In the semiconductor light receiving device according to the second embodiment, the p-side electrode layer 22 and the n-side electrode layer 23 are formed in the same direction with respect to the semiconductor substrate 15, so that either one of the electrodes is formed. Need not be wire bonded. Therefore, it is possible to prevent the problem of connection failure due to wire bonding.

Further, since the p-side electrode layer 22 and the n-side electrode layer 23 have the convex portions 24 and 25, when the convex portions of the semiconductor light receiving element and the electrode wiring of the mounting substrate are fixed with an adhesive such as solder. In addition, accurate positioning between the semiconductor light receiving element and the mounting substrate can be easily performed by the adhesive action between the convex shape and the solder. Thereby, it is also possible to prevent a defect such as a connection failure due to wire bonding caused by a displacement of the light receiving element.

(Third Embodiment) Hereinafter, a semiconductor light receiving device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 4A is a sectional view of the semiconductor light receiving element according to the third embodiment, and FIG. 4B is a rear view of the semiconductor light receiving element according to the third embodiment. FIG. 4A is a cross-sectional view taken along line XX in FIG. 4B.

As shown in FIG. 4A, an n-InGaAsP is formed on a first main surface 32 of an n-InP semiconductor substrate 31.
A filter layer 33 made of n-InGaAs, a light absorption layer 34 made of n-InGaAs, and a buffer layer 35 made of n-InP are sequentially formed. In the buffer layer 35, a p-type diffusion region 36 in which Zn is diffused is formed.
Extends to a part of the light absorption layer 34. The composition wavelength of the filter layer 33 is 1.4 μm, and the light absorption layer 34
Has a composition wavelength of 1.6 μm.

On the buffer layer 35, an insulating layer 37 is formed. On the diffusion region 36, a p-side electrode layer 38
Is formed, and the p-side electrode layer 38 is electrically connected to the diffusion region 36 via the contact layer. Further, the p-side electrode layer 38 is formed to extend to a part on the insulating layer 37.

The through hole 39 is formed so as to penetrate the semiconductor substrate 31, the filter layer 33, the light absorbing layer 34, and the buffer layer 35. A conductor 40 made of gold or the like is embedded in the through hole 39. An insulating film 41 is formed between the side surface of the through hole 39 and the conductor 40.

The back surface p-side electrode layer 44 is formed on the second main surface 42 of the semiconductor substrate 31 via the insulating layer 43. The back surface p-side electrode layer 44 has a circular convex portion 45 having a convex cross section. The p-side electrode layer 38 and the back side p-side electrode layer 44
It is electrically connected to the conductor 40 in the through hole 39.
The n-side electrode layer 46 is formed on the second main surface 4 of the semiconductor substrate 31.
2 is formed directly on. The n-side electrode layer 46 has a circular convex portion 47 having a convex cross section. As shown in FIG. 4B, the planar shape of the back side p-side electrode layer 44 and the n-side electrode layer 46 is rectangular, and has three convex portions 45 and 47, respectively.

The second main surface 42 between the back side p-side electrode layer 44 and the n-side electrode layer 46 of the semiconductor substrate 31 below the diffusion region 36 is provided with a light receiving portion 4 for receiving signal light from outside.
8

In the semiconductor light receiving element according to the third embodiment, the p-side electrode on the first main surface 32 side of the semiconductor substrate 31 is formed on the second main surface 42 side by the through hole 39, and the p-side electrode is Since the n-side electrode and the n-side electrode are formed in the same direction with respect to the semiconductor substrate 31, it is not necessary to wire-bond one of the electrodes. Therefore, it is possible to prevent the problem of poor connection due to wire bonding.

Also, since the back side p-side electrode layer 44 and the n-side electrode layer 46 for connecting to the wiring electrodes of the mounting substrate have the convex portions 45 and 47 having a convex cross section, the wiring electrodes Put an adhesive such as solder between the part 45 or the convex part 47,
When the semiconductor light receiving element is mounted on the mounting substrate, the adhesive that has protruded between the back surface p-side electrode layer 44 and the wiring electrode or between the n-side electrode layer 46 and the wiring electrode is formed on the side of the convex portions 45 and 47. It is possible to prevent the adhesive from flowing into the light receiving section 48 and the mounting board.

Further, since the back side p-side electrode layer 44 and the n-side electrode layer 46 have the projections 45 and 47, the projections 45 and 47 of the semiconductor light receiving element and the electrode wiring of the mounting board are bonded by soldering or the like. At the time of fixing with an agent, accurate positioning between the semiconductor light receiving element and the mounting substrate can be easily performed by the adhesive action between the convex shape and the solder. Thereby, it is also possible to prevent a defect such as a connection failure due to wire bonding caused by a displacement of the light receiving element.

(Fourth Embodiment) Hereinafter, a light receiving module according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a sectional view of a light receiving module according to the fourth embodiment.

The light receiving module according to the fourth embodiment comprises:
Oscillates 1.3 μm band signal light (output signal light),
It receives signal light (input signal light) in the 5 μm band.

As shown in FIG. 5, a semiconductor laser 51 oscillating in a 1.3 μm band is provided on a first mount 50 provided in a storage case 49. A second mount 52 made of silicon is provided in the storage case 49. The semiconductor laser 5 is mounted on the second mount 52.
A groove is formed in the optical axis direction of the laser light emitted from
An optical fiber 53 is arranged in the groove. Further, a groove is formed in the second mount 52 in a direction perpendicular to the optical axis direction, and a wavelength selection filter 54 is provided in the groove in the optical fiber 53.
Are provided so as to intersect. The wavelength selection filter 54 transmits the signal light in the 1.3 μm band but has a wavelength of 1.55 μm.
The m-band signal light has the property of being reflected.

The second mount 5 which is also a mounting board
2, wiring electrodes 55a and 55b are formed. The wiring electrodes 55a and 55b each have a convex portion 5 having a convex cross section.
6a and 56b. A light receiving element 59 having a p-side electrode 57 and an n-side electrode 58 on the same surface is arranged on the wiring electrodes 55a and 55b. The p-side electrode 57 and the n-side electrode 58 of the light receiving element 59 have convex portions 60 and 61, respectively, and the light receiving element 59 includes the convex portion 60 and the wiring electrode 55a.
Are arranged so as to face each other, and so that the protrusion 61 and the protrusion 56b of the wiring electrode 55b face each other. Also, between the convex portion 60 and the convex portion 55a, and the convex portion 6
1 and the convex portion 55b, an adhesive 62 made of solder is fixedly formed, and the light receiving element 59 is mounted on the second mount 5.
The second wiring electrodes 55a and 55b are electrically connected. The light receiving element 59 is mounted on the second mount 52 by flip chip bonding.

A space between the light receiving element 59 and the second mount 52 is filled with a wavelength selection gel 63 made of a matching material. The wavelength selection gel 63 is mixed with a powdery material having a property of absorbing the signal light in the 1.3 μm band but transmitting the signal light in the 1.55 μm band, and stray light in the 1.3 μm band is received by the light receiving element. 59 is prevented from entering the light. The wavelength selection gel 63 also has a function of reducing the refractive index difference between the light receiving surface of the light receiving element 59 and the wavelength selection filter 54.

According to the light receiving module of the fourth embodiment, when the light receiving element 59 is mounted on the wiring electrodes 55a and 55b by flip-chip bonding, the solder is formed on the projections 56a and 56b of the wiring electrodes 55a and 55b. Is applied, and the convex portions 60 and 61 of the electrodes of the light receiving element 59 are arranged on the adhesive 62. As a result, the positions of the convex portions 60 and 61 of the light receiving element 59 and the convex portions 56a and 56b of the wiring electrodes 55a and 55b are automatically adjusted by the action of the convex shape. Therefore, the light receiving element 59 and the second
The position of the mount 52 can be precisely adjusted, so that the light receiving element 59 can efficiently receive the signal light.

FIG. 5 shows the locus of the signal light 64 in the 1.55 μm band as the signal light received by the light receiving element 59. The signal light 64 in the 1.55 μm band is transmitted through the optical fiber 53, is reflected by the wavelength selection filter 54, and enters the light receiving element 59. Also, in the figure, the locus of the signal light 65 in the 1.3 μm band is illustrated as the signal light emitted from the semiconductor laser 51. The 1.3 μm-band signal light 65 is emitted from the semiconductor laser 51, transmitted through the optical fiber 53, transmitted through the wavelength selection filter 54, and transmitted outside the light receiving module.

[0057]

According to the first semiconductor light receiving element of the present invention,
A semiconductor light receiving element having a light absorbing layer located on a first main surface side of a semiconductor substrate and a light receiving section located on a second main surface side of the semiconductor substrate, wherein the light receiving layer is located on a second main surface side of the semiconductor substrate. The formed first electrode has a convex portion having a convex cross section.

According to the first semiconductor light receiving element, since the first electrode has the convex portion, when the first semiconductor light receiving element is mounted on the mounting substrate with an adhesive such as solder, the mounting is performed. The adhesive between the wiring electrode of the substrate and the protrusion of the first semiconductor light receiving element protrudes, and the adhesive enters around the side of the protrusion. Thus, the signal light received by the adhesive covering the light receiving portion can be prevented from being blocked, so that the optical module using the first semiconductor light receiving element can efficiently receive the signal light. Also, it is possible to prevent the electrode wiring from being short-circuited by flowing into the electrode wiring of the mounting board, so that an optical module can be produced with a high yield.

A second semiconductor light receiving element according to the present invention is a semiconductor light receiving element having a light absorbing layer and a light receiving portion located on the first main surface side of the semiconductor substrate, and is provided near the light receiving portion. The first electrode and the second electrode each have a convex portion having a convex cross section.

According to the second semiconductor light receiving element, since the first electrode and the second electrode have the convex portions, the second semiconductor light receiving element is mounted on the mounting substrate with an adhesive such as solder. At this time, the adhesive between the wiring electrode of the mounting board and the convex portion of the second semiconductor light receiving element protrudes, and the adhesive enters around the side of the convex portion. Accordingly, the signal light received by covering the light receiving portion with the adhesive can be prevented from being blocked, so that the optical module using the second semiconductor light receiving element can efficiently receive the signal light. Also, it is possible to prevent the electrode wiring from being short-circuited by flowing into the electrode wiring of the mounting board, so that an optical module can be produced with a high yield.

A third semiconductor light receiving element according to the present invention is a semiconductor light receiving element having a light absorbing layer located on a first main surface side of a semiconductor substrate and a light receiving portion located on a second main surface side of the semiconductor substrate. An element having a first electrode having a convex portion having a convex cross section and a second electrode having a convex portion having a convex cross section on the second main surface side of the semiconductor substrate; An electrode wiring is formed on the diffusion region formed thereon, a through-hole penetrating the semiconductor substrate and the light absorbing layer is formed, and the first electrode and the electrode wiring are formed in the through-hole. It is characterized by being electrically connected by the formed conductor.

According to the third semiconductor light receiving element, since the first electrode and the second electrode have the convex portions, the third semiconductor light receiving element is mounted on the mounting substrate with an adhesive such as solder. At this time, the adhesive between the wiring electrode of the mounting board and the convex portion of the third semiconductor light receiving element protrudes, and the adhesive enters around the side of the convex portion. Thus, the signal light received by the adhesive covering the light receiving portion can be prevented from being blocked, so that the optical module using the third semiconductor light receiving element can efficiently receive the signal light. Also, it is possible to prevent the electrode wiring from being short-circuited by flowing into the electrode wiring of the mounting board, so that an optical module can be produced with a high yield.

Further, the first electrode and the second electrode
Are formed on the same main surface side of the semiconductor substrate. Therefore, when the third semiconductor light receiving element is mounted on the mounting substrate by flip chip bonding, the first electrode and the second electrode are mounted on the mounting substrate. Since the electrodes can be simultaneously mounted on the wiring electrodes, it is not necessary to wire-bond either one of the electrodes, and it is possible to prevent the high-speed operation from being hindered by the capacitance of the wire bonding.

A light receiving module according to the present invention comprises: a substrate having therein an optical transmission path for transmitting output signal light and input signal light; a semiconductor light emitting element for emitting output signal light to one end of the optical waveguide; An optical spectroscope provided in the optical transmission path, transmitting at least a part of the output signal light and guiding at least a part of the input signal light to the outside of the optical transmission path,
A light receiving module provided on the substrate and including a semiconductor light receiving element on which input signal light is incident by the optical spectroscope, wherein the semiconductor light receiving element includes an electrode having a convex portion, and a wiring on the substrate is provided. It is characterized by being electrically connected to the electrode.

According to the light receiving module of the present invention, when the semiconductor light receiving element is mounted on the substrate by flip-chip bonding, the positioning of the semiconductor light receiving element and the electrode wiring is automatically performed by the convex portion of the electrode of the semiconductor light receiving element. Is made. Accordingly, the semiconductor light receiving element and the substrate can be precisely aligned, and the semiconductor light receiving element can efficiently receive the signal light. In addition, since it is possible to prevent the electrode wiring from being short-circuited by flowing into the electrode wiring of the mounting board, an optical module can be produced with a high yield.

[Brief description of the drawings]

FIG. 1A is a sectional view of a semiconductor light receiving element according to a first embodiment of the present invention. FIG. 1B is a rear view of the semiconductor light receiving element according to the first embodiment of the present invention.

FIG. 2A is a cross-sectional view of a semiconductor light receiving element according to a modification of the first embodiment of the present invention. FIG. 2B is a rear view of the semiconductor light receiving element according to a modification of the first embodiment of the present invention.

3A is a sectional view of a semiconductor light receiving device according to a second embodiment of the present invention. FIG. 3B is a plan view of a semiconductor light receiving device according to a second embodiment of the present invention.

FIG. 4A is a sectional view of a semiconductor light receiving element according to a third embodiment of the present invention. FIG. 4B is a rear view of the semiconductor light receiving element according to the third embodiment of the present invention.

FIG. 5 is a sectional view of a light receiving module according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a conventional 1.55 μm pass band semiconductor light receiving element.

FIG. 7 is a cross-sectional view showing a mounting form of a conventional semiconductor light receiving element.

[Explanation of symbols]

1, 15, 31, 101 semiconductor substrate 2, 16, 32 first main surface 3, 19, 33, 102 filter layer 4, 18, 34, 103 light absorption layer 5, 17, 35, 104 buffer layer 6, 20, 36, 105 Diffusion region 7, 21, 37, 43, 106 Insulating layer 8, 22, 38, 107 P-side electrode layer 9, 42 Second main surface 10, 13, 23, 46, 108 N-side electrode layer 11, 14 , 24, 25, 45, 47, 56a, 56
b, 60, 61 Convex parts 12, 30, 48, 109 Light receiving part 26 Adhesive layer 27 First multilayer film 28 Second multilayer film 29 Glass substrate 39 Through hole 40 Conductor 41 Insulating film 44 Back surface p-side electrode layer 49 Storage case 50 First mount 51 Semiconductor laser 52 Second mount 53 Optical fiber 54 Wavelength selection filter 55a, 55b, 113, 114 Wiring electrode 57 P-side electrode 58 N-side electrode 59 Light receiving element 62, 112 Adhesive 63 Wavelength selection Gel 64 1.55 μm band signal light 65 1.3 μm band signal light 110 Semiconductor light receiving element 111 Mounting substrate 115 Gold wire

Continued on the front page (72) Inventor Masato Ishino 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term (reference) 2H037 AA01 BA02 BA11 CA37 DA03 DA11 DA16 5F049 MA04 MB07 NA10 NB01 SE09 SS04 TA03 TA05 TA06 TA14 WA01

Claims (19)

[Claims] 1. A semiconductor light receiving element having a light absorbing layer located on a first principal surface side of a semiconductor substrate and a light receiving portion, wherein a first electrode formed near the light receiving portion has a cross section. A semiconductor light receiving element having a convex portion. 2. The semiconductor light receiving device according to claim 1, wherein said light receiving section is located on a second main surface side of said semiconductor substrate. 3. The semiconductor light receiving device according to claim 2, wherein a diffusion region is formed on the light absorption layer, and a second electrode is formed on the diffusion region. 4. The semiconductor light receiving device according to claim 2, wherein the first electrode has a plurality of projections. 5. The semiconductor light receiving device according to claim 1, wherein said light receiving portion is located on a first main surface side of said semiconductor substrate. 6. The semiconductor light receiving device according to claim 5, wherein a diffusion region is formed on the light absorption layer, and a second electrode electrically connected to the diffusion region is formed. . 7. The semiconductor light receiving device according to claim 6, wherein an insulating film is formed between said second electrode and said light absorbing layer. 8. The semiconductor light receiving device according to claim 6, wherein a glass substrate having a dielectric multilayer film on both sides is disposed on the diffusion region via an adhesive layer. 9. The semiconductor according to claim 6, wherein a plurality of said convex portions of said first electrode and a plurality of said convex portions of said second electrode are provided. Light receiving element. 10. A second electrode having a convex section having a convex cross section formed in the vicinity of the light receiving section, an electrode wiring formed on a diffusion region formed on the light absorbing layer, The semiconductor device according to claim 1, further comprising: a through hole penetrating the semiconductor substrate and the light absorbing layer; and a conductor formed in the through hole so as to electrically connect the first electrode and the electrode wiring. Item 3. A semiconductor light receiving element according to item 2. 11. The semiconductor light receiving device according to claim 10, wherein an insulating film is formed between said conductor, said light absorbing layer and said semiconductor substrate. 12. The semiconductor device according to claim 10, wherein an insulating layer is formed between said semiconductor substrate and said first electrode.
Or a semiconductor light receiving element according to claim 11. 13. The method according to claim 12, wherein the light-receiving portion and the light-absorbing layer are
13. The semiconductor light receiving element according to claim 1, further comprising a filter layer that absorbs signal light in the 1.3 μm band but does not absorb signal light in the 1.55 μm band. 14. A substrate provided with an optical transmission path for transmitting output signal light and input signal light therein, a semiconductor light emitting element for emitting output signal light to one end of the optical waveguide, and provided on the optical transmission path. An optical splitter that transmits at least a part of the output signal light and guides at least a part of the input signal light to the outside of the optical transmission line; and an optical splitter provided on the substrate, where the input signal light is incident by the optical splitter. A light-receiving module including a semiconductor light-receiving element having a light-receiving section, wherein the semiconductor light-receiving element includes an electrode formed near the light-receiving section, the electrode having a convex section having a convex cross section, and wiring on the substrate. A light receiving module, which is electrically connected to an electrode. 15. The light receiving module according to claim 14, wherein an adhesive is formed between the protrusion of the electrode and the wiring electrode. 16. The light receiving module according to claim 15, wherein the adhesive is solder. 17. The semiconductor device according to claim 17, wherein the wiring electrode has a convex portion, and the convex portion of the wiring electrode is arranged at a position facing the convex portion of the electrode of the semiconductor light receiving element. The light receiving module according to any one of claims 14 to 16. 18. The light receiving module according to claim 14, wherein a wavelength selecting material is formed between said semiconductor light receiving element and said substrate. 19. The apparatus according to claim 14, wherein the wavelength selection material absorbs signal light having a wavelength in the 1.3 μm band but does not absorb signal light having a wavelength in the 1.55 μm band.
The light receiving module according to claim 18.