JP2005093722A - Optical function device and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical function device that is made compact and highly integrated. <P>SOLUTION: The optical function device is provided with a substrate made of Si or SiGe and a photoelectric conversion device mounted to the substrate. Since the photoelectric conversion device uses the optical function device made of a direct transition type semiconductor, the optical function device that has a simplified structure and is highly integrated and a method for manufacturing the optical function device having such features can be provided. In addition, if a controlling device that controls the optical function device using a semiconductor forming the substrate is formed on the substrate, the optical function device wherein the photoelectric conversion device and the controlling device are formed at a high density can be realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical functional element and an optical functional element manufacturing method, and more particularly to an optical functional element using a direct transition type semiconductor and an optical functional element manufacturing method.

  Research and practical application of optical functional devices using opto-electric composite substrates are becoming important as communication capacity increases. The optical functional element has, for example, a light emitting unit that generates an optical signal, such as a semiconductor laser (LD) or a light emitting diode (LD), a pin photodiode or an avalanche diode (APD) as a basic configuration. And a photoelectric conversion element that performs photoelectric conversion, such as an optical signal receiving unit (light receiving unit) using a photo-detector (PD).

  Further, the optical functional element is composed of a coupling part that couples elements such as a light emitting part and a light receiving part, and a control element that is a driving part of the light emitting part and the light receiving part.

  FIG. 1A is a perspective view schematically showing a conventional optical functional element, and FIG. 1B is an enlarged view of a portion where the photoelectric conversion element of the optical functional element is formed.

  Referring to FIG. 1A, the optical functional element 10 includes a chip 10A including a photoelectric conversion element and a chip 10B including a control element of the photoelectric conversion element. The chip 10A and the chip 10B are electrically connected by a wiring portion 11. Connected. In the chip 10A, a light emitting / receiving unit 10a including a substrate on which a photoelectric conversion element is formed is formed.

  FIG. 1B is an enlarged schematic view of the light emitting / receiving unit 10a. The light receiving / emitting unit 10a includes a photoelectric conversion element 2 formed on the direct transition type semiconductor substrate 1, and It consists of an electrode pad 4 and a wire 5 electrically connected to the electrode pad.

  Further, in the control unit 10b that controls the photoelectric conversion element formed on the chip 10B, a control element that controls the photoelectric conversion element such as a MOS transistor is formed on an indirect transition semiconductor substrate such as Si. ing.

  Thus, conventionally, a chip on which a photoelectric conversion element is formed and a chip on which a control element is formed are formed separately, and the chip on which the photoelectric conversion element and the control element are formed is wired and used as an optical functional element. Has been.

  For example, among the photoelectric conversion elements, a direct transition type semiconductor in which recombination of electrons and holes between semiconductor bands directly is used to form a light emitting element such as an LD or LED. Specifically, it is known that GaAs, InGaAs, InGaAsP, GaN, or the like is used for the light emitting element, and the wavelength band where gain is obtained is controlled from the mixing ratio of such ternary and quaternary semiconductors. The oscillation wavelength of the laser is determined by the condition of the resonator.

  On the other hand, the control element of such a photoelectric conversion element uses an integrated circuit technology, for example, an indirect transition type semiconductor integrated circuit using a MOS MOS transistor, and requires a higher speed operation. In this case, a MOS transistor using SiGe, which is an indirect transition semiconductor, is used.

  As described above, when an optoelectric composite substrate of an optical functional element is configured, elements made of different semiconductor materials need to be integrated.

  However, when an attempt is made to integrate a photoelectric conversion element and a control element of the photoelectric conversion element in the optical functional element, the photoelectric conversion element and the control element are different from each other in the semiconductor material constituting them. However, it has been difficult to form a high integration, and it has been difficult to achieve high integration.

  For example, among the photoelectric conversion elements, the direct-transition semiconductor after forming a stacked structure by crystal growth in order to use a light-emitting element formed by crystal growth on a direct-transition semiconductor substrate for an LD that is a light-emitting element It is difficult to form a control element such as a conventional MOS transistor on a substrate, which has been a problem in highly integrating elements using a photoelectric conversion element and a control element.

  As described above, as a technique for integrating elements made of different kinds of semiconductors, a technique for bonding different kinds of semiconductors directly on a substrate by direct bonding or wafer fusion without using crystal growth is available. At the research level, the fusion of InP and GaAs substrates was announced. (For example, refer to Non-Patent Document 1.) Further, a GaInAsP / InP light emitting substrate is fused on a GaAs substrate, and then a photoelectric conversion film is formed on the GaInAsP / InP light emitting substrate by crystal growth to oscillate a surface emitting laser. Is obtained. (For example, refer nonpatent literature 2).

Further, a method has been proposed in which an element is formed on a block made of a semiconductor and the block is fitted to a semiconductor substrate. (For example, refer to Patent Document 1).
JP 2002-83953 A JP 2001-91912 A APL, vol. 56, no. 8, p. 737, 1990 APL, vol. 58, no. 18, p. 1961, 1991 IEEE Photon. Technol. Lett., Vol 8, no. 11, p. 1507, 1996

  However, the above-mentioned method of bonding or fusing wafers becomes wafer-level fusing, and the fusing conditions differ depending on the materials to be bonded. Therefore, it is difficult to form two or more different elements on the same substrate. is there. Further, in the bonding for each wafer, the portion where the electrode bats and the like other than the utilized portion are disposed is removed, so that there are many portions where an expensive crystal growth wafer is wasted.

  In addition, in the method using a block made of a semiconductor, for example, it is necessary to prepare two sheets of a convex portion using a Si substrate for the block and a concave portion in which the block is embedded, and when mounting a device having different functions Therefore, since a Si substrate must be prepared for each Si block, and it is necessary to perform a substrate bonding technique process for each block, there is a problem that the substrate is wasted and the manufacturing cost is increased.

  As described above, it has been difficult to highly integrate a photoelectric conversion element and an optical functional element including an element that controls the photoelectric conversion element with a simple structure.

  Accordingly, an object of the present invention is to provide a novel and useful optical functional element and a method for manufacturing the optical functional element that solve the above-described problems.

  A specific object of the present invention is to provide an optical functional element with a simple structure and highly integrated, and a method for manufacturing an optical functional element that can be highly integrated with a simple structure.

  The present invention uses the following means in order to solve the above problems.

  An optical functional element comprising a substrate made of Si or SiGe and a photoelectric conversion element mounted on the substrate as defined in claim 1, wherein the photoelectric conversion element is made of a direct transition type semiconductor. By using the optical functional element, it is possible to downsize and highly integrate the optical functional element.

  According to a second aspect of the present invention, the photoelectric conversion element is a light receiving element or a light emitting element, and the optical functional element having the light receiving element or the light emitting element is used. Can be miniaturized and highly integrated.

  Further, as described in claim 3, the photoelectric conversion element is a light receiving / emitting element that receives and emits light. It becomes possible to miniaturize and highly integrate functional elements.

  In addition, as described in claim 4, a plurality of the photoelectric conversion elements are mounted on the substrate, and the plurality of photoelectric conversion elements include the light receiving element and the light emitting element. When the element is used, it becomes possible to reduce the size and increase the integration of the optical functional element having the light receiving element and the light emitting element.

  In addition, as described in claim 5, the photoelectric conversion element is configured such that the incident direction or the emission direction of the signal light of the photoelectric conversion element is substantially perpendicular to the surface of the substrate on which the photoelectric conversion element is mounted. When an optical functional element characterized by mounting the element is used, optical communication in a direction substantially perpendicular to the substrate becomes possible with a miniaturized and highly integrated optical functional element.

  In addition, as described in claim 6, the photoelectric conversion is performed so that the incident direction or the emission direction of the signal light of the photoelectric conversion element is substantially parallel to the surface of the substrate on which the photoelectric conversion element is mounted. When an optical functional element characterized by mounting an element is used, optical communication in a direction substantially parallel to the substrate becomes possible with an optical functional element that is miniaturized and highly integrated.

  The optical functional element according to claim 7, wherein the photoelectric conversion element is a light emitting element, and a polarizer that polarizes the direction of light emitted from the light emitting element is provided on the substrate. Can be used to polarize the direction of light emitted from the light emitting element with a miniaturized and highly integrated optical functional element.

  Further, as described in claim 8, when an optical functional element characterized in that a control element for controlling the photoelectric conversion element using a semiconductor constituting the substrate is formed on the substrate, An optical functional element in which photoelectric conversion elements and control elements are formed with high density can be realized.

  In addition, as described in claim 9, a wiring portion electrically connected to the photoelectric conversion element is formed on the substrate, and the photoelectric conversion element and the control element are electrically connected via the wiring portion. The optical functional element according to claim 8, wherein the photoelectric converting element and the control element are formed with high density, and the optical functional element is controlled by the control element. be able to.

  In addition, as described in claim 10, a voltage is applied to the photoelectric conversion element through the wiring portion. When the optical functional element according to claim 9 is used, the photoelectric conversion element It becomes possible to control the application of voltage.

  In addition, as described in claim 11, the photoelectric conversion element is substantially cylindrical, and when the optical functional element according to any one of claims 1 to 10 is used, stress or The possibility of damaging the photoelectric conversion element due to an impact is reduced, which is preferable.

  The optical function according to any one of claims 1 to 11, wherein the photoelectric conversion element is mounted in a hole formed in the substrate. When the element is used, the mounting accuracy of the photoelectric conversion element is improved.

  Moreover, as described in Claim 13, the said photoelectric conversion element is installed so that it may be enclosed by the insulating material formed on the said board | substrate, Any 1 among Claims 1-12 characterized by the above-mentioned. When the optical functional element described in the item is used, the photoelectric conversion element is prevented from being damaged or moved, and insulation is secured.

  In addition, as described in claim 14, the first layer in which the photoelectric conversion element is embedded and the second layer in which the photoelectric conversion element formed on the first layer is embedded are stacked. When the optical functional element according to any one of claims 1 to 13 is used, the photoelectric conversion element can be mounted at a higher density.

  Moreover, as described in claim 15, the photoelectric conversion element includes a material selected from the group consisting of GaInAsP, AlGaInAs, GaInNAs, GaAsSb, GaInAs, and AlGaAs. When the optical functional element described in any one of the above items is used, an optical functional element having a photoelectric conversion element using the material can be formed.

  According to another aspect of the present invention, there is provided an optical functional element having a photoelectric conversion element and an optical waveguide connected to the photoelectric conversion element, wherein the photoelectric conversion element is made of a direct transition type semiconductor, By using an optical functional element in which the element is mounted so as to be embedded in the optical waveguide, the optical functional element can be reduced in size.

  In addition, as described in claim 17, the photoelectric conversion element is a light receiving element or a light emitting element. When the optical functional element according to claim 16 is used, the photoelectric conversion element has a light receiving element or a light emitting element. An optical functional device can be realized.

  In addition, as described in claim 18, the photoelectric conversion element has a structure mounted on a substrate made of Si or SiGe. When the optical functional element according to claim 16 or 17, the substrate is used. An optical functional element that is miniaturized and can be realized.

  In addition, as described in claim 19, a first surface formed on the photoelectric conversion element faces the optical waveguide, and a second surface of the photoelectric conversion element facing the first surface is The optical functional element according to any one of claims 16 to 18, wherein the photoelectric conversion element mounted on the optical waveguide is attached to the substrate. It can be implemented.

  Further, as described in claim 20, a control element for controlling the photoelectric conversion element using a semiconductor constituting the substrate is formed on the substrate. When any one of the optical functional elements is used, a miniaturized optical functional element in which photoelectric conversion elements and control elements are formed at high density can be realized.

  In addition, as described in claim 21, the photoelectric conversion element has a substantially cylindrical shape, and when the optical functional element according to any one of claims 16 to 20 is used, stress or impact is generated. Therefore, the possibility of damaging the photoelectric conversion element is preferable.

  A method for manufacturing an optical functional element comprising a photoelectric conversion element made of a direct transition type semiconductor mounted on a first substrate made of Si or SiGe, wherein the direct transition type semiconductor comprises: A film forming step of forming a photoelectric conversion film by crystal growth on a second substrate comprising: a patterning step of etching the photoelectric conversion film to form the photoelectric conversion element; and When using the method for manufacturing an optical functional element, comprising: a separation step of separating the substrate from the substrate; and a mounting step of mounting the photoelectric conversion element on the first substrate. An optical functional element can be manufactured.

  23. The method of manufacturing an optical functional element according to claim 23, wherein, in the second separation step, the photoelectric conversion element is separated from the second substrate by a wet etching process. When the is used, the photoelectric conversion element can be easily separated from the second substrate.

  In addition, as described in claim 24, in the separation step, the photoelectric conversion element is separated from the second substrate by removing the second substrate by CMP (chemical mechanical polishing). When the method for producing an optical functional element according to claim 22 is used, the photoelectric conversion element can be easily separated from the second substrate.

  Further, in the mounting step, the photoelectric conversion element is configured such that a side of the photoelectric conversion element facing the second substrate in the film formation step faces the first substrate. When the method for producing an optical functional element according to any one of claims 22 to 24 is used, the photoelectric conversion element can be easily mounted on a substrate. Is preferred.

  In the mounting step, the side of the photoelectric conversion element that faces the side facing the second substrate in the film forming step faces the first substrate. The photoelectric conversion element is mounted as described above, and when the method for producing an optical functional element according to any one of claims 22 to 24 is used, the light emission surface or the incident surface of the photoelectric conversion element is formed. A state can be made favorable.

  In addition, as described in claim 27, after the patterning step, a transfer step of mounting the photoelectric conversion element on a dummy substrate is further provided, and in the mounting step, the photoelectric conversion element mounted on the dummy substrate is 27. The method of manufacturing an optical functional element according to any one of claims 22 to 26, wherein the photoelectric conversion element can be easily mounted by mounting on the first substrate. become.

  In addition, as described in claim 28, by providing a patterning film on which the photoelectric conversion elements of some of the plurality of photoelectric conversion elements are selectively mounted on the dummy substrate. The number of the photoelectric conversion elements mounted on the substrate is controlled using the method for manufacturing an optical functional element according to claim 27, wherein the photoelectric conversion elements mounted on the first substrate are controlled. The pattern can be controlled, which is preferable.

  In addition, according to a twenty-ninth aspect of the present invention, there is further provided a step of forming a control element for controlling the photoelectric conversion element using a semiconductor constituting the first substrate on the first substrate. 29. The optical functional element manufacturing method according to any one of claims 22 to 28, wherein an optical functional element in which photoelectric conversion elements and control elements are formed at a high density can be manufactured. Become.

  Furthermore, as described in claim 30, the photoelectric conversion film includes a material selected from the group consisting of GaInAsP, AlGaInAs, GaInNAs, GaAsSb, GaInAs, and AlGaAs. When the method for producing an optical functional element described in any one of the above items is used, an optical functional element having a photoelectric conversion element using the above material can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the manufacturing method of the optical function element which can be highly integrated with a simple structure and highly integrated with the simple structure.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view schematically showing an optical functional device 20 according to a first embodiment of the present invention.

  Referring to FIG. 1, the optical functional element 20 includes a light emitting / receiving unit 22 formed on an indirect transition type substrate 21 made of, for example, Si, and a control unit 25. In the light emitting / receiving unit 22, a photoelectric conversion element 23 made of a direct transition type semiconductor is mounted on a substrate 21 made of Si. The photoelectric conversion element 23 is configured to be controlled by a control element formed in the control unit 25 that is electrically connected to the photoelectric conversion element 23 by a wiring 24.

  The control element includes, for example, an element such as a MOS transistor, and is formed in the control unit 25 adjacent to the light emitting / receiving unit 22 so as to control the photoelectric conversion element 23. The substrate 21 is made of, for example, Si. If high speed operation is required, a substrate made of SiGe can be used.

  In the case of forming the light emitting / receiving unit 22, for example, a photoelectric conversion film is first deposited by crystal growth on a direct transition type semiconductor substrate, and the photoelectric conversion film is etched to form a photoelectric conversion element. The photoelectric conversion element is mounted on a Si substrate. Details of this will be described later. As the photoelectric conversion element, for example, a light emitting element such as an LD, a light receiving element such as a PD, or a gun light emitting element that combines light emission and light reception with one element can be used.

  In this way, a photoelectric conversion element made of a direct transition semiconductor is mounted on the indirect transition semiconductor substrate so as to be adjacent to a control element using the indirect semiconductor formed on the indirect transition semiconductor substrate. As a result, high integration of the optical functional element is enabled.

  That is, since the photoelectric conversion element and the control element made of different semiconductor materials are integrated on the same substrate, for example, as shown in FIG. 2, the width W1 of the optical functional element can be reduced, and the optical functional element is highly integrated. Therefore, the optical functional element can be reduced in size and weight.

  In addition, the structure is simple compared to the case where the photoelectric conversion element and the control element are formed by bonding or bonding the substrates, and it is suitable for further miniaturization and higher integration, and the manufacturing cost is suppressed. Play. In addition, when mass production of optical functional elements is taken into account, it can be manufactured with a simple structure and thus has a high yield.

  Next, details of the light emitting / receiving unit 22 and the control unit 25 will be described.

  3A and 3B are diagrams schematically showing cross-sectional views of configuration examples of the light emitting / receiving unit 22 and the control unit 25 of the optical functional element 20, and FIG. 3A shows the light receiving / emitting unit. FIG. 3B shows the control unit.

  First, referring to FIG. 3A, the substrate 101 in this figure corresponds to the substrate 21 in FIG. 2, and the light receiving element 102 corresponding to the photoelectric conversion element 23 in FIG. An element 108 is mounted.

  The light receiving element 102 is a photodiode, and includes a photoelectric conversion film 103 and a joint 104. When the signal light L2 that is incident light and is substantially perpendicular to the substrate 101 is incident on the photoelectric conversion film 103, the photoelectric conversion film 103 receives the photoelectric conversion. Electrons and holes are generated in the film 103 and are detected as current.

  The light emitting element 108 is formed of, for example, a surface emitting laser, and includes a photoelectric conversion film 110 and a bonding portion 109 formed of a black reflecting mirror (DBR) formed so as to hold the photoelectric conversion film 110. The photoelectric conversion film 110 takes the form of a quantum well, a strained quantum well, a quantum wire, or a quantum box, and recombines electron hole pairs generated by current application to emit light having a frequency corresponding to the band gap. For example, as shown in the figure, signal light L1 substantially perpendicular to the substrate 101 is emitted.

  Such a light emitting device is formed by etching a photoelectric conversion film deposited by crystal growth on a direct transition semiconductor substrate, for example, a substrate made of GaAs, InP, or GaN, and mounted on a Si substrate. . The material constituting the light emitting element 108 can be expressed by a combination of the photoelectric conversion film / junction portion, for example, GaInAsP / InP, AlGaInAs / InP, GaInNAs / GaAs, GaAsSb / GaAs, GaInAs / GaAs, and AlGaAs / GaAs. Either can be used.

  As the light receiving element, it is possible to use an element formed by etching a film formed by crystal growth on a direct transition type semiconductor substrate in the same manner as the light emitting element. In the case of a student element, the light receiving element can be formed using an indirect transition type semiconductor. For example, the light receiving element can be formed on a Si substrate with a structure using Si.

  In addition, wiring portions 105 and 106 are connected to the light receiving element, and wiring portions 111 and 112 are connected to the joint portion 109 of the light emitting element 108 so that electric power is supplied as necessary. The structure is controlled by being electrically connected to the control element formed in the above.

  The wiring parts 105, 106, 111, and 112 are made of copper, aluminum, gold, silver, or the like used in electronic circuits, and the p side is made of gold and zinc or titanium platinum at the part that makes ohmic contact with the semiconductor. An alloy such as a gold germanium alloy is used on the n side. Such a joining technique or wiring technique can use a general method used for a semiconductor laser, a photodiode, or the like.

  A protective film 107 made of an insulating film is formed around the light receiving element 102 and the light emitting element 108. This is formed for the purpose of insulation between the wiring parts, support of the wiring parts, holding / protection of the photoelectric conversion elements, and insulation. The protective film 107 is preferably made of an optically transparent material, but may take a form in which an optical signal can be transmitted and received by exposing a light incident / exit portion.

  The light receiving element 102 and the light emitting element 108 have a substantially cylindrical shape. For example, in the case of the light emitting element 108, the diameter of the cylinder is approximately 100 μm. Thus, when a photoelectric conversion element having a fine structure is mounted on a substrate, it is cut into a direct linear semiconductor substrate on which the photoelectric conversion element is formed, for example, a chip of about 1 mm square, and the chip is formed on the substrate 101. Bonding is performed so that the surface on which the element is formed on the chip faces the substrate 101. For joining, techniques such as adhesion, semiconductor fusion, and joining of metals can be used.

  Therefore, by removing the back surface (the surface on which no element is formed) of the chip by polishing or wet etching, a photoelectric conversion element made of a direct transition type semiconductor is mounted on the substrate 101 made of an indirect transition type semiconductor. be able to. This manufacturing method will be described later.

  Conventionally, for example, a method has been used in which different types of wafers are bonded and a photoelectric conversion element is configured at a specific location of the optical functional element. When the method for bonding at the wafer level is used in this way, an area for wasting a substrate on which the photoelectric conversion element is formed becomes large, and an expensive direct transition semiconductor substrate such as GaAs is consumed. There has been a problem that the manufacturing cost of the optical functional element is increased.

  In particular, when an advanced semiconductor process technology such as a laser active layer or DBR of a surface emitting laser is required, or in the case of a photoelectric conversion element made of a rare metal such as In, a photoelectric conversion element that can be taken out from a single substrate is used. The manufacturing cost greatly depends on the number. In the case of the present invention, it is possible to efficiently manufacture and mount a photoelectric conversion element. As will be described later, there are a large number of photoelectric conversion elements that can be manufactured from one substrate, and therefore, an optical functional element. There is an effect of suppressing the manufacturing cost.

  Next, referring to FIG. 3B, control elements for controlling photoelectric conversion elements mounted on the substrate 101 such as the light receiving element 102 and the light emitting element 108 on the substrate 101. Is formed. The control element is configured by using a semiconductor material constituting the substrate 101, and for example, a MOS transistor (for example, CMOS) is formed.

  The control element shown in FIG. 3B includes a gate insulating film 114A formed on an element region separated by an element isolation insulating film 112 on the substrate 101, and a gate formed on the gate insulating film 114A. It includes an electrode 114 and diffusion layers 115A and 115B formed on both sides of the gate electrode 114.

  The gate electrode 114 is covered with side wall insulating films 113A and 113B, and an insulating film 116 is formed on the Si substrate 101 so as to cover the gate electrode 114 and the side wall insulating films 113A and 113B. Further, a protective film 117 is formed on the insulating film 116 as necessary.

  In the insulating film 116 and the protective film 117, a contact hole leading to the diffusion layer 115B is formed, a barrier film 118 is formed on the inner wall of the contact hole, and the barrier film 118 is further formed. A contact plug 119 made of, for example, W (tungsten) is embedded in the contact hole. The contact plug 119 is electrically connected to the diffusion layer 115B through the barrier film 118.

  An insulating film 120 is formed on the protective film 117, and a cap film 121 is formed on the insulating film 120.

  A wiring groove is formed in the inter-wiring insulating film 110 and the cap film 121 by etching. A wiring portion 122 and a barrier film 122a are formed in the wiring groove so as to surround the wiring portion 122. Are electrically connected to the contact plug 119 through the barrier film 122a. The wiring part 122 is connected to the photoelectric conversion element and has a structure for controlling the photoelectric conversion element. For example, the control element of the photoelectric conversion element performs direct modulation of the semiconductor laser, detection signal processing, amplification function, and the like.

  By using this embodiment, it is possible to arrange elements having different functions of different materials, for example, photoelectric conversion elements and control elements for controlling the photoelectric conversion elements at a high density in the same plane, so that complex light reception is possible. Light-emitting elements, specifically optical modulators, optical switches, spatial light modulators, spatial light switches, light-receiving / emitting elements for optical interconnections, optical pickups for optical memories, light sources for displays, parallel optical processors for optical computing, etc. Optical functional elements can be highly integrated and miniaturized.

  In addition, the shape and mounting method of the photoelectric conversion element are not limited to the case of the present embodiment, and for example, as shown in Examples 3 to 18 below, various modifications and changes can be used. In any case, the same effects as those described in the present embodiment and the first embodiment can be obtained.

  FIG. 4 is a modified example of the second embodiment, and is a diagram schematically showing a cross-sectional view of a configuration example of the light receiving and emitting unit of the optical functional element 20. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 4, in this embodiment, holes 102A and 108A for mounting the light receiving portion 102 and the light emitting portion 108 are provided on the substrate 101, respectively. The hole portions 102A and 108A have, for example, a so-called tapered shape in which the bottom surface in contact with the photoelectric conversion element is a substantially circular hole, and the diameter of the hole portion increases in the direction away from the substrate from the bottom surface. Yes.

  The light receiving element 102 is mounted in the hole 102A and the light emitting element 108 is embedded in the hole 108A. In this way, the photoelectric conversion element may be mounted so as to be embedded in the hole. In this case, particularly when the photoelectric conversion element is mounted in the tapered hole, positioning of the photoelectric conversion element at the time of mounting is facilitated, and the accuracy of the position where the photoelectric conversion element is mounted is improved.

  In the case of this embodiment, the wiring part 111 in FIG. 3A and the wiring part 113 corresponding to the wiring part 105 are formed on the back surface of the substrate 101. In this way, the wiring portion can be formed on the back surface of the substrate.

  The hole and the photoelectric conversion element have the same size. For example, the diameter of the hole is about 100 μm or less. Since the photoelectric conversion element is mounted so as to be embedded in the hole, the photoelectric conversion element is formed about 5 to 10% smaller than the hole as necessary. Further, the depth at which the photoelectric conversion element is embedded in the hole is preferably 50 μm or less, and more preferably 10 μm or less. The depth may be such that the photoelectric conversion element is buried and an optical signal cannot be exchanged.

If the photoelectric conversion element is a surface emitting laser, the size of the hole is preferably about 5 to 20 μm in diameter, and the cross-sectional shape of the hole is not limited to a circle, but includes a circle or a polyhedron having one side. It may be a rectangular structure. In the case where the photoelectric conversion element is a light receiving element, the size of the hole is preferably about 20 to 100 μm in diameter, and similarly, the cross-sectional shape of the hole is not limited to a circle, but a circle with one side or A rectangular structure including a polyhedron may be used. The size of these holes or photoelectric conversion elements depends on the light receiving sensitivity of the light receiving elements.
When the holes 102A and 108A are formed on the substrate 101, they can be formed by ordinary photolithography and dry etching. Further, it can be formed by wet etching using a mask. However, when the hole is formed by wet etching, anisotropic etching is performed depending on the etching solution, and the side wall angle may not be vertical. In that case, it is necessary to perform etching in consideration of an etching shape margin corresponding to the angle of the side wall and the etching depth.

  The hole for mounting the photoelectric conversion element formed in the substrate 101 does not need to have a bottom surface parallel to the substrate surface, and can be variously modified and changed.

  FIG. 5 schematically shows a modification of the configuration of the light receiving and emitting unit described in the third embodiment. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 5, in the case of the present embodiment, a hole 114 for mounting the light emitting unit 108 is formed obliquely with respect to the surface of the substrate 101. Therefore, the light emitting element 108 made of a surface emitting laser mounted along the hole 114 can change the light emitting direction according to the shape of the hole. In this embodiment, electrodes 109A and 109B are provided at the joint 109, respectively, and ohmic contact between the electrode and the joint is established by a process such as annealing. Therefore, the wiring portions 112A and 112B and the light emitting element 108 are reliably electrically connected.

  Next, FIGS. 6A and 6B schematically show the configuration of the light receiving and emitting unit of Example 5 according to the present invention. 6A is a plan view, and FIG. 6B is a cross-sectional view taken along the line BB in FIG. 6A. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  6A and 6B, a plurality of holes 117 are formed in the substrate 101, and a plurality of photoelectric conversion elements, for example, light emitting elements 108 are mounted in the holes 117. Yes. A protective film 116 made of an insulating film is formed so as to cover the surface of the substrate 101 and the light emitting element 108, and functions to protect the photoelectric conversion element and to hold and insulate the wiring portion.

  In addition, a wiring portion 115 formed on the protective film 116 is connected to the bonding portion 109, and a wiring portion 113 is formed on the back surface of the substrate 101, and power is individually supplied to a plurality of photoelectric conversion elements. In addition, the structure is connected to the control element so that the operations of the plurality of photoelectric conversion elements are individually controlled.

  As described above, a plurality of holes may be provided in the substrate and a plurality of photoelectric conversion elements may be mounted. In that case, the plurality of photoelectric conversion elements are individually controlled by the control element.

  In this embodiment, the electrodes are formed on the back surface of the substrate 101. However, as shown in FIG. 7, electrodes may be formed on the photoelectric conversion elements to connect the wiring portions.

  FIG. 7 shows a light emitting / receiving unit according to the sixth embodiment of the present invention, which is a modification of the fifth embodiment. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  In this embodiment, electrodes 109A and 109B are bonded to the bonding portion 109 of the light emitting element 108 through ohmic contact by annealing. The electrode 109B formed on the substrate 101 side is electrically connected to a wiring portion 118 formed from the substrate to the side wall surface of the hole 117A. A wiring portion 115 formed on the protective film 116 is electrically connected to the electrode 109A formed so as to face the electrode 109B with the photoelectric conversion film 110 interposed therebetween.

  In this manner, the photoelectric conversion element mounting method and wiring method can be used with various modifications and changes.

  In Examples 1 to 6, the case where a substantially cylindrical photoelectric conversion element is mainly used as the light receiving and emitting part of the optical functional element has been described as an example, but the shape of the photoelectric conversion element is not limited to this. Absent. For example, as shown in FIGS. 8A and 8B, a photoelectric conversion element having a housing shape can be used. In the first to sixth embodiments, the traveling direction of the signal light emitted from the light emitting element and the signal light incident on the light receiving portion is relative to the upper surface of the substrate, that is, the surface on which the element is formed on the substrate. It was a substantially vertical direction, that is, a direction away from or closer to the substrate. In the case of the present embodiment, the traveling direction of signal light such as emitted or incident light is substantially parallel to the surface on which the element on the substrate is formed.

  FIGS. 8A and 8B schematically show the structure of the light receiving and emitting unit according to Example 7 of the present invention, FIG. 8A is a plan view, and FIG. ) Is a sectional view taken along the line DD in FIG. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIGS. 8A and 8B, a channel-shaped hole 120 is formed in the substrate 101, and a housing-shaped photoelectric conversion element 108 ′ is mounted in the hole 120. . The photoelectric conversion element 108 'is composed of, for example, a surface emitting laser or a waveguide type light receiving element. In the case of the present embodiment, the photoelectric conversion element 108 ′ is used as a light emitting element or a light receiving element as needed.

  The photoelectric conversion element 108 ′ has a structure including a photoelectric conversion film 110 ′ and a joint 109 ′ made of a black reflecting mirror (DBR) formed so as to hold the photoelectric conversion film 110 ′. The photoelectric conversion film 110 ′ takes the form of a quantum well, a strained quantum well, a quantum wire, or a quantum box, and recombines electron hole pairs generated by current application to emit light having a frequency corresponding to the band gap. For example, as shown in the figure, the signal light L1 ′ is obtained. In the case where the photoelectric conversion element is used as a light receiving element, an electron hole is generated when light enters, a current is generated, and the incident signal light L2 'can be detected.

  In this embodiment, the photoelectric conversion element 108 'is embedded in the hole 120, and a protective film 121 made of an insulating film is formed so as to cover the photoelectric conversion element 108'. A wiring part 122 formed on the protective film 121 is electrically connected to the joint part 109 ′ of the element 108 ′. A wiring portion 123 is formed on the back surface of the substrate 101 (the surface on which no element is formed). By connecting the wiring portions in this way, power is supplied to the photoelectric conversion element 108 ′, and the structure is controlled by being connected to the control element.

  In the case of the present embodiment, the functions of the light receiving element and the light emitting element can be realized by the same element depending on the voltage application direction. That is, since the element having the same structure can be used as a light receiving / emitting element capable of receiving and emitting light, the functions of the light receiving element and the light emitting element can be properly used as necessary. Such control is performed by a control element formed on the substrate 101.

  In addition, a light emitting / receiving element made of different materials may be used depending on required sensitivity and operation speed. In addition, with the configuration of this embodiment, a waveguide type light receiving element can be used as the light receiving element, and the sensitivity is higher than that of the conventional surface light receiving element, and a higher speed response is possible. For example, 10 Gbps It can be used for the above large-capacity and high-speed optical communication. The structure used in this example is suitable for embedding an edge emitting laser or a waveguide type light receiving element in a hole such as a side wall surface of a substrate.

  The hole 120 can be configured by conventional photolithography and dry etching, and the width of the hole is preferably 10 μm or less and the depth of the hole is preferably 1 to 10 μm. The width of the hole is more preferably formed so that the current confinement structure can be used effectively corresponding to the width in which the transverse mode becomes the single mode.

Further, the hole 120 can be formed by wet etching. In the case of wet etching, a V-shaped hole can be formed by anisotropic etching.
When mounting a light emitting element in the hole formed in this way, it is preferable to mount a surface emitting laser having a circular structure rather than an edge emitting laser. That is, in the case of this embodiment, since the light resonance direction is preferably parallel to the substrate, an edge emitting laser is suitable.

  As described above, the structure in which the photoelectric conversion element of the light emitting / receiving unit is formed so that the substrate and the signal light (incident light or emitted light) are substantially parallel to the substrate is not limited to the present embodiment. Modification / change is possible, and a modification of the present embodiment is shown in the eighth embodiment.

  Next, FIGS. 9A and 9B are schematic diagrams illustrating a configuration example of the light emitting and receiving unit according to the eighth embodiment of the present invention, which is a modification of the seventh embodiment illustrated in FIGS. 8A and 8B. Indicate. FIG. 9A schematically shows a cross-sectional view of the light emitting / receiving portion, and FIG. 9B is a cross-sectional view taken along the line CC in FIG. 9A. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

Referring to FIGS. 9A and 9B, the substrate 101 is provided with a stepped shape, and an optical waveguide including a light emitting element 108, a core portion 124, and a cladding portion 125 (on the substrate 101). Optical fiber) 123 is mounted. The optical waveguide 124 can be configured by depositing quartz or glass on a substrate or by depositing an organic optical material.
The step shape is formed so that the signal light emitted from the emission end 109 </ b> A of the light emitting element 108 is substantially parallel to the core portion 409 of the optical waveguide 408.

  Further, as shown in FIG. 9B, a groove-like hole 126 formed so that the cross section is V-shaped is formed on the surface of the substrate 101 on which the light emitting element 108 is installed. The light emitting element 108 is mounted so that the inner wall surface of the hole 126 and the light emitting element 108 are in contact with each other.

  The hole 126 is processed into a V shape by anisotropic etching by wet etching. Specifically, the substrate 101 is subjected to wet etching in multiple stages to form V-shaped grooves having different depths.

  In addition, wiring portions 121 and 122 are connected to the joint portion 109 of the light emitting element 108 so that power can be supplied to the light emitting element 108 and the control element formed on the substrate 101 can be electrically connected. The light emitting element 108 is controlled by the control element.

  When the structure of this embodiment is used, alignment can be performed with extremely high accuracy, so that a structure in which the light emitting element or the light receiving element and the optical axis of the signal light in the optical waveguide are accurately combined can be achieved. That is, the light emitting element or the light receiving element and the optical waveguide can be coupled with high efficiency.

  Next, as Example 9 of the present invention, FIG. 10 is a cross-sectional view schematically showing the structure of the light receiving and emitting part. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  A hole is formed in the substrate 101 for mounting the light emitting element 108, and the light emitting element 108 is mounted on the bottom surface of the hole so as to be embedded in the hole.

  The light emitting element 108 is mounted such that the signal light emitted from the light emitting element 108 and the bottom surface of the hole portion are substantially parallel. A protective film 132 made of an insulating film is formed in the hole so as to cover the light emitting element 108 so as to fix and protect the light emitting element 108 and for insulation.

  Electrodes 109A and 109B in which ohmic contacts are formed are formed on the light emitting element 108, and are connected to the wiring parts 133 and 134, respectively. It has become a structure.

  The side wall surface of the hole is formed obliquely with respect to the bottom surface. The side wall surface made of Si or the wiring portions 133 and 134 formed on the side wall surface functions as an optical deflector 135 that deflects the signal light emitted from the light emitting element 108.

  For example, when using the side wall surface with the Si substrate exposed as the optical deflector 135, it is preferable to form the side wall surface by, for example, anisotropic etching of Si. Since the surface formed by anisotropic etching is smooth at the atomic layer level, light can be reflected with high reflectivity due to this smoothness. Further, the side wall surface may be formed by dicing or oblique dry etching. In order to improve the reflectance of the side wall surface, a surface to which a metal or a multilayer film is attached may be used. Although metal deposition or plating can be used to attach the metal, metal deposition is preferred for forming a smooth surface.

  The reflectance of the signal light on the side wall surface depends on the metal material and the wavelength of the light. For example, at a wavelength of 850 nm, it can be inferred that the reflectance is 95% or more when a silver, gold, or copper film is used on the side wall surface, and the reflectance is 80% or more when an aluminum film is used. Thus, it is possible to select a reflective film according to a use and cost.

  Further, when the wiring parts 133 and 134 are used as the signal light optical deflector 135, a sufficient reflectance can be obtained by using a metal such as silver, gold, copper or aluminum for the wiring part. It becomes.

  The protective film 132 is preferably an optical material that is transparent to the signal wavelength. For example, when a polymer material is used, epoxy is used for a wavelength of 850 nm and fluorine is used for a wavelength of 1.3 μm. It is preferable to use fluorinated polyimide.

  Thus, in this embodiment, by providing the optical deflector 135 in the light emitting direction, the light traveling direction can be changed from substantially parallel to substantially perpendicular to the substrate surface (bottom surface of the hole). .

  Next, FIGS. 11A and 11B schematically show the configuration of the light emitting and receiving unit according to the fifth embodiment of the present invention. FIG. 11A is a plan view, and FIG. 11B is an xx cross-sectional view in FIG. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  In this embodiment, an example of a structure in which a pad for connecting to an external wiring is formed on a substrate 101 on which a photoelectric conversion element is formed is shown.

  Referring to FIGS. 11A and 11B, a hole 141 is formed in the substrate 101 so that the light emitting element 108 is embedded therein, and further, the light emitting element 108 is covered. A protective film 141 is formed so as to be filled, and a protective film 142 is formed on the substrate 101.

  The protective film 142 and the adhesive layer 143 may be made of different materials or may be made of the same material. For example, the protective film 142 or the adhesive layer 143 can be made of an organic material such as polyimide, benzocyclobutene (BCB), or epoxy, or an inorganic material.

  A wiring portion 146 is formed on the bottom surface of the hole portion, and the wiring portion 146 is electrically connected to a pad 145 formed on the substrate 101 via a bottom surface of a groove portion formed on the substrate 101. It has a structure.

  On the bottom surface of the hole portion, an electrode 109B having an ohmic contact with the light emitting element 108 is electrically connected on the wiring portion 146. On the side of the light emitting element 108 facing the electrode 109B, the electrode 109A is similarly placed in ohmic contact and is electrically connected to the wiring portion 144.

  Further, the tenth embodiment can be modified as shown in FIG. FIG. 12 is a diagram schematically showing a cross section of a light receiving and emitting part of Example 12 according to the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 12, in this embodiment, a so-called SOI (Silicon-on-Insulator) substrate is used to reduce the stray capacitance of the circuit. For this reason, it is possible to reduce the stray capacitance caused by the substrate and, for example, increase the operating speed of the MOS transistor used as a control element formed on the substrate, thereby realizing a higher-speed optical functional element. Become.

  Specifically, an insulating layer 147 is formed on the substrate 101, and the Si layer 101A is formed on the insulating layer, for example, by crystal growth or by bonding, and used as a substrate for forming a light emitting / receiving portion. ing.

  In this case, since the Si layer 101A is insulated from the substrate 101 by the insulating layer 147, if a hole is formed so as to penetrate the insulating layer 147, it is possible to electrically separate the upper and lower sides.

  Next, FIG. 13 shows a cross-sectional view schematically showing the structure of the light emitting and receiving part of Example 12 according to the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 12, a hole 151 is provided in the substrate 101, and a photoelectric conversion element such as a light emitting element 108 is mounted so as to be embedded in the hole 151. A protective film 153 made of an insulating film is formed from the hole portion 151 to the surface of the substrate 101 for the purpose of insulating the wiring portion and holding and protecting the photoelectric conversion element.

  A wiring part 154 is formed on the protective film 153 and is electrically connected to the light emitting element 108. A wiring part 155 is formed on the back surface of the substrate 101. The wiring part 155 is configured to be electrically connected to the light emitting element 108 via a semiconductor fusion part 152 between the light emitting element 108 and the bottom surface of the hole 151.

  Power is supplied to the light emitting layer 108 through the wiring portions 154 and 155, and the light emitting element 108 is controlled by a control element formed on the substrate 101.

  The semiconductor fusion part 152 is bonded to the bonding part 109 and the substrate 101. Semiconductor fusion is a technique for joining dissimilar semiconductors that are difficult to grow by epitaxial growth due to lattice mismatch.

  The semiconductor fusion is performed as follows. First, both the first semiconductor and the second semiconductor to be bonded are subjected to surface treatment to remove the natural oxide film, and oxygen is occupied by the first semiconductor and the second semiconductor from which the oxide film has been removed. A hydroxyl group is attached to the covalently bonded moiety by solution treatment. Next, by bonding the first semiconductor and the second semiconductor after the treatment, they are bonded by van der Waals force through hydrogen bonds of their acid groups. Furthermore, when hydrogen is poured into the bonding surface while heating, the hydroxyl group is removed as water vapor, and a semiconductor bonding surface is formed.

This method is sometimes referred to as Wafer Fusion, and may be used, for example, when performing heterogeneous semiconductor bonding with a semiconductor laser.
By using this method, the present invention does not use a metal surface at the interface between a photoelectric conversion element made of a direct transition type semiconductor and a semiconductor substrate made of Si or SiGe, and conducts at the fusion surface of two different types of semiconductors. Making it possible.

  According to this embodiment, the wiring structure can be simplified, and the structure of the optical functional element can be simplified, and the manufacturing cost of the optical functional element can be reduced. In addition, if the back surface is an n-side electrode, sufficient electrical connection can be obtained even when the thickness of the substrate is increased by using electrons with high mobility.

  Further, in Example 2 shown in FIGS. 3A and 3B, a case where a MOS transistor is used as a control element for controlling the photoelectric conversion element is shown, but the present invention is not limited to this. is not. Moreover, the installation location and structure of the control element and the photoelectric conversion element on the substrate 101, or the wiring method can be changed or modified as necessary.

  For example, as Example 13 of the present invention, FIG. 14 shows an example in which a light emitting / receiving unit having a photoelectric conversion element and a control unit are arranged on the substrate 101. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 14, a wiring part 164 is formed on the substrate 101, and a protective film 161 made of an insulating film is formed on the wiring part 164. The hole 161A formed in the protective film 161 is installed so that the light emitting element 108 is inserted therein, and is electrically connected to the wiring portion 164. Further, a wiring part 163 that is electrically connected to the light emitting element 108 is formed on the protective film 161.

  Further, the control unit 25 having the control element 165 to which the wiring units 166 and 167 are connected is formed on the substrate 101 so as to be adjacent to the photoelectric conversion element formed in the light emitting / receiving unit 22. Yes. The control element 165 is an element that is connected to, for example, a photoelectric conversion element and drives and controls the photoelectric conversion element and amplifies a signal.

  Further, the light emitting / receiving unit and the control unit, that is, the photoelectric conversion element and the control element are not limited to the structure formed adjacent to each other as described above. For example, control is performed so as to be surrounded by a plurality of formed photoelectric conversion elements. It is also possible to form an element on the substrate so that photoelectric conversion elements and control elements are interspersed on the substrate, that is, a plurality of light emitting / receiving units and a plurality of control units are mixed. Various modifications and changes can be made depending on the design of the optical functional element.

  With such a configuration, it is possible to integrate a direct transition type photoelectric conversion element and an indirect transition type control element with a simple structure, and to reduce the manufacturing cost. An element can be realized.

  In addition, the photoelectric conversion element and the control element are not limited to a single layer structure, and may have a multilayer structure such as a two-layer structure or a three-layer structure.

  Next, an example in which the photoelectric conversion elements of the light emitting and receiving unit are formed in multiple layers is shown in FIG. FIG. 15 is a cross-sectional view schematically showing the configuration of the light receiving and emitting unit in Example 14 according to the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 15, a protective film 171 made of an insulating film is formed on the substrate, and a protective film 172 is further formed on the protective film 171. The light emitting element 108 is mounted in the protective film 171 and in the protective film 172. Wiring portions 173 and 174 are electrically connected to the light emitting element 108 mounted in the protective film 171, and wiring portions 175 and 176 are electrically connected to the light emitting element 108 mounted in the protective film 172, respectively. Thus, power can be supplied to the light emitting elements, and the light emitting elements mounted in multiple layers can be individually controlled by the control elements.

  In this manner, the photoelectric conversion elements can be further integrated by forming the photoelectric conversion elements in multiple layers. Moreover, it is preferable that the photoelectric conversion elements formed in multiple layers are mounted so as not to block each other's signal light.

  Further, for example, a through hole 178 may be formed in the protective film so as not to block received or emitted signal light. The material of the protective film is preferably a material that is transparent with respect to the wavelength of the light used for the signal light. In that case, the through hole is unnecessary. The material is an organic or inorganic material. For example, if the wavelength of the signal light is 850 nm, it is preferable to use a material such as epoxy.

  Since the wiring portion generally uses metal, it is necessary to have a wiring structure that does not cover the light emitting portion (light receiving portion). However, the wiring portion has a line width of 1 μm or less, or a photoelectric conversion element. In particular, when a surface emitting laser is used as the light emitting element, considering that the light emission surface is about 20 μm, the presence of the wiring portion in the emission portion does not cause a large loss.

  Next, an example of the electrical connection method between the photoelectric conversion element and the wiring portion and a detailed example of the mounting method will be described with reference to FIGS. The connection method and the mounting method described in this figure can be modified and changed as necessary for the cases shown in the first to fourteenth embodiments. FIG. 16A is a cross-sectional view schematically showing a state where the photoelectric conversion element is mounted, and FIG. 16B is a cross-sectional view taken along line AA of FIG. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIGS. 16A and 16B, the substrate 101 is provided with a substantially cylindrical hole, and a photoelectric conversion element such as the substantially cylindrical light emitting element 108 is formed on the bottom surface of the hole. Is implemented. The light emitting element 108 is mounted on the bottom surface of the hole through, for example, a metallic electrode 201A.

  The electrode 201A is electrically connected to the light emitting element 108 by annealing. In addition, on the side of the light emitting element 108 facing the electrode 201A, an electrode 201B made of metal and electrically connected to the light emitting element 108 is provided in the same manner as the electrode 201A. The electrode 201B has, for example, a ring shape so as not to completely block the emission part of the light emitting element.

A protective film 207 made of an insulating film such as SiO ₂ is provided so as to cover the side wall surface of the hole 101B and the surface on the substrate 101, and a wiring portion made of Cu, for example, is formed on the protective film 207. 204 is provided. A substantially ring-shaped gap between the wiring portion 204 and the light emitting element 108 is filled with a protective film 208 made of an insulating material. The protective film 208 is also formed on the wiring portion 204, and the protective film 208 is further formed. On the top, a wiring portion 205 made of, for example, Cu is formed.

  Wiring portions 204 and 205 are electrically connected to the light emitting element 108 to supply power, and the light emitting element is controlled by a control element connected to the wiring portion.

  Specifically, the wiring portions 204 and 205 are electrically connected to the electrodes 201A and 201B of the light emitting element 108, respectively. In this case, for example, the connection between the electrode 201A and the wiring 204, and the connection between the electrode 201B and the wiring 205 is made by connecting portions 202A and 202B made of metal, which are formed by electroplating, respectively.

  According to the present embodiment, it is possible to realize an optical functional element that is excellent in high-frequency characteristics and excellent in positioning as an optical wiring. In addition, since the photoelectric conversion element to be mounted has a structure in which a gap is provided without being in close contact with the side wall surface of the hole or the wiring part formed on the side wall surface, It is possible to improve the reliability of the optical functional element by reducing the stress applied to the light emitting element due to the temperature rise.

  The protective film 208 has an effect of insulating the wiring portion 204 and the wiring portion 205 and holding the light emitting element 108 to prevent displacement. Further, since the protective film 208 filled in the gap between the wiring portion 204 and the light emitting element 108 has a ring shape, an impact or stress is applied to the impact or stress from the periphery of the light emitting element 108. Regardless of the direction, the effect of reducing damage is obtained. The protective film 208 is preferably made of a polymer material such as polyimide.

  Although the case where the photoelectric conversion element is mounted on the substrate to form the optical functional element has been described so far, the present invention is not limited to this. For example, by mounting a photoelectric conversion element made of a direct transition semiconductor in an optical waveguide having a core part and a cladding part, an optical functional element that is smaller and simpler in shape than a conventional optical functional element can be obtained. It can be realized.

  FIGS. 17A to 17C are diagrams showing an example of an optical functional element formed by embedding a photoelectric conversion element in an optical waveguide, and FIG. 17A schematically shows the optical functional element. FIG. 17A is a cross-sectional view when a light-emitting element is used as a photoelectric conversion element, and FIG. 17C is a cross-sectional view when a light-receiving element is used as a photoelectric conversion element. . However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 17A, the optical functional element 300 includes a substantially cylindrical optical waveguide 301 and a photoelectric conversion element mounted on the optical waveguide 301, for example, the light emitting element 108. The optical waveguide 301 is made of, for example, a quartz material and has a core portion 302 and a cladding portion 303.

  The end portion of the optical waveguide 301, that is, the end portion of the clad portion 302 is provided with an installation portion 304, which is a substantially cylindrical hole, for mounting the light emitting device 108. It is mounted so as to be embedded in the installation unit 304. As described above, in this embodiment, the light emitting element is mounted so as to be embedded in the installation portion 304 that is formed in the optical waveguide, for example, a substantially cylindrical hole portion. Can be miniaturized.

  Further, for example, the cylindrical diameter D1 of the light emitting element is about 30 μm, and the diameter of the substantially cylindrical core portion is about 5 to 10 μm in the single mode and about 50 to 62.5 μm in the multimode, The diameter D2 is about 125 μm.

  Conventionally, since it has been necessary to integrate a light emitting / receiving section including a photoelectric conversion element formed on a substrate with an optical waveguide, it has been difficult to highly integrate and downsize an optical functional element including the optical waveguide. According to the present embodiment, it is possible to reduce the size of the optical functional element by mounting the photoelectric conversion element made of a direct transition type semiconductor so as to be embedded in the optical waveguide. Even when mounting or when a plurality of optical waveguides are formed, it is possible to configure the optical functional element without increasing its size, that is, to achieve high integration of the optical functional element.

  FIG. 17B is a cross-sectional view of the optical functional element shown in FIG. Referring to FIG. 17B, the emission surface of the signal portion of the light emitting element 108 is installed so as to face the core portion, and the surface of the light emitting element that faces the emission surface is on the substrate 305. Has been implemented. The substrate 305 is made of an indirect transition type semiconductor such as Si or SiGe, and the control element 308 of the light emitting element is formed thereon.

  A wiring portion 306 that is electrically connected to the light emitting element 108 is formed on the inner wall surface of the installation portion 304, and wiring that is electrically connected to the light emitting element 108 is formed on the substrate 305. The unit 307 is connected to supply power to the light emitting element, and the control element 308 and the light emitting element 108 are electrically connected, and the light emitting element is controlled by the control element.

  Conventionally, it is necessary to integrate an optical waveguide and an optical functional element formed on a chip having different light receiving and emitting portions and control portions as shown in FIG. According to this embodiment, since the light emitting element and the control element can be mounted on the same substrate, it is possible to reduce the size and increase the integration when mounting the control element on the optical functional element. Yes.

  FIG. 17C illustrates a modification example of the optical functional element illustrated in FIG. In the case shown in this figure, a light receiving element 311 is used instead of the light emitting element 108 as the photoelectric conversion element. A wiring portion 312 that is electrically connected to the light receiving element 311 is formed on the inner wall surface of the installation portion 304, and wiring that is electrically connected to the light receiving element 311 is formed on the substrate 305. The unit 312 is connected to supply power to the light receiving element, and the light receiving element is controlled by the control element 308.

  Even when a light receiving element is used as the photoelectric conversion element, the same effects as when the light emitting element is used as the photoelectric conversion element are obtained.

  Next, an example of packaging the optical functional device 300 shown in Embodiment 16 is shown in FIG. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 18, the optical functional element 300 and the substrate 305 are connected to a substantially cylindrical block 320, and a part of the block 320 is housed in a substantially cylindrical connection portion 322 of the connector 330. In this way, it is connected.

  The block 320 has power supply electrodes 322A and 322B formed on a cylindrical side wall portion. In addition, a plurality of electrode pin insertion holes 323 for connecting signal lines are formed. The connector 330 has a plurality of electrode pins 323 to be inserted into the electrode pin insertion holes 323.

  The communication of the operation signal requires two signal lines in the case of unidirectional communication. For example, in the case of two-way communication in which the light emitting element and the light receiving element are combined and mounted, the signal line 4 are required.

  Also, in this case, by using the end face of the optical waveguide for electrical connection, it is possible to perform both optical transmission and electrical transmission with the same size (thickness) as a conventional optical transmission connector. In comparison, it is possible to realize a small-sized micro optical connector.

  In addition, by arranging the optical waveguide and the connector, it is possible to perform high-bandwidth optical transmission in a space-saving manner.

  Next, a method for producing the photoelectric conversion element described in Example 1 to Example 17, mounting the photoelectric conversion element on a substrate, and manufacturing an optical functional element will be described below with reference to FIGS. .

  FIGS. 19A to 19G are diagrams schematically showing a method of manufacturing an optical functional element according to Example 18 of the present invention, following the procedure.

  In this embodiment, a light emitting layer, which is a photoelectric conversion film made of a direct transition type semiconductor such as AlGaAs, GaInNAs, GaInPAs, or GaInN, is grown on a substrate such as GaAs, InP, or GaN by epitaxial growth. A light emitting element is formed, and the photoelectric conversion element is mounted on a Si substrate.

  First, in the step shown in FIG. 19A, an etch stop layer 405 is formed on a substrate 401 made of GaAs, and n-GaAs is formed on the etch stop layer 405 by, for example, MOCVD (metal organic chemical vapor deposition). A bonding layer 403A made of / AlAs and serving as a black reflecting mirror (DBR) is formed.

  On the bonding layer 403A, a photoelectric conversion film 402 made of, for example, GaInAs / GaAs, which becomes a light emitting layer, is formed by crystal growth. On the photoelectric conversion film 402, a bonding layer 403B made of p-GaAs / AlAs and serving as a black reflecting mirror (DBR) is formed. Furthermore, a current confinement layer having an AlAs oxide film structure may be formed for lowering the threshold and improving the light emission efficiency.

  On the bonding layer 403B, an electrode 406 made of, for example, Au / Zn / Au for connecting the wiring portion may be formed by vapor deposition. (See FIG. 19B).

  Next, in the step shown in FIG. 19B, the shape of the light-emitting element having a size (diameter) of 50 μm or less by a dry or wet etching method using a mask formed by lithography or electron beam exposure is used. Patterning is performed to form a light emitting element 404 including the bonding portion 403A, the photoelectric conversion film 402, and the bonding portion 403B, to which the electrode 406 is attached.

  Next, in a step shown in FIG. 19C, a protective film 407 is formed by applying, for example, a liquid organic material by a spin coating method so as to cover the light emitting element 404.

  Next, in the step shown in FIG. 19D, the light emitting element 404 is separated from the substrate 401 by, for example, wet etching. In this case, it is preferable to separate the substrate 401 and the light emitting element 404 by providing an etching layer in advance between the substrate 401 and the light emitting element and removing the etching layer by wet etching. Further, the method of separating the substrate 401 from the light emitting element 404 may be performed by removing the substrate 401 by CMP (chemical mechanical polishing), for example.

  Further, an ion slicing method may be used as a method of separating the light emitting element 404 and the substrate 401. In the ion slicing method, for example, ions are implanted into the interface between the light-emitting element 404 and the substrate 401, and the light-emitting element and the substrate are heated, whereby the ion-implanted portion, ie, the interface between the light-emitting element 404 and the substrate 401 In this method, the light emitting element and the substrate are separated by cutting the nearby bond.

  Specifically, before the step illustrated in FIG. 19A, ions are implanted into the substrate 401 in advance using an ion implantation apparatus, and the light emitting element 404 and the substrate 401 are separated by heating in this step. To do.

  Next, the protective film 407 is cut to form a protective film 407 including a desired number of light emitting elements 404 in order to mount a required number of light emitting elements formed on the substrate.

  Next, in the step shown in FIG. 19E, for example, the protective film 407 is dry-etched with oxygen plasma so that the issuing element 404 protrudes partially on the side facing the substrate 401. To.

  Next, in the step shown in FIG. 19F, the light emitting element is mounted in the hole 408A of the substrate 408 made of, for example, Si. A wiring portion may be formed in advance on the substrate. Further, a control element for controlling the light emitting element may be formed on the substrate 408 in advance, and the control element may be formed after mounting the light emitting element. A method for forming the control element will be described later.

  Next, in the step shown in FIG. 19G, the protective film 407 is etched by, for example, oxygen plasma dry etching so that a part of the electrode 406 is exposed. Further, a wiring portion 410 is formed on the insulating layer 407 so as to be in contact with the electrode 406, and the electrode and the wiring portion are electrically connected.

  Further, a wiring portion 409 is formed on the back surface (the side where no element is formed) of the substrate 408. The wiring portion 409 may be formed on the substrate in advance before mounting the light emitting element. A layer made of AuGe may be formed between the substrate 408 and the wiring portion 409, for example, as an n-side electrode. Further, as the material of the wiring portions 409 and 410, for example, Au, Cu, Al or the like can be used.

  As shown in this embodiment, it is preferable to use a relatively inexpensive Si or SiGe that can constitute the control element of the photoelectric conversion element. The control element may be formed in advance by the semiconductor manufacturing process, or the control element may be formed after the light emitting element is mounted.

  In the present embodiment, an example is shown in which a photoelectric conversion element mainly made of a direct transition type semiconductor is separated and mounted on a Si or SiGe substrate. However, for example, a control element made of a direct transition type semiconductor is separated from the direct transition type semiconductor substrate. It is also possible to mount on an indirect transition type semiconductor substrate such as Si or SiGe.

  For example, when forming a control element that requires high-speed operation, it is formed by crystal growth using a direct transition semiconductor substrate such as GaAs, and the formed control element is described in this embodiment. It is possible to mount on a substrate such as Si or SiGe using the method. In this case, high-speed operation of the control unit is realized, and the optical functional element can be miniaturized and highly integrated.

  Further, in this embodiment, since the photoelectric conversion element can be mounted on the substrate by, for example, mechanical manipulation, there is an effect that the photoelectric conversion element can be mounted with high accuracy.

  Moreover, the manufacturing method of an optical functional element is not limited to a present Example. Although the modification of a present Example is shown as Examples 19-24 below, there exists an effect similar to a present Example in any case.

  In FIG. 20, the manufacturing method of the optical functional element by Example 19 of this invention is demonstrated according to a procedure based on FIG. 20 (A)-(E). However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  First, the steps shown in FIGS. 19A to 19B are performed to obtain the state shown in FIG. That is, the process shown in FIG. 20A is the same as the process shown in FIG.

  Next, in a step shown in FIG. 20B, a dummy substrate 412 is attached over the protective film 407, and the substrate 401 is removed by CMP while holding the dummy substrate 412, and the light emitting element 404 is removed. Is separated from the substrate 401. Further, the light emitting element 404 and the substrate 401 may be separated by wet etching. When wet etching is used, it is preferable to epitaxially grow an etch stop layer having high etching selectivity on the substrate. The ion slicing method may be used for separating the substrate and the light emitting element.

  Next, in the step illustrated in FIG. 20C, the protective film 407 including the light-emitting elements 404 is cut so that a necessary number of the light-emitting elements 404 are included, and the cut protective films 407 are removed using a solvent. The light emitting element 404 is separated from the protective film 407 by being melted by 413.

  Next, the solvent 414 containing the separated light-emitting element 404 is dropped on a substrate 408 made of Si in which the hole 408A is formed, and the substrate 408 is vibrated, whereby the light-emitting element 404 is placed in the hole 408A. Fill.

  Next, in a step shown in FIG. 20E, after the solvent is evaporated, a protective film 407 ′ is formed so as to cover the light emitting element 404. Next, in the same manner as in FIG. 19G, the wiring portions 409 and 410 are electrically connected to the light-emitting element 404 to form an optical functional element.

  In the case of this embodiment, the direction in which the light emitting element 404 is mounted at the time of mounting may be opposite to the time when the light emitting element 404 is formed. It is desirable to have a vertically symmetric structure across 402.

  Next, FIGS. 21A to 21F show a method for manufacturing an optical functional element according to Example 20 of the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  First, the steps shown in FIGS. 19A to 19B of Example 18 are performed to obtain the state shown in FIG. 21A that is the same as the state shown in FIG.

  Next, in a step shown in FIG. 21B, a protective film 423 made of, for example, polyimide is formed so as to cover the periphery of the light emitting element 404. In the case of forming the protective film 423, the protective film 423 is formed so that a part of the light emitting element protrudes from the protective film 423.

  Next, in the step shown in FIG. 21C, the substrate 401 is inverted, and the surface of the electrode 406 and the substrate 408 bonded to the electrode 406 is activated by sputtering in a vacuum processing container. The electrode 406 and the substrate 408 are brought into close contact with each other to perform room temperature bonding, and the light emitting element 404 is transferred from the substrate 401 to the substrate 408.

  Next, in the step shown in FIG. 21D, the substrate 401 is removed by CMP, for example, and the light-emitting element 404 is separated from the substrate 401 to obtain the state shown in FIG.

In this case, it is possible to separate the substrate 401 and the light emitting element 404 by providing an etching layer in advance between the substrate 401 and the light emitting element and removing the etching layer by wet etching. In the step shown in FIG. 21E, the protective film 423 may be removed, but may be used as it is as the protective film of the light-emitting element. The protective film 423 can be removed by using HF when the protective film 423 is SiO ₂ . In the case where an organic polymer such as an epoxy resin is used for the protective film 423, it can be removed with a mixed solution of sulfuric acid and nitric acid or sulfuric acid and hydrofluoric acid.

  Further, when the light emitting element 404 is mounted on the substrate 401, if a hole is provided in the substrate, an effect of improving the positioning accuracy of the light emitting element is obtained.

  Next, in the step illustrated in FIG. 21F, the wiring portion is electrically connected to the light-emitting element in the same manner as in the case illustrated in FIG. That is, a protective film 407 ′ is formed so as to cover the light emitting element 404, and the wiring portions 409 and 410 are electrically connected to the light emitting element 404 to form an optical functional element.

  According to this embodiment, transfer between substrates of light emitting elements can be performed more easily using different types of substrates.

  Next, FIGS. 22A to 22C show a method for manufacturing an optical functional element according to Example 21 of the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  First, the substrate 401 is bonded onto the substrate 431 in the step shown in FIG. In this case, bonding can be performed by room temperature bonding, fusion bonding, cathode bonding, or adhesive bonding.

  Next, in the step shown in FIG. 24B, the substrate 401 is polished by CMP, for example, so that a thin film layer of GaAs, for example, is formed on the substrate 431.

  Next, in the same manner as the process shown in FIGS. 19A to 19B of Example 18, the light emitting element 404 and the electrode 406 are formed on the thin film layer, and the state shown in FIG. And In FIG. 22C, GaAs is not shown in the thin film layer.

  Next, an optical functional element is formed by performing the same processing as in FIGS. In this case, the substrate 401 in the steps of FIGS. 21B to 21F corresponds to the substrate 431 of this embodiment.

  In this embodiment, since the substrate 401 and the substrate 431 are bonded, for example, it is easy to form an etching layer on the bonding surface in advance before bonding. Therefore, when the formed light emitting element is separated from the substrate, the substrate and the light emitting element can be easily separated by wet etching. In addition, it is preferable to form a separation layer between the substrate 401 and the substrate 431 because the transfer of the light-emitting element is facilitated.

  Next, FIGS. 23A to 23F show a method for manufacturing an optical functional element according to Example 22 of the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  In this embodiment, a process for transferring a light emitting element from a substrate to another substrate is added by the same method as that in Embodiment 20.

First, the step shown in FIG. 23A is the same as the state shown in FIG. 21A. Next, in the step shown in FIG. 23B, the steps shown in FIGS. In the same manner as in the process, the light-emitting element 404 formed over the substrate 401 is transferred to the substrate 440 which is a dummy substrate, so that the state shown in FIG.

  Next, in the step shown in FIG. 23D, similarly to the step shown in FIG. 23B, the light emitting element 404 transferred onto the substrate 440 is further transferred onto the substrate 408, The state shown in FIG.

  Next, in the state shown in FIG. 23F, an optical functional element is formed in the same manner as the step shown in FIG.

  In the case of this embodiment, as a result of the light-emitting element being transferred twice, in the process of FIG. 23F, when the light-emitting element 404 is mounted on the substrate 408, the same process as the process of forming the light-emitting element is performed. It is in the direction. For this reason, for example, as compared with the case of FIG. 21F described in the first embodiment 20, there is an effect that the state of the light emission surface is good. This is because the light emission surface does not become an etching or polishing surface, that is, the surface system and crystal state of the emission surface are good, and the threshold value is lowered.

  In addition, when the light emitting element is transferred after the light emission state is inspected in the state of FIG. 23A, the final light emission surface is the same as the state of FIG. Therefore, the probability of occurrence of light emission defects due to transfer becomes very low. Therefore, the inspection process is shortened and the yield of the product is improved, so that the manufacturing cost can be suppressed.

  Next, FIGS. 24A to 24E show a method for manufacturing an optical functional element according to Example 23 of the present invention. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  In the case of the present embodiment, the number of times that the light emitting element is transferred from one substrate to another is three.

  First, the steps shown in FIGS. 23A to 23C are performed, a light emitting element is formed over the substrate 401, the light emitting element is transferred onto the substrate 440, and then the step shown in FIG. 24A is performed. .

  In the step shown in FIG. 24A, the light emitting element 440 transferred onto the substrate 440 is further transferred onto the substrate 450. However, on the substrate 450, a patterning sheet including a close contact portion 451A which is a portion having a strong contact force with the light emitting element 404 and a non-contact portion 451B having a weak contact force is pasted. Therefore, when the light emitting element 404 is transferred, only the light emitting element 404 pressed by the contact portion 451A is selectively transferred as shown in FIG.

  Next, in the step shown in FIG. 24C, the light emitting element 404 transferred to the patterning sheet 451 on the substrate 450 is transferred to the substrate 408, and the state shown in FIG. And

  In the step illustrated in FIG. 24E, the light-emitting element and the wiring portion are electrically joined to form an optical functional element in a manner similar to the process illustrated in FIG.

  According to this embodiment, when mounting light emitting elements, it is possible to easily control the interval between the mounted light emitting elements.

  In addition, the direct transition type substrate for forming the photoelectric conversion element is expensive, and it takes time and cost to form the photoelectric conversion element. In this embodiment, the photoelectric conversion elements are formed at a high density. In addition, it is possible to reduce the manufacturing cost by effectively using the direct transition type substrate, reducing the wasted area, and further improving the productivity of the photoelectric conversion element. In this case, even if the photoelectric conversion elements are formed at a high density, the mounting interval, that is, the mounting pattern can be easily controlled as necessary.

  For this reason, it becomes possible to provide electrical wiring between the photoelectric conversion elements by optimizing the mounting interval, and to form a mounting pattern in consideration of the cooling efficiency of the photoelectric conversion elements. Reliability is improved.

  FIGS. 25A and 25B are plan views comparing the conventional photoelectric conversion element and the photoelectric conversion element according to the present invention, and FIG. 25A shows a state in which the photoelectric conversion element of the conventional optical functional element is mounted. (B) shows a state in which the photoelectric conversion element of the optical functional element according to the present invention is mounted.

  Referring to FIG. 25A, conventionally, for example, a substantially cylindrical photoelectric conversion element having a diameter of about 20 μm is formed on a substrate 501 made of a substantially square direct transition semiconductor having a side length H1 of about 300 μm. 502 is formed, and one or two electrode pads each having a side of about 50 to 120 μm are provided on the substrate 501.

  As described above, conventionally, the ratio of the electrode pad to the substrate is larger than that of the photoelectric conversion element, and when the photoelectric conversion element is manufactured, it is necessary to consider the area of the electrode pad. There was a limitation on the number of possible photoelectric conversion elements.

  In this embodiment, since the photoelectric conversion element formed on the direct transition substrate is mounted on a substrate made of, for example, Si or SiGe, the area of the electrode pad shown in FIG. Therefore, the number of photoelectric conversion elements that can be formed from a direct transition type semiconductor substrate can be increased.

  For example, as shown in FIG. 25B, it is possible to form, for example, about 25 photoelectric conversion elements 505 having a substantially cylindrical diameter of about 20 μm from the substrate 501, and in this embodiment, compared to the conventional method. The productivity is approximately 25 times higher.

  Moreover, the photoelectric conversion element produced in this way can freely control and change the mounting pattern, for example, by adopting the method as shown in Example 23.

  Next, with respect to the manufacturing method of the optical functional element shown in FIG. 16 in Example 15, specifically, the electrical connection method between the photoelectric conversion element and the wiring section and the mounting details, FIGS. ) Will be explained step by step. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

First, in the step shown in FIG. 26A, a hole 101a having a diameter of 50 μm is provided in the substrate 101 by a method such as dry etching or wet etching, and the side wall surface of the hole 101a and the hole of the substrate 101 are provided. A protective film 207 made of, for example, SiO ₂ is formed so as to cover the surface where no part is formed.

  Next, a wiring portion 204 made of, for example, Cu is formed so as to cover the protective film 207. The bottom surface 101b of the hole 101a is dried by dropping a hydrophilic material onto the Si surface as a base treatment.

  Next, in a step shown in FIG. 26B, a photoelectric conversion element, for example, the light emitting element 108 having a substantially cylindrical shape is mounted. In this case, for example, an electrode 201A is formed between the joint 109 and the bottom surface 101b, and an ohmic contact by, for example, annealing is established to ensure electrical connection between the electrode 201A and the joint 109. It is preferable to keep it.

  Next, in the step shown in FIG. 26C, the substrate and the light emitting element are immersed in an electroless plating bath, and the portion subjected to the hydrophilic treatment, that is, the portion where the bottom surface 101b is exposed is electrolessly plated by electroplating. A connecting portion 202A made of the above is formed, and the electrode 201A and the wiring portion 207 are reliably electrically connected.

  Next, in a step shown in FIG. 26D, a substantially ring-shaped gap between the wiring portion 204 and the light emitting element 108 is formed with a protective material 206 made of an insulating material, for example, a polymer material such as polyimide. Fill body. Further, a wiring portion 205 made of Cu, for example, is formed on the protective material 206.

  Further, it is preferable that an electrode 201B made of metal, which is electrically connected to the light emitting element 108 in the same manner as the electrode 201A, is provided on the side of the light emitting element 108 facing the electrode 201A. The electrode 201B has a ring shape so as not to completely block the emission part of the light emitting element.

  Next, in the step shown in FIG. 26E, as in the case shown in FIG. 26C, a connection portion 202B made of electroless copper is formed by electroplating, and the electrode 201B and the wiring portion are formed. 205 is securely connected electrically. In the case where electroplating is not used, a method of directly electrically connecting the wiring portion 205 and the electrode 201B may be used.

  Further, the method of forming the connection portion is not limited to the above method, and for example, electroless plating, electroforming, vapor deposition, sputtering, copper foil coating, or the like may be used alone or in combination. However, when electroless plating or electroforming is used, bonding is performed with a high filling rate and low resistance between the narrow gaps filled with photoelectric conversion elements in the small diameter holes provided in the Si substrate. Since it is possible to form a part, it is suitable. Furthermore, electroless plating is preferable because a thick film can be applied to a portion subjected to hydrophilic treatment. However, since electroless plating has problems in uniformity, film strength, and time required for plating, it is more preferable to form the joint by a method combined with electrolytic plating in which these do not cause a problem.

  In addition, silicon patterning and copper and insulator patterns are compared using conventional methods such as vapor deposition, sputtering, CVD, resist coating, photolithography, wet etching, dry etching, lift-off, etc. Can be formed easily. Also, if there are materials that are damaged by these processes, it is effective to mask them in advance.

  Next, a method for forming the control element of the control unit shown in FIG. 3B according to the second embodiment will be described step by step based on FIGS. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  First, an element isolation insulating film 112 is formed on the substrate 101 made of Si to create an element formation region, and then an impurity is diffused in the element formation region. Next, after forming the gate insulating film 114A and the gate electrode on the gate insulating film, impurity implantation and diffusion are performed to form diffusion layers 115A and 115B.

  Next, in the step shown in FIG. 27B, an insulating film 116 is formed so as to cover the gate electrode 114 and the side wall insulating films 113A and 113B, and a protective film is formed on the insulating film 116 as necessary. 117 is formed.

  A contact hole leading to the diffusion layer 115B is formed in the insulating film 116 and the protective film 117 by dry etching, and a barrier film 118 is formed on the inner wall of the contact hole by, for example, sputtering or CVD (chemical vapor deposition). To do. Further, a contact plug 119 made of W (tungsten) is buried in the contact hole in which the barrier film 118 is formed, for example, by CVD. The contact plug 119 is electrically connected to the diffusion layer 115B through the barrier film 118.

Next, in a step shown in FIG. 27C, an insulating film 120 made of, for example, SiO ₂ is formed on the protective film 117, and a cap film 121 is formed on the inter-wiring insulating film 120.

  Next, a wiring groove is formed in the inter-wiring insulating film 110 and the cap film 121 by dry etching, a wiring portion 122 is formed in the wiring groove, and a barrier film 122a is formed so as to surround the wiring portion 122. The wiring portion 122 is configured to be electrically connected to the contact plug 119 through the barrier film 122a. The wiring part 122 is connected to the photoelectric conversion element of the optical functional element and has a structure for controlling the photoelectric conversion element.

  In this embodiment, an example in which a MOS transistor is formed is shown. However, the control element according to the present invention is not limited to this, and various other control elements such as an element for increasing the signal of the photoelectric conversion element are also available. Can be used.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the specific embodiments described above, and various modifications and changes can be made within the scope described in the claims.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the manufacturing method of the optical function element which can be highly integrated with a simple structure and highly integrated with the simple structure.

(A) is the figure which showed the conventional optical functional element typically, (B) is the figure which expanded a part of optical functional element of (A). FIG. 2 is a plan view schematically showing an optical functional element according to Example 1. (A) is the figure which showed typically the cross section of the light emitting / receiving part of the optical function element by Example 2, (B) is the figure which showed typically the cross section of the control part of an optical function element. 6 is a diagram schematically showing a cross section of an optical functional device according to Example 3. FIG. FIG. 6 is a diagram schematically showing a cross section of an optical functional element according to Example 4. (A) is the top view of the optical functional element by Example 5, (B) is the figure which showed typically the cross section of the optical functional element of (A). FIG. 10 is a diagram schematically showing a cross section of an optical functional device according to Example 6. (A) is a top view of the optical functional element by Example 7, (B) is the figure which showed typically the cross section of the optical functional element of (A). (A) is the figure which showed typically the cross section of the optical functional element by Example 8, (B) is a partial expanded sectional view of the optical functional element of (A). 10 is a diagram schematically showing a cross section of an optical functional device according to Example 9. FIG. (A) is the top view of the optical functional element by Example 10, (B) is the figure which showed typically the cross section of the optical functional element of (A). It is the figure which showed typically the cross section of the optical functional element by Example 11. FIG. It is the figure which showed typically the cross section of the optical functional element by Example 12. FIG. It is the figure which showed typically the cross section of the optical functional element by Example 13. FIG. It is the figure which showed typically the cross section of the optical functional element by Example 14. FIG. (A) is the figure which showed typically the cross section of the optical functional element by Example 15, (B) is a top view of the optical functional element of (A). (A) is the perspective view which showed typically the optical functional element by Example 16, (B) is sectional drawing of the optical functional element of (A), (C) is the optical functional element of (B). It is sectional drawing which shows the modified example. It is the figure which showed typically the packaging method of the optical function element of FIG. 17 (A). (A)-(G) is the figure which showed the manufacturing method of the optical functional element by Example 18 later on in order. (A)-(E) are the figures which showed the manufacturing method of the optical functional element by Example 19 later on in order. (A)-(F) is the figure which followed the procedure for the manufacturing method of the optical functional element by Example 20. (A)-(C) are the figures which showed the manufacturing method of the optical functional element by Example 21 later on in the procedure. (A)-(F) is the figure which followed the procedure for the manufacturing method of the optical functional element by Example 22. (A)-(E) is the figure which followed the procedure for the manufacturing method of the optical functional element by Example 23. (A) is the figure which showed the state by which the photoelectric conversion element was mounted in the board | substrate with the conventional optical function element, (B) is the state with the photoelectric conversion element mounted in the board | substrate with the optical function element by this invention FIG. (A)-(E) is the figure which showed the manufacturing method of the optical function element by Example 25 later on in order. (A)-(C) is the figure which followed the procedure for the manufacturing method of the control part of an optical functional element.

Explanation of symbols

10, 20, 300 Optical functional element 10A, 10B Chip 10a, 22 Light emitting / receiving unit 10b, 25 Control unit 2, 23, 502, 505 Photoelectric conversion element 3, 24 wiring unit 4 Pad 5 Wire 101, 401, 408, 431 440, 450 Substrate 102, 311 Light receiving element 108, 108 ′, 404 Light emitting element 103, 109, 109 ′, 403A, 403B Junction 104, 110, 110 ′ Photoelectric conversion film 105, 106, 111, 112, 113, 112A, 112B, 115, 118, 121, 122, 122, 123, 133, 134, 144, 146, 154, 155, 163, 164, 166, 167, 172, 173, 175, 176, 204, 205, 306, 307, 312, 409, 410 Wiring part 107 Protective film 112 Element isolation insulation 113A, 113B Side wall insulating film 114 Gate electrode 114A Gate insulating film 115A, 115B Diffusion layer 116, 120 Insulating layer 107, 117, 121, 132, 141, 142, 153, 161, 170, 171, 207, 208, 407, 407 ', 423 Protective film 118, 122a Barrier film 119 Contact plug 122 Wiring part 108A, 102A, 114, 117, 117A, 120, 126, 131 Hole part 109A, 109B, 201A, 201B Electrode 123, 301 Optical waveguide 124, 302 Core Part 125, 303 Clad part 135 Polarizer 145 Pad 165 Control element 320 Block 322A, 322B Electrode 323 Electrode pin insertion hole 330 Connector 331 Electrode pin

Claims (30)

A substrate made of Si or SiGe;
An optical functional element comprising a photoelectric conversion element mounted on the substrate,
The photoelectric conversion element is made of a direct transition type semiconductor.   The optical functional element according to claim 1, wherein the photoelectric conversion element is a light receiving element or a light emitting element.   The optical functional element according to claim 1, wherein the photoelectric conversion element is a light receiving and emitting element that receives and emits light.   The optical functional element according to claim 2, wherein a plurality of the photoelectric conversion elements are mounted on the substrate, and the plurality of photoelectric conversion elements include the light receiving element and the light emitting element.   The photoelectric conversion element is mounted so that an incident direction or an emission direction of signal light of the photoelectric conversion element is substantially perpendicular to a surface of the substrate on which the photoelectric conversion element is mounted. The optical functional element according to any one of 1 to 4.   The photoelectric conversion element is mounted such that an incident direction or an emission direction of signal light of the photoelectric conversion element is substantially parallel to a surface of the substrate on which the photoelectric conversion element is mounted. The optical functional element according to any one of 1 to 4.   The said photoelectric conversion element consists of light emitting elements, The polarizer which polarizes the direction of the emitted light from the said light emitting element was provided on the said board | substrate, The any one of Claims 1-4 characterized by the above-mentioned. Optical functional element.   The optical functional element according to claim 1, wherein a control element for controlling the photoelectric conversion element using a semiconductor constituting the substrate is formed on the substrate.   The wiring part electrically connected to the photoelectric conversion element is formed on the substrate, and the photoelectric conversion element and the control element are electrically connected via the wiring part. 9. The optical functional device according to 8.   The optical functional element according to claim 9, wherein a voltage is applied to the photoelectric conversion element through the wiring portion.   The optical functional element according to claim 1, wherein the photoelectric conversion element has a substantially cylindrical shape.   The optical functional element according to claim 1, wherein the photoelectric conversion element is mounted in a hole formed in the substrate.   The optical functional element according to claim 1, wherein the photoelectric conversion element is installed so as to be surrounded by an insulating material formed on the substrate.   The first layer in which the photoelectric conversion element is embedded and the second layer in which the photoelectric conversion element formed on the first layer is embedded are laminated. 14. The optical functional device according to claim 1.   15. The optical functional element according to claim 1, wherein the photoelectric conversion element includes a material selected from the group consisting of GaInAsP, AlGaInAs, GaInNAs, GaAsSb, GaInAs, and AlGaAs. An optical functional element having a photoelectric conversion element and an optical waveguide connected to the photoelectric conversion element,
The photoelectric conversion element is made of a direct transition type semiconductor, and the photoelectric conversion element is mounted so as to be embedded in the optical waveguide.   The optical functional element according to claim 16, wherein the photoelectric conversion element is a light receiving element or a light emitting element.   18. The optical functional element according to claim 16, wherein the photoelectric conversion element has a structure mounted on a substrate made of Si or SiGe.   A first surface formed on the photoelectric conversion element faces the optical waveguide, and a second surface of the photoelectric conversion element facing the first surface faces the substrate. The optical functional device according to any one of claims 16 to 18.   The optical functional element according to any one of claims 16 to 19, wherein a control element for controlling the photoelectric conversion element using a semiconductor constituting the substrate is formed on the substrate.   The optical functional element according to any one of claims 16 to 20, wherein the photoelectric conversion element has a substantially cylindrical shape. A method for producing an optical functional element, wherein a photoelectric conversion element made of a direct transition type semiconductor is mounted on a first substrate made of Si or SiGe,
A film forming step of forming a photoelectric conversion film by crystal growth on a second substrate made of a direct transition type semiconductor;
A patterning step of forming the photoelectric conversion element by etching the photoelectric conversion film;
A separation step of separating the photoelectric conversion element from the second substrate;
And a mounting step of mounting the photoelectric conversion element on the first substrate.   23. The method of manufacturing an optical functional element according to claim 22, wherein, in the second separation step, the photoelectric conversion element is separated from the second substrate by a wet etching process.   23. The optical functional element according to claim 22, wherein in the separation step, the photoelectric conversion element is separated from the second substrate by removing the second substrate by chemical mechanical polishing (CMP). Production method.   The mounting step includes mounting the photoelectric conversion element such that a side of the photoelectric conversion element facing the second substrate in the film formation step faces the first substrate. 25. The method for producing an optical functional element according to any one of Items 22 to 24.   In the mounting step, the photoelectric conversion element is mounted such that a side of the photoelectric conversion element facing a side facing the second substrate in the film formation step faces the first substrate. 25. The method for manufacturing an optical functional element according to any one of claims 22 to 24. After the patterning step, further provided a transfer step of mounting the photoelectric conversion element on a dummy substrate,
27. The method of manufacturing an optical functional element according to claim 22, wherein, in the mounting step, the photoelectric conversion element mounted on the dummy substrate is mounted on the first substrate. .   On the dummy substrate, by providing a patterning film on which a part of the photoelectric conversion elements of the plurality of photoelectric conversion elements is selectively mounted, the photoelectric conversion element mounted on the first substrate 28. The method of manufacturing an optical functional element according to claim 27, wherein the number is controlled.   The step of forming a control element for controlling the photoelectric conversion element using the semiconductor constituting the first substrate on the first substrate is further provided. The manufacturing method of the optical function element of any one of Claims 1. 30. The optical functional device according to claim 22, wherein the photoelectric conversion film contains a material selected from the group consisting of GaInAsP, AlGaInAs, GaInNAs, GaAsSb, GaInAs, and AlGaAs. Method.

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