JPH0567770A - Photoelectronic integrated circuit device - Google Patents

Abstract

PURPOSE:To provide an photoelectronic integrated circuit device with a structure easy to manufacture and a simple photo-coupling structure as well as an accurate and simplified power supply for each photoelectronic IC chip. CONSTITUTION:A plurality of projecting parts 6 for mounting photoelecrtrnoic IC chips 4 are provided in an optical wiring board 1. A slope 5 coated with a reflecting film 2 is formed at the surrounding side part of the projecting part 6. The slope 5 is formed corresponding to the location of a light emitting device 11 and a photodetector 12 in the photoelectronic IC chip 4 so that light emitted from the emitting device 11 is reflected by the slope 5 and is transmitted along an optical waveguide 3. Then, the light reflected by another slope 5 is incident on the photodetector 12 in the photoelectronic IC chip 4. In this case, the slope 5 has a reflecting film 2 without an additional manufacturing step that a special angle shape is added for total reflection. Moreover, the reflecting film 2 functions as an interconnection for power supply.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optoelectronic integrated circuit device in which a plurality of optoelectronic integrated circuits each including an electronic circuit, a light emitting element and a light receiving element are optically coupled.

[0002]

2. Description of the Related Art In systems such as workstations and personal computers, demands for smaller size and higher performance have recently been increasing. One of the main components of these systems is semiconductor electronic circuit technology. However, if the pattern of metal wiring is miniaturized for high integration, the problem of transmission delay occurs, and further, there is a gap between wirings. When the space is narrowed, inductive noise, mutual interference, etc. become a problem.

Therefore, attention has been focused on a method in which transmission between electronic devices is performed by optical coupling regardless of electrical wiring. As an example of a device for performing such optical coupling, Japanese Patent Application Laid-Open No. 6-58242
In Japanese Patent Laid-Open No. 1-112014, an optical wiring board is attached to a substrate on which a light receiving element and a light emitting element are formed, and V
An apparatus for forming a groove and an optical waveguide is disclosed. That is, the light from the light emitting element is reflected by the side surface of the V-shaped groove, propagates in the optical waveguide, and reaches the light receiving element.

[0004]

However, in the optical coupling technique described in the above publication, the optical wiring board itself is made of SiO ₂ . For the reflection of light on the side surface of the V-shaped groove, total reflection below the critical angle of SiO ₂ is used. Therefore, the shape of the V-shaped groove is limited, and the manufacturing process is complicated because the V-shaped groove is formed.

Further, when a large number of optoelectronic integrated circuit boards on which electronic circuits are formed for high integration are connected to an optical wiring board, electric power is supplied to each optoelectronic integrated circuit board for the purpose of supplying a power supply voltage or the like. However, when the electrical wiring is performed by wire bonding, the wiring of the wire is complicated, and a problem such as a short circuit newly occurs.

In view of the above-mentioned technical problems, the present invention provides an optoelectronic integrated circuit device which is a device for performing optical coupling between substrates and which has a structure suitable for mass production from the manufacturing process thereof. The purpose of 1. A second object of the present invention is to provide an optoelectronic integrated circuit device having a structure that is advantageous for wiring power supplies between substrates.

[0007]

In order to achieve the above-mentioned first object, an optoelectronic integrated circuit device of the present invention comprises an optoelectronic integrated circuit substrate on which an electronic circuit, a light emitting element and a light receiving element are formed, and the light emitting element. The element and the light receiving element have an inclined surface, and a continuous optical waveguide is provided on the inclined surface, and a reflective film for reflecting light for optical coupling between the substrates is formed on the inclined surface. An optical wiring board is provided.

The optoelectronic integrated circuit substrate has a structure in which an electronic circuit, a light emitting element, and a light receiving element are formed on the substrate, and the light emitting element and the light receiving element are arranged on the peripheral side of the substrate so that the electronic circuit section is formed. Can be arranged in the central portion of the substrate, and the optical wiring substrate can be attached at the central portion. Also,
The optoelectronic integrated circuit substrate itself may have a three-dimensional structure in which a plurality of substrates are laminated in a direction perpendicular to the main surface, or the light for optical coupling may be light having a wavelength that passes through the optoelectronic integrated circuit substrate.

The optical wiring board is a substrate on which the inclined surface and the optical waveguide are formed, and the light emitting direction and the light receiving direction of the light emitting element and the light receiving element are perpendicular to the main surface, and the optical wiring board is By setting the inclined surface at 45 ° with respect to the main surface of the substrate,
The optical waveguide is directed in the main surface of the substrate. A silicon substrate or the like is used as such an optical wiring substrate, but the optical wiring substrate is not particularly limited thereto.

A film of metal or the like is formed as a reflective film on the inclined surface, and the light of the optical coupling is reflected by the reflective film. In order to achieve the second object, the reflective film can be made conductive so that it also serves as a wiring. When both the wiring and the reflection film are used, a part of the reflection film deposited on the entire surface can be patterned in a portion of the electronic circuit or in another region to be used as a wiring such as a power line.

[0011]

On the inclined surface of the optical wiring board, the light from the light emitting element is reflected to reach the optical waveguide, or the light from the optical waveguide is reflected on the inclined surface to reach the light receiving element. Since the reflecting film is formed on this inclined surface, total reflection is possible by the reflecting film, and the angle of the inclined surface may be, for example, 45 ° with respect to the waveguide along the main surface of the substrate. become.

For each optoelectronic integrated circuit board,
Electrical wiring is required for power supply etc.,
In the present invention, the reflective film is made conductive so that it can also serve as a wiring. Therefore, new wiring for supplying power is unnecessary.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the drawings.

[First Embodiment] FIG. 1 is a perspective view of an optoelectronic integrated circuit device according to the present embodiment. A plurality of optoelectronic IC chips 4 are arranged and mounted on the surface of the flat optical wiring board 1, and a waveguide 3 is formed between the plurality of optoelectronic IC chips 4.

The optical wiring substrate 1 is obtained by processing the surface of a silicon substrate by a method described later, and has a plurality of convex protrusions formed in a substantially square shape corresponding to the region where the optoelectronic IC chip 4 is to be arranged. The portion 6 is formed on the surface of the substrate. The circumference of each convex portion 6 is an inclined surface 5 that rises at an angle of 45 ° from the main surface of the substrate. A reflection film 2 is formed on the entire surface of the optical wiring board 1 to have a required film thickness, and the inclined surface 5 is formed.
The surface of is also covered with the reflective film 2. A silicon oxide film 7 is formed on the surface of the optical wiring substrate 1 other than the convex portions 6, and the optical waveguide 3 is formed between the convex portions 6 which is a part of the silicon oxide film 7. ..

The reflection film 2 is an aluminum, gold or other metal film, and the reflectance of the inclined surface 5 is remarkably enhanced by metal reflection. Since the reflective film 2 is a metal film, it has excellent conductivity, and in this embodiment,
In particular, it functions as a wiring for supplying power to the optoelectronic IC chip 4.

The optical waveguide 3 serves as an optical path for optical transmission between the convex portions 6, and since the optical waveguide 3 is formed on the silicon oxide film 7 deposited on the surface of the optical wiring board 1, the optical path is formed on the substrate. It will be along the main surface. Between the pair of optoelectronic IC chips 4, a plurality of optical waveguides 3 are continuously provided between one inclined surface 5 and another inclined surface 5 for bidirectional transmission and different signal transmission. Be done. Each optical waveguide 3 used for optical coupling of the pair of optoelectronic IC chips 4 extends in parallel, and a high refractive index portion 8 having a high refractive index is provided between the optical waveguides 3. The high refractive index portion 8 is formed by ion implantation of protons or the like.

The optoelectronic IC chip 4 is a substantially square semiconductor chip, has an electronic circuit section 10 composed of a semiconductor integrated circuit in the center of one main surface thereof, and emits light around the electronic circuit section 10. It is a hybrid substrate of an optical element and an electronic element having an element 11 and a light receiving element 12. The electronic circuit section 10 is
It is an integrated circuit portion such as a drive circuit for the light emitting element 11 and the light receiving element 12, a signal processing circuit, an arithmetic processing circuit, and a memory.
At the time of mounting, in this embodiment, the element forming surface of the optoelectronic IC chip 4 faces the optical wiring substrate 1 side, and the electronic circuit section 10 is mounted so as to contact the convex section 6. The light emitting element 11 of the optoelectronic IC chip 4 emits light in a direction perpendicular to the main surface of the chip, and similarly, the light receiving element 12 is sensitive to a light beam in a direction perpendicular to the main surface of the chip. .. The positions of the light emitting element 11 and the light receiving element 12 are peripheral areas near the ends of each optoelectronic IC chip 4, and the positions thereof are positions corresponding to the inclined surface 5 of the optical wiring board 1.

FIG. 2 is a diagram showing a state of optical coupling between the optoelectronic IC chips 4. In each optoelectronic IC chip 4 mounted on the convex portion 6 of the optical wiring board 1, the light receiving element 12 and the light emitting element 11 are located on the inclined surface 5. The inclined surface 5 has the reflection film 2 formed thereon and is processed at 45 ° to function as a reflection mirror. Therefore, the light beam emitted from the light emitting element 11 perpendicularly to the main surface of the chip is reflected by the inclined surface 5 and is guided to the optical waveguide 3. The light from the optical waveguide 3 is reflected by the inclined surface 5 to be a light beam perpendicular to the main surface and is received by the light receiving element 12.

Since the reflective film 2 also functions as a conductive film and is used for supplying power to each optoelectronic IC chip 4, it is patterned to have a required wiring pattern. In addition, the optoelectronic IC chip 4 is connected to a power supply terminal of the chip. The power supply line, the ground line, and the like using the reflective film 2 can be shared by the respective optoelectronic IC chips 4, which is extremely effective when the number of chips is large.

In the optoelectronic integrated circuit device of this embodiment as described above, the optical coupling between the optoelectronic IC chips 4 is performed by the optical wiring substrate 1 having the inclined surface 5 covered by the reflection film 2, and therefore mutual interference by light is caused. Signal transmission without signal distortion is performed. Further, the structure of the inclined surface 5 for totally reflecting the incident light is a structure in which the reflection film 2 is covered, and is obtained by the steps described below.

Further, since the reflection film 2 also functions as a wiring for supplying power, when the number of the optoelectronic IC chips 4 increases, the wiring structure becomes effective.

Next, an example of a method of manufacturing the optoelectronic integrated circuit device of this embodiment will be described with reference to FIGS.

First, as shown in FIG. 6, the silicon substrate 2
1 is processed to form a convex portion 23 with an inclined surface 22 on the surface of the silicon substrate 21. The formation of the convex portion 23 is performed by using anisotropic etching such as dry etching, and the inclined surface 22 is processed so as to form an angle of 45 ° with the main surface. Then, the reflective film 24 is deposited on the entire surface of the silicon substrate 21 on which the convex portions 23 are formed. Reflective film 2
When 4 is an aluminum film, it can be formed by vapor deposition or the like.

After forming the reflection film 24 on the silicon substrate 21, the reflection film 24 is formed by photolithography.
Is patterned into a required power supply pattern.

Next, as shown in FIG. 7, the silicon substrate 2
A silicon oxide film 25 is formed as a material layer for forming a waveguide on the entire surface of 1 by, for example, the CVD method. The film thickness of the silicon oxide film 25 is such that the concave portions between the convex portions 23 are sufficiently filled.

After the silicon oxide film 25 is formed thick, the film thickness of the silicon oxide film 25 is reduced by mechanical polishing or the like, and the silicon oxide film 25 is ground to the extent that the upper surface of the convex portion 23 is exposed as shown in FIG. .. When the silicon oxide film 25 is shaved to the extent that the reflection film 24 on the convex portion 23 is not exposed, a contact hole for power supply is formed in the convex portion 23.

Next, as shown in FIG. 9, protons are injected into the silicon oxide film 25 to form a high refractive index layer. The pattern of the high refractive index layer is a pattern for forming parallel waveguides, and ions are implanted by using a resist or the like (not shown) as a mask.

After the optical waveguide is formed on the silicon oxide film 25, as shown in FIG. 10, the optoelectronic IC chip 26 on which the light receiving element, the light emitting element and the electronic circuit section are already formed is placed on each convex portion 23. It At this time, the power supply terminal of the optoelectronic IC chip 26 is connected to the reflection film 24, and the light receiving element and the light emitting element of the optoelectronic IC chip 26 are placed on the inclined surface 22.

[Second Embodiment] This embodiment is a modification of the first embodiment, and the optical wiring board 31 of the present embodiment is similar to the first embodiment in that the inclined surface 39 is provided around the periphery. The projection 33 is provided on the surface, and the reflective film 32 is formed on the surface of the inclined surface 39. The optical waveguide 3 is provided in the concave portion around the convex portion 33.
8 is formed.

The optoelectronic IC chip 34 has one main surface 34.
Although the light receiving element 37, the light emitting element 36, and the electronic circuit section 35 are formed in a, in the present embodiment, the wavelength of the light used for the optical coupling is the light of the wavelength that passes through the optoelectronic IC chip 34. Therefore, the light generated by the light emitting element 36 is the photoelectron I
The light passes through the C chip 34, is reflected by the reflection film 32 on the inclined surface 39, and goes toward the optical waveguide 38. Further, the light from the optical waveguide 38 is reflected by the reflection film 32 of the inclined surface 39, and then the optoelectronic IC
The light passes through the chip 34 and is received by the light receiving element 37.

In such optical coupling by the light transmitted through the optoelectronic IC chip 34, the integrated circuit such as the electronic circuit section 35 can be mounted without being on the optical wiring board 31 side.
Further, it is possible to perform quality inspection for each optoelectronic IC chip 34 from the one main surface 34a side while using a probe or the like. Further, by forming a microlens on the back surface of the optoelectronic IC chip 34, the light input / output efficiency can be increased.

[Third Embodiment] This embodiment is based on an optoelectronic IC.
This is an example in which the chip is three-dimensionalized. The structure of the main part is shown in FIG.
Shown in. Similar to the second embodiment, the optical wiring board 31 of the present embodiment has the convex portion 33 having the inclined surface 39 on the periphery, and the reflective film 32 is formed on the surface of the inclined surface 39. There is. An optical waveguide 38 is formed in the concave portion around the convex portion 33.

The optoelectronic IC chip 41 is composed of substrates 42, 43 and 44 which are vertically laminated on three principal surfaces, and the light receiving element 45 is formed on the uppermost substrate 44, and the light emitting element 4 is formed.
6 is formed on the intermediate substrate 43. The positions of the light receiving element 45 and the light emitting element 46 are positions that overlap with the inclined surface 39 of the optical wiring board 31 in plan view, but the light from the light emitting element 46 passes through the substrate 42 of the lowermost layer and the inclined surface 39. The light that reaches the bottom and is received by the light receiving element 45 is
And the intermediate substrate 43.

In the case where the optoelectronic IC chips 41 are laminated in this way, the wiring path is greatly shortened and the wiring delay can be reduced. In this embodiment, the photoelectron I
Although the C chip has a structure in which three substrates are laminated, the present invention is not limited to this, and may be a structure in which two or more substrates are laminated or other types of substrates are combined and laminated. It is also possible. Further, a structure may be adopted in which a plurality of light receiving elements or light emitting elements are formed so as to overlap in the main surface direction of the substrate so as to be multiplexed.

[Fourth Embodiment] This embodiment is an example in which optical coupling is performed in the same optoelectronic IC chip. As shown in the cross section of FIG. 5, in the optoelectronic integrated circuit device of the present embodiment, an optical waveguide 59 for optical coupling inside one optoelectronic IC chip 55 is formed on the surface of the optical wiring board 51. A convex portion 53 is formed on the surface of the optical wiring board 51.
The end of 3 becomes an inclined surface 54 covered with the reflective film 52.
In the cross section of FIG. 5, the optical waveguide 59 between the pair of convex portions 53 is shown.
Is dedicated to the optoelectronic IC chip 55 and is not used for optical transmission with other optoelectronic IC chips. The other optical waveguide 58 is used for optical coupling with another optoelectronic IC chip as in the other embodiments. In the optoelectronic IC chip 55, a light emitting element 57 and a light receiving element 56 for optical coupling with another optoelectronic IC chip are formed, and further, a light emitting element 57i and a light receiving element 56i for optical coupling in the chip are formed. ..
These light emitting elements 57 and 57i and light receiving elements 56 and 56i
Needless to say, each is formed at a position where it overlaps the inclined surface 54 in plan view.

In the case of using the optoelectronic IC chip 55 and the optical wiring board 51 having such a structure, signal transmission in the optoelectronic IC chip 55 can be performed by light, and transmission distortion and mutual interference peculiar to electric wiring can be achieved. It will be possible to solve the problem of.

[0038]

In the optoelectronic integrated circuit device of the present invention, optical coupling between optoelectronic integrated circuit substrates is performed by an optical wiring board having an inclined surface coated with a reflection film, and therefore mutual interference and signal distortion due to light occur. No signal transmission is done. Further, the structure of the inclined surface for totally reflecting the incident light is a structure in which a reflective film is coated, and total reflection is possible without requiring a special angle, etc., and the manufacturing process thereof is also simplified. ..

Further, in the present invention, since the reflective film also functions as a wiring for supplying power, wire bonding or the like for each optoelectronic integrated circuit board becomes unnecessary, which is effective when the number of optoelectronic integrated circuit boards increases. It has a wiring structure.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing the structure of an example of an optoelectronic integrated circuit device of the present invention, showing a part of an optoelectronic IC chip while disassembling it.

FIG. 2 is a sectional view taken along an optical transmission line of an example of the optoelectronic integrated circuit device.

FIG. 3 is a sectional view of a key portion showing an optoelectronic integrated circuit device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a key portion showing an optoelectronic integrated circuit device according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a principal part of an optoelectronic integrated circuit device according to a fourth embodiment of the present invention.

FIG. 6 is a process sectional view up to a substrate processing process in a manufacturing method of an example of the optoelectronic integrated circuit device of the present invention.

FIG. 7 is a process cross-sectional view up to the silicon oxide film forming process in the manufacturing method of the example of the optoelectronic integrated circuit device of the present invention.

FIG. 8 is a process sectional view up to a polishing process in a manufacturing method of an example of the optoelectronic integrated circuit device of the present invention.

FIG. 9 is a process cross-sectional view up to the ion implantation process in the manufacturing method of the example of the optoelectronic integrated circuit device of the present invention.

FIG. 10 is a process cross-sectional view up to a step of mounting an optoelectronic IC chip in a manufacturing method of an example of the optoelectronic integrated circuit device of the present invention.

[Explanation of symbols]

 1, 31, 51 ... Optical wiring substrate 2, 32, 52 ... Reflective film 3, 38, 58, 59 ... Optical waveguide 4, 34, 41, 55 ... Optoelectronic IC chip 5, 39, 54 ... Inclined surface 6, 33, 53 ... Convex part 7 ... Silicon oxide film 10 ... Electronic circuit part 11, 36, 46, 57, 57i ... Light emitting element 12, 37, 45, 56, 56i ... Light receiving element

Claims (2)

[Claims] 1. An optoelectronic integrated circuit substrate on which an electronic circuit, a light emitting element and a light receiving element are formed, an inclined surface facing at least the light emitting element or the light receiving element, and an optical waveguide continuous to the inclined surface. And an optical wiring board having a reflective film formed on the inclined surface for reflecting light for optical coupling between the optoelectronic integrated circuit boards. 2. The optoelectronic integrated circuit device according to claim 1, wherein the reflective film has conductivity and also serves as a wiring to the substrate.