JP4529194B2 - Optoelectronic integrated circuit device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optoelectronic integrated circuit device, and is particularly suitable for application to high-speed signal processing.
[0002]
[Prior art]
Conventionally, aluminum (Al) wiring has been used exclusively for wiring in a semiconductor integrated circuit device, and recently, copper (Cu) wiring with lower resistance has begun to be used. However, with these metal wirings, there is a limit to the speeding up and high integration of future semiconductor integrated circuit devices, and new wiring technology is required. One promising means for this is an optical wiring technique for exchanging signals by light.
[0003]
Conventionally, as a device using such an optical wiring, a device in which a modularized optical component (including a light emitting element or a light receiving element) is mounted on a substrate is the most common.
[0004]
[Problems to be solved by the invention]
However, the conventional apparatus using the optical wiring has a problem that it is difficult to reduce the size and the high integration because it is difficult to reduce the size of the modularized optical component.
[0005]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optoelectronic integrated circuit device that can be miniaturized, highly integrated and increased in speed.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an optoelectronic integrated circuit device according to the first invention of the present invention comprises:
A plurality of circuit blocks are formed monolithically on the substrate,
Signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and transmission of signals inside each circuit block of the plurality of circuit blocks is performed through wiring made of a conductor.
It is characterized by this.
[0007]
An optoelectronic integrated circuit device according to a second aspect of the present invention is:
A plurality of circuit blocks are formed monolithically on the substrate, signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and each of the circuit blocks in the plurality of circuit blocks The signal transmission is an optoelectronic integrated circuit device that is performed through a wiring made of a conductor,
An optical switch monolithically formed on a substrate is provided between at least two circuit blocks.
It is characterized by this.
[0008]
An optoelectronic integrated circuit device according to a third aspect of the present invention comprises:
A plurality of circuit blocks are formed monolithically on the substrate, signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and each of the circuit blocks in the plurality of circuit blocks The signal transmission is an optoelectronic integrated circuit device that is performed through a wiring made of a conductor,
At least two circuit blocks are connected monolithically on the substrate by a linear optical transmission line for signal transmission by light, and monolithically on the substrate in the middle of the optical transmission line With formed optical switch
It is characterized by this.
[0009]
An optoelectronic integrated circuit device according to a fourth aspect of the present invention comprises:
A plurality of circuit blocks are formed monolithically on the substrate, signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and each of the circuit blocks in the plurality of circuit blocks The signal transmission is an optoelectronic integrated circuit device that is performed through a wiring made of a conductor,
At least two circuit blocks are connected to each other by a linear optical transmission line that is monolithically formed on a substrate and is used to transmit a signal by light, and at least one circuit of at least two circuit blocks. An optical switch monolithically formed on the substrate is provided between the block and the optical transmission line.
It is characterized by this.
[0010]
In the present invention, at least two circuit blocks that perform mutual signal transmission by light have light emitting elements and / or light receiving elements. The area between the at least two circuit blocks is optionally made of vacuum, air or an optically transparent material, typically a dielectric. The signal transmission by light between the at least two circuit blocks may be performed by a single signal, may be performed by a bus-type multiplexed signal, and further by a holographic signal (holographic signal). May be. When a bus type multiplexed signal or holographic signal is used, more signals can be transmitted.
[0011]
In the present invention, each circuit block of the plurality of circuit blocks typically includes at least one electronic element, for example, a transistor. As this electronic element, one using an elemental semiconductor such as silicon or one using a compound semiconductor such as GaAs can be used, and these electronic elements may be mixed. Further, Al, Cu, or the like can be used as a conductor that is a material for wiring for transmitting signals inside each circuit block.
[0012]
In the present invention, as a substrate on which a plurality of circuit blocks are formed monolithically, a compound semiconductor substrate such as a silicon substrate or a GaAs substrate, an SOI (Silicon on Insulator) substrate, an insulating substrate, or the like can be used.
[0013]
In some cases, in addition to a plurality of circuit blocks monolithically formed on the substrate, one or a plurality of modularized components may be mounted on the substrate.
[0014]
In the second, third and fourth inventions of the present invention, basically any optical switch may be used as long as it can be formed monolithically on a substrate. The one having a switching speed corresponding to is selected. Specifically, as this optical switch, for example, an optical switch using an electric field effect such as an optical switch using a liquid crystal or an electro-optic crystal (for example, Optical Volume 21 No. 8 (August 1992) p. 510), semiconductor-based optical switches (for example, Optical Volume 21 No. 8 (August 1992) p.527), organic thin films (derivatives having a special molecular structure in squarylium (SQ) dyes) The optical switch used (for example, Nikkan Kogyo Shimbun, July 13, 1998) can be used.
[0015]
In the third and fourth aspects of the present invention, as the material for the optical transmission line, an optical material having a small optical signal propagation loss is used. Specifically, for example, an organic material such as an organic resin resist is used. Alternatively, an inorganic material such as silicon oxide or silicon nitride is used. This optical transmission line is typically formed in a state where the lower part is buried in a groove formed on the surface of the substrate. The cross-sectional shape of the optical transmission line is preferably substantially circular from the viewpoint of efficient optical signal transmission, but may be other shapes such as an ellipse or a rectangle.
[0016]
In the first, second, third and fourth inventions of the present invention configured as described above, signals between circuit blocks are transmitted by transmitting signals between at least two circuit blocks by light. Unlike the case where transmission is performed by an electrical signal through a metal wiring, signal delay or signal loss due to parasitic capacitance or parasitic resistance can be eliminated. In addition, since signal transmission between at least two circuit blocks is performed by light, high-speed signal processing and high information density can be achieved. In addition, these circuit blocks are monolithically formed on the substrate by a film forming technique, an etching technique, an impurity doping technique, etc., so that the apparatus is compared with a case where modularized optical components are mounted on the substrate. Can be miniaturized and highly integrated. Furthermore, wiring used for signal transmission inside each circuit block can be easily formed by a conventional established wiring technique.
[0017]
In the second, third and fourth inventions of the present invention, an optical switch is provided between the circuit blocks, in the middle of the optical transmission line connected between the circuit blocks, or between the circuit block and the optical transmission line. Thus, using this optical switch, it is possible to easily select an optical signal transmitted between circuit blocks, and to increase the density of information. In addition, since this optical switch is monolithically formed on the substrate, the device can be made smaller and more integrated than a case where a modularized optical switch is mounted on the substrate.
[0018]
In the third and fourth aspects of the present invention, a linear optical transmission path for transmitting a signal between at least two circuit blocks by light is formed monolithically on the substrate together with the circuit block. As a result, it is possible to reliably transmit an optical signal between circuit blocks through the optical transmission path with high reliability, and to achieve downsizing and high integration of the apparatus.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings of the embodiments, the same or corresponding parts are denoted by the same reference numerals.
[0020]
FIG. 1 shows an optoelectronic integrated circuit device according to a first embodiment of the present invention.
[0021]
As shown in FIG. 1, in the optoelectronic integrated circuit device according to the first embodiment, a plurality of circuit blocks A are formed on a silicon substrate 1.₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂Are formed monolithically using a process technique such as a film formation technique, an etching technique, and an impurity doping technique. These circuit blocks A₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂,..., And the function of each circuit block are determined in accordance with what functions the optoelectronic integrated circuit device has. For example, when the optoelectronic integrated circuit device has a function of performing a specific signal processing, a circuit necessary for the signal processing is included in these circuit blocks A.₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂,... Are configured by a part or all of. In each circuit block, electronic elements such as transistors are connected by metal wiring (not shown) made of Al, Cu, or the like according to a required function. In contrast, signal transmission between circuit blocks adjacent to each other is performed by light. Specifically, each circuit block has a light receiving element and / or a light emitting element in addition to an electronic element such as a transistor, and can receive an optical signal from an adjacent circuit block or can be connected to an adjacent circuit block. An optical signal can be transmitted, or both. In this case, the optical signal received by the light receiving element is subjected to predetermined processing within the circuit block provided with the light receiving element. The light emitting element is driven by an output obtained as a result of signal processing in a circuit block provided with the light emitting element, and an optical signal is generated. The optical signal transmitted between the circuit blocks may be a single signal, a bus-type multiplexed signal, or a holographic signal, and these may be mixed.
[0022]
The integration scale of elements in each circuit block is selected according to a required function, but may be the same scale as a standard cell or a macro cell in a custom IC, for example.
[0023]
Next, a specific example of the structure of the light emitting / receiving unit of each circuit block will be described. Here, the circuit block A shown in FIG.₁, B₁The same applies to other circuit blocks.
[0024]
FIG. 2 shows a first example of the light emitting / receiving unit. As shown in FIG. 2, in this first example, circuit blocks A adjacent to each other.₁, B₁The light emitting / receiving section a having a light emitting element and / or a light receiving element on end faces facing each other substantially perpendicular to the substrate surface₁, B₁Is provided. Here, for example, a GaP light emitting diode is used as the light emitting element, and for example, a GaAs photodiode is used as the light receiving element. These light emitting / receiving portions a₁, B₁In between, the optical signal is exchanged in a direction parallel to the substrate surface.
[0025]
FIG. 3 shows a second example of the light emitting / receiving unit. As shown in FIG. 3, in this second example, circuit blocks A adjacent to each other.₁, B₁The end faces facing each other are inclined by, for example, 45 ° with respect to the substrate surface, and light emitting / receiving portions a having light emitting elements and / or light receiving elements on these end faces₁, B₁Is provided. As these light emitting elements and light receiving elements, the same elements as in the first example can be used. In this case, circuit block A₁, B₁An optical signal generated in the direction of 45 ° with respect to the substrate surface from the light emitting element of the light receiving and emitting unit of one circuit block is reflected by the reflecting mirror 2 arranged in parallel to the substrate surface, and the other circuit block The light is incident on the light receiving element of the light receiving and emitting unit from the direction of 45 ° with respect to the substrate surface and received.
[0026]
FIG. 4 shows a third example of the light emitting / receiving unit. As shown in FIG. 4, in this third example, circuit blocks A adjacent to each other.₁, B₁The light emitting / receiving section a having a light emitting element and / or a light receiving element on end faces facing each other substantially perpendicular to the substrate surface₁, B₁Is provided. As these light-emitting elements and light-receiving elements, those similar to those in the first example can be used, but as the light-emitting elements, surface-emitting type elements are used. In this case, circuit block A₁, B₁An optical signal is emitted in a direction perpendicular to the substrate surface from the light emitting element of the light receiving and emitting unit of one of the circuit blocks, and this optical signal is reflected by being inclined in a direction of 45 ° with respect to the substrate surface. The light is reflected by the mirrors 3 and 4 and is incident on the light receiving element of the other circuit block from the vertically upper side to be received by the light receiving element.
[0027]
A method of manufacturing the optoelectronic integrated circuit device according to the first embodiment will be described with reference to FIGS. Here, FIGS. 5 and 6 are cross-sectional views taken along line XX of FIG. First, as shown in FIG. 5, a circuit block layer 5 is formed on a silicon substrate 1 by a film forming technique, an etching technique, an impurity doping technique, or the like according to a normal LSI manufacturing process. Next, as shown in FIG. 6, the circuit block layer 5 is selectively etched away by, for example, an anisotropic etching technique to remove the circuit block A.₁・ ・ ・ ・ ・ ・ B₁... are formed. Next, each circuit block is provided with a light emitting / receiving unit a as shown in FIG. 2, FIG. 3, or FIG.₁, B₁Are formed using a compound semiconductor epitaxial growth technique or the like. Thus, the target optoelectronic integrated circuit device is manufactured.
[0028]
As described above, according to the first embodiment, the circuit block A₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂...,... Are transmitted by light, so that signal delay or signal loss due to parasitic capacitance or resistance can be eliminated. In addition, it is possible to increase the speed of signal processing and the density of information. Moreover, these circuit blocks A₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂Are monolithically formed on the silicon substrate 1, thereby reducing the size and integration of the device compared to the conventional case where the modularized optical components are mounted on the substrate. be able to. Further, a metal wiring made of Al, Cu or the like for signal transmission inside each circuit block can be easily formed by a conventionally established wiring technique. As described above, a small, highly integrated, and high-speed optoelectronic integrated circuit device can be realized.
[0029]
Next explained is an optoelectronic integrated circuit device according to the second embodiment of the invention. FIG. 7 shows this optoelectronic integrated circuit device.
[0030]
As shown in FIG. 7, in the optoelectronic integrated circuit device according to the second embodiment, a plurality of circuit blocks A are formed on a silicon substrate 1.₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂Are monolithically formed, and an optically transparent film 6 is formed so as to fill a portion between these circuit blocks. In this case, signal transmission between circuit blocks adjacent to each other is performed by light through the optically transparent film 6. The optically transparent film 6 is preferably made of a material that is optically low in signal propagation loss with respect to the optical signal to be used, and specifically, a resist made of an organic resin or a heat-resistant insulation. Body SiO₂Etc. are used. Since other things are the same as those of the first embodiment, description thereof is omitted.
[0031]
In order to manufacture the optoelectronic integrated circuit device according to the second embodiment, the process proceeds in the same manner as shown in FIGS. 5 and 6, and then an optically transparent film 6 is formed on the entire surface of the substrate as shown in FIG. Is deposited. Specifically, the optically transparent film 6 is formed by applying a resist over the entire surface of the substrate when a resist made of an organic resin is used as the material. This method is effective when only a heat treatment of approximately 200 ° C. or less is performed as a step after the formation of the optically transparent film 6. Further, as the material of the optically transparent film 6, SiO₂In the case of using this, the optically transparent film 6 can be formed by a liquid phase CVD method using a sol-gel reaction. In the film formation by this liquid phase CVD method, the growth temperature is set to, for example, 0 ° C., and the growth is performed, so that SiO having high fluidity is obtained.₂By growing the film and then performing a heat treatment at a low temperature, for example, 400 ° C. for about 15 minutes, SiO 2₂The OH group contained in the film is removed, and this SiO₂Allow the membrane to solidify. SiO₂Is a heat-resistant insulator, and therefore the process temperature after the formation of the optically transparent film 6 can be tolerated up to about 1000 ° C.
[0032]
According to the second embodiment, the same advantages as those of the first embodiment can be obtained.
[0033]
Next explained is an optoelectronic integrated circuit device according to the third embodiment of the invention. FIG. 9 shows this optoelectronic integrated circuit device, and FIG. 10 shows an enlarged sectional view of a portion between adjacent circuit blocks in this optoelectronic integrated circuit device.
[0034]
As shown in FIGS. 9 and 10, in the optoelectronic integrated circuit device according to the third embodiment, a plurality of circuit blocks A are formed on a silicon substrate 1.₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂,... Are formed monolithically, and the optical switch 7 is similarly formed monolithically in a portion between these circuit blocks. Various switches can be used as the optical switch 7 depending on the application. For example, an optical switch using a field effect such as an optical switch using liquid crystal can be used. The liquid crystal for the optical switch can be formed by, for example, a coating technique and etching. In this case, a control electrode (not shown) for applying an electric field to the liquid crystal is one of the light emitting elements of the light emitting / receiving unit of one circuit block and the light receiving elements of the light emitting / receiving unit of the other circuit block opposite thereto. Each set may be provided above and below the optical switch 7 or may be provided in common for a plurality of sets. This control electrode can be formed of, for example, a metal film such as a polycrystalline silicon film doped with impurities or an Al film, and is formed on the liquid crystal through a protective film as necessary. In this case, transmission of optical signals between circuit blocks adjacent to each other is controlled by turning on / off the optical switch 7. Since other things are the same as those of the first embodiment, description thereof is omitted.
[0035]
In order to manufacture the optoelectronic integrated circuit device according to the third embodiment, after proceeding in the same manner as shown in FIGS. 5 and 6, an optical switch 7 is provided between the circuit blocks as shown in FIG. Form. Specifically, for example, the optical switch 7 is formed by forming a liquid crystal and a control electrode in a portion between circuit blocks.
[0036]
According to the third embodiment, the same advantages as those of the first embodiment can be obtained, and the optical switch 7 is provided between the circuit blocks. It is possible to easily select an optical signal transmitted between blocks and to obtain an advantage that information density can be increased.
[0037]
Next explained is an optoelectronic integrated circuit device according to the fourth embodiment of the invention. FIG. 12 shows this optoelectronic integrated circuit device, and FIG. 13 shows an enlarged sectional view of a portion between adjacent circuit blocks in this optoelectronic integrated circuit device.
[0038]
As shown in FIGS. 12 and 13, in the optoelectronic integrated circuit device according to the fourth embodiment, a plurality of circuit blocks A are formed on a silicon substrate 1.₁, A₂・ ・ ・ ・ ・ ・ B₁, B₂,... Are formed monolithically, and the optical switch 7 is similarly formed monolithically in a portion between these circuit blocks. And, for example, SiO so as to cover these circuit blocks and the optical switch 7₂A passivation film 8 such as a film or a SiN film is formed. Various switches can be used as the optical switch 7 depending on the application. For example, an optical switch using a field effect such as an optical switch using liquid crystal can be used. In this case, the control electrode (not shown) is connected to the optical switch 7 for each set of the light emitting element of the light emitting / receiving unit of one circuit block and the light receiving element of the light emitting / receiving unit of the other circuit block opposite thereto. May be provided above and below, or may be provided in common for a plurality of sets. In this case, transmission of optical signals between circuit blocks adjacent to each other is controlled by turning on / off the optical switch 7. Since other things are the same as those of the first embodiment, description thereof is omitted.
[0039]
In order to manufacture the optoelectronic integrated circuit device according to the fourth embodiment, after proceeding in the same manner as shown in FIGS. 5 and 6, the optical switch 7 is provided between the circuit blocks as shown in FIG. Then, a passivation film 8 is formed on the entire surface of the substrate by, for example, a CVD method.
[0040]
According to the fourth embodiment, the same advantages as those of the third embodiment can be obtained.
[0041]
Next explained is an optoelectronic integrated circuit device according to the fifth embodiment of the invention.
[0042]
As shown in FIG. 15, in the optoelectronic integrated circuit device according to the fifth embodiment, the optical switch 7 is formed across the circuit blocks on both sides thereof. Since other things are the same as those of the third embodiment, description thereof is omitted.
[0043]
The fifth embodiment can provide the same advantages as those of the third embodiment.
[0044]
Next explained is an optoelectronic integrated circuit device according to the sixth embodiment of the invention.
[0045]
As shown in FIG. 16, in the optoelectronic integrated circuit device according to the sixth embodiment, the optical switch 7 is formed across the circuit blocks on both sides thereof. Others are the same as those in the fourth embodiment, and a description thereof will be omitted.
[0046]
According to the sixth embodiment, the same advantages as those of the fourth embodiment can be obtained.
[0047]
In the optoelectronic integrated circuit devices according to the first to sixth embodiments described above, the optical switch 7 is formed in a region between adjacent circuit blocks, but an optical signal from a certain circuit block is used as an optical wiring. In some cases, the signal is transmitted to another circuit block through the transmission line, and at that time, the transmission of the optical signal is controlled by the optical switch. Then, next, an optoelectronic integrated circuit device according to a seventh embodiment of the present invention using such an optical transmission line will be described.
[0048]
As shown in FIG. 17, in the optoelectronic integrated circuit device according to the seventh embodiment, the light receiving and emitting part of the circuit block, for example, the circuit block A₁Light emitting / receiving part a₁One end of the optical transmission line 9 is connected to the optical switch 7 via the optical switch 7. The optical transmission line 9 is monolithically formed on the silicon substrate 1. The other end of the optical transmission line 9 is connected to a light emitting / receiving unit of another circuit block. This optical transmission line 9 is made of a transparent material with a small optical signal propagation loss, such as an organic resin resist or SiO 2₂It is formed by. Specifically, the optical transmission line 9 is formed as shown in FIG. 18, for example. An optical signal emitted from the light emitting element of the light receiving / emitting part of the circuit block is incident on one end face of the optical transmission path 9, propagates through the inside thereof, is emitted from the other end face, and is received and emitted by the other circuit block. The light is incident on and received by the light receiving element. One or a plurality of optical transmission lines 9 are formed as needed between circuit blocks that transmit optical signals, and a plurality of optical transmission lines 9 are usually formed on the entire silicon substrate 1. FIG. 19 shows a state in which a plurality of optical transmission lines 9 are provided on the silicon substrate 1. Further, the optical transmission line 9 may be bent in the middle as shown in FIG. 20 as necessary. Since other things are the same as those of the first embodiment, description thereof is omitted.
[0049]
Next, a method for forming the optical transmission line 9 will be described. Here, the first method using an organic resin resist as the material of the optical transmission line 9 and the SiO 2 as the material of the optical transmission line 9 are used.₂This will be described separately from the second method using the method.
[0050]
21 to 27 show the first method. In this first method, first, as shown in FIG. 21, the entire surface of the silicon substrate 1 is made of Si by, eg, CVD._ThreeN_FourAfter the film 10 is formed, a resist pattern (not shown) having a predetermined shape with an opening corresponding to the optical transmission path forming portion is formed thereon by lithography, and using this resist pattern as a mask, for example, reactive ion etching By performing anisotropic etching with the (RIE) method, Si_ThreeN_FourAn opening 10 a is formed in the film 10. The width of the opening 10a is selected to be a little narrower than the diameter of the optical transmission line 9 to be finally formed. Next, after removing the resist pattern,_ThreeN_FourUsing the film 10 as a mask, the silicon substrate 1 is etched by, for example, the RIE method to form the groove 11. At this time, the cross-sectional shape of the groove 11 is rectangular.
[0051]
Next, as shown in FIG._ThreeN_FourBy performing isotropic etching, for example, wet etching, of the silicon substrate 1 using the film 10 as a mask, the cross-sectional shape of the groove 11 is made semicircular with a diameter equal to the diameter of the optical transmission line 9 to be finally formed.
[0052]
Next, Si_ThreeN_FourAfter the film 10 is removed by etching (FIG. 23), an organic resin resist film 12 is applied on the silicon substrate 1 as shown in FIG. The thickness of the resist film 12 is selected according to the diameter of the optical transmission line 9 to be finally formed.
[0053]
Next, a predetermined portion of the resist film 12 is exposed and then developed to form a resist pattern 13 having a width slightly larger than the diameter of the groove 11 in the groove 11 as shown in FIG.
[0054]
Next, as shown in FIG. 26, the resist pattern 13 is heated to an appropriate temperature according to the type of the resist and reflowed to make the upper half surface of the resist pattern 13 a smooth curved surface.
[0055]
Next, for example, by performing an ashing process using oxygen plasma, the upper half surface of the resist pattern 13 is processed so that the resist pattern 13 as a whole has a substantially circular cross-sectional shape. Thereafter, the resist pattern 13 is cured by, for example, vacuum drying or plasma irradiation. As a result, as shown in FIG. 27, the optical transmission line 9 made of an organic resin resist and having a substantially circular cross-sectional shape is formed.
[0056]
28 to 33 show the second method. In the second method, first, as shown in FIG. 28, Si is formed on the entire surface of the silicon substrate 1 by, eg, CVD._ThreeN_FourA film 10 is formed, and a resist pattern 14 having a predetermined shape with an opening corresponding to the optical transmission path forming portion is formed thereon by lithography. The width of the opening of the resist pattern 14 is selected to be slightly narrower than the diameter of the optical transmission line 9 to be finally formed. Next, anisotropic etching is performed by, for example, the RIE method using the resist pattern 14 as a mask to thereby form Si._ThreeN_FourAn opening 10a is formed in the film 10, and then anisotropic etching is performed to etch the silicon substrate 1 to form a groove 11. At this time, the cross-sectional shape of the groove 11 is rectangular.
[0057]
Next, as shown in FIG. 29, the resist pattern 13 and Si_ThreeN_FourBy performing isotropic etching, for example, wet etching, using the film 10 as a mask, the cross-sectional shape of the groove 11 is made to be a semicircle having a diameter equal to the diameter of the optical transmission line 9 to be finally formed.
[0058]
Next, as shown in FIG. 30, for example, ashing using oxygen plasma is performed to narrow the width of the resist pattern 14 to the same width as the groove 11.
[0059]
Next, as shown in FIG. 31, the resist pattern 14 is used as a mask to form Si._ThreeN_FourBy etching the film 10, Si_ThreeN_FourThe width of the opening 10 a of the film 10 is made the same as that of the groove 11.
[0060]
Next, as shown in FIG. 32, SiO 2 is deposited on the entire surface of the silicon substrate 1 by a liquid phase CVD method using a sol-gel reaction.₂Do 15 growths. At this time, this SiO₂No. 15 is obtained by performing growth with its growth temperature set at, for example, 0 ° C., so that a material exhibiting high fluidity is obtained._ThreeN_FourIt grows spontaneously and spontaneously into a substantially circular cross-sectional shape on the silicon substrate 1 in the groove 11 inside the opening 10a of the film 10. Although not shown, this SiO₂Usually, the resist pattern 14 also grows thinly.
[0061]
Next, the resist pattern 14 is removed by performing an ashing process using, for example, oxygen plasma. At this time, SiO thinly grown on the resist pattern 14₂The film is removed by lift-off. Next, by performing heat treatment at a low temperature, SiO 2₂OH group contained in 15 is removed, and this SiO₂15 is solidified. Specifically, this heat treatment is performed at 400 ° C. for about 15 minutes, for example. After this, Si_ThreeN_FourThe film 10 is removed by etching. As a result, as shown in FIG.₂An optical transmission line 9 having a substantially circular cross-sectional shape is formed.
[0062]
According to the second method, the heat-resistant insulator is SiO.₂Is used as the material of the optical transmission line 9, the process temperature after the formation of the optical transmission line 9 can be allowed to about 1000 ° C., and the etching resistance is also excellent. For this reason, the freedom degree of the process after formation of the optical transmission line 9 is high. Further, the resist pattern 14 and Si_ThreeN_FourUsing the pattern of the film 10 as a mask, SiO is formed by liquid phase CVD.₂The circular cross-sectional shape required for the optical transmission line 9 can be easily obtained simply by performing the above growth. Further, the diameter of the optical transmission line 9 can be reduced to a critical dimension determined by the resolution of lithography.
[0063]
According to the seventh embodiment, the same advantages as those of the third embodiment can be obtained, and transmission of optical signals between circuit blocks is performed by the optical transmission line 9 formed monolithically on the silicon substrate 1. It is possible to obtain an advantage that the process can be performed reliably and with high reliability.
[0064]
Next explained is an optoelectronic integrated circuit device according to the eighth embodiment of the invention.
[0065]
As shown in FIG. 34, in the optoelectronic integrated circuit device according to the eighth embodiment, the optical switch 7 is formed across the circuit blocks on both sides and the optical transmission line 9. Others are the same as in the seventh embodiment, and a description thereof will be omitted.
[0066]
The eighth embodiment can provide the same advantages as those of the seventh embodiment.
[0067]
In the above-described optoelectronic integrated circuit devices according to the seventh and eighth embodiments, the case where the optical switch is provided between the circuit block and the optical transmission line has been described. However, this optical switch is provided in the middle of the optical transmission line. Sometimes. Then, next, an optoelectronic integrated circuit device according to a ninth embodiment of the present invention corresponding to this case will be described.
[0068]
As shown in FIG. 35, in the optoelectronic integrated circuit device according to the ninth embodiment, an optical switch 7 is provided in the middle of the optical transmission line 9. The optical switch 7 is monolithically formed on the silicon substrate 1. One end of the optical transmission line 9 is connected to a light emitting / receiving unit of a circuit block, and the other end is connected to a light emitting / receiving unit of another circuit block. This optical transmission line 9 is made of a transparent material with a small optical signal propagation loss, such as an organic resin resist or SiO 2₂It is formed by. Specifically, the optical transmission line 9 is formed as shown in FIG. 36, for example. An optical signal emitted from the light emitting element of the light receiving / emitting part of the circuit block is incident on one end face of the optical transmission path 9, propagates through the inside thereof, is emitted from the other end face, and is received and emitted by the other circuit block. At this time, the transmission of the optical signal is controlled by turning on / off the optical switch 7. One or a plurality of optical transmission lines 9 are formed as needed between circuit blocks that transmit optical signals, and a plurality of optical transmission lines 9 are usually formed on the entire silicon substrate 1. FIG. 37 shows a state in which a plurality of optical transmission lines 9 are provided on the silicon substrate 1. Further, the optical transmission line 9 may be formed to be bent in the middle as shown in FIG. Since other things are the same as those of the first embodiment, description thereof is omitted.
[0069]
According to the ninth embodiment, the same advantages as those of the seventh embodiment can be obtained.
[0070]
Next explained is an optoelectronic integrated circuit device according to the tenth embodiment of the invention.
[0071]
As shown in FIG. 39, in the optoelectronic integrated circuit device according to the tenth embodiment, the optical switch 7 is formed across the optical transmission lines 9 on both sides thereof. Others are the same as in the seventh embodiment, and a description thereof will be omitted.
[0072]
According to the tenth embodiment, the same advantages as those of the seventh embodiment can be obtained.
[0073]
Next explained is an optoelectronic integrated circuit device according to the eleventh embodiment of the invention.
[0074]
As shown in FIG. 40, FIG. 41, or FIG. 42, in the optoelectronic integrated circuit device according to the eleventh embodiment, the optical switch 7 has a rectangular cross section. Others are the same as in the seventh embodiment, and a description thereof will be omitted.
[0075]
According to the eleventh embodiment, the same advantages as those of the seventh embodiment can be obtained.
[0076]
Next explained is an optoelectronic integrated circuit device according to the twelfth embodiment of the invention.
[0077]
As shown in FIG. 43, in the optoelectronic integrated circuit device according to the twelfth embodiment, the optical switch 7 is formed in a rectangular cross-sectional groove 16 formed in the silicon substrate 1 in a direction perpendicular to the optical transmission line 9. Is formed. When an optical switch using a field effect such as an optical switch using liquid crystal is used as the optical switch 7, the control electrode (not shown) is provided for each optical transmission line 9. It may be provided vertically, or may be provided in common for a plurality of optical transmission lines 9. Others are the same as in the seventh embodiment, and a description thereof will be omitted.
[0078]
According to the twelfth embodiment, the same advantages as those of the seventh embodiment can be obtained.
[0079]
The optoelectronic integrated circuit device according to the present invention can basically be applied to any circuit, but can be applied to the circuits shown in FIGS. 44 to 48, for example. All or a part of the circuits shown in FIGS. 44 to 48 can be configured in the same manner as the optoelectronic integrated circuit device according to the present invention, thereby enabling miniaturization, high integration and high speed of these circuits. It becomes.
[0080]
The example shown in FIG. 44 is a graphics LSI using AGP (Accelerated Graphics Port), which includes a 2D graphics processing block, a 3D graphics processing block, a video signal processing block, an RGB image processing block, and the like ( Nikkei Electronics, April 6, 1998, pp. 55-65).
[0081]
The example shown in FIG. 45 is a 68-bit adder ("Design of High Performance Microprocessor Architecture Intel 80960", by Myers, Tomizawa, Shinsei, Maruzen, 1990, p. 205).
[0082]
The example shown in FIG. 46 is an example of a stored-program machine, which illustrates the use of a decoder and memory for implementing a state machine that controls the data path (Introduction to VLSI Systems, C. Mead & L Conway, Addison Wesley, 1980, p. 201).
[0083]
The example shown in FIGS. 47 and 48 is another example of a stored program machine (Introduction to VLSI Systems, C. Mead & L. Conway, Addison Wesley, 1980, p. 201, p. 203).
[0084]
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.
[0085]
For example, the structures, materials, processes, and the like described in the first to twelfth embodiments are merely examples, and structures, materials, processes, and the like different from these may be used as necessary.
[0086]
Specifically, in the first to twelfth embodiments described above, the case where a silicon substrate is used has been described, but a compound semiconductor substrate such as a GaAs substrate may be used.
[0087]
【The invention's effect】
As described above, according to the present invention, a plurality of circuit blocks are formed monolithically on the substrate, and signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light. A small, highly integrated and high-speed optoelectronic integrated circuit device can be realized.
[0088]
Further, according to the present invention, a plurality of circuit blocks are formed monolithically on the substrate, signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and at least between the two circuit blocks. In addition, by having an optical switch monolithically formed on the substrate, it is possible to easily select an optical signal transmitted between circuit blocks at a small size, high integration and high speed, and to increase the density of information. An optoelectronic integrated circuit device capable of achieving the above can be realized.
[0089]
Further, according to the present invention, a plurality of circuit blocks are formed monolithically on the substrate, signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and at least between the two circuit blocks. However, it is connected by a linear optical transmission line that is monolithically formed on the substrate for transmitting signals by light, and an optical switch that is monolithically formed on the substrate is provided in the middle of the optical transmission line. Thus, an optoelectronic integrated circuit device can be realized that is small, highly integrated, and capable of selecting an optical signal transmitted between circuit blocks easily and achieving high density of information. Can do.
[0090]
Further, according to the present invention, a plurality of circuit blocks are formed monolithically on the substrate, signal transmission between at least two circuit blocks of the plurality of circuit blocks is performed by light, and between at least two circuit blocks Are connected by a linear optical transmission line that is monolithically formed on the substrate and performs signal transmission by light, and at least one of the at least two circuit blocks and the optical transmission line In the meantime, by having an optical switch formed monolithically on the substrate, it is possible to easily select an optical signal transmitted between circuit blocks with a small size, high integration, and high speed, and a high level of information. An optoelectronic integrated circuit device capable of increasing the density can be realized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an optoelectronic integrated circuit device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a first example of a light receiving and emitting part of a circuit block in the optoelectronic integrated circuit device according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a second example of the light receiving and emitting part of the circuit block in the optoelectronic integrated circuit device according to the first embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a third example of the light receiving and emitting part of the circuit block in the optoelectronic integrated circuit device according to the first embodiment of the present invention.
FIG. 5 is a cross-sectional view for explaining the method of manufacturing the optoelectronic integrated circuit device according to the first embodiment of the present invention.
FIG. 6 is a cross-sectional view for explaining the manufacturing method of the optoelectronic integrated circuit device according to the first embodiment of the present invention.
FIG. 7 is a perspective view showing an optoelectronic integrated circuit device according to a second embodiment of the present invention.
FIG. 8 is a cross-sectional view for explaining the manufacturing method of the optoelectronic integrated circuit device according to the second embodiment of the present invention.
FIG. 9 is a perspective view showing an optoelectronic integrated circuit device according to a third embodiment of the present invention.
FIG. 10 is an enlarged sectional view showing a portion between adjacent circuit blocks in an optoelectronic integrated circuit device according to a third embodiment of the present invention.
FIG. 11 is a cross-sectional view for explaining the manufacturing method of the optoelectronic integrated circuit device according to the third embodiment of the present invention.
FIG. 12 is a perspective view showing an optoelectronic integrated circuit device according to a fourth embodiment of the present invention.
FIG. 13 is an enlarged sectional view showing a portion between adjacent circuit blocks in an optoelectronic integrated circuit device according to a fourth embodiment of the present invention.
FIG. 14 is a cross-sectional view for explaining the manufacturing method of the optoelectronic integrated circuit device according to the fourth embodiment of the present invention.
FIG. 15 is an enlarged sectional view showing a portion between adjacent circuit blocks in an optoelectronic integrated circuit device according to a fifth embodiment of the present invention.
FIG. 16 is an enlarged sectional view showing a portion between adjacent circuit blocks in an optoelectronic integrated circuit device according to a sixth embodiment of the present invention.
FIG. 17 is an enlarged sectional view showing a connection portion between a circuit block and an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 18 is a perspective view showing a first example of an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 19 is a perspective view showing a second example of the optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention.
FIG. 20 is a perspective view showing a third example of the optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention.
FIG. 21 is a cross-sectional view illustrating a first method for forming an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 22 is a cross-sectional view illustrating a first method for forming an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 23 is a sectional view for explaining a first method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 24 is a sectional view for explaining a first method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 25 is a cross-sectional view illustrating a first method for forming an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 26 is a cross-sectional view illustrating a first method for forming an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 27 is a sectional view for explaining a first method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 28 is a cross sectional view for explaining a second method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 29 is a sectional view for explaining a second method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 30 is a cross-sectional view for explaining a second method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 31 is a cross-sectional view illustrating a second method for forming an optical transmission line in an optoelectronic integrated circuit device according to a seventh embodiment of the present invention.
FIG. 32 is a cross sectional view for explaining a second method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 33 is a cross-sectional view for explaining a second method for forming an optical transmission line in the optoelectronic integrated circuit device according to the seventh embodiment of the present invention;
FIG. 34 is an enlarged sectional view showing a connection portion between a circuit block and an optical transmission line in an optoelectronic integrated circuit device according to an eighth embodiment of the present invention.
FIG. 35 is an enlarged cross-sectional view of a portion of an optical transmission line provided with an optical switch in an optoelectronic integrated circuit device according to a ninth embodiment of the present invention.
FIG. 36 is a perspective view showing a first example of an optical transmission line in an optoelectronic integrated circuit device according to a ninth embodiment of the present invention.
FIG. 37 is a perspective view showing a second example of the optical transmission line in the optoelectronic integrated circuit device according to the ninth embodiment of the present invention.
FIG. 38 is a perspective view showing a third example of the optical transmission line in the optoelectronic integrated circuit device according to the ninth embodiment of the present invention.
FIG. 39 is an enlarged cross-sectional view of a portion of an optical transmission line provided with an optical switch in an optoelectronic integrated circuit device according to a tenth embodiment of the present invention.
FIG. 40 is a perspective view showing a first example of an optical transmission line in an optoelectronic integrated circuit device according to an eleventh embodiment of the present invention.
FIG. 41 is a perspective view showing a second example of the optical transmission line in the optoelectronic integrated circuit device according to the eleventh embodiment of the present invention.
FIG. 42 is a perspective view showing a third example of the optical transmission line in the optoelectronic integrated circuit device according to the eleventh embodiment of the present invention.
FIG. 43 is an enlarged perspective view showing an optical transmission line of a portion provided with an optical switch in an optoelectronic integrated circuit device according to a twelfth embodiment of the present invention.
FIG. 44 is a schematic diagram showing a first example of a circuit to which the optoelectronic integrated circuit device according to the present invention can be applied.
FIG. 45 is a schematic diagram showing a second example of a circuit to which the optoelectronic integrated circuit device according to the present invention can be applied.
FIG. 46 is a schematic diagram showing a third example of a circuit to which the optoelectronic integrated circuit device according to the present invention can be applied.
FIG. 47 is a schematic diagram showing a fourth example of a circuit to which the optoelectronic integrated circuit device according to the present invention can be applied.
FIG. 48 is a schematic diagram showing a fifth example of a circuit to which the optoelectronic integrated circuit device according to the present invention can be applied.
[Explanation of symbols]
1 ... Silicon substrate, A₁, A₂, B₁, B₂... Circuit block, a₁, B₁・ ・ ・ Light emitting / receiving unit 2, 3, 4 ... Reflector, 6 ... Optically transparent film, 7 ... Optical switch, 8 ... Passivation film, 9 ... Optical transmission line 10 ... Si_ThreeN_FourMembrane, 10a ... opening, 11 ... groove, 13, 14 ... resist pattern, 15 ... SiO₂

Claims (20)

A plurality of circuit blocks are formed monolithically by selectively etching away the circuit block layer formed on the substrate according to the LSI manufacturing process , and signals between at least two circuit blocks of the plurality of circuit blocks are formed. Transmission is performed by light, and transmission of signals inside each of the plurality of circuit blocks is performed through a wiring made of a conductor.
Between the at least two circuit blocks is formed monolithically on the substrate with the lower portion buried in a groove formed on the surface of the substrate, for performing signal transmission by light , The cross-sectional shape is connected by a linear optical transmission line having a substantially circular shape, and is formed monolithically on the substrate between at least one of the at least two circuit blocks and the optical transmission line. An optoelectronic integrated circuit device having an optical switch.   2. The optoelectronic integrated circuit device according to claim 1, wherein the optical switch is an optical switch using a field effect, a semiconductor optical switch, or an optical switch using an organic thin film.   2. The optoelectronic integrated circuit device according to claim 1, wherein the optical switch is an optical switch using liquid crystal.   2. The optoelectronic integrated circuit device according to claim 1, wherein the optical transmission line is made of an organic material.   2. The optoelectronic integrated circuit device according to claim 1, wherein the optical transmission line is made of an organic resin resist.   2. The optoelectronic integrated circuit device according to claim 1, wherein the optical transmission line is made of an inorganic material.   2. The optoelectronic integrated circuit device according to claim 1, wherein the optical transmission line is made of silicon oxide or silicon nitride. 2. The optoelectronic integrated circuit device according to claim 1, wherein the at least two circuit blocks include a light emitting element and / or a light receiving element. 2. The optoelectronic integrated circuit device according to claim 1, wherein transmission of a signal by light between the at least two circuit blocks is performed by a single or multiple signal. 2. The optoelectronic integrated circuit device according to claim 1, wherein the substrate is a silicon substrate, a compound semiconductor substrate, an SOI substrate, or an insulating substrate. A plurality of circuit blocks are formed monolithically by selectively etching away the circuit block layer formed on the substrate in accordance with the LSI manufacturing process. Signals between at least two circuit blocks of the plurality of circuit blocks are formed. Transmission is performed by light, and transmission of signals inside each of the plurality of circuit blocks is performed through a wiring made of a conductor.
Between the at least two circuit blocks is formed monolithically on the substrate with the lower portion buried in a groove formed on the surface of the substrate, for performing signal transmission by light, An optoelectronic integrated circuit device having an optical switch monolithically formed on the substrate in the middle of the optical transmission line, which is connected by a linear optical transmission line having a substantially circular cross section. 12. The optoelectronic integrated circuit device according to claim 11, wherein the optical switch is an optical switch using a field effect, a semiconductor optical switch, or an optical switch using an organic thin film. 12. The optoelectronic integrated circuit device according to claim 11, wherein the optical switch is an optical switch using liquid crystal. 12. The optoelectronic integrated circuit device according to claim 11, wherein the optical transmission line is made of an organic material. 12. The optoelectronic integrated circuit device according to claim 11, wherein the optical transmission line is made of an organic resin resist. 12. The optoelectronic integrated circuit device according to claim 11, wherein the optical transmission line is made of an inorganic material. 12. The optoelectronic integrated circuit device according to claim 11, wherein the optical transmission line is made of silicon oxide or silicon nitride.   12. The optoelectronic integrated circuit device according to claim 11, wherein the at least two circuit blocks include a light emitting element and / or a light receiving element. 12. The optoelectronic integrated circuit device according to claim 11, wherein signal transmission by light between the at least two circuit blocks is performed by a single or multiple signal. 12. The optoelectronic integrated circuit device according to claim 11, wherein the substrate is a silicon substrate, a compound semiconductor substrate, an SOI substrate, or an insulating substrate.

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