JPH04302176A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a means of optical interconnection including a semiconductor device provided with a cooling structure. CONSTITUTION:A light propagation section 7 is provided to a cooling structure 6, and light signals 8 are transmitted from or received by an optoelectronic element 2 provided to a semiconductor element 1 through the intermediary of the light propagation section 7. As light signals can be transmitted without being blocked by the cooling structure 6, an ultrahigh speed semiconductor device can be realized taking advantage of the merits of light signals such as high speed and large bandwidth.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device for optical interconnection.

0002

2. Description of the Related Art Conventional semiconductor devices are manufactured by, for example, the Society of Applied Physics, Optical Society of Japan, edited by the Micro-Optics Research Group, Micro-Optics Special Seminar VIII (1990), Micro-optics and Packaging Technology, PP. As described in No. 22-31, a cooling structure such as a heat conductor or cooling fins was attached to a semiconductor element connected to a wiring board. In particular, the machine cycle is nse
In semiconductor devices used in c-order ultra-high-speed computers,
In order to improve performance, it was necessary to increase the integration of semiconductor elements and increase the speed of signal transmission between elements and devices through high-density packaging. Machine cycles will continue to be shortened in the future.
As semiconductor devices become more highly integrated and packaged at a higher density, the amount of heat generated by the devices tends to increase. As a method to further speed up signal transmission, for example, the same magazine, pp. 8
Optical interconnections have been proposed as described in No. 0-92. In this method, an optoelectronic element section is provided on a semiconductor element connected to a substrate, and wiring is established between the elements using an optical waveguide, a hologram, or the like. Optical wiring has high speed and broadband characteristics, so signal waveform deterioration and delay are less likely to occur compared to electrical wiring. In the future, it is said to be particularly useful for clock signal wiring that will require high-speed signal transmission on the order of GHz or higher. Note that in the conventional proposed example, a cooling structure was not attached to the semiconductor element.

0003

[Problems to be Solved by the Invention] In future ultra-high-speed semiconductor devices, since the amount of heat generated by the devices will increase, a cooling structure will be essential, and optical interconnection will need to be applied for signal transmission. In the above conventional technology, the cooling structure is made of a metal material that blocks light, and no consideration is given to an optical wiring method that avoids the cooling structure, so optical interconnection cannot actually be performed. There was a problem.

An object of the present invention is to provide technical means that enable optical interconnection to be implemented in a semiconductor device having a cooling structure.

Another object of the present invention is to more specifically provide an optical wiring system for a cooling structure.

Another object of the present invention is to provide a means for preventing stray light of an optical signal, or a means for increasing the efficiency of optical coupling between an optical signal and an optoelectronic element.

Another object of the present invention is to provide a semiconductor device that takes into consideration constituent materials and manufacturability.

Still another object is to provide a means for wiring a clock signal to a semiconductor device using an optical signal.

Another object of the present invention is to provide technical means for using a plurality of semiconductor devices as a system.

0010

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object of enabling optical interconnection, the present invention provides at least a portion of a cooling structure with a portion for propagating an optical signal. More specifically, a cooling structure such as a cooling fin uses a light transmitting member or has through holes.

[0011] Furthermore, in order to prevent stray light, an optical signal shielding member is provided in a portion other than the light propagation section, and in order to increase optical coupling efficiency, a wavefront converting optical element such as a lens is provided in the semiconductor element or the cooling structure, or a cooling The fins are pin-shaped.

In addition, the semiconductor element and the optoelectronic element are made of silicon semiconductor as constituent materials, and the wavelength is 0.9μ.
The cooling structure uses a member that transmits light of less than m. The cooling fins are also made by processing silicon crystal material.

Furthermore, in order to perform clock wiring using an optical signal, an optical signal modulated at the same frequency is transmitted to a plurality of optoelectronic element sections. Furthermore, the phases of the optical signals are aligned and the optical path lengths of the optical propagation sections are made equal.

In order to use a plurality of semiconductor devices as a system, the devices are connected to each other by optical signals, or each device is driven in synchronization with optical signals.

[0015]

[Operation] By providing a light propagation section in a cooling structure such as a cooling fin, optical signals can be transmitted and received to and from a semiconductor element via this light propagation section, making optical wiring possible. Since the light propagation section is composed of a member or a through hole that transmits the optical signal, the optical signal is not blocked or attenuated as in the conventional case.

Furthermore, by shielding stray light, crosstalk of optical signals can be prevented. By providing the wavefront conversion optical element, it is possible to increase the efficiency of incidence of optical signals into the optoelectronic element and the efficiency of output of optical signals from the optoelectronic element. By making the cooling fins pin-shaped, the pins themselves can be used as optical waveguides.

In addition, the semiconductor element and the optoelectronic element can be monolithically formed on a silicon semiconductor, and the optoelectronic element can receive optical signals with a wavelength of 0.9 μm or less. By using silicon as a constituent material of the cooling fins, the fins can be processed by crystal anisotropic etching instead of mechanical processing.

Furthermore, by using optical signals of the same frequency or the same phase as clock signals, it is possible to distribute clock signals faster than electrical wiring to semiconductor elements.

Furthermore, distributed processing can be performed by signally connecting a plurality of semiconductor devices to each other using optical signals, and parallel processing can be performed by driving them synchronously.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device to which the present invention is applied will be explained below with reference to the drawings.

FIG. 1 shows a block diagram of a first embodiment of the present invention. In FIG. 1, a semiconductor element 1 is connected to a wiring board 4 by a connecting body 3, and a cooling structure 6 is attached. Although the connection body 3 is shown as a protruding electrode such as a solder bump, it may also be connected by tape automated bonding or the like. The wiring board 4 is made of a multilayer wiring board made of ceramics such as AlN or mullite, or silicon wafer, and has input/output terminals 5. The cooling structure 6 is composed of cooling fins, heat conductors, etc., as described in the above-mentioned literature. According to the invention, the semiconductor device 1 is provided with an optoelectronic device section 2, and the cooling structure 6 is provided with a section 7 for propagating an optical signal 8 (arrow in FIG. 1). According to the first embodiment, the semiconductor element 1
The optical signal 8 can be transmitted or received by the optical signal 8, and signal wiring using light becomes possible.

Specific methods for constructing the light propagation section 7 include a method of constructing the cooling structure 6 from a member that transmits the optical signal 8, and a method of providing through holes in the cooling structure 6. The former has the advantage that it is easier to design the structure of the cooling structure 6 than the latter, and the latter has the advantage that members can be selected more freely than the former.

By the way, as a method for constructing the optoelectronic element part 2 on the semiconductor element 1, there is a method in which the semiconductor element 1 and the optoelectronic element part 2 are monolithically formed using a GaAs-based or InP-based compound semiconductor, or a method in which a compound semiconductor is formed on a silicon semiconductor element. There are methods for monolithically forming semiconductor elements or for hybrid packaging. Furthermore, when the optoelectronic element section 2 only performs reception, the optoelectronic element section 2 can be monolithically formed on a silicon semiconductor element. In this case, it is necessary to use light with a wavelength of 0.9 μm or less as the optical signal 8 in view of the light receiving sensitivity of the optoelectronic element section 2, and the light with a wavelength of 0.9 μm or less is transmitted through the light propagation section of the cooling structure 6. It is necessary to use a member such as a glass-based material or a visible light-transmissive ceramic.

FIG. 2 shows a block diagram of a second embodiment of the present invention. In FIG. 2, a semiconductor device 11 is connected to a multilayer wiring board 14 by a connecting body 13, and a cooling structure 16 is attached. Multilayer wiring board 14 has input/output terminals 15. The cooling structure 16 is composed of cooling fins 17 and coolant channels 18. According to the present invention, the semiconductor element 11 is provided with the optoelectronic element part 12, and the cooling fin 17 is connected to the optical signal 21 (
It was composed of a member that transmits the arrows in FIG. 2, and was used as a light propagation section. For example, if light with a wavelength of 1.3 μm is used as the optical signal 21, the cooling fins 17 may be made of silicon,
Sapphire, translucent AlN ceramics, etc. were used. Alternatively, composite members such as metal fins embedded with glass were used. According to the second embodiment, the semiconductor element 11 can transmit and receive optical signals 21 via the cooling fins 17.

The member 19 provided in the cooling structure 16 for shielding the optical signal 21 can prevent stray light of the optical signal 21, that is, crosstalk. Furthermore, the wavefront conversion element 20 such as a lens or hologram provided in the cooling structure 16 can improve the optical coupling efficiency between the optical signal 21 and the optoelectronic element section 12, thereby increasing the signal level. Furthermore, by changing the cooling fin 17 from a thin plate shape to a pin shape, cooling efficiency is improved, and the pin itself can be used as a waveguide for the optical signal 21, preventing the optical signal 21 from spreading and achieving low-loss transmission. can. In other words, these effects make it possible to realize highly reliable signal transmission.

When the cooling fins 17 are made of silicon, the fin shape can be processed all at once by crystal anisotropic etching, which has the advantage of higher productivity than machining.

FIG. 3 shows a configuration diagram of an embodiment of a system using a plurality of semiconductor devices according to the present invention. In Figure 3,
Semiconductor element 101, wiring board 102, and cooling structure 103
A semiconductor device consisting of a semiconductor element 104 and a wiring board 1
A semiconductor device consisting of a cooling structure 106 and a cooling structure 106 is connected to a multilayer printed circuit board 107. semiconductor element 101,
104 and the wiring boards 102 and 105, and the optoelectronic element portions of the semiconductor elements 101 and 104 are not shown for simplicity. Light source 109 is modulated by frequency source 108 . The optical signal (arrow in FIG. 3) transmitted from the light source 109 propagates in the air, is deflected by the hologram 110, and is transmitted to the optoelectronic element portions of the semiconductor devices 101 and 104 via the optical propagation portions of the cooling structures 103 and 106. reach.

According to this embodiment, it is possible to distribute optical signals of the same frequency to a plurality of optoelectronic element sections, and in particular, GHz
This is effective for clock signal wiring that is faster than the order of magnitude. In addition, the hologram 110 and the cooling structures 103 and 106
By designing the optical propagation sections to have equal optical path lengths, optical signals of the same phase can be sent to each optoelectronic element section, and phase adjustment of the clock signal becomes unnecessary. Furthermore, multiple semiconductor devices can be synchronized with each other and driven as a system.
It becomes possible to perform larger-scale signal processing, for example, parallel processing. In addition to the above method using a hologram, methods for distributing optical signals include methods using lenses, optical fibers, optical waveguides, and the like.

FIG. 4 shows a configuration diagram of an embodiment of a system using a plurality of semiconductor devices according to the present invention. In Figure 4,
Semiconductor element 201, wiring board 202, and cooling structure 203
a semiconductor device consisting of a semiconductor element 204 and a wiring board 2;
05 and a cooling structure 206 is connected to a multilayer printed circuit board 207. semiconductor element 201,
204 and the wiring boards 202 and 205, and the optoelectronic element portions of the semiconductor elements 201 and 204 are not shown for simplicity. Each optoelectronic element section includes a cooling structure 203,
They are mutually connected by optical signals (arrows in FIG. 4) via the optical propagation section 206 and the optical waveguide substrate 208. The substrate material of the optical waveguide substrate 208 can be glass, silicon wafer, etc., and the waveguide material can be glass, polymer material, etc. According to this embodiment, it is possible to wire signals between a plurality of semiconductor devices at high speed, and it is suitable for performing distributed processing with a machine cycle on the order of nanoseconds or less, for example.

[0030]

According to the present invention, since optical interconnection can be implemented in a semiconductor device having a cooling structure, an ultra-high speed semiconductor device having a machine cycle on the order of nsec or less can be realized. Since a part of the cooling structure is used as an optical wiring path, there is no need to provide an extra optical wiring mechanism.

Further, crosstalk of optical signals can be prevented, the signal level can be improved, and the cooling fins themselves can be used as optical waveguides, so that highly reliable and low-loss optical wiring can be obtained.

In addition, since the optoelectronic element portion can be monolithically formed in the semiconductor element, there is an effect that the semiconductor device can be made smaller and simpler. Furthermore, the cooling fins can be processed all at once by crystal anisotropic etching, which has the effect of improving productivity.

Furthermore, the GH
Since a clock signal of z order or higher can be transmitted, there is an effect that the performance of the semiconductor device can be improved.

Furthermore, since distributed processing or parallel processing can be performed on a plurality of semiconductor devices, an ultra-high speed semiconductor device system can be constructed.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an embodiment of the semiconductor device system of the present invention.

FIG. 4 is a configuration diagram of an embodiment of the semiconductor device system of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Semiconductor element, 2...Optoelectronic element part, 3...Connection body, 4...
Wiring board, 6... Cooling structure, 7... Light propagation section, 8... Optical signal.

Claims (14)

[Claims] 1. A semiconductor device comprising at least one semiconductor element, a wiring board to which the semiconductor element is connected, and a cooling structure attached to the semiconductor element, wherein the semiconductor element includes at least one optoelectronic element section. A semiconductor device comprising: a portion for propagating an optical signal in at least a portion of the cooling structure, and the optical signal is transmitted or received by the optoelectronic element portion via the propagation portion. 2. The semiconductor device according to claim 1, wherein the propagation section is made of a member that transmits the optical signal. 3. The semiconductor device according to claim 1, wherein the propagation section is constituted by a through hole provided in the cooling structure. 4. The semiconductor device according to claim 2, wherein the cooling structure is provided with at least one cooling fin, and the cooling fin is made of a member that transmits the optical signal. 5. The semiconductor device according to claim 2 or 4, wherein at least a portion of the semiconductor element or the cooling structure is provided with a member for shielding the optical signal. 6. The semiconductor device according to claim 2 or 4, wherein at least a portion of the semiconductor element or the cooling structure is provided with an optical element that converts the wavefront of the optical signal. . 7. The semiconductor device according to claim 4, wherein the cooling fin has a pin shape. 8. The semiconductor device according to claim 2, wherein the semiconductor element and the optoelectronic element section are made of a silicon semiconductor, and the propagation section is made of a member that transmits light having a wavelength of 0.9 μm or less. semiconductor device. 9. A semiconductor device according to claim 4, wherein said cooling fin is made of a silicon crystal material. 10. The semiconductor device according to claim 1, wherein an optical signal modulated at the same frequency is transmitted to a plurality of said optoelectronic element sections. 11. The semiconductor device according to claim 10,
A semiconductor device characterized in that optical signals of the same phase are transmitted to a plurality of the optoelectronic element sections. 12. The semiconductor device according to claim 10,
A semiconductor device characterized in that the optical path lengths of the propagation section are made equal. 13. A system using a plurality of semiconductor devices according to claim 1, wherein the plurality of semiconductor devices are signal-connected to each other by the optical signal. 14. A system using a plurality of semiconductor devices according to claim 8, wherein the plurality of semiconductor devices are driven in synchronization with each other by the optical signal.