Silicon on insulator semiconductor composition containing thin synthetic diamone films

Information

  • Patent Grant
  • 5131963
  • Patent Number
    5,131,963
  • Date Filed
    Friday, August 26, 1988
    36 years ago
  • Date Issued
    Tuesday, July 21, 1992
    32 years ago
Abstract
A process is provided for making a semiconductor element comprising a single-crystal layer of silicon on a diamond insulator.
Description
Claims
  • 1. A semiconductor element consisting of a semiconductor material supported by a polysilicon substrate, wherein an insulating diamond layer is disposed between said semiconducting material and said polysilicon substrate.
  • 2. A multilayer semiconductor electronic component consisting of, in order, a substrate, an insulating diamond layer, a silicon layer and a layer comprising islands of semiconductor material separated by diamond insulation.
  • 3. A semiconductor electronic component according to claim 2 wherein said substrate comprises polysilicon.
  • 4. A semiconductor electronic component according to claim 2 wherein said semiconductor material comprises gallium arsenide.
BACKGROUND OF THE INVENTION

This is a continuation of application Ser. No. 121,308 filed Nov. 16, 1987, now abandoned. The present invention is directed to a method for making semiconductor elements comprising a single crystal layer of silicon on a diamond insulator. The present invention is further directed to novel semiconductor elements made according to that process. A component useful for integrated circuits is an active semiconductor film on an insulating substrate, since it has superior operational characteristics compared to a noninsulated active semiconductor film. For example, a conventional noninsulated active semiconductor film made of silicon, which itself is not an insulator, suffers from the problem of cross-talk, which is the transportation of charge carriers along the silicon substrate between adjacent transistors in an integrated circuit. As a consequence of this problem, silicon semiconductor films on insulators have been developed, which include the formation of single-crystal silicon films on insulating substrates such as sapphire, spinale and on amorphous silicon dioxide, followed by recrystallization of the polysilicon films. This technology, termed SOI (silicon on insulator) technology has additional advantages in that the insulator layer provides a shield against ionizing radiation which could generate charge carriers within the bulk silicon, thus leading the flow of parasitic currents between circuit elements. Also, complementary metallic oxide semiconductor (CMOS) circuits may suffer from the problem known as latch-up whereby different elements of the circuit interfere with each other through the bulk silicon when such crosscommunication is undesirable. Cross-talk, and in particular latch-up, are problems confronting the further reduction in dimension of circuit elements for integrated circuits. The problems with current SOI technology, such as silicon on sapphire, silicon on silicon dioxide, and the like, include the following. When sapphire is used as the insulator, the quality of epitaxial silicon films deposited on sapphire are inferior to conventional Czochralski crystals, or expitaxial films deposited on single-crystal silicon. Very thin (on the order of 1-2 microns) silicon epitaxial films are typically poor in quality with a large density of defects which severely limit the capabilities of circuits built with them. Thus, the achievement of high-quality thin epitaxial silicon films is required to maximize the advantage of SOI technology, but such thin films have heretofore not been achievable with acceptable performance. Silicon on sapphire technology is also extremely expensive since it requires the growth of a single sapphire crystal, slicing of the single crystals into wafers, polishing the wafers, and depositing the silicon on the wafers by CVD (chemical vapor deposition) techniques. Growing silicon on silicon dioxide insulators, followed by recrystallization of the polysilicon films by thermal annealing, while theoretically possible, has not yet achieved acceptable quality or efficiency of manufacture. Therefore, due to the above disadvantages of SOI technologies heretofore known, particularly to the disadvantage of extreme expense in producing the SOI semiconductors, broadbased commercial markets for SOI semiconductors have failed to materialize, with the only substantial market being specialized military uses where costs of production are of less concern. It is therefore an object of the present invention to provide a novel silicon on insulator technology wherein the insulator is synthetic diamond. It is a further object of the present invention to provide novel silicon on diamond semiconductors which may be readily made using relatively inexpensive processing techniques. These and other objects will be apparent from the following description and appended claims and will further be apparent from the practice of the invention. The present invention provides semiconductor elements comprising a single crystal layer of silicon on a diamond insulator. A basic element is formed by the steps of diffusing into one surface of a substrate an etch-stop material which is not etchable by at least one etching process which etches the substrate, to form a diffusion-prepared layer; epitaxially depositing a silicon layer onto the. diffusion prepared layer of the substrate; depositing a diamond layer onto the epitaxial silicon layer; removing the substrate by an etching process which does not etch the etch-stop material whereby the etching ceases at the diffusion-prepared layer; and selectively removing the diffusion-prepared layer to form the semiconductor element. A support layer may also be deposited upon the surface of the diamond insulator which is not in contact with the silicon layer. This basic element is further processed to provide novel semiconductor elements comprising single layers of silicon on diamond for various applications.

US Referenced Citations (6)
Number Name Date Kind
4447497 Manasevit May 1984
4768011 Hattori et al. Aug 1988
4863529 Imai et al. Sep 1989
4891329 Reisman et al. Jan 1990
4939043 Biricik et al. Sep 1990
4981818 Anthony et al. Jan 1991
Continuations (1)
Number Date Country
Parent 121308 Nov 1987