| 摘要 |
760,649. Coating with metals; gold alloy. RADIO CORPORATION OF AMERICA. Oct. 6, 1954 [Nov. 2, 1953]. No. 28822/54. Classes 82(1) and 82(2) [Also in Group XXXVI] A material is fused to a silicon surface region bearing a film of silicon oxide by placing a fluoride salt and said material on said surface region and heating the material, fluoride salt and surface region to a temperature below the melting point of silicon and at least as high as the alloy formed of said material and silicon. The fluoride salt may be the fluoride of said material formed by immersing the material in HF. As shown, to produce a semiconductor device, a pellet 4 of an alloy consisting of, by weight, about 25 per cent Sb and 75 per cent Au is first immersed in concentrated HF to produce a coating 6 comprising fluoride salts, allowed to dry and then placed on the surface of a wafer 2 of p-type semiconductive silicon. The wafer and pellet are heated together at 550‹-800‹C. for 2-5 minutes and cooled slowly. Other pellet materials specified are alloys of Su with Sb, As, or Bi. Alternatively, the fluoride salt may be distributed throughout said material e.g. a mixture of pulverized Sb or Au and 5-20 per cent of a powdered fluoride, such as antimony trifluoride or stannic fluoride, may be moulded to form a pellet. A non-rectifying connection to silicon may be made by fusing Sn to silicon using trifluoride. The following materials may also be fused to silicon. B, Al, Ga, In, Tl, P, As, Sb, Bi, Cu, Ag, Zn, Cd, and alloys of these elements with one another.
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