| 摘要 |
1,062,398. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES CORPORATION. Feb. 14, 1966 .[April 28, 1965], No. 6355/66. Heading H1K. A diffusion mask for a body of semi-conductor material comprises an epitaxial layer of a further semi-conductor material. As described, a film of silicon dioxide is deposited on a wafer . of gallium arsenide and is then, by photolithographic methods, removed from the whole surface with the exception of those areas into which diffusion is to take place. The exposed gallium arsenide surface is then covered by an epitaxially-grown layer, about 4 microns thick, of germanium, by means of a disproportionation process. The remaining silicon dioxide film is dissolved away in hydrogen fluoride and zinc is diffused into the gallium arsenide through the apertures in the germanium layer. Alternatively, the silicon dioxide film may be left in place so that the diffusion-occurs mainly at the interface between the silicon dioxide and the germanium. The germanium layer is finally removed by immersion in 30% hydrogen peroxide. A silicon masking layer may be used on a gallium phosphide substrate.
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