| 摘要 |
An electric circuit element, e.g. a cryotron, is formed by a photolysis process. As shown, a glass substrate 42 is given a lead coating from a source 24, a silicon monoxide coating from a source 26, then a tin coating. The coatings are made through a mask 52. The holder 42 is then rotated though 180 degrees, gaseous nitromethane fed into the evacuated chamber 10, and a light source 76 energized to direct ultraviolet light through a mask 74 on to the tin coating, so that the parts of the coating exposed to the light are converted to an etch resistant pattern. The light passes through a quartz pipe 72, the temperature of which is controlled by a heating wire 80 and <PICT:0997642/C6-C7/1> a cooling coil 85. The nitromethane is then removed by suction and the coatings etched either in situ by a vapour phase etchant, e.g. hydrogen chloride, or by removing the substrate and placing it in a liquid etchant, e.g. nitric acid. After etching, the holder 42 is again rotated through 180 degrees and further coatings of silicon monoxide and lead applied. In a modification, Fig. 2B (not shown), a semi-conductor circuit is formed by depositing germanium on a substrate, forming a pattern with nitromethane and etching. Interconnection lines of zinc and antimony are applied and the whole heated to diffuse some of the material of the lines into the germanium. The films which may be used in this process are: (1) Group IV and transition metal elements, e.g. Sn, Ge, Si, Fe, Pb; (2) binary alloy films of Group IV elements, e.g. Sn-Ge, Pb-Sn, Ge-Si, Pb-Ge, and binary alloys of transition elements, e.g. Ni-Fe, Ti-Fe; (3) intermetallic compounds of Group II-V, III-V, II-VI and III-VI elements such as GaAs, CdS, ZnP, InTe, GaP, InSe, InAs. The gas used for photolysis may be inorganic, e.g. nitrogen dioxide, dinitrogen tetroxide, chlorine dioxide, and a mixture of nitrous oxide and oxygen or organic, e.g. R-NO2, where R is selected from the group methyl, ethyl, propyl, iso-propyl, butyl, isobutyl, tert.-butyl and sec.-butyl or halo-alkanes (methylene chloride), nitroaryl (nitrobenzene), nitroalkylaryl (nitrotoluene) and haloaromatic (phenyl chloride).
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