| 摘要 |
1,049,417. Semi-conductor devices. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. May 13, 1965 [June 12, 1964], No. 24464/64. Heading H1K. The emitter of a controlled rectifier is made by alloying a perforated impurity containing foil to a body of silicon and subsequently applying a different contact material over the alloyed foil so that it makes ohmic contact with the adjacent region of the silicon body through the perforations in the foil. Typically the emitter foil is of gold-antimony and has from 30-100 uniformly spaced holes of about 0À01 inch diameter occupying from 7À5-17% of the area of the foil. The holes may be punched or drilled in the foil but are preferably formed by rolling the foil from a compaction of the alloy and particles of a soluble filler e.g. sodium chloride and then dissolving away the particles. After alloying, the emitter is vapour coated with gold or aluminium, with the rest of the silicon body masked. Following sintering at 450‹ C. in hydrogen a molybdenum contact is attached to the coating. Reference has been directed by the Comptroller to Specification 969,592. |
