| 摘要 |
1,070,303. Semi-conductor devices. HITACHI Ltd. Dec. 9, 1965 [Dec. 17, 1964]. No. 52349/65. Heading H1K. Metal is deposited from the vapour phase through a photo-sensitive resist mask on to a semi-conductor in two stages, the second stage at a lower temperature than the first. To bond a deposited metal to a semi-conductor the temperature of deposition must be in the neighbourhood of the metal-semi-conductor eutectic. But to prevent contamination of the surface of the deposited metal by carbonized resist, deposition should occur at a temperature below that at which the resist volatilizes or carbonizes. These considerations define the temperatures of the two stages, which for deposition of aluminium on silicone are 550‹ and 200‹ C. respectively for periods sufficient to deposit 0.2 to 1.0Á in the first stage and up to 0.2Á in the second. The clean deposit of the second stage provides for ready attachment of wire terminals, e.g. of aluminium or gold, which may be attached to it by thermocompression bonding. A complete process, otherwise conventional, for producing a planar transistor is described in the Specification with reference to Fig. 2 (not shown). |
