| 摘要 |
1313334 Semi-conductors TEXAS INSTRUMENTS Inc 27 July 1970 [21 Aug 1969] 36242/70 Heading H1K A semi-conductor circuit 11 (Fig. 1) comprises silicon body 12 with diffused collector and emitter junctions 13, 14 covered by a passivating SiO 2 layer 15 apertured for ohmic non- alloyed contact by collector, emitter, and base electrodes 16, 17, 18 having successive layers 19, 20, 21 of titanium, tungsten and gold. Titanium film is vacuum evaporated from a tungsten filament during rotation of the substrate and tungsten and gold are deposited by successive sputtering. Thereafter the films are selectively patterned through photoresist masks using aqueous hydrofluoric and nitric acids for titanium potassium ferrocyanide and sodium oxalate for tungsten, and buffered potassium cyanide for gold. An avalanche diode (Fig. 2) comprises a silicon body 23 of n conductivity having a ntype region 24 of higher resistivity than 23 overlain by p-type low resistivity region 25 forming junction 26. On this ohmic non-alloyed contact layers 27, 28, 29 of titanium, tungsten and gold are deposited as above, and similar layers of titanium and gold 30, 32 are deposited on the opposite surface; the gold layer 39 being bonded to a gold plated copper stud by thermocompression or ultrasonic welding. In application to integrated circuits a tripartite electrode layer may be covered by insulant apertured at selected locations, with interconnection through the apertures by a second tripartite layer. Application to Schottky barrier diodes and to semi-conductor devices of germanium and of III-V compounds, e.g. gallium arsenide, gallium phosphide, indium arsenide are also described. |
