DISPOSITIFS SEMICONDUCTEURS, TELS QUE TRANSISTORS DE PUISSANCE ET LEUR PROCEDE DE FABRICATION

摘要

1322141 Overlay transistors RCA CORPORATION 3 Jan 1972 [5 April 1971] 42/72 Heading H1K The "overlay" transistor shown is characterized by the material of the base contact grid 44. The grid is made of a high melting point intermetallie compound of the semi-conductor: the silicon device shown uses platinum silicide or rhodium silicide, the grid being formed by the deposition and sintering of the platinoid metal, the excess of which is then removed. The temperature stability of the grid means that it may be formed before the formation (by diffusion) of the plurality of emitter segments 26. Emitter contact is made (through the oxide films 30, 36) by a layer 40 (optional) of polycrystalline silicon and a superposed metal layer 41. The transistor of Figs. 1 (not shown) and 2 differs from that of Fig. 4 (not shown). In the former contact pads for both base and emitter lie on the collector oxide whereas in the latter the emitter pad overlies the base and emitter regions. In both the base grid is contacted by metal over part of its area.