| 摘要 |
1,227,649. Integrated circuits. INTERNATIONAL BUSINESS MACHINES CORP. 6 Aug., 1969 [4 Sept., 1968], No. 39276/69. Heading HlK. [Also in Division H3] An integrated circuit includes a plurality of transistors comprising a common emitter region separated by a base zone from a plurality of highly conductive collector regions which have extensions to the wafer surface but are effectively mutually isolated by highly resistive material of the same conductivity type which also isolates the transistor from adjoining circuit elements. The Fig. 1 arrangement is a logic switch, shown in Fig. 4 in circuit form in association with emitter followers 80, 82 which may, if desired, be integrated into the same wafer. The three input transistors 68-72 are defined by those parts of the cruciform emitter 14 associated with base contacts 58, 60, 62, respectively, the relevant parts of base zone 54 and common collector zone 26, while reference transistor 66 comprises the part of the emitter adjacent base contact 64 and the separate collector zone 28. The base zone has a sheet resistance of 25 k#/sq. beneath the emitter and 1 k#/sq. elsewhere to resistively isolate the base contacts (resistors 98 in Fig. 4), while the collector zones have a low sheet resistance and are extended to the surface by heavily doped plugs 30, 32. As shown, the input transistors have a common collector zone and electrode 38 but they may have separate plugs and externally commoned electrodes or in a modified circuit may have individual collector zones, plugs and contacts. Emitter current is distributed to various collector zones in accordance with the biasing of the base contacts, clear separation resulting from operating the low current gain emitter at a high current density. |
