| 摘要 |
1,153,893. Transistors. TEXAS INSTRUMENTS Ltd. 29 July, 1966, No. 34239/66. Heading H1K. A transistor comprises a semi-conductor body with an annular base region containing a plurality of spaced, discrete emitter regions and interdigitating ohmic contact electrodes to the emitter and base regions. In the NPN embodiment shown in Figs. 1 and 4, a silicon N + body 2 has deposited thereon an N-type layer into which is diffused impurity to produce annular P-type base region 1. In this region, a plurality of discrete emitter N-type zones 3 are produced, three such zones underlying each of the fingers 10 which project from annular ring 9, the fingers and ring constituting the emitter contact. Contact to the base zone is provided by by fingers 7 which project from a central region 6 which overlies an oxide layer on the silicon wafer. The collector contact is formed by a deposited layer 11, to which is soldered metallic disc 17 with projecting wire or stud 18. Connection to base contact region 6 is provided by disc 14 and wire 13 and to the emitter contact by a flat ring 15. The contacts may be provided by providing a molybdenum and a gold coating, and the connection thereto may be provided by gold-plated copper elements soldered with gold/ indium or gold/germanium alloys. The emitter portions may consist of discrete radial strips instead of a plurality of regions in the area corresponding to the strips. The device is enclosed in a glass or ceramic cup 27 with lid 28 or alternatively, may be potted, the arrangement is thus suitable for coaxial assembly. |
