| 摘要 |
1529498 Bipolar transistors RCA CORPORATION 2 Dec 1976 [15 Dec 1975] 50282/76 Heading H1K In a bipolar transistor, e.g. as shown in Fig. 3, the base zone of which has low and high resisitivity sections 24, 26 protection against collector junction breakdown is afforded by zone 32 surrounding and forming a PN junction with base zone section 24 and so located and designed that the depletion region of collector junction 11 punches through to it and hence causes avalanche breakdown of its junction with section 24 before avalanching of junction 11 occurs. Protection against emitter junction breakdown on reverse biasing is provided by conduction across the junction between zone 46 and collector zone 12 which is connected in parallel with the emitter-collector path by the metallization 38 shown. The optional provision of N+ zone 48, which is similarly positioned to zone 32 with reference to the collector junction and also contacts metallization 38 reinforces the collector junction projection by providing a punchthrough path parallel to the emitter-collector path. In the construction shown, which has a generally annular configuration zone 46 and zones 32, 48 are formed by the steps used to produce base zone section 26 and emitter zone 18 respectively.
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