| 摘要 |
<p>1,250,070. Semi-conductor devices. ITT INDUSTRIES Inc. 18 Sept., 1969 [25 Sept., 1968], No. 46056/69. Heading H1K. Leakage channels in the base region of a planar transistor are interrupted by an annular zone of the opposite conductivity type which surrounds the emitter region at a distance greater than the depletion layer thickness when it is biased by a blocking potential lower than the breakdown voltage of its associated junction. As shown, Figs. 3 and 4, an NPN planar transistor is provided with a P-type annular channel stopper region 7 at the surface of the base region 5 surrounding the emitter region 3. Region 7 is biased by means of three small transistor structures formed in the common N type collector region and their emitter-base junctions 10a, 10b, 10c are connected in series between the collector region and the annular region 7 so that they are reverse biased and form a potential divider. The device may be constructed in an N-type epitaxial layer on a P-type substrate and may form part of an integrated circuit employing diffused isolating regions 13. The base region 5 of the main transistor is contacted at region 11 which may be highly doped. Other methods of biasing the annular region are described with reference to Figs. 6 and 7 (not shown), in which a further base-collector junction is connected in series between the collector and the annular region, and Fig. 8 (not shown), in which the annular region is connected to a zone in an electrically isolated part of the I.C. A temperature compensated Zener diode, Fig. 10 (not shown), is simulated by a series connection of the base-emitter junctions of transistor structures. Three of the transistors are provided with annular channel stopper regions in their base regions. In one of these transistors the annular region is biased by strapping it to the collector region and in the other two transistors the annular regions are connected together and to the base of a further transistor structure, the emitter junction of which is connected to a suitable point of the series junction chain.</p> |
