| 摘要 |
1,181,923. Semi-conductor devices. BROWN, BOVERI & CO. Ltd. 24 Jan., 1968 [26 Jan., 1967], No. 3684/68. Heading H1K. The surface of the body of a PNPN semiconductor device is bevelled so that in crosssection it has two outer portions at different angles 9 and 11 to the junctions, and between them a portion at an angle 10 intermediate in magnitude to these two. Angle 9 lies between 20 and 35 degrees, angle 10 between 3 and 5 degrees and angle 11 is substantially 2 degrees, the exact values depending upon the doping concentrations of the semi-conductor regions. A part 12 of the surface of region 2 adjacent the emitter 1 may be parallel to the surface 13 of the emitter. The angles are formed by grinding a flat circular PNPN body by three dome-shaped grinding shells of different radius in succession, grinding the largest angle first and the smallest last.
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