| 摘要 |
886,637. Semi-conductor devices. SIEMENS & HALSKE A.G. July 1, 1959 [July 2, 1958], No. 22634/59. Class 37. In a voltage - dependent capacitor of the type including a PN junction the cross-sectional area of at least one of the semi-conductor zones adjacent the junction decreases continuously or in a stepwise manner. Thus as the space charge region is expanded by the operating voltage the capacity is further reduced by the decrease in area of the material. Fig. 1 shows a junction consisting of weakly-N-type material 1 which decreases uniformly in area in a direction perpendicular to the junction. The P-type material 2 is more strongly doped. The effect of the weakly doped N region is to increase the expansion of the space charge zone. Fig. 2 shows a construction in which the cross-sectional area of the N-type material 5 is reduced in a step-wise fashion. Layer 7 is P-type and is formed by alloying an acceptor material into the layer 5. |
