| 摘要 |
1,237,414. Semi-conductor devices. TOKYO SHIBAURA ELECTRIC CO. Ltd. 15 Nov., 1968 [11 April, 1968], No. 54316/68. Heading H1K. In a semi-conductor device comprising a PN junction between high and low resistivity layers a continuous groove is formed extending from a major surface of the semi-conductor body through the junction and terminating in the high resistivity layer. The groove is inclined to an axis normal to said major surface so that the part of the high resistivity layer enclosed by it decreases in cross-section towards the bottom of the groove. The silicon controlled rectifier shown in Fig. 1 is made by diffusing gallium into a high resistivity N type wafer 3 to form a P type layer into which a gold-antimony member 6 is alloyed to form N type cathode zone 5. After ultrasonically bonding gate wire 7 to the P type layer adjacent the cathode and aluminium soldering tungsten anode 8 to the P layer on the other face the wafer periphery is rendered conical by blasting with an air jet containing entrained alumina particles while rotating the body. Then groove 9 is similarly cut using a suitably angled jet. If desired the wafer face on which the cathode is formed is depressed at its centre. Another embodiment consists of a bilateral 5 zone switch with its outermost zones short circuited to the neighbouring inner zones by the anode and cathode contacts (Fig. 5, not shown). The function of the groove is to increase the breakdown voltage of the junction. |
