| 摘要 |
1,220,315. Semi-conductor devices. BROWN, BOVERI & CO. Ltd. 14 July, 1969 [15 July, 1968], No. 35239/69. Heading H1K. In a semi-conductor device having three regions of alternate conductivity types, the junctions between which emerge at the edge of the body, the edge is bevelled and an annular groove is formed in the smaller face extending completely through the region in which it is formed to divide this region and the associated junction into two parts. As shown, Fig. 2, the edge 5 of a thyristor is bevelled and a groove 11 is ultrasonically machined in the upper face 1 to divide the upper P-type base region into two portions 4, 12. This groove allows the depletion layer associated with the junction between regions 2 and 3 under reverse bias to spread further into region 3 without surface breakdown occurring since without the groove breakdown would occur as soon as the upturned edge of the depletion layer contacted the junction between regions 3 and 4. The semi-conductor body is of Si and is mounted on a Mo support 6. The emitter region 9 and its electrode 8 are annular and surround a central gate contact (not shown). The angle α between the wall 14 of the groove 11 and the junction between regions 3 and 4 is preferably 20 degrees or less. |
