| 摘要 |
1381400 Semi-conductor devices BBC BROWN BOVERI & CO Ltd 23 June 1972 [25 June 1971] 29504/72 Heading H1K A semi-conductor device, e.g. a surge diverter with at least two series opposed diodes retained in a common housing (not shown), and provided with pressure contacts 9, 10 comprises a wafer of, e.g. Ge or Si having three npn layers 2, 3, 4 separated by PN junctions 5, 6; the edges being bevelled. Dished inserts 7, 8, e.g. of Ag are applied to the faces and overlap the ends, and the remaining space is filled with, e.g. a synthetic resin 11, to protect the PN junctions. Metal discs 9, 10 of, e.g. Mo, Wo, Ta, Cu or Cu alloys exert symmetrical pressures on the inserts 7, 8, and their contact faces are coated with, e.g Ni. In manufacture the surfaces of a monocrystalline n doped Si wafer may be p-doped with B by ampoule thermal diffusion to a boundery concentration of at least 10<SP>19</SP> atoms/ cm.<SP>3</SP> and a concentration of 10<SP>16</SP> atoms/cm.<SP>3</SP> at 35Á depth, after which the p-doped zone is removed from the edges which are then bevelled and etched. Thereafter the wafer is clamped between inserts and the edge spaces filled with synthetic resin. The wafer is slidably clamped between pressure contacts, and plural such wafers may be assembled in series cascade with interconnecting metal electrodes similar to discs 9, 10 under pressure in a spring loaded clamping frame (Fig. 2, not shown). |
