| 摘要 |
1374682 High power storage diodes FMC CORP 13 July 1972 [5 Nov 1971] 32761/72 Heading H1K A high power storage diode having a substantially constant reverse current phase followed by a rapid reverse voltage build up after switching from forward to reverse current conditions, comprises a lightly doped P type silicon base region at least 100 Á thick, between an N type region diffused with phosphorus to an average concentration of from 2 x 10<SP>20</SP> to 5 x 10<SP>20</SP> atoms/c.c. and a P type region diffused with boron to an average concentration of at least 2 x 10<SP>20</SP> atoms/c.c. Typically the phosphorus is diffused in at 1250‹ C. in a flow of phosphorus oxychloride. After lapping the N + region from one side of the body this is painted with boron trioxide, the rest of the body masked and the boron diffused in by heating at 1300‹ C. in nitrogen. The reverse storage time may be increased by subsequent diffusion at 1100‹ C. for 4-15 minutes of nickel electrolessly plated on one of the end regions. The characteristics of the device and how these are varied by base width doping and current path cross-section are discussed. |
