Halbleitervorrichtung mit einem isolierenden Bereich und Verfahren zu ihrer Herstellung

摘要

1287221 Anodically rendering silicon porous NIPPON TELEGRAPH & TELEPHONE PUBLIC CORP 27 Jan 1970 [29 Jan 1969] 3876/70 Heading C7B [Also in Division H1] A selected portion of a silicon body is converted into porous silicon by an anodic process in an aqueous solution of HF. The conversion can be continued to substantial depths. The porous silicon is an insulator, has the same dimensions as the original region, can be etched by an aqueous solution of HF and HNO 3 , is readily oxidized and allows rapid diffusion of impurities. The concentration of the HF solution should be at least 10%. In a specific example a wafer of P type Si is polished, etched, masked with islands of Si 3 N 4 , and electrolytically processed in a 46% aqueous solution of HF using the Si body as the anode and a platinum cathode. P type Si is converted at a much higher rate than N type material. The process is used in the production of various semi-conductor devices (see Division H1).