Accession Number : AD0289015

Title :   BETA-SILICON CARBIDE AND ITS POTENTIAL FOR DEVICES

Corporate Author : STANFORD RESEARCH INST MENLO PARK CALIF

Personal Author(s) : NELSON,W.E.

Report Date : 15 NOV 1962

Pagination or Media Count : 1

Abstract : The resistivities of crystals of beta-SiC grown during this quarter increased nearly another order of magnitude over those obtained during the last report period. This increase, from approximately .5 to 3.8 ohm-cm, accompanied progress in minimizing the sources of N contamination during crystal growth. Routine degassing of graphite crucibles at 2150 C and 10 to the -5th power mm Hg within the crystal grower was achieved. Analyses of Si stock used for crystal growth revealed N contents as high as 43 ppm. Specially purified low-N-content Si rod was obtained, and a vacuum extraction procedure for removing any remaining dissolved N was developed. Analyses of ordinary standard tank He used for the crystal growing furnace atmosphere revealed N contamination as high as 600 ppm. Analyzed premium grade He containing less that 10 ppm N was received from suppliers and a new bakeable purification train is being constructed to assure a N-free furnace atmosphere. (Author)

Descriptors :   *CARBIDES, *SILICON COMPOUNDS, *SINGLE CRYSTALS, CONTROLLED ATMOSPHERES, CRUCIBLES, GRAPHITE, IMPURITIES, MANUFACTURING, NITROGEN, RESISTANCE (ELECTRICAL)

Distribution Statement : APPROVED FOR PUBLIC RELEASE