METHOD FOR DIFFUSING AN IMPURITY SUBSTANCE INTO SILICON CARBIDE

1,238,729. Electroluminescence. MATSUSHITA ELECTRIC INDUSTRIAL CO. Ltd. 10 Sept., 1968 [11 Sept., 1967 (2)], No. 43033/68. Heading C4S. [Also in Division H1] An impurity substance is implanted into SiC by ion beam bombardment followed by annealing at a temperature in the range 1200 to 1600‹ C. The SiC may be N type containing nitrogen or P type and the impurity may be boron, aluminium, indium, or gallium to produce P type conductivity or phosporus, arsenic, antimony or nitrogen to produce N type conductivity. PN, PIN, P+P or N+N type junctions may be formed and the device may constitute a luminescent diode or an integrated circuit. Mention is also made of combining luminescent diodes and integrated circuits to provide a modulated radiation output and to convert input D.C. supply to a pulsed supply for driving the diodes. The implanted impurity may be restricted to selected areas by means of a perforated metal mask. A thin ion implanted layer may be formed over the entire top face of a body and electrodes applied which together with electrodes on the lower face form one or more luminescent diodes in a desired pattern, the luminescent area being limited to the contacted areas of the top face due to the high sheet resistance of the layer. The light is emitted through the bulk of the body, which is transparent. The electrodes on the lower face are displaced relative to those on the upper face.