Verfahren zur Herstellung hochohmiger Siliziumkarbid-Dioden

摘要

A normal grown crystal of high doped silicon carbide of one conductivity type has formed on one face by deposition from the gas phase, an epitaxial layer of high ohmic resistance monocrystalline silicon carbide either of opposite type so forming the p-n junction or of the same type but differently doped. In this case the p-n junction is formed by deposition of a second epitaxial layer this time of the opposite conductivity type or by diffusion over the whole body the side opposite to the epitaxial layer and the edge then being reduced by lapping. Epitaxial layer formation is by hydrogen reduction of a silane and a hydrocarbon at between 1500 and 1800 degrees C, the hydrogen being first purified by palladium diffusion and the liquid compounds degassed.