Electrical Contacts to Silicon Carbide

Abstract

Rectifying junctions may be made by heating silicon-aluminum or silicon-boron alloys in contact with n-type silicon carbide. The measured solubility of carbon in liquid silicon is consistent with the view that these junctions are produced by an alloying and regrowth mechanism. Nonrectifying contacts may be made in an analogous manner using silicon-phosphorous alloys. Visible radiation is emitted uniformly over the rectifying junctions when current is passed in the forward direction, with a quantum efficiency of the order of 10−6. Current flow in the reverse direction is associated with the appearance of ``blue spots,'' similar in appearance to the points of light that are often observed when silicon junctions are biased in the avalanche region.