Nonalloyed ohmic contacts to n-type Group III(a)-V(a) semiconductors

Abstract

A nonalloyed ohmic contact (110-112, 120-122) to an n-type Group III(a)-V(a) compound semiconductor body (102-104) is formed by epitaxially growing a Group III(a)-V(a) n.sup.++ -layer (106-108, 106'-108') doped to at least 10.sup.19 cm.sup.-3 between the semiconductor body and a metal contact layer (110-112). The metal layer forms an ohmic contact without requiring heating above the eutectic temperature. In order to avoid contamination of the metal-semiconductor interface, a metal contact layer (120-122) may be deposited in situ after MBE growth of the n.sup.++ -layer. This technique results in both a metal-semiconductor interface with smoother morphology and also an ohmic contact without heating above the eutectic temperature. These procedures are specifically described with reference to the fabrication of GaAs FETs.

Dependencies are inferred from the claim text.