Nonalloyed contacts to p-type GaAs

摘要

mation of low resistance ohmic contacts to semiconductor devices in which no melting ('alloying') of the contacting metals occurs is highly desirable. To form these contacts a very thin depletion layer must be created at the metal-semiconductor, MS, interface with tunneling occurring at the Fermi level. We describe two contacting schemes to p-type GaAs that avoid the alloying step and permit the use of robust refractory metals for the contacts. The p-contact will be important in proposed photo conductive switches using a P-i-N structure instead of the more common N-i-N structure. The work reported describes our studies of (a) a simple diffusion apparatus to create degenerate hole concentrations near the semiconductor interface and (b) a very stable highly doped epitaxial layer grown using Liquid Phase Epitaxy (LPE).