Ohmic contacts for group III-V n-type semiconductors using epitaxial germanium films

摘要

A solid-state diffusion method for providing ohmic contacts to n-type Group III-V semiconductor materials, such as gallium arsenide (GaAs). The material is successively cleaned, etched, rinsed, re-etched, rinsed and placed in an oil-free vacuum. The substrate is then heated to desorb surface oxides and an epitaxial layer of germanium and a layer of nickel, or other refractory, are deposited on the substrate at specific temperatures. Next, the structure is annealed in the vacuum at temperatures sufficient to diffuse the germanium into the GaAs material and to establish an ohmic contact.