Au ohmic contacts to p-type Hg1-xCdxTe utilizing thin interfacial layers

Ohmic behavior is observed in electroless Au contacts to p-type Hg1-xCdxTe. The authors' investigation of the interfacial chemistry of such contacts suggest that this ohmic behavior may be due to the presence of a Te,O, and Cl layers. To verify this correlation with interfacial chemistry, thin plasma oxide layers were used in evaporated Au contacts. The annealed plasma oxidized contacts exhibit low contact resistances. This behavior was attributed to a low interface state density at the interfacial state density at the interfacial layer/Hg1-xCdxTe interface. In comparison, as developed and annealed Au contacts without a thin interfacial layers were rectifying with a large barrier height