Surface passivation and oxidation of cadmium telluride and properties of metal-oxide-CdTe structures

The oxidation of single-crystal p-type CdTe of {111} orientation by thermal, wet chemical, and plasma techniques has been investigated. The C-V measurements of metal-oxide-semiconductor (MOS) structures prepared from various oxides indicate that device quality thermal oxide can be prepared by hydrogen annealing of CdTe prior to oxidation. The thermal oxide consists mainly of TeO2. MOS structures prepared from oxidation of the Cd(111) or Te(1̄1̄1̄) face of CdTe show low oxide fixed charge density (1011/cm2) and low interface state density (1010/cm2 eV). MOS structures prepared from wet chemical oxide and plasma oxide have less desirable properties.