Analysis of Plasma Oxidised Hg1-xCdxTe Surfaces

Abstract

ABSTRACTWe report for the first time on the application of Field Enhanced Plasma Oxidation (FEPO) to the passivation of Hg1-xCdxTe. Oxide layers of thickness 250-500Å were grown on Hg0.4Cd0.6Te at temperatures in the range from 30°C to 100°C. The index of refraction of the oxide layer, as determined by ellipsometry, was between 1.99 and 2.10. Auger depth profiles of the surfaces showed a compositional variation through the oxide with predominantly a mix of Cd and Te oxides in a film depleted in Hg. The oxides had dielectric constants of 3.6 to 4.5, and dielectric strength greater than 1 × 107 V/cm. The oxide/semiconductor interfaces had high densities of “slow” states but were capable of being depleted and accumulated.