Ge/GeO₂Interface Control with High-Pressure Oxidation for Improving Electrical Characteristics

Abstract

High-pressure oxidation (HPO) of germanium (Ge) for improving electrical properties of Ge/GeO2 stacks was investigated. The capacitance–voltage (C–V) characteristics of metal/GeO2/Ge capacitors fabricated with HPO revealed improved electrical properties without any post-deposition annealing, and the interface states density (Dit) was reduced to 2×1011 eV-1 cm-2 near the midgap. Moreover, the refractive index of thermally oxidized GeO2 was increased by HPO. It is also discussed from a thermodynamic viewpoint of the Ge/GeO2 system that the GeO desorption from Ge/GeO2 stacks could be efficiently suppressed by HPO.