A study of the chemical oxide/InP interface by deep-level transient spectroscopy

Abstract

Metal-insulator-semiconductor structures prepared by chemical oxidation of the InP surface in HNO3 solutions are studied before and after aging and annealing. One interfacial deep level with an activation energy ΔE=0.4 eV and a capture cross section σ=3.7×10−14 cm2 is observed on a freshly oxidized structure. After aging in air the characteristics of the deep level are ΔE=0.2 eV and σ=6×10−20 cm−2. Annealed aged structures exhibit two interfacial deep levels, one with ΔE=0.4 eV and σ=10−14 cm2 and the other with ΔE=0.2 eV and σ=2.1×10−19 cm2; this latter is located further in the bulk of InP. Some hypotheses are proposed to explain the instability phenomena observed in these devices.