Preparation and Electrical Properties of an Anodic Oxide of InP

Electrical properties of an anodic oxide of InP grown in tartaric acid/propylene glycol electrolytes with p H of 2–12 have been studied. The oxide composition is varied from P 2 O 5 ‐ rich to In 2 O 3 ‐ rich , depending on the p H of the electrolyte employed A subsequent annealing is necessary to dehydrate grown oxides. Annealing at a temperature higher than 300°C degrades the electrical properties of the oxide / InP interface, and interface instability due to the annealing increases with increasing In 2 O 3 content in the oxide. The oxide grown in the p H 5–7 electrolyte at 1–2 mA/cm 2 current density and then annealed at 200°C has an interface‐state density of ≲10 12 cm −2 · eV −1 at ( E c − 0.1 ) eV and of ∼ 8 × 10 10 cm − 2 · eV − 1 near the midgap.