Electrical and optical characteristics of InP enhancement mode metal/insulator/semiconductor field effect transistors with a novel anodic double-layer gate insulator

High mobility enhancement mode InP metal/insulator/semiconductor field effect transistors (MISFETs) were fabricated with an anodic Al₂O₃/anodic native oxide double-layer gate insulator grown by a simple anodization process. Effective electron mobilities in the channel as high as 1500-3000 cm² V^-1s^-1 were achieved after a post-growth annealing in H₂ at 400 °C for 30 min. The slow drain current drift phenomenon was also greatly reduced by the annealing. The optical properties of the double-layer gate insulator MISFETs were also investigated, and a current gain as high as 10⁴ was obtained. A brief phenomenological discussion on the gain mechanism is given.