Gate-first inversion-type InP metal-oxide-semiconductor field-effect transistors with atomic-layer-deposited Al₂O₃ gate dielectric

We present n-channel enhancement-mode inversion-type indium phosphide (InP) metal-oxide-semiconductor field-effect transistors with atomic-layer-deposited Al₂O₃ gate dielectric. It has been found that applying sulfur passivation and postdeposition annealing in the process improves the drive current and subthreshold swing. Transistors on semi-insulating InP substrates show much higher drive current than the ones on p-type InP due to the asymmetric distribution of interface state along the bandgap between InP and Al₂O₃. The effects of transient and slow traps on the transistor performance have also been investigated using constant electrical stress measurements and pulse measurements.