Inversion-mode InP MISFET using a photochemical phosphorus nitride gate insulator

An inversion-mode n-channel InP MISFET is fabricated using a photochemical phosphorus nitride film as a gate insulator. An effective electron mobility of ∼1700 to 2200 cm2/Vs is obtained and the drain current maintains more than 80% of its initial value after 103 s at room temperature. These values are much superior to the characteristics of InP MISFETs using thermally deposited phosphorus nitride gate insulators. These improvements are probably caused by the reduction of thermal degradation of InP substrates through the application of the photochemical CVD technique.