Nanocrystalline Diamond Gate FET for on-State Current Improvement

A nanocrystalline diamond gate field-effect transistor (FET) is demonstrated for the improvement of on-state current with a CMOS-compatible process. A nanocrystalline diamond film was deposited on a Si₃N₄/SiO₂ gate dielectric as a gate material. The diamond thin film served as a gate electrode; hence, an n-channel FET was successfully demonstrated. As a control group, a polysilicon gate FET with the same structure was also fabricated. Compared to the polysilicon gate FET, the diamond gate FET showed doubled on-state current, which was primarily attributed to the strain effect of the diamond gate acting on the channel.