High-performance 90-nm dual-gate nMOSFETs with field-plate technology

In this letter, high-performance 90-nm dual-gate nMOSFETs with field-plate (FP) metal were demonstrated for high-power and low-frequency noise device applications. The proposed dual-gate nMOSFETs with FP metals had a higher maximum oscillation frequency f_MAX, a lower noise power spectral density, and a higher output power P_out than traditional dual-gate architecture. These improvements were obtained because two extra FP-induced depletion regions were present, and the total electrical field was suppressed, yielding high output resistance and higher output power. These FP-induced depletion regions also pushed the carriers into deeper channels and reduced the number of opportunities for carriers to be trapped by surface states between gate and drain terminals. Based on the dependence of the normalized noise power spectral density S_IDID₂ on the gate voltage, the FP dual gate had a low noise power spectral density and a low range of Hooge factors at high current.