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Abstract: SrTiO3 thin films were deposited on AlGaN/GaN wafer by a simple, low-temperature liquid-phase deposition (LPD) method, and applied as the gate dielectric in metal oxide semiconductor high electron mobility transistor (MOSHEMT). X-ray diffraction and electrical characteristics were measured to investigate the film phase and leakage current. AlGaN/GaN MOSHEMTs with 20nm-thick SrTiO3 as the gate dielectric were also fabricated. Compared with its counterpart HEMT, MOSHEMT shows lower leakage current and larger breakdown voltage. The suppressed gate leakage current improves both I on/I off ratio and subthreshold slope. Larger maximum drain current density could be achieved with higher V on in the MOSHEMT. Flatter transconductance and wider gate voltage swing of the MOSHEMT demonstrate better device linearity. The lower low-frequency noise is obtained due to the lower surface states. [Copyright &y& Elsevier]

Abstract: InGaP/InGaAs metal–oxide–semiconductor (MOS) pseudomorphic high-electron-mobility transistor (PHEMT) with a nanoscale liquid phase-oxidized InGaP as the gate dielectric is demonstrated. Not only does the MOS-PHEMT have the advantages of the MOS structure, but it also has high-carrier density and a high-mobility 2DEG channel. Using selective oxidation of InGaP by liquid phase oxidation, the MOS-PHEMT can be fabricated without additional recess processes. The MOS-PHEMT exhibits larger transconductance, lower gate leakage current, higher breakdown voltage, higher cut-off frequency, lower minimum noise figure, and higher power-added efficiency than does its counterpart (reference PHEMT). The interface roughness effect on the DC and RF performance of devices is also discussed. [Copyright &y& Elsevier]