InP-based MOSFET technology utilizing a liquid phase oxidized InGaAs gate

We first report the characteristics of InGaAs-oxide grown by a liquid phase oxidation using a gallium-ion-contained nitric acid solution and an oxygen plasma treatment and depletion-mode In_0.53Ga_0.47As- and InP-channel MOSFETs using the InGaAs-oxide. The characteristics of InGaAs-oxide showed low leakage current and small capacitance-voltage hysteresis. 1.5×50 μm² depletion-mode In_0.53Ga_0.47Asand InP-channel MOSFETs were fabricated by using a conventional optical lithography. The gate oxide was formed by a liquid phase oxidation of InGaAs ohmic cap layer and subsequently an oxygen plasma treatment after mesa etching and ohmic metallization. The drain current-voltage characteristics of In_0.53Ga_0.47As- and InP-channel MOSFETs showed a complete pinch-off and saturation. The f_T and f_max of the In_0.53Ga_0.47As-channel MOSFET were approximately 9 GHz and 10 GHz, respectively, and those of the InP-channel MOSFET were approximately 10.5 GHz and 70 GHz, respectively.