Performance Enhancement on an InGaP/InGaAs PHEMT With an Electrophoretic Deposition Gate Structure

Interesting pseudomorphic high electron mobility transistors using an electrophoretic deposition (EPD) approach are fabricated and studied. Due to the low-temperature deposited gate structure, the studied device exhibits enhanced performance with less thermal damages and improved Schottky contact properties by EPD approach. In comparison with a thermal evaporation (TE) device, the higher turn-on voltage, lower gate current, and lower interface state density are observed for the EPD device. For the gate dimension of 1 × 100 μm
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the EPD device shows the higher maximum drain saturation current of 242.2 (231.9) mA/mm and excellent maximum extrinsic transconductance of 151.6 (132.5) mS/mm at 300 (420) K. Besides, the EPD device presents a comparable RF performance as compared with the TE one. Due to the improved device performance and advantages of low cost, simple process, flexible deposition on varied substrate, and adjustable metal grain size, the reported EPD approach shows the promise for high-performance device applications.