Microporous SiO2 with huge electric-double-layer capacitance for low-voltage indium tin oxide thin-film transistors

Abstract

Electric-double-layer (EDL) effect is observed in microporous SiO2 dielectric films deposited at room temperature by plasma-enhanced chemical vapor deposition method. Indium tin oxide thin-film transistors gated by such microporous SiO2 gate dielectric are fabricated at room temperature, and a low operating voltage of 1.5 V is obtained due to the huge EDL specific capacitance (2.14 μF/cm2). The field-effect electron mobility is estimated to be 118 cm2 V−1 s−1. Current on/off ratio and subthreshold gate voltage swing are estimated to be 5×106 and 92 mV/decade, respectively. Room-temperature deposited microporous SiO2 dielectric is promising for low-power field-effect transistors on temperature sensitive substrates.