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

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 mu F/cm(2)). The field-effect electron mobility is estimated to be 118 cm(2) V-1 s(-1). Current on/off ratio and subthreshold gate voltage swing are estimated to be 5x10(6) and 92 mV/decade, respectively. Room-temperature deposited microporous SiO2 dielectric is promising for low-power field-effect transistors on temperature sensitive substrates.