Elevated-Metal-Metal-Oxide Thin-Film Transistor: Technology and Characteristics

A new device architecture, dubbed elevated-metal- metal-oxide (EMMO) thin-film transistor (TFT), is presently proposed. During a heat-treatment process in oxygen, conductive source and drain regions spontaneously populated by donor defects are formed, while the defects in the channel region are simultaneously passivated. Compared with that of the conventional back-channel-etched TFT, this architecture inherently accommodates an etch-stop/passivation layer without increasing the mask count. EMMO TFT demonstrated using indium- gallium-zinc oxide as an active layer exhibited good performance metrics: a peak field-effect mobility of ~14 cm 2 /Vs, a steepest pseudo-subthreshold slope of ~120 mV/decade, a leakage current lower than ~10 -14 A, an on/off-current ratio above ~10 10 , and stability against environmental and electrical stress.