p-Type Thin Film Field Effect Transistors Based on Lithium-doped Nickel Oxide Channels Grown by Pulsed Laser Deposition

Staggered back-gated Field Effect Transistor (FET) structures were made by growing Li-doped NiO on Si3N4/SiO2/Si (111) using room temperature pulsed laser deposition. Optical studies showed over 80% transmission for the NiO: Li channel at wavelengths > 500nm. The MISFET revealed rectifying transfer characteristics, with a V-ON close to zero, a channel mobility of similar to 1 cm(2)/Vs, a gate leakage current (at +5V) of 0.8 mA and an I-ON/I-OFF ratio (at a Vgs of -15V) of similar to 10(3). The transistors showed enhancement-mode output characteristics indicative of a p-type channel with sharp pinch-off, hard saturation, a comparatively high (milliampere range) Id and a relatively low on-resistance of similar to 11 k Omega. Hence the adoption of Li doping in NiO channels would appear to be a promising approach to obtain p-type TFTs with superior transparency, speed and energy efficiency.