P-channel NiO thin film transistors grown with high k ZrO2 gate oxide for low voltage operation

Abstract

A low voltage operative and optically transparent p- type Nickel oxide thin film transistor (TFT) was realized. We have systematically investigated the structural and transport properties of both NiO and ZrO2 thin films grown by dc magnetron sputtering. It is shown that a 30 nm thickness of ZrO2 thin film act as gate oxide dielectric for the TFTs. The Metal-Insulator-Metal (MIM) study revealed a high dielectric constant (k) of 28 and the leakage current density significantly persisted at ∼1 nA cm−2 at an applied field of 7 MV cm−1. Further, active layer of p-NiO film was deposited on ZrO2 gate oxide dielectric film and were processed at different post annealing temperatures. The TFTs electrical characteristics with the staggered bottom gate configuration of ITO/ZrO2/NiO/Ag exhibits a stable 104 of Ion/Ioff ratio with a field effect mobility of 15.8 cm2V−1s−1 and recorded sub-threshold swing slope of 512 mV/dec. Moreover, the trap density of 1.82 × 1012 cm−3 was estimated from the Levinson’s plot. Overall, the post annealing temperature seems to improve the transport characteristics of the fabricated TFTs.