Submicrometer p-Type SnO Thin-Film Transistors Fabricated by Film Profile Engineering Method

We reported the fabrication of submicrometer p-type tin monoxide (SnO) thin-film transistors (TFTs) with a channel length of 0.2μm for back-end-of-line applications using a film profile engineering (FPE) approach. Material analyses indicate that the as-deposited SnO films are amorphous, while be transformed to polycrystalline after a thermal annealing in oxygen ambient. Fabricated p-type SnO FPE-TFTs of a channel length of 0.2μm were manifested with ON/OFF current ratio higher than 10⁵ and subthreshold slope of 320 mV/decade, superior to the data of submicrometer SnO devices ever reported. The extracted field-effect mobility is about 0.25 cm²/V·s. After ruling out the influence of source/drain series resistance, the intrinsic field-effect mobility is found to be about 1 cm/V·s.