Sputter-Deposited Thin Gate SiO_2 Films for High Quality Polycrystalline Silicon Thin Film Transistors

摘要

Polycrystalline silicon thin film transistors (poly-Si TFTs) with sputter-deposited thin gate SiO_2 films down to 9.5 nm have been fabricated and characterized. High performance n- and p-channel poly-Si TFTs were obtained by using sputter-deposited gate SiO_2 films. Electrical characteristics of on-current, threshold voltage and subthreshold slope were improved by thinning gate SiO_2 film. It was also clarified that "punch-through" short-channel effect was effectively suppressed by thinning gate SiO_2 films down to 9.5 nm. Moreover, high speed operation of complementary circuit consisted of n- and p-channel poly-Si TFTs was confirmed. In addition, sputter-deposited SiO_2 films showed excellent insulating properties of high breakdown electric field and low leakage current.