Novel top-gate zinc oxide thin-film transistors (ZnO TFTs) for AMLCDs

High-performance top-gate thin-film transistors (TFTs) with a transparent zinc oxide (ZnO) channel have been developed. ZnO thin films used as active channels were deposited by rf magnetron sputtering. The electrical properties and thermal stability of the ZnO films are controlled by the deposition conditions. A gate insulator made of silicon nitride (SiNx) was deposited on the ZnO films by conventional P-CVD. A novel ZnO-TFT process based on photolithography is proposed for AMLCDs. AMLCDs having an aperture ratio and pixel density comparable to those of a-Si: H TFT-LCDs are driven by ZnO TFTs using the same driving scheme of conventional AMLCDs.