Effects of Stress Mismatch on the Electrical Characteristics ofAmorphous Silicon TFTs for Active-Matrix LCDs

摘要

The effect of stress match between silicon nitridern(SiNBxB) and hydrogenated amorphous silicon (a-Si:H)rnlayers on the electrical characteristics of thin-filmrntransistors (TFTs) has been investigated. The resultrnshows that modifying the deposition conditions of a-rnSi:H and SiNBxB thin films can reduce the stressrnmismatch at a-Si:H/SiNx interface. Moreover, for bestrna-Si:H TFT characteristics, the internal stress of gaternSiNBxB layer with slightly nitrogen-rich should bernmatched with that of a-Si:H channel layer. The ONrncurrent, field-effect mobility, and stability of TFTs canrnbe enhanced by controlling the stress match betweenrna-Si:H and gate insulator. The improvement of theserncharacteristics appears to be due to both the decreasernof the interface state density between the a-Si:H andrnSiNx layer, and the good dielectric quality of thernbottom nitride layer.