Electrical characteristics of low temperature polysilicon TFT with a novel TEOS/oxynitride stack gate dielectric

Abstract

This investigation is the first to demonstrate a novel tetraethylorthosilicate. (TEOS)/oxynitride stack gate dielectric for low-temperature poly-Si (LTPS) thin film transistors (TFTs), composed, of a plasma-enhanced chemical vapor deposition (PECVD) thick TEOS oxide/ultrathin oxynitride grown by. PECVD N2O-plasma. The stack oxide shows a very high electrical breakdown field of 8.4 MV/cm, which is approximately 3 MV/cm larger than traditional PECVD TEOS oxide. The field effective mobility of stack oxide UPS TFTs is over 4 times than that of traditional TEOS oxide UPS TFTs. these. improvements are attributed to the high quality N2O-plasma grown ultrathin oxynitride forming strong Si drop N bonds, as well as to reduce the trap density in the dxynitride/poly-Si interface.