Fabrication of TFTs using plasma CVD poly-Si at very low temperature

Abstract

Polycrystalline-Si (poly-Si) films prepared by conventional plasma CVD with SiF/sub 4//SiH/sub 4//H/sub 2/ gases at a very low temperature (300 degrees C) have been applied to thin film transistors (TFTs). The thickness dependance of crystallinity and the surface morphology are characterized. Top gate coplanar TFT have been fabricated with optimized poly-Si. The characteristics are improved by annealing (400 degrees C). It increased the field effect mobility ( mu /sub e/) to 10.1 cm/sup 2//Vs and reduced off current (I/sub off/) by more than one order of magnitude.<>