Novel Small-Dimension poly-Si TFTs with Improved Driving Current and Suppressed Short Channel Effects

摘要

A novel small-dimension poly-Si TFT with ultrathin channel (300 A) and W-raised source/drain is proposed. The kink effect is effectively suppressed due to the reduced channel thickness. Tungsten film selectively grown on the source/drain region greatly improves the sheet resistance as well as increases the drain current. Furthermore, the W film is selectively deposited under low temperature (300°C). The process is simple and compatible with conventional low-temperature poly-Si (LTPS) process. Characteristics of devices with different channel thicknesses and dimensions are also studied, revealing that new devices with ultrathin channel are free from the floating body effect.