Dependence of Single-Crystalline Si TFT Characteristics on the Channel Position Inside a Location-Controlled Grain

Abstract

To obtain high-performance thin-film transistors (TFTs), a comprehensive study of the channel position of TFTs inside a location-controlled grain was carried out. The location of the grain is precisely controlled by the /spl mu/-Czochralski process using an excimer laser. The grain was grown from a thin Si column embedded in SiO/sub 2/ (grain filter). The characteristics of the TFTs drastically improved when the channel region was not centered above the grain filter. With TFTs whose current-flow direction is parallel to the radial direction of the grain filter, an electron mobility and subthreshold swing of /spl sim/600cm/sup 2//V/spl middot/s and 0.21V/dec respectively were obtained.