Thin-Film Transistors in CO2-Laser Crystallized Silicon Films On Fused Silica

Abstract

ABSTRACTThin-film transistors (TFT) have been fabricated in scanned CO2 laser-crystallized silicon films on bulk fused silica. In n-channel enhancement-mode transistors, it is demonstrated that an excessively large leakage current can be electric-field modulated with a gate electrode located beneath the silicon layer. This dual-gate configuration provides direct verification on bulk glass substrates of back-channel leakage as has recently been demonstrated for beam-crystallized silicon films on thermal oxides over silicon wafers. With the application of deep-channel ion implantation to suppress back-channel leakage, high-peformance TFTs have been fabricated in single-crystal silicon films on fused silica. The results demonstrate that scanned CO 2 laser processing of silicon films on bulk glass can provide the basis for a silicon-on-insulator technology.