POLYCRYSTALLINE SILICON-GERMANIUM THIN-FILM TRANSISTORS

The fabrication of p- and n-channel MOS thin-film transistors (TFT's) in polycrystalline silicon-germanium (poly-Si1-xGex) films is described, and their electrical characteristics are presented. Various technological issues are then addressed in order to provide direction for further work in optimizing the fabrication process. The initial devices fabricated in this work exhibit well behaved electrical characteristics; enhanced performance is expected to accompany improvements in the crystallization and defect-passivation processes. Compared to a poly-Si TFT technology, an optimized poly-Si1-xGe(x) TFT technology may ultimately be able to provide a lower-temperature, shorter-time processing capability at little expense to device performance and it is therefore promising for large-area electronics applications.