Amorphous silicon thin-film transistors on steel foil substrates

We report the successful fabrication of high-quality a-Si:H thin-film transistors (TFTs) on stainless steel foil substrates. TFTs with an inverted-staggered structure were grown on 200-μm thick stainless steel foil. These TFTs show typical ON/OFF current ratios of 10/sup 7/, OFF currents on the order of 10/sup -12/ A, good linear and saturation current behavior, subthreshold slopes of 0.5 V/decade, and linear channel mobilities of 0.5 cm²/V. In addition, we have demonstrated that these TFTs are capable of withstanding significant mechanical shocks, as well as macroscopic deformation of the substrate, while remaining functional. This work demonstrates that transistor circuits can be made on a flexible, nonbreakable substrate. Such circuits would be highly useful in reflective or emissive displays, and in other applications that require rugged macroelectronic circuits.