Digital lithography for thin-film transistor fabrication

This work presents a novel digital-lithographic method, in which an electronically generated and digitally aligned etch mask is jet-printed onto a process surface. This method was used to fabricate hydrogenated amorphous silicon thin-film transistor (TFT) arrays. The digital lithographically fabricated arrays had features as small a 40 μm with 5 μm layer-to-layer registration and pixel resolution of 75 dpi over a four-inch diameter wafer. The resulting TFTs, with on/off ratios of 108 and threshold voltages of 2-3 V were then integrated with a-Si sensor media for an image sensor. The image sensor was operated as an X-ray and light detector.