Printed a-Si:H transistors for large area electronics
Printing technology can be used to fabricate amorphous silicon thin-film transistor arrays. We describe a process based on jet-printed etch masks in place of conventional photo-lithography. The wax-based etch masks with a minimum feature size of ~ 40 ƒÝm were printed using a multi-ejector piezoelectric print-head. Bottom-gate TFTs in a 64¡Ñ64 pixel array of 338 ƒÝm size, were created using a four-mask process. TFTs have current-voltage characteristics comparable to conventional devices, with mobility 0.7 cm2/Vs and on/off ratio exceeding 108. The arrays were configured for x-ray imaging by adding an a-Si:H p-i-n photodiode layer, and were also used to drive a reflective display.
Street, R. A.; Wong, W. S.; Ready, S. E.; Lujan, R. A. Printed a-Si:H transistors for large area electronics. physica status solidi (c); special issue on Amorphous and Microcrystalline Silicon – Materials Science and Devices. 2004 March; 1 (5): 1316-1323.