Integrated Amorphous and Polycrystalline Silicon TFTs with a Single Silicon Layer

Abstract

AbstractSelective exposure of an a-Si:H film to a room temperature hydrogen plasma using a patterned SiNx, capping layer and a subsequent anneal at 600°C, resulted in polycrystalline and amorphous silicon regions in a single silicon layer on the same glass substrate. Top-gate non-self-aligned TFTs were fabricated in both the amorphous and polycrystalline regions with all shared processing steps and no laser processing using a re-hydrogenation step. The TFTs had good characteristics, with field-effect mobilities upto 1.2 cm2/Vs and 15 cm2/Vs for the a-Si:H and the poly-Si TFTs, respectively, and ON/OFF ratios >105 in either case.