A BCE-type a-Si TFT with an island metal masking structure

Abstract

A new back channel etched hydrogenated thin film transistor (TFT) device with an island metal masking structure has been proposed and fabricated. The TFT structure contained a continuous layer deposition process of SiN/sub x//a-Si/n+a-Si/metal, and finally resulted in an additional metal layer between source/drain metals and islands. The channel metal was etched in the S/D metal mask patterning simultaneously. Results showed the newly designed TFT device exhibiting some characteristics: (i) good S/D metal/n+a-Si contact, (ii) prevention of plasma damage during processing especially for oxygen plasma ashing and (iii) without additional mask. These advantages will be helpful for a wider range of process window in large area mass production a-Si TFT fabrications.