THIN ACTIVE LAYER A-SI-H THIN-FILM TRANSISTORS

We show that hydrogenated amorphous silicon thin-film transistors (TFT 's) with active layer thickness less than SO nm have improved performa nce for display applications, Using two-dimensional (2-D) modeling, we find previously observed degradation for thin active layers is due to electric field effects in the contact regions of staggered inverted d evices and affects only the saturation characteristics; linear region performance actually improves with decreasing thickness, We have fabri cated devices with extremely thin active layer (10 nm), and indeed fin d excellent linear region characteristics. In addition, direct tunneli ng across the undoped regions at device contacts reduces electric fiel d effects, resulting in excellent saturation region characteristics, a nd gate-induced channel accumulation reduces the Schottky barrier widt h at direct metal contacts so that even devices without doped contact regions (i.e., tunneling contacts) are possible.