A novel ultrathin elevated channel low-temperature poly-Si TFT

A novel ultrathin elevated channel thin film transistor (UT-ECTFT) made usi ng low-temperature poly-Si is proposed. The structure has an ultrathin chan nel region (300 Angstrom) and a thick drain/source region, The thin channel is connected to the heavily doped drain/source through a lightly doped ove rlapped region, The lightly doped overlapped region provides an effective w ay to spread out the electric field at the drain, thereby reducing signific antly the lateral electric field there at high drain bias. Thus, the UT-ECT FT exhibits excellent current saturation characteristics even at high bias (V-ds = 30 V, V-gs = 20 V). Moreover, the UT-ECTFT has more than two times increase in on-state current and 3.5 times reduction in off-state current c ompared to conventional thick channel TFT's.