Suppression of leakage current in low-temperature metal-induced unilaterally crystallized polycrystalline silicon thin-film transistor using an improved process sequence and a gate-modulated lightly-doped drain structure

Two techniques of reducing leakage current (I/sub lk/) in low-temperature metal-induced unilaterally crystallized (MIUC) polycrystalline silicon (poly-Si) thin-film transistors (TFT) are reported. These are (a) reversal of the conventional order of lateral crystallization after heavy junction implantation for improved crystallization quality and (b) incorporation of a gate-modulated lightly-doped drain structure for decreasing the electric field strength in the drain/channel junction region. MIUC poly-Si TFTs fabricated using these techniques were used to realize active-matrix organic light-emitting diode displays. Compared to displays built using conventional metal-induced lateral crystallization (MILC) process and device technology, I/sub lk/ induced crosstalk was effectively suppressed and image quality was improved in displays realized using the new MILC process sequence and device structure.