Effects of longitudinal grain boundaries on the performance of MILC-TFTs

Compared to conventional solid phase crystallized (SPC) thin-film transistors (TFTs), metal induced laterally crystallized (MILC) TFTs exhibit significantly enhanced performance at reduced processing temperature. It is concluded that the major improvements in MILC-TFTs result from the growth of the crystal grains in a direction longitudinal to that of the current flow, whereas in SPC-TFTs, the grain boundaries are randomly oriented. It is also observed in this work that while the MILC-TFTs are less sensitive to short-channel effects (SCEs), their leakage current exhibits higher sensitivity to channel length reduction. These differences again can be traced to the different arrangements of the grain boundaries in the two types of devices.