High performance low temperature metal-induced unilaterally crystallized polycrystalline silicon thin film transistors for system-on-panel applications

Abstract

Thin film transistors (TFTs) with low-temperature processed metal-induced laterally crystallized (MILC) channels and self-aligned metal-induction crystallized (MIC) source and drain regions have been demonstrated recently as potential devices for realizing electronics on large-area, inexpensive glass panels. While these TFTs are better than their solid-phase crystallized counterparts in many device performance measures, they suffer from higher off-state leakage current and early drain breakdown. A new technology is proposed, employing metal-induced-unilateral crystallization (MIUC), which results in the removal from the edges of and within the channel region all major grain boundaries transverse to the drain current flow. Compared to the conventional "bilateral" MILC TFTs, the new MIUC devices are shown to have higher field-effect mobility, significantly reduced leakage current, better immunity to early drain breakdown, and much improved spatial uniformity of the device parameters. Thus they are particularly suitable for realizing low temperature CMOS systems on inexpensive glass panels.