Laterally crystallized polysilicon TFTs using patterned light absorption masks

We present a novel technique to fabricate laterally-crystallized TFTs. Thick Si is placed over the drain of the TFT. This is then subjected to an RTA step to nucleate the film in the drain region, and then to an low temperature solid-phase crystallization (LT-SPC) grain-growth step. This results in a substantial device performance improvement. The simplicity and non-contact nature of this technique makes it promising for the fabrication of high-performance TFTs. Optimization, and the use of a high temperature process, should enable near single-crystal performance using a simple, low-cost process.