Alois Herkommer

P-59: Thin-beam Crystallization Method for Fabrication of LTPS

Thin film transistors fabricated using Low Temperature Polycrystalline Silicon (LTPS) have several well-known advantages over those made with amorphous Silicon: higher electron mobility, smaller size, higher speed. However, LTPS has not been widely adopted due to the relatively high cost and low yield of the process relative to a-Si. We have investigated a laser annealing process that offers an improvement for both throughput and yield when compared to existing processes. The process uses a very narrow laser beam (∼5 microns) at high repetition rates to create large poly-Si crystals via lateral growth. The beam length is long enough to allow the substrate to be scanned in a single pass, resulting in better uniformity without any seams seen in multi-pass techniques. In this presentation, we will present results from a prototype system used to validate the critical elements of the process.

The Delano diagram, a powerful design tool

A power density model is introduced into the Delano diagram. The correlation of the system length and the peak power density are outline especially for 2-f-systems with a low Lagrange invariant and high energy transfer.