Excimer Laser Crystallization of Silicon Films: Artificially-Controlled Super Lateral Growth for Grain Boundary Location-Controlled and Single Crystal Island Materials for Thin Film Transistor Applications

摘要

This report describes new excimer-laser crystallization (ELC) techniques for producing high-quality Si films for AMLCD applications. These artificially controlled super-lateral growth (ACSLG) processes deliver crystalline silicon films with microstructures optimized for thin-film transistor applications. The ACSLG methods described herein include: (1) a low-temperature method for producing grain-boundary-location-controlled (GLC) Si films on glass substrates, (2) a high-temperature method for producing single-crystal islands (SCI) on quartz substrates, (3) a realistic two-dimensional program for simulation of ELC, and (4) low-temperature sequential lateral solidification of Si films. Preliminary TFT devices have yielded near-record performance characteristics and demonstrate that the ACSLG materials are superior to existing materials for fabrication of TFTs. The sequential lateral solidification (SLS) process possesses two characteristics not found in any other technique: (1) it can produce the best material (single-crystal silicon films) for TFT devices, and (2) it does so directly on low-cost, low-temperature substrates. The impact of the SLS process will be to create a new materials/device technology: low-temperature single-crystal silicon TFTs, which will: (1) displace conventional low- and high-temperature polycrystalline silicon TFT technology; (2) eliminate the need to utilize silicon-on-insulator (SOI) processes; and (3) ultimately enable the realization of highly integrated AMLCDs and system-on-glass products.