Sputtering Technology of Si Films for Low-Temperature Poly-Si TFTs

In this paper we discuss the development of sputter-Si technology for application in the area of poly-Si TFT Liquid Crystal Displays. We present the motivation behind this development and the state-of-the-art in materials and devices, based on PVD-Si precursor material. The Si-sputtering process is analyzed and data are presented on the quality of as-sputtered and post-annealed Si-films. The current drawbacks of Si sputtering are discussed, especially with respect to particles, film contamination and equipment availability. Based on the available data, strategies are presented to overcome these problems. PVD-Si technology has come a long way and has become a viable candidate as a Si-deposition method for next generation of poly-Si based applications. This technique is expected to play an even more important role, as the p-Si TFT-LCD industry moves to ultra-low temperature processing and, in parallel, the need increases for process cost reductions.