High resolution optics for thin Si-film crystallization using excimer lasers: present status and future development

摘要

Crystallization of thin Si-films using excimer lasers is a well introduced technique to the manufacturing process of flat panel display poly-Si back plates. The crystallization is performed by a Line Beam exposure which is scanned with a typical overlay of 95% over the Si-coated glass plate. The poly-Si film is obtained with a very good homogeneity of typically 100-150 cm~2/Vs electron mobility. Thus this performance is of importance for the system on glass (SOG) driver microelectronic circuits and is a key technology for high resolution (200ppi) LCD displays for mobile phones, personal digital assistance (PDA) and for the near future OLEDs (organic light emitting display). A recently considered process to obtain even improved perfo rmance poly-Si films is the sequential lateral solidification proposed by J. Im of Columbia University. This process requires a high resolution lines and spaces pattern which is designed to grow linear crystals or even single crystal like areas. High resolution optics for high power throughput is the relevant technique to introduce the SLS-process (sequential lateral solidification) into next generation production lines.