Novel Phase Modulator for ELA-Based Lateral Growth of Si

Phase-modulated excimer laser annealing (ELA) is an advanced excimer-laser crystallization method characterized by the intensity modulation of irradiated light by a phase modulator. In this method, a temperature gradient is formed in melted Si and large crystal grains are laterally grown at predetermined positions. In order to form grains with a high packing efficiency, a periodic “V-shaped” form of the light intensity distribution is desired. In the present study, a novel duty phase modulator is developed for projection-type PMELA. The light intensity distribution on the sample surface can be freely controlled and its design method is simple. We confirmed that a V-shaped light intensity distribution could be achieved by preparing a prototype duty phase modulator. In addition, crystallization was carried out with this duty phase modulator and 5 - μ m -long crystal grains with a high packing efficiency were successfully grown.