Silicon Crystallization by Pulsed Rapid Thermal Annealing

A new method of forming polysilicon from amorphous silicon in several seconds is presented in this paper. This solid-phase crystallization process was carried out with the pulsed rapid thermal annealing method using the contact metal as the seed. The crystal-growth process was monitored with the optical microscope and the polysilicon structure was confirmed from the micro-Raman shift measurement. Polysilicon films have been formed within the channel length of 12, 30, and 50 micrometers using 1-, 3-, and 5-pulse of the 1-second 800degreeC heating/5-second cooling cycles, separately. When the film was annealed in a furnace at 500degreesC, it took more than 13 hours to form polysilicon film within a 12-micrometer channel. Since the substrate is only exposed to the high temperature for a very short period of time, heat effects to the substrate can be minimized. This method has the potential of being used in the fabrication of small geometry devices on large-area lower temperature glass substrates.