Polycrystalline silicon formation by pulsed rapid thermal annealing of amorphous silicon

Abstract

A method of forming polycrystalline silicon (polysilicon) from amorphous silicon in several seconds is presented in this letter. This solid-phase crystallization process was carried out with the pulsed rapid thermal annealing method using a metal as the seed. The crystal-growth process was monitored with an optical microscope and the polysilicon structure was confirmed by a micro-Raman shift measurement. Polysilicon film within a 30-micrometer channel was formed using 3 pulses of 1-s 800°C heating/5-s cooling. It took more than 13 h using a 500°C furnace annealing method 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 in the substrate are minimized. This method has the potential for use in the fabrication of small geometry devices, such as thin film transistors, on large-area, low temperature glass substrates. © 1996 American Institute of Physics.