Polycrystalline silicon prepared by metal induced crystallization

Growth of large-grain polycrystalline silicon has been demonstrated using silicide-mediated crystallization of amorphous silicon (a-Si) by a pulsed rapid thermal annealing (RTA). The Ni atoms in concentration of 4.6 X 10(12)/cm(2) on the a-Si surface were heated at 700 degreesC in the RTA system for 10 s, ten times with 60 s intervals between the heat pulses. The Ni atoms on a-Si aggregate together, forming NiSi2 precipitates. The crystallization proceeds from the NiSi2 nuclei until the neighboring crystallites collide and forms distinct grain boundaries. It was found that 3.6 X 10(7) Ni atoms form a seed for metal induced crystallization and the grain size was 40 mum when the Ni density was 4.6 X 10(12)/cm(2) on the a-Si. The grain size increases with decreasing metal density on a-Si. (C) 2003 Elsevier Science B.V. All rights reserved.