Metal induced crystallization (MIC) of a-Si produced by magnetron sputtering

The aluminum-induced crystallization (AIC) method was used to crystallize amorphous silicon (a-Si) using evaporated Al. A 50-nm and 200 nm thick Al film was deposited on carbon coated nickel grids and on the Corning 7059 glass respectively using a thermal evaporation system. After Al evaporation, samples were immediately transferred to an ultra-high vacuum, multi-chamber deposition system where a-Si film of approximately 50 nm and 500 nm was deposited on top of the Al films on the grids and glass respectively using magnetron sputtering. The samples were annealed for 30 minutes at various temperatures. XRD, TEM, and SEM were used to investigate the structural behavior of these films, as a function of annealing temperature. TEM pictures show indications of crystallization for annealing temperatures at 200 °C. XRD patterns show that crystallization starts at 240 °C and increases monotonically with increasing the annealing temperature. A hillocks structure were obtained after annealing at a crystallization temperature while a smooth surfaces were found for non-crystallized films as revealed from SEM. The role of the thickness of a-Si layer and the Al in the crystallization of the amorphous silicon were presented and discussed.