Aluminum-induced crystallization of silicon suboxide thin films

Polycrystalline silicon (poly-Si) thin films are fabricated by aluminum-induced crystallization (AIC) of amorphous silicon suboxide (a-SiOx, x = 0.22) at 550 °C for 20 h. AIC of a-SiO0.22 via thermal annealing of a-SiO0.22/Al bilayer structures leads to layer exchange with the formation of poly-Si films with (111) preferential orientation and high-crystalline quality-coated with a layer of a mixture of Al, Si, and O atoms with inclusions of silicon nanocrystallites. The initial a-SiO0.22/Al thickness ratio approximately equal to 1 provides the formation of a discontinuous poly-Si film with a crystallized fraction of 85%, as shown by optical microscopy.