Excimer laser crystallization of sputtered a-Si films on plastic substrates

In this work, thin films of amorphous silicon (a-Si) were formed on plastic substrates by sputtering deposition and crystallized using excimer laser irradiation. As the entire process is conducted at room temperature, and the laser irradiation-induced heating is confined to the thin film, the plastic substrate is not subjected to thermal stresses. The microstructure resulting from the laser irradiation was dependent on the laser irradiation energy density and the composition of the underlying buffer layers. It was found that a layer of AlN deposited as a buffer between the plastic and the a-Si film increased the endurance of the a-Si film under laser irradiation, and resulted in polycrystalline Si grains up to 100nm in diameter.