Surface-nano-texturing by aluminum-induced crystallization of amorphous silicon

Aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) has been studied extensively to produce large poly-Si grains for electronic and photovoltaic applications such as thin-film transistors, solar cells, and display panels. This paper reports a novel use of AIC of a-Si technique in nano-scale surface-texturing for tribological applications. Various nano-textured samples were fabricated by using AIC of a-Si technique employing different a-Si thickness and annealing conditions. The crystalline properties of these nano-textured surfaces (NTSs) were then characterized using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscope (TEM), and atomic force microscope (AFM). The adhesion and friction properties of the NTSs and a smooth Si surface were studied by a Triboindentor. These characterizations show that the nano-textures on the NTSs were poly-silicon crystallites and the NTSs significantly reduced the adhesion and friction forces compared to the smooth surface. Both texture height and density were found to affect the adhesion and friction performances of the NTSs.