Dependence of crystal orientation in Al-induced crystallized poly-Si layers on SiO2 insertion layer thickness

We have fabricated poly-Si thin films on fused silica substrates by the Al-induced crystallization (AIC) method with SiO2 insertion layers of various thicknesses (0–20 nm). The growth morphologies of poly-Si layers were dramatically changed by the SiO2 thickness, i.e., thin layers (2 nm) provided high growth rates and (100) orientations, and thick layers (10 nm) provided low growth rates and (111) orientations. These results showed that the crystal orientation of AIC-Si significantly depends on the diffusion rate of Si atoms into the Al layer.

► Poly-Si layers were formed by Al-induced crystallization method. ► The incubation time and growth rate of the Si grains depended on the SiO2 insertion layer thickness. ► With increasing SiO2 layer thickness, the crystal orientation of the Si changed gradually from the (100) to (111) orientation.