Transient recrystallization of amorphous silicon films

We have investigated crystallization of amorphous silicon films on SiO2/Si substrates using conventional furnace annealing, incoherent light-based rapid thermal annealing (RTA), and pulsed excimer laser (wavelength = 248 nm, energy density = 0.1–0.6 J cm−2). The effect of a 50 nm SiO2 capping layer on the final microstructure was examined for each annealing technique, using transmission electron microscopy (TEM) and X-ray diffraction (XRD). A discussion of the phenomenological effects of the capping layer on resultant microstructure is included. For laser annealing, the effects of varying the thickness of the intermediate SiO2 layer were examined and the resultant microstructure was characterized for grain size and crystallized orientation using TEM. Grain sizes ranging from 50 to 200 nm were observed. Electrical properties of the crystallized films were presented for the various resultant microstructures. The effect of laser interactions with multi-layered structures were simulated by solving the heat condition equation with the appropriate boundary conditions and the results are included.