Thin Solid Films, Vol.515, No.7-8, 3847-3853, 2007
Effects of doping on structural change and hydrogen bonding in laser crystallized polycrystalline silicon films
Doped polycrystalline silicon films were produced by employing a step-by-step laser crystallization of doped hydrogenated amorphous silicon (a-Si:H). The influence of laser crystallization on structural properties and hydrogen bonding were investigated using Raman backscattering spectroscopy and hydrogen effusion measurements. Crystallization with low laser fluence, E-L, results a stratified structure with polycrystalline silicon layer at the top of an amorphous layer. In fully crystallized polycrystalline silicon the Raman lines in both P- and B-doped specimens are asymmetric, which is indicative of the Fano effect. From the hydrogen effusion spectra, the hydrogen density-of-states distribution is derived. Laser crystallization results in an increase of the hydrogen binding energy by about 0.2-0.3 eV compared to the amorphous starting material. (c) 2006 Elsevier B.V. All rights reserved.
Keywords:doped polycrystalline silicon;laser crystallization;Raman spectroscopy;hydrogen effusion;hydrogen bonding;hydrogen density-of-states