Microstructural tuning of polycrystalline silicon films from hydrogen diluted amorphous silicon films by AIC

In the present study, the effect of hydrogen dilution in amorphous silicon on its crystallization kinetics and defect distribution using AIC has been studied. The a -Si films were deposited at different ratios of H2/(H2+SiH4) using plasma enhanced chemical vapour deposition (ECR-PECVD) on glass-ceramic substrates. The thicknesses of aluminium and a -Si:H films were 0.20 μm and 0. 37 μm, respectively. The bi-layer structures were annealed in a tube furnace at 475 °C for 8 hours in a nitrogen atmosphere. The results indicated that as the hydrogen dilution for a -Si:H films increased from 0% to 85%, the AIC grown poly-Si films were more stressed compressively, while the Raman peak broadened from 6.7 cm-1 to 8.6 cm-1. It was found that the initiation of crystallization temperature as well as microstructure of poly-Si films was dramatically influenced by the hydrogen content in precursor a -Si films. The distribution of microstructural defects analysed by Electron Back Scattering Diffraction (EBSD) method indicated that frequency of low angle grain boundaries (LAGB) were more at higher hydrogen dilution ratios while coincident site lattice boundaries (CSL) of first order (Σ3), second order (Σ9) and third order (Σ27) were less sensitive to the hydrogen dilutions/content (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)