Crystallinity and Si-H bonding configuration of nc-Si : H films grown by layer-by-layer (LBL) deposition technique at different RF power
Document Type
Article
Publication Date
1-1-2008
Abstract
A set of hydrogenated nanocrystalline silicon (nc-Si:H)films prepared in a home-built plasma enhanced chemical vapour deposition (PECVD) system using the layer-by-layer (LBL) deposition technique have been studied. The 13.56 MHZ rf power was varied from 20 to 100 W to study the influence of rf power on the structural properties of the nc-Si:H films. The structure of the films was studied by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy Appearance of XRD peaks at 2 theta angles of 28 degrees and 56 degrees which correspond to silicon orientation of (111) and (311) respectively were observed in all films deposited on c-Si substrate indicating evidence of crystallinity in the films. The crystallite sizes were in the range of 8 to 100nm as determined using the Scherrer technique. The intergrated intensities of absorption bands at 630 cm(-1), 780 - 880 cm(-1) and 2000 - 2090 cm(-1) from FTIR spectrum which corresponds to various Si-H bonding configurations in the films were studied and were related to the presence of small clusters of nanoctystallites embedded in (in amorphous matrix. Based on the dependence of amplitudes of Si-H vibrational modes on crystallite size and rf power the properties and the role of hydrogen in nc-Si:H films prepared using the LBL technique were discussed.
Keywords
nc-Si:H, XRD, crystallite size, FTIR
Divisions
PHYSICS
Publication Title
Sains Malaysiana
Volume
37
Issue
3
Publisher
Penerbit Universiti Kebangsaan Malaysia