High-rate deposition of highly crystallized silicon films from inductively coupled plasma

We have studied microcrystalline silicon (muc-Si) film growth from inductively coupled RF plasma (ICP) of monosilane (SiH4) and hydrogen gas mixtures and demonstrated the feasibility of ICP for a high rate growth of highly crystallized Si films at a temperature as low as 250 degreesC. Using 15% SiH4 diluted with H-2, a deposition rate of similar to 1.0 nm s(-1) was achieved for crystalline films, for which Raman scattering spectra show the TO phonon peak intensity ratio for the crystalline/disordered phase is > 5 for film thickness > 1 mum. By measuring optical emission from the SiH4 ICP, we suggest that the relative flux of hydrogen radicals to the growing film surface with respect to the flux of film precursors during monatomic layer growth is a key parameter in obtaining highly crystallized films at a higher growth rate. Strong influence of the crystallinity on the optical and electrical properties has also been confirmed for films prepared with different SiH4 concentrations or different film thickness. (C) 2003 Elsevier Science B.V. All rights reserved.