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

Abstract

We have studied microcrystalline silicon (μc-Si) film growth from inductively coupled RF plasma (ICP) of monosilane (SiH 4) 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 °C. Using 15% SiH 4 diluted with H 2, a deposition rate of ∼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 μm. By measuring optical emission from the SiH 4 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 SiH 4 concentrations or different film thickness.