Characterization of poly-Si thin films deposited by magnetron sputtering onto Ni prelayers

A method of producing a polycrystalline silicon thin film on a foreign substrate without subsequent annealing has been developed. Thermally evaporated 5-100 nm thick Ni films served as prelayers for magnetron sputtered Si thin films. A continuous film was obtained as a result of metal induced growth of polysilicon during low temperature (below 600°C) deposition. The film uniformity is promising for large area device applications. The influence of the Ni prelayer thickness on the grain size of thus obtained films was investigated. Atomic force microscopy and cross-sectional scanning electron microscopy studies revealed features in the 150-600 nm size range while x-ray diffraction and Raman spectra analysis predicted 50-100 nm diam randomly oriented grains and a complete absence of an amorphous phase. The carrier lifetime was evaluated to be 11 μs.