Growth And Characterization Of Large Grained Poly-Si Films Grown On Biaxially Textured Ni-W Substrate By Hot-wire CVD

Polycrystalline Si (Poly-Si) film with highly crystalline nature, and having most of the grains in the range of 50-100 µm has been grown over biaxially textured Ni-W substrate by Hot-wire chemical vapor deposition technique, using a single buffer layer of CeO2 thin film. This result has been achieved for the SiH4 source gas diluted to 95% with added H2 gas, and for the substrate temperature of 840±10oC and a deposition pressure of 40 mTorr. XRD analysis shows that the Poly-Si films have grown with (111) and (200) orientations. Raman studies reveal that a crystalline volume fraction of 95.3% has been achieved. The imaginary part of pseudo dielectric function, <ε2>, as extracted from ellipsometric data, shows two prominent shoulders at energy positions 3.4 eV and 4.2 eV corresponding to the optical absorption of crystalline Si, indicating a high crystallinity of the Poly-Si film. SEM micrograph shows that the grown Poly-Si film is following the morphology and grain size as that of biaxia