Properties of Large Grain-Size poly-Si Films by Catalytic Chemical Sputtering

Abstract

ABSTRACTLarge grain-size polycrystalline Si (poly-Si) films are obtained on glass substrate by newly developed catalytic chemical sputtering method at low temperatures around 400 C. Si films are also epitaxially grown on (100) single-crystalline Si substrates. In the method Si films are deposited by the chemical transport of SiH4 species generated by the reaction between solid Si target and catalytically generated H atoms. Efficient deposition is realized using the remarkable difference in the etch rate depending on Si target temperatures. That is, SiH4 species are efficiently generated on cooled Si target by atomic-H etching and deposited on substrates with suppressed etching phenomena by heating. Full-width at half maximum of transverse-optical Raman signals originating from crystalline phase for the obtained poly-Si films is narrower than that for poly-Si prepared by excimer-laser annealing. It was noticeable that the grain size exceeds 1 m for the films with a thickness of about 1 m. Growth mode of poly-Si films especially in the initial stage is remarkably changed with a difference in the substrate material. It was found that formation of seed layer enhances the growth of poly-Si films on glass substrate.