Polycrystalline silicon thin film and transistor using the same

Abstract

According to the present invention, a polycrystalline silicon thin film with a large crystal grain size is formed on a substrate, other than single crystalline silicon, e.g. on a glass substrate with a low strain point, by plasma CVD or photo CVD, and the polycrystalline silicon thin film thus obtained has a high (100) orientation percentage and a low (220) orientation percentage, a low hydrogen content, a low fluorine content in the film, and a large crystal grain size. It has excellent flatness and is suitable for microstructure fabrication and for the manufacture of a thin film transistor. Because a thin film transistor with a large area can be produced, it is also usable for many applications such as liquid crystal display. By introducing a high concentration of dopant into the interface region between the polycrystalline silicon film and the substrate, the growth of the polycrystalline grain is enhanced because the high concentration of dopant becomes the nucleus for crystal growth.

Dependencies are inferred from the claim text.