Semiconductor substrate semiconductor device and liquid crystal display device

Abstract

A method of forming an Si film by a bias sputtering process comprises the steps of generating plasma between a target electrode holding a target material provided in a vacuum container and a substrate electrode holding a deposited film forming substrate, provided opposingly to the target electrode, by the use of a high-frequency energy to cause the target material to undergo sputtering, and applying a bias voltage to at least one of the target electrode and the substrate electrode to form an Si film comprised of atoms deposited by sputtering on the substrate, wherein; a mixed-gas environment comprising a mixture of an inert gas and a hydrogen gas is formed in the vacuum container, and the target material is subjected to sputtering while controlling H.sub.2 O gas, CO gas and CO.sub.2 gas in the mixed-gas environment to have a partial pressure of 1.0.times.10.sup.-8 Torr or less each, to form an epitaxial film on the substrate while maintaining a substrate temperature in the range of from 400.degree. C. to 700.degree. C. A semiconductor substrate comprises an Si layer having a carbon content, a hydrogen content and a rare gas (X) content of C.ltoreq.1.times.10.sup.18 cm.sup.-3, 1.times.10.sup.15 cm.sup.-3 .ltoreq.H.ltoreq.1.times.10.sup.20 cm.sup.-3 and 1.times.10.sup.16 cm.sup.-3 .ltoreq.X, respectively, and having a difference of 15 nm or less between a maximum value and a minimum value of surface roughness.

Dependencies are inferred from the claim text.