Patent ID: 9318328
Filing Date: 2016-04-19
CPC Classification: C23C,H01L

Claim Text:
1. A method of forming a silicon film on a groove provided on a surface of an object to be processed, the groove being formed of a bottom surface, a sidewall surface and an opening, the method comprising: forming a first silicon film doped with impurities including boron on a first bottom surface and a first sidewall surface of a first groove to form a second groove inside the first groove, the second groove being formed of a second bottom surface, a second sidewall surface and a second opening, wherein the first silicon film is formed by supplying a silicon-containing gas and a boron-containing gas simultaneously and the second groove has a transversal cross section continuously becoming wider from the second bottom surface of the second groove to the second opening of the second groove; immediately after forming the first silicon film, etching the second bottom surface and the second sidewall surface to form a third groove inside the first groove, the third groove being formed of a third bottom surface, a third sidewall surface and a third opening, wherein the third groove has a transversal cross section continuously becoming wider from the third bottom surface of the third groove to the third opening of the third groove; and forming a second silicon film doped with impurities including boron on the third bottom surface and the third sidewall surface of the third groove to fill the third groove, wherein the second silicon film is formed by supplying the silicon-containing gas and the boron-containing gas simultaneously, thereby preventing void or seams from generating in the first and second silicon films.