METHOD OF FORMING FILM BY PLASMA

摘要

When a CF film used as an interlayer insulating film of a semiconductor device is heated to about 400 to 450 DEG C so as to form tungsten interconnection, fluorine-containing gases are desorbed from the CF film, causing various problems such as corrosion of the interconnection and reduction in the thickness of the film. To solve these conventional problems, heat stability must be enhanced. According to the invention, a compound gas of C and F such as C4F8 gas, a hydrocarbon gas such as C2H4 gas, and a CO gas are used as film-forming gases, and transformed into a plasma, in order to form a CF film on a semiconductor wafer (10) from the active species at a process temperature of 400 DEG C. Addition of the CO gas contributes to forming diamond-like bonds rather than graphite-like bond. Therefore the bonds are strong and hardly cut even at high temperatures, enhancing heat stability.