摘要 |
In an insulating film structure having a barrier insulating film, a via interlayer insulating film, a wiring interlayer insulating film, and a hard mask film stacked in this order on an underlayer wiring, a via hole pattern is formed in the insulating film structure, then a groove pattern is formed in the hard mask film, and a grove is formed in the insulating film structure using this as a mask. According to the prior art, the via side wall is oxidized equally severely in the both processes. The trench side wall is oxidized severely in the via first process according to the prior art, whereas, according to the present invention, the oxidation thereof is suppressed to such an extent that an almost non-oxidized state can be created. |