| abstract |
(57) [Problem] To achieve a low dielectric constant by adding a benzene nucleus to a silica insulating film used as an interlayer insulating film, Prevent wiring delay. SOLUTION: At the time of depositing a silica film by plasma or LPCVD, an organic substance having a benzene nucleus such as phenyltrimethylsilane or toluene is added to a raw material so that the silica film contains a benzene nucleus. The relative dielectric constant decreases as the benzene nucleus content increases, and reaches about εr = 3 at a carbon composition of 30 at%. In addition, by performing heat treatment in a vacuum or the like, benzene nuclei in the film can be removed to form holes, and the dielectric constant can be further reduced. By applying these silica insulating films to the interlayer insulating film, wiring delay in a semiconductor device having a multilayer wiring structure can be reduced, and high density and high speed can be achieved. |