Patent ID: 8716148

Claim:
A semiconductor device manufacturing method comprising: forming an inter-layer insulation film containing silicon, oxygen and carbon over a semiconductor substrate by chemical vapor deposition; making UV cure on the inter-layer insulation film being heated at a temperature of 350° C. or below after the forming the inter-layer insulation film; making helium plasma processing on the inter-layer insulation film after the UV cure; forming a cap film on the inter-layer insulation film after the helium plasma processing, a thickness of the cap film is thinner than a thickness of the inter-layer insulation film; forming a photoresist pattern on the cap film, forming a hole in the inter-layer insulation film using the photoresist pattern as a mask; and forming an interconnection in the hole, wherein a relative dielectric constant of the inter-layer insulation film is set to 2.7 or below by the helium plasma processing on the inter-layer insulation film.