A method of manufacturing a semiconductor is provided. The method includes the steps of forming a priming insulation film on a substrate, forming a first insulation film on the priming insulation film, forming an opening with a diameter of d.sub.1 in the first insulation film, and forming a second insulation film on the first insulation film including the opening The film thickness distribution of the second insulation film in the step of forming the second insulation film is .+-.y %, wherein the diameter d.sub.1 of the opening satisfies the following relationship: d.sub.1.ltoreq.6500/y+85 nm.