Method of manufacturing contact structure

摘要

A contact structure is formed with no voids in an interlayer insulation film and good surface planarity. A first insulation film (21) formed of p-TEOS is deposited to cover a substrate (1) and wires (4) formed on the substrate (1). A second insulation film (22) which is coating glass is formed by SOG. The surface is etched back from the opposite side to the substrate (1); therefore, the second insulation film (22) is etched. The etching is stopped at the point where the surface (21a) of the first insulation film (21) on the wires (4) is exposed. This ensures good surface,planarity. A third insulation film (23) is stacked on top of the second insulation film (22), and portions of the third insulation film (23) above the wires (4) are isotropically etched to form openings (51). At this time, the isotropic etching does not extend over the second insulation film (22).