| 摘要 |
PROBLEM TO BE SOLVED: To secure a sufficient thickness of an interlayer insulating film on a bit line in a region other than a capacitor forming region in a memory cell of a COB(capacitor over bit line) structure, and realize simplification of a photographic plate-making step at the time of forming a storage node and uniformity of capacitor capacitance. SOLUTION: In forming a storage node on interlayer insulating films 7, 10, undoped silicon oxide films are formed as the interlayer insulating film 7, 10, and a BPSG(borophosphosilicate glass) film having a high selection ratio with respect to undoping is formed on the surface. After an etching mask is formed on the BPSG film, anisotropic etching is carried out to form an aperture corresponding to a storage node contact 11. Also, isotropic etching is carried out to the BPSG film by dehydrated vapor phase HF processing, thus forming an aperture for producing the storage node 11. After a conductive substance is buried in the aperture to form the storage node 11, the BPSG film is removed by dehydrated vapor phase HF processing. |
