Method of manufacturing semiconductor device including steps of forming groove and recess, and semiconductor device

摘要

An interlayer insulation film (31) on a plug (11) is etched using a silicon nitride film (32) used in pattern etching of a bit line (12) as a hard mask such that the plug (11) projects into a groove (40). Another silicon nitride film (33) is provided to cover an exposed surface of the groove (40), the bit line (12) and the silicon nitride film (32), thereby forming another interlayer insulation film (34) on the silicon nitride film (33) to fill the groove (40). The silicon nitride films (33, 32) are used as an etching stopper to etch the interlayer insulation film (34) above the plug (11). The silicon nitride film (33) on the plug (11) is etched to expose the plug (11) into a recess.