Method of manufacturing a semiconductor memory device

摘要

According to one embodiment, a semiconductor memory device includes a substrate, an upper-layer wire provided on the substrate, a lower-layer wire provided on the substrate, a memory cell located at an intersection of the upper-layer wire and the lower-layer wire and includes a diode and a storage layer, a conductive layer located between the upper-layer wire and the memory cell in a direction perpendicular to the substrate surface, and an interlayer insulating film provided between memory cells. The position of an interface between the upper-layer wire and the interlayer insulating film is lower than a top surface of the conductive layer.

主权项

1. A method of manufacturing a semiconductor device, comprising:
forming a first interlayer insulating film; forming a lower-layer wire on the first interlayer insulating film; forming a storage layer and a conductive layer on the lower-layer wire; processing the conductive layer, the storage layer, and the lower-layer wire down to the first interlayer insulating film to form a trench; burying and forming a second interlayer insulating film in the trench; first etching back the second interlayer insulating film by a CMP method using the conductive layer as a stopper; second etching back a top surface of the second interlayer insulating film by a different process than the CMP method of the first etching back, to be lower than a top surface of the conductive layer; and forming an upper-layer wire on the second interlayer insulating film and on the conductive layer.