METHOD FOR FORMING STORAGE ELECTRODE OF SEMICONDUCTOR MEMORY DEVICE HAVING STABLE STRUCTURE

摘要

PURPOSE: A method for forming a storage electrode of a semiconductor memory device is provided to control easily an etching state of a BPSG layer by performing sequentially a process for etching a nitride layer and a process for etching an anti-reflective layer and the BPSG layer. CONSTITUTION: A contact plug is formed on the first insulating layer of a wafer. An etch-stop layer(40) is formed on the first insulating layer including the contact plug. The second insulating layer(42) is formed on the etch-stop layer. An anti-reflective layer(44) is formed on the second insulating layer. An opening part(48) is formed by performing selectively an anisotropic etch process for the anti-reflective layer and the second insulating layer. The etch-stop layer within the opening part is exposed. A top part of the contact plug and the first insulating layer are exposed by etching selectively the etch-stop layer. The top part is projected from the opening part by etching partially the anti-reflective layer and the first insulating layer. Polysilicon is coated along a profile of the projected opening part. The polysilicon is removed from the second insulating layer around the opening part. A projected polysilicon pattern is formed by removing the second insulating layer.