Method of forming self-aligned contact and method of manufacturing semiconductor memory device by using the same

摘要

In an embodiment a method of forming self-aligned contacts in a semiconductor memory device includes: forming conductive stacks of conductive layers on a semiconductor substrate; forming insulating spacer layers on sidewalls of the conductive stacks; forming an insulating layer; forming a capping insulating layer covering portions of the insulating layer; and forming conductive pads that fill the contact holes to contact the semiconductor substrate. The capping insulating layer has a function of a buffer, so an etched amount of mask layers insulating the conductive layers is minimized, and a probability of a short circuit between capacitor electrodes and the conductive stacks is greatly reduced.