Integrated circuit memory devices having self-aligned contact

Abstract

A method for manufacturing a semiconductor memory device in which a bit line and a storage electrode of a capacitor are connected to an active area of a semiconductor substrate, respectively, via a contact pad formed in a self-aligning manner. The method includes the steps of forming gate electrodes on the semiconductor substrate, the gate electrodes being covered with a nitride spacer. Then, a thermal oxide layer is formed on the exposed surface of the semiconductor substrate between the gate electrodes. Then, an etch stop layer is formed on the entire surface of the resultant structure having the thermal oxide layer to an appropriate thickness such that the space between the gate electrodes is not buried. Then, a first interlayer dielectric (ILD) film covering the space between the gate electrodes and the top of the gate electrodes is formed, and the first ILD film is then patterned to form a landing pad hole which exposes the spacer and the etch stop layer. Then, the etch stop layer and the thermal oxide layer are removed to expose the surface of the semiconductor substrate, and the landing pad hole is then filled with a conductive material to form landing pads.