METHOD FOR MANUFACTURING SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a semiconductor memory device is to form a step on a sidewall of a contact while securing a space between a storage electrode and a gate electrode, thus to increase a surface area of the storage electrode. CONSTITUTION: An isolation layer is formed on a part of a substrate. An interlayer dielectric and the first silicon layer are formed after a gate electrode and source/drain electrodes are formed on the isolation layer. On the first silicon layer is formed a sacrificial layer whose etching selectivity is larger than that of the first silicon layer. The first silicon layer and the sacrificial layer on a part of the source electrode are etched using a contact mask of a storage electrode(20), and a silicon spacer(8) is formed on the etched sidewall of the sacrificial layer and the first silicon layer. The exposed interlayer dielectric and the sacrificial layer are etched to form a contact hole(9) of the storage electrode, using the first silicon layer and the spacer as an etching stopper. The second silicon layer is formed through the contact hole. The storage electrode is formed by etching the first/second silicon layers.