SEMICONDUCTOR DEVICE AND METHOD FOR FABRICATING THE SAME

摘要

A semiconductor device is provided to reduce the number of times of using a mask for forming a capacitor under bitline structure to once and eliminate the necessity for a sacrificial material layer for separating a lower electrode by forming an outer cylindrical capacitor. An interlayer dielectric(220), an etch stop layer(224) and a sacrificial insulation layer are formed on a semiconductor substrate(210). The sacrificial insulation layer, the etch stop layer and the interlayer dielectric are patterned to form a contact hole to which a predetermined region of the semiconductor substrate is exposed. The contact hole is filled with a contact plug(228). The sacrificial insulation layer is completely removed to expose the entire upper surface of the etch stop layer and the upper part of the contact plug. A dielectric layer and an upper electrode are formed on the etch stop layer to cover the exposed contact plug. The interlayer dielectric and the sacrificial insulation layer can be made of silicon oxide. The etch stop layer can include a silicon oxynitride layer or a silicon nitride layer.