METHOD FOR FORMING CAPACITOR OF MIM STRUCTURE

摘要

PURPOSE: A method for forming a capacitor of an MIM(Metal-Insulator-Metal) structure is provided to improve the electrical characteristics of the capacitor by depositing an Ru thin film after the nitridation process for a lower layer and to secure capacitance enough by applying a dielectric layer of Y2O3(X)TiO2(1-X). CONSTITUTION: An interlayer dielectric(2) having a contact hole is formed on a semiconductor substrate(1). A recessed poly-plug(3) is formed in the contact hole. The contact hole is completely filled with a barrier layer(4). A sacrificial layer is formed on the resultant structure. A trench is formed by selectively etching the sacrificial layer for exposing the barrier layer and the interlayer dielectric. NH3 plasma treatment is carried out on the resultant structure for the nitridation of the exposed barrier layer and interlayer dielectric. An Ru thin film is formed on the resultant structure. A storage node electrode(6a) is formed by polishing the Ru thin film until the sacrificial oxide layer is exposed and removing the sacrificial oxide layer. A dielectric layer(7) is formed on the storage node electrode. The dielectric layer is made of a composite film of Y2O3(X)TiO2(1-X).