METHOD FOR PREVENTING A W STUD RESIDUE AT VIA MIM PROCESS

摘要

A method for preventing a tungsten stud residue is provided to enhance the reliability of a semiconductor device by preventing the generation of a tungsten stud residue in a via MIM(Metal Insulator Metal) process. A via hole is formed on an interlayer dielectric, wherein the interlayer dielectric is composed of an oxide layer and a nitride layer. The via hole is filled with a tungsten plug. A first CMP process is performed on the resultant structure to remove an upper portion of the tungsten plug. An over etch end point is set to remove the nitride layer from the interlayer dielectric. An over etch process is performed on the oxide layer to the end point by a second CMP process. At this time, the nitride layer is completely removed from the resultant structure.