Semiconductor memory device and method for forming the same

摘要

A semiconductor memory device and a method for forming the same. The method includes forming an insulating layer on a semiconductor substrate having a conductive region, forming a contact hole that exposes the conductive region by etching the insulating layer, forming a barrier metal layer that covers a sidewall and a bottom of the contact hole, and forming a contact plug in the contact hole by interposing the barrier metal layer therebetween. An etching process may be preformed that recesses the barrier metal layer and the contact plug in such a manner that a top surface of the contact plug protrudes upward beyond a top surface of the barrier metal layer. A capping plug may be formed covering the recessed barrier metal layer and the recessed contact plug. A capacitor may be formed on the capping plug.