Method for forming contact plug of semiconductor device

Abstract

The present invention provides a method for forming a contact plug of a semiconductor device capable of preventing an attack to conductive patterns. The method includes the steps of: forming a plurality of conductive patterns on a substrate; forming an insulating layer on top of an entire structure including the plurality of the conductive pattern; forming a contact hole by selectively etching the insulating layer; forming a conductive layer for a contact plug on the entire structure including the contact hole; forming a metal sacrificial layer on the entire structure including the conductive layer; exposing the conductive layer by performing an etchback process to the metal sacrificial layer, wherein the metal sacrificial layer is left on a lower topology area induced by the conductive patterns; and forming plugs, each being isolated by polishing the remained metal sacrificial layer, the conductive layer and the insulating layer through the use of slurry.