METHOD FOR DETECTING DEFECT AT THE CHEMICAL MECHANIC POLISHING PROCESS

摘要

A method for detecting a defect of a CMP(chemical mechanical polishing) process is provided to grasp the state of the surface of a wafer without using expensive defect inspection equipment by examining defects like scratch of a polishing oxide layer by an electrical inspection method. An etch-stop layer(30) is formed on a wafer(10). A buffer oxide layer(20) is formed on the wafer. A predetermined thickness of a polishing oxide layer(40) is formed on the etch-stop layer. A CMP process is performed on the polishing oxide layer to form a scratch. The polishing oxide layer having the scratch is isotropically etched to increase the area of the scratch of the polishing oxide layer. The polishing oxide layer having the scratch with the increased area is removed to correspond to a predetermined combo pattern so that a trench of a predetermined depth is formed. A conductive metal layer is formed on the resultant wafer. The conductive metal layer is flatly removed to expose the polishing oxide layer so that a defect pattern and the combo pattern corresponding to the scratch exposed by the polishing oxide layer. A probe of an electrical inspecting apparatus comes in contact with both lateral pad electrodes of the combo pattern to electrically inspect whether the defect pattern crossing the combo pattern exists.