Disclosed is a method for monitoring an edge bead removal process for a
copper metal interconnection. The method includes the steps of (a)
forming a copper metal layer on a semiconductor wafer, (b) performing the
edge bead removal (EBR) process of removing the copper metal layer formed
in an edge area of the semiconductor wafer, and (c) determining whether
copper residues exist by measuring a reflection coefficient Rc of the
copper metal layer formed in a center area of the semiconductor wafer and
a reflection coefficient (Rb) in the edge area of the semiconductor wafer
which is subject to the edge bead removal (EBR) process.