Patent ID: 6372545
Filing Date: 2002-04-16
Classification: H01L

Abstract:
A method for forming an under bump metal, comprising the steps;providing a semiconductor structure having an exposed I/O pad; forming a patterned passivation layer over the semiconductor structure, the patterned passivation layer having an opening exposing a first portion of the I/O pad; laminating, exposing and developing a dry film resistor (DFR) layer to form a patterned dry film resistor (DFR) layer over the patterned passivation layer; the patterned dry film resistor (DFR) layer having an opening exposing a second portion of the I/O pad; the patterned dry film resistor (DFR) layer opening having opposing side walls with a predetermined profile with an undercut; wherein the undercut of the opposing side wall profile is from about 3.0 to 5.0 &mgr;m; forming a metal layer over the patterned dry film resistor (DFR) layer, the exposed third portion of the I/O pad, and over at least a portion of the opposing side walls of the patterned dry film resistor (DFR) layer opening; and lifting off the patterned dry film resistor (DFR) layer with the metal layer over patterned dry film resistor (DFR) layer and over at least the portion of the opposing side walls, leaving the metal layer over the exposed second portion of the I/O pad; the metal layer over the exposed second portion of the I/O pad being an under bump metal.