A method of patterning a metal layer in a semiconductor die comprises
forming a mask on the metal layer to define an open region and a dense
region. The method further comprises etching the metal layer at a first
etch rate to form a number of metal segments in the open region and
etching the metal layer at a second etch rate to form a number of metal
segments in the dense region, where the first etch rate is approximately
equal to the second etch rate. The method further comprises performing a
number of strip/passivate cycles to remove a polymer formed on sidewalls
of the metal segments in the dense region. The sidewalls of the metal
segments in the dense region undergo substantially no undercutting and
residue is removed from the sidewalls of the metal segments in the dense
region.