A method of forming a conductor structure can result in vertical sidewalls. The method deposits a lining over a plurality of spaced-apart stacks of active layers. An isolation material is formed over the lining, over and in between the spaced-apart stacks. A plurality of trenches in the isolation material is arranged to cross over the plurality of spaced-apart stacks of active strips, leaving at least a residue of the lining on a bottom of the trenches between the stacks of active strips and over a sidewall of the spaced-apart stacks of active strips. The residue of the lining on the bottom of the trenches and the sidewalls of the spaced-apart stacks of active layers is selectively removed. Then the plurality of trenches is filled with conductive or semiconductor material to form the damascene structure.