Aspects of the present invention relate to approaches for preventing contact encroachment in a semiconductor device. A first portion of a contact trench can be etched partway to a source-drain region of the semiconductor device. A dielectric liner can be deposited in this trench. A second etch can be performed on the lined trench to etch the contact trench channel the remainder of the way to the source-drain region. This leaves a portion of the dielectric liner remaining in the trench (e.g., covering the vertical walls of the trench) after the second etch.