A gate stack can be etched to form a trench extending through the gate stack, the trench removing a portion of the gate stack to separate the gate stack into a first gate stack portion and a second gate stack portion. A dielectric material is deposited in the trench to form a dielectric region, the dielectric region having an air gap in the dielectric material. The air gap may extend upward from beneath the gate stack to an area interposed between the end of the first gate stack portion and the end of the second gate stack portion. Contacts to the first gate stack portion and contacts to the second gate stack portion may be formed which are electrically isolated from each other by the dielectric material and air gap formed therein.