Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. A first dielectric layer is deposited over a first gate structure in a first device area and a second gate structure in a second device area, and then planarized. A second dielectric layer is deposited over the planarized first dielectric layer, and then removed from the first device area. After removing the second dielectric layer from the first device area, the first dielectric layer in the first device area is recessed to expose the first gate structure. A silicide is formed on the exposed first gate structure.