In manufacturing a radio frequency (RF) switch, a heat spreader is provided. A first dielectric is deposited over the heat spreader. A trench is etched in the first dielectric. A heating element is deposited in the trench and over at least a portion of the first dielectric. A thermally conductive and electrically insulating material is deposited over at least the heating element, where the thermally conductive and electrically insulating material is self-aligned with the heating element. A conformability support layer is optionally deposited over the thermally conductive and electrically insulating material and the first dielectric. A phase-change material is deposited over the optional conformability support layer and the underlying thermally conductive and electrically insulating material and the first dielectric.