Embodiments disclosed herein relate generally to capping processes and structures formed thereby. In an embodiment, a conductive feature, formed in a dielectric layer, has a metallic surface, and the dielectric layer has a dielectric surface. The dielectric surface is modified to be hydrophobic by performing a surface modification treatment. After modifying the dielectric surface, a capping layer is formed on the metallic surface by performing a selective deposition process. In another embodiment, a surface of a gate structure is exposed through a dielectric layer. A capping layer is formed on the surface of the gate structure by performing a selective deposition process.