Semiconductor devices and methods of manufacturing the semiconductor devices are described herein. A method includes forming a first opening through a dielectric layer, the first opening exposing a conductive region. A wet cleaning is used after the forming the first opening, and the first opening is treated after the wet cleaning the first opening, the treating the first opening comprising turning a sidewall treatment precursor and a bottom treatment precursor into a first plasma mixture, the sidewall treatment precursor being different from the bottom treatment precursor. The first opening is filled with a conductive material after the treating the first opening.