A method includes forming a fin over a substrate, forming an isolation region adjacent the fin, forming a dummy gate structure over the fin, and recessing the fin adjacent the dummy gate structure to form a first recess using a first etching process. The method also includes performing a plasma clean process on the first recess, the plasma clean process including placing the substrate on a holder disposed in a process chamber, heating the holder to a process temperature between 300° C. and 1000° C., introducing hydrogen gas into a plasma generation chamber connected to the process chamber, igniting a plasma within the plasma generation chamber to form hydrogen radicals, and exposing surfaces of the recess to the hydrogen radicals. The method also includes epitaxially growing a source/drain region in the first recess.