A method of forming a semiconductor includes forming a first recess in a first semiconductor fin protruding from a substrate and forming a second recess in a second semiconductor fin protruding from the substrate first semiconductor fin and forming a source/drain region in the first recess and the second recess. Forming the source/drain region includes forming a first portion of a first layer in the first recess and forming a second portion of the first layer in the second recess, forming a second layer on the first layer by flowing a first precursor, and forming a third layer on the second layer by flowing a second precursor, the third layer being a single continuous material.