In an embodiment, a method of forming a semiconductor device includes forming a hydrophobic coating on an inner surface of an exhaust line, connecting the exhaust line to a semiconductor processing chamber, introducing a first precursor into the semiconductor processing chamber, introducing a second precursor into the semiconductor processing chamber, wherein the first precursor reacts with the second precursor to form a layer of oxide material, and pumping the first precursor and the second precursor from the semiconductor processing chamber and through the exhaust line.