Methods of curing a silicon oxide layer on a substrate are provided. The methods may include the processes of providing a semiconductor processing chamber and a substrate and forming an silicon oxide layer overlying at least a portion of the substrate, the silicon oxide layer including carbon species as a byproduct of formation. The methods may also include introducing an acidic vapor into the semiconductor processing chamber, the acidic vapor reacting with the silicon oxide layer to remove the carbon species from the silicon oxide layer. The methods may also include removing the acidic vapor from the semiconductor processing chamber. Systems to deposit a silicon oxide layer on a substrate are also described.