Abstract: Chlorine trifluoride (ClF3) is an excellent chemistry for in-situ cleaning of process equipment for chemical vapor deposition (CVD) of metals. ClF3 is a weakly-bound molecule that breaks down exothermically on contact with most hot conducting films such as Ti and TiN without plasma, giving it an advantage over other chemistries. The energy released from the reaction is used to volatize the reaction byproducts. Cooler reactor surfaces, however, are coated with a halogen-rich, less conductive film that may not be as reactive with ClF3. To improve the ClF3 reaction, additives such as nitrous dioxide are employed. These additives react with ClF3 and supply reactive ions energetic enough to volatize the byproduct.