An AlF3 layer grows on the showerhead in our plasma-enhanced chemical vapor deposition chamber during fluorinated between-wafer cleans. The additional impedance caused by the AlF3 layer reduces the power transferred to the plasma, changing film characteristics during subsequent depositions. Moreover, nonuniform AlF3 growth on the showerhead causes nonuniform plasma densities that result in across-wafer variation in film properties. Proper selection of pressure during the clean affords greater control over the growth and uniformity of AlF3. Better management of AlF3 growth yields better control of film characteristics and renders increased tool availability.