A method of depositing a phosphosilicate glass (PSG) film on a substrate disposed in a substrate processing chamber includes depositing a first portion of the PSG film over the substrate using a high-density plasma process. Thereafter, a portion of the first portion of the PSG film may be etched back. The etch back process may include flowing a halogen precursor to the substrate processing chamber, forming a high-density plasma from the halogen precursor, and terminating flowing the halogen precursor after the etch back. The method also includes flowing a halogen scavenger to the substrate processing chamber to react with residual halogen in the substrate processing chamber, and exposing the first portion of the PSG film to a phosphorus-containing gas to provide a substantially uniform phosphorus concentration throughout the first portion of the PSG film.