IMPURITY CONTROL IN HDP-CVD DEPOSITION/ETCHING/DEPOSITING PROCESSES

PROBLEM TO BE SOLVED: To provide improved techniques for filling a gap formed on a substrate with a silicon oxide film. SOLUTION: A first portion of silicon oxide is deposited over a substrate and within a gap using a high-density plasma process. Thereafter, a portion of the deposited first portion of the silicon oxide film is etched back. This includes flowing a halogen precursor from a halogen-precursor source to a substrate processing chamber, forming a high-density plasma from the halogen precursor, and terminating flowing the halogen precursor after the portion has been etched back. Thereafter, a halogen scavenger is flowed to the substrate processing chamber to react with residual halogen in the substrate processing chamber. Thereafter, a second portion of the silicon oxide film is deposited over the first portion of the silicon oxide film and within the gap using a high-density plasma process. COPYRIGHT: (C)2009,JPO&INPIT