Patent ID: 6881276

Claim:
A method for cleaning a residue accumulated from a prior deposition from a wall within a deposition chamber, comprising the steps of: (a) flowing a cleaning gas into the deposition chamber; (b) forming a plasma of a cleaning gas within the deposition chamber so that at least a portion of the molecules of the cleaning gas are dissociated, wherein the plasma includes one or more reactive species that react with said residue on the wall; (c) monitoring the intensity of an emission line of a constituent of the partially dissociated cleaning gas; (d) monitoring the intensity of a background light emission in the chamber; (e) determining a ratio of the intensity of the cleaning gas emission line to the background emission; (f) monitoring the determined ratio over time; (g) comparing the determined ratio to a threshold value; and (h) controlling the flow of the cleaning gas based on the comparing step.