Patent ID: 7902080

Claim:
A method of filling a gap on a substrate with silicon oxide, the method comprising: introducing an organo-silicon precursor and an oxygen precursor to a deposition chamber; reacting the precursors to form a first silicon oxide layer in the gap on the substrate; etching the first silicon oxide layer to reduce the carbon content in the layer; forming a second silicon oxide layer on the first layer, and etching the second layer to reduce the carbon content in the layer, wherein the etching operation of the first and second silicon oxide layers comprises: exposing the layer to a first plasma having a first density, wherein the first plasma dissociates larger carbon molecules in the layer, and exposing the layer to a second plasma having a second density that is higher than the first density, wherein the second plasma dissociates silicon-hydroxide bonds in the layer; and annealing the silicon oxide layers after the gap is filled.