Patent ID: 8119527

Claim:
A method of filling a high aspect ratio feature provided on a partially manufactured semiconductor substrate, the method comprising: introducing a tungsten-containing precursor and a reducing agent into a processing chamber; depositing a layer of a tungsten-containing material on the partially manufactured semiconductor substrate via a chemical vapor deposition reaction between the tungsten-containing precursor and the reducing agent, such that the layer partially fills the high aspect ratio feature; and selectively removing a portion of the deposited layer to form an etched layer in a mass transport regime by introducing an etchant into the processing chamber and without using an in-situ plasma such that the reduction in the average thickness of the deposited layer near an opening of the high aspect ratio feature is greater than the reduction in the average thickness of the deposited layer inside the high aspect ratio feature, wherein the mass transport regime corresponds to a lower concentration of the etchant inside the high aspect ratio feature than near the opening of the high aspect ratio feature.