MULTI-STEP DEP-ETCH-DEP HIGH DENSITY PLASMA CHEMICAL VAPOR DEPOSITION PROCESSES FOR DIELECTRIC GAPFILLS

A method of forming a dielectric material in a substrate gap using a high-density plasma is described. The method may include depositing a first portion of the dielectric material into the gap with the high-density plasma. The deposition may form a protruding structure that at least partially blocks the deposition of the dielectric material into the gap. The first portion of dielectric material is exposed to an etchant that includes reactive species from a mixture that includes NH3 and NF3. The etchant forms a solid reaction product with the protruding structure, and the solid reaction product may be removed from the substrate. A final portion of the dielectric material may be deposited in the gap with the high-density plasma.