Patent ID: 7776748

Claim:
A method of determining a redeposition rate for a plasma process using a previously calibrated wafer including a plurality of patterned regions of selective-redeposition structures in a layer of a material on a carrier substrate, the method comprising: receiving the previously calibrated wafer on a wafer support within a vacuum chamber in an ionized plasma vapor deposition (IPVD) system; determining an initial thickness of the material at a bottom portion of at least one of the selective-redeposition structures on the previously calibrated wafer and an initial thickness of the material in a flat field region between adjacent patterned regions of the selective-redeposition structures on the previously calibrated wafer; exposing the previously calibrated wafer to the plasma process for an exposure time so as to etch the material from the bottom portion of the selective-redeposition structures on the previously calibrated wafer and from the flat field region between adjacent patterned regions of the selective-redeposition structures on the previously calibrated wafer; determining a final thickness of the material at the bottom portion of the at least one of the selective-redeposition structures on the previously calibrated wafer and a final thickness of the material in the flat field region between adjacent patterned regions of the selective-redeposition structures on the previously calibrated wafer; determining an actual etch rate (R actual ) of the material in the at least one of the selective-redeposition structures on the previously calibrated wafer from the initial and final thicknesses of the material at the bottom portion of the at least one of the selective-redeposition structures on the previously calibrated wafer and the exposure time; determining an apparent etch rate (R apparent ) of the material from the initial and final thicknesses of the material in the flat field region between adjacent patterned regions of the selective-redeposition structures on the previously calibrated wafer and the exposure time; and determining the redeposition rate from a difference between the actual etch rate (R actual ) and the apparent etch rate (R apparent ).