A method for determining the anti-reflective coating (or bottom anti-reflective coating) over-etch time adjust with real-time process feedback is presented. The critical dimension CDresist of the patterned photoresist is measured and a first wafer with median values chosen (101) from a lot. A first time t* is found (102) and used to form the desired structure. Using the measured critical dimension of the formed structure on the first wafer a second time tlot is found (104). Finally, an over-etch time t(x) is found and used to etch the remaining wafers in the lot (106).