The invention is directed to a method for determining an overlay correlation set between two successive patterned material layers on a substrate. The method comprises steps of providing a first material layer having a first overlay mark formed therein over the substrate and then using an exposure tool with a first overlay correlation set to form a patterned photoresist layer on the first material layer, wherein the patterned photoresist layer comprises a mark pattern and the mark pattern is located over the first overlay mark for defining a later formed second material layer on the first material layer to be a second overlay mark. Thereafter, a pre-process metrology overlay parameter set between the first overlay mark and the mark pattern is obtained. The first overlay correlation set at the exposure tool is adjusted according to the pre-process metrology overlay parameter set.