A method of processing first and second semiconductor wafers is provided. Each of the first and second semiconductor wafers has a first layer and a second layer over the first layer. A first lithographic process is performed on the first layer over the first semiconductor wafer using a first inter-field correction and a first intra-field correction. An overlay error of the first lithographic process is determined. A second inter-field correction and a second intra-field correction are computed based on the first inter-field correction, the first intra-field correction, and the measured overlay error. A second lithographic process is performed on the second layer over the second semiconductor wafer, based on the second inter-field correction and the second intra-field correction.