Patent ID: 6842230

Claim:
An exposing method of exposing an overlaying layer by aligning with the pattern of an overlaid layer by using an exposure unit of the scan exposing type which performs exposures in a shot area by moving a reticle and a wafer synchronously along the scanning direction, the exposing method comprising: preparing a reticle having a matrix of four or more marks in the scanning direction and four or more in the direction orthogonal to the scanning direction; transferring the marks formed on the reticle to each shot area of a first pilot wafer, by using a first exposure unit which is used for exposing the overlaid layer; detecting the position coordinates of the marks transferred to each shot area of the first pilot wafer in a predetermined coordinate systems; transferring the marks formed on the reticle to each shot area of a second pilot wafer, by using a second exposure unit which is used for exposing the overlaying layer; detecting the position coordinates of the marks transferred to each shot area of the second pilot wafer in the predetermined coordinate systems; referring to the position coordinates of the marks transferred by using the first and second exposure units; calculating the difference between the respective coordinate elements of the two referenced position coordinates; calculating from the calculated difference a correction parameter for correcting a lens aberration; and exposing the overlaying layer, in the state where the optics of the second exposure unit are being corrected based on the calculated correction parameter.