An exposure system includes a wafer processing apparatus for performing a preparation-for-exposure
process on a wafer before an exposure process is performed, an exposure apparatus
for performing the exposure process on the wafer subjected to the preparation-for-exposure
process performed by the wafer processing apparatus, wherein the exposure apparatus
also performs a calibration process to correct an error caused by a time-varying
environmental parameter and/or caused by the exposure apparatus itself, and a host
computer connected to the wafer processing apparatus and the exposure apparatus
via communication means. Depending on the time needed for the wafer processing
apparatus to perform the preparation-for-exposure process, the host computer outputs
a calibration execution command for performing the calibration process to the exposure
apparatus. Thereby, the total time from the start of processing a lot to the end
thereof is minimized and thus, the total throughput is improved.
