Method of verifying proximity effect correction in electron beam lithography

摘要

Verifying whether correcting data used for proximity effect correction is normal before or during actual lithographic writing. A lithographically written region is virtually divided into subfields. Verification of a correcting value for proximity effect correction for each subfield is normal is made. The correcting values (in percent) for proximity effect corrections for the subfields are stored in a memory. The correcting values are successively supplied to a FIFO and to a comparator. A reference value from a register is also supplied to the comparator. The correcting value for the first subfield r(1) and the output data from the FIFO are supplied to the comparator. The output data from the FIFO includes data about subfields located above and left, respectively, of the subfield r(1). The comparator produces the differences between the incoming values and takes their absolute values. The absolute values are compared with a reference value from the register.