Patent ID: 7525110

Claim:
A lithographic apparatus for writing a pattern on a workpiece, said apparatus comprising: a pattern writing unit having a radiation source for emitting an energy beam and a beam column functioning as a beam pattern generator for deflecting the beam to timely adjust its traveling to thereby form a prespecified pattern image on the workpiece; a control unit connected to said pattern writing unit and including means for correcting proximity and fogging effects occurrable during pattern writing using the beam; said means including a first calculator unit operative to determine through computation a proximity effect-corrected dose for correction of the proximity effect, a functional module for calculation of a fogging-corrected dose for correction of the fogging effect while including therein influence of the proximity effect, a combiner unit responsive to receipt of the doses calculated for combining these doses together to thereby determine a total corrected dose and for generating at its output a signal indicative of the total corrected dose, and a beam controller responsive to receipt of the output signal for using said total corrected dose to provide a beam control signal for transmission to said beam column; and said functional module having a second calculator unit for calculation of a variable real value indicating influence of the proximity effect to be taken into account during correction of the fogging effect, and a third calculator unit operatively associated with said second calculator unit for using the variable value of the proximity effect to thereby calculate the fogging-corrected dose.