OPERATION TEMPERATURE ADJUSTMENT METHOD OF CATHODE AND LITHOGRAPHY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method of optimizing a cathode temperature of an electron gun in a short time when regulating an emission current in order to obtain a desired current density.SOLUTION: An operation temperature adjustment method of a cathode includes the steps of: acquiring an approximation formula approximating a correlation between an emission current value and an operation temperature of the cathode; measuring a current density of an electron beam emitted from the cathode in the state where an n-th emission current value and an n-th operation temperature of the cathode are set to an electron beam source; determining whether the measured current density is within an allowable range; changing the set n-th emission current value into an (n+1)th emission current value in the case where the current density is not within the allowable range; and using the approximation formula to compute an operation temperature of the cathode corresponding to the (n+1)th emission current value and setting the computed operation temperature to the electron beam source as an (n+1)th operation temperature of the cathode.