DEFLECTING DISTORTION CORRECTING METHOD IN ELECTRON BEAM EXPOSURE DEVICE

摘要

PURPOSE:To correct deflecting coordinates which includes a distortion due to coordinates conversion coefficient using a recovery coefficient with the uniform, accurate and less capacity of a memory by dividing a deflecting region by small coordinates capable of being approximated in an orthogonal coordinates, and obtaining the coordinates conversion coefficient and recovery coefficient. CONSTITUTION:When M, N are approached to infinity , the conversion coefficient amn-fmn between small orthogonal coordinates 4(x,y) corresponding to divided small coordinates 2(X,Y) become continuous functions a(x,y)-f(x,y). An error epsilonmn in the actual data amn independently accords with a normal distribution, unknown base number is represented as amn=beta0+beta1x+beta2x2+beta3y+betay2+epsilonmn with presumed value, beta1-beta4 and beta0 are calculated so that the total of epsilonmn2 becomes minimum by the minimum squaring method to obtain a(x,y). Similarly, b(x,y)- f(x,y) are obtained to complete XY-xy due to the coefficient of continuous function. The coefficients are stored at actually drawing time, the definition of the small coordinates by the conventional method is eliminated, and irregular accuracy in the correction of the deflecting distortion can be eliminated.