Patent ID: 6027841
Filing Date: 2000-02-22
Classification: B82Y,H01J

Abstract:
A method for projecting a pattern, defined by a mask, onto a sensitive substrate, comprising:(a) providing a mask defining the pattern;(b) placing the mask in a trajectory of a charged particle beam passing through an illumination-lens assembly so as to selectively cause the charged particle beam to illuminate a desired region of the mask;(c) passing charged particles of the beam transmitted through the illuminated mask region through a projection-lens assembly, located downstream of the mask, to a sensitive substrate so as to form an image of the illuminated mask region on a selected region of the sensitive substrate;(d) providing multiple deflectors at respective locations downstream of the mask; and(e) for each of the deflectors, determining a respective energizing current or voltage according to a first function that corrects aberrations except deflection distortion, the first function being of independent variables including coordinates (X.sub.w,Y.sub.w) of an ideal position of the selected region on the substrate corresponding to the illuminated mask region, a height (Z) of the substrate, a beam current (I) passing through the pattern features inside the illuminated mask region, and a measure of the pattern-feature distribution (s) within the illuminated mask region.