Mask alignment system for electron beam pattern generator

摘要

A mask alignment system for electron beam pattern generators whereby an electron beam pattern may be repeatedly directed to a mask blank in an extremely accurate predetermined matrix pattern. In accordance with the invention a master mask is fabricated having a reference grid pattern thereon. This reference pattern is reproduced as an electrically conductive grid pattern on each electron sensitized mask blank for a mask set. Electrical connection is made to the grid pattern, when the mask blank is placed in an electron beam pattern generator, and controlled scanning of the beam is used to intercept the reference grid and provide an output signal current as the result thereof so as to allow correction of the electron beam pattern position for the error in position in the mask blank because of step and repeat inaccuracies in the X-Y positioner supporting the mask blank. Perfection in the master grid is not required since deviations from the true desired position will repeat throughout the mask set, so as to allow proper alignment of each mask in the mask set throughout the entire mask plane.