Method of evaluating shaped beam of charged beam writer and method of

Abstract

A method of evaluating a shaped beam generated by a charged beam writer, comprises the steps of: a first step of shaping line beams by dividing into 1/n one side of the shaped beam having a dimension 'a' in an x direction and a dimension 'b' in a y direction perpendicular to the x direction, where n is the number of divisions; a second step of irradiating the shaped line beam upon a surface of the sample or the movable stage for a constant time or longer; a third step of shaping a beam by adding a bias value .delta. to each line beam width in the divided direction; a fourth step of irradiating the line beam obtained by adding the bias value to the shaped line beam upon a photosensitive substance on the sample surface for a constant time for exposure; a fifth step of repeating the fourth step exposure (n-1) times by shifting the line beam obtained by adding the bias value to the line beam, in the direction that one side of the shaped beam is divided into 1/n, and developing the photosensitive substance, to obtain a pattern width .theta.; a sixth step of repeating the above first to fifth steps by changing the number of divisions n and the bias value .delta.; and a seventh step of obtaining a change rate .DELTA..theta./.DELTA.n of the pattern width .theta. relative to the number of divisions n for each bias value .delta., to obtain an offset drift rate on the basis of the obtained change rate and the bias value. The method can evaluate a beam offset drift rate between the set beam dimension and the actual beam dimension, so that a microscopic pattern can be formed at a high precision.