| 摘要 |
PROBLEM TO BE SOLVED: To provide a distortion adjustment method for reducing distortions in the entire main field, even in a charged particle beam projection aligner in a separated transfer system having a large subfield. SOLUTION: Distortion in the transfer image of a subfield A' on an optical axis is measured for adjusting the excitation of a lens in the conventional excitation adjustment method of a projection lens. In addition to the conventional adjustment, a beam from a electron source 1 is flexed by an irradiation system deflector 2, so that the track of a is drawn for irradiating a reticle end, namely a subfield A at the end of a main field. Beam tracks b and c are apart from the center of projection lenses 4 to by a considerable amount, thus causing distortion in the subfield to be several hundreds times larger than an image transferred through conventional tracks b' and c' along the optical axis. The distortion which is magnified by several hundreds times is measured, and the current in projection lenses 4 to 7 is adjusted by a control power supply 11, so that the distortion becomes minimum.
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