Patent ID: 8405816

Claim:
A pattern formation method in which a pattern is formed on an object by using a variable molding mask and an optical system the variable molding mask having a plurality of modulation elements that are two-dimensionally placed at an incident position of an illumination light and that spatially individually modulate at least one of amplitude, phase and polarization states of the illumination light, and generating a pattern made up of light areas and dark areas, and the optical system forming an image of the pattern generated by the variable molding mask on the object, the method comprising: acquiring information on a target pattern; and controlling the plurality of modulation elements of the variable molding mask such that at least one of the number and positions of a plurality of the modulation elements on the variable molding mask, which contribute to image-forming of a pattern by irradiating the illumination light, is changed while a plurality of basic patterns are overlaid on the object based on the information on the target pattern, and forming the target pattern in which the pattern has a line width of non-integer multiples of a size of an image of the modulation element at least partially on the object, by the overlaying of the plurality of basic patterns, wherein the plurality of basic patterns are each made up of light areas and dark areas, and the modulation elements corresponding to the light areas and the modulation elements corresponding to the dark areas are different from each other in at least one of a distribution and a placement on the variable molding mask.