Patent ID: 7144685

Claim:
A method of forming a latent image pattern in a photoresist film, said method comprising the steps of: providing a photomask, for near-field light exposure, comprising a transparent support member and a shading member on the support member, the shading member having a constant thickness and a pattern of apertures with widths not greater than a wavelength of light from a light source, wherein the shading member includes at least two apertures of different widths, and the thickness of the shading member is set such that differences between light intensities directly below each of the apertures of different widths is 20% or less based on a largest light intensity of the light intensities directly below each of the apertures of different widths; placing the photomask on the photoresist film formed on a work substrate; and irradiating through the transparent support member and the pattern of apertures in the shading member of the photomask with the light from the light source to form a latent image pattern in the photoresist film based on the pattern of apertures on the photomask.