| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a photomask which accurately expresses gradation. <P>SOLUTION: The photomask is provided with a transparent base board (42) and a phase grating comprising a plurality of grooves of a constant pitch (P) which are formed on the base board. The depth and width of each groove of the phase grating carries an exposure pattern. Then, an inequality P<λ/NAi is set, whereinλrepresents a wavelength of exposing light of an exposure device which irradiates the photomask, and NAi represents the incident side numerical aperture of an image-forming lens. By this, the image of the grating is not formed, and the exposure patterns, which are expressed by the depths and widths of the respective grooves of the phase grading, are transferred to a photosensitive material. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
