| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a photomask enabling a more accurate tone representation. <P>SOLUTION: The photomask has a transparent substrate (42) and a phase grating structured from a plurality of grooves of a fixed pitch (P) formed on the substrate, wherein either the depth or width of the respective grooves of the phase grating is made to bear the exposure pattern. When the wavelength of the exposure light of an exposure apparatus irradiating the photomask is set toλand the incident side numerical aperture of the imaging system lens is set to NAi, these factors satisfy P<λ/NAi. Thereby, the grating will no longer be imaged, and the exposure pattern represented with the depth or width of the respective grooves of the phase grating will be transcribed onto a photosensitive material. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
