| 摘要 |
A mask (50) for use in lithographic printing includes a pattern (54) formed of a material which is substantially opaque with respect to a wavelength of radiation being used in the lithographic printing. The pattern (54) on the mask (50) corresponds to a desired feature to be formed on a substrate and includes a grating (58) having an alternating pattern of opaque and transparent regions (60, 62). The alternating pattern provides destructive interference of radiation at the substrate in a region corresponding to the desired feature due to diffraction, thereby improving resolution at the substrate. In addition, the alternating pattern (60, 62) on the mask (50) increases a number of focal planes at which the destructive interference occurs and thereby improves a focus process latitude by providing an acceptable resolution over variations in a distance between the mask (50) and the substrate.
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