| 摘要 |
An apparatus 10 for exposing a curved grating pattern of monochromatic light on a photoresist coated semiconductor wafer 12 includes an argon gas laser 14 that outputs a monochromatic light beam 16. This monochromatic light beam 16 is filtered and collimated to produce a monochromatic light beam with a planar wavefront 24. A portion of this planar wavefront passes through a cylindrical lens array 26 and a first baffle slit 30, producing multiple cylindrical wavefront 34 that is incident upon a hypotenuse face 38 of a right angle prism 40. Another portion of the planar wavefront passes through a second baffle slit 32, producing a smaller planar wavefront 36 that is also incident upon the hypotenuse face 38 of the right angle prism 40. A destructive interference between a reflected multiple cylindrical wavefront 92 and a direct planar wavefront 90 inside the prism 40 produces a curved grating pattern of monochromatic light on an adjacent prism face 42. This curved grating pattern of monochromatic light is projected toward the semiconductor wafer 12, thereby exposing the photoresist coated wafer surface 48 with the curved grating pattern.
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