摘要 |
The present invention relates to manufacturing grayscale masks that are used for mass-producing grayscale DOEs. More specifically, the present invention provides a method whereby a grayscale mask is fabricated by using an absorber layer and a photoresist with a laser writer. The method of the present invention includes the steps of providing a substrate with a known layer of absorber and a layer of photoresist, exposing the photoresist to a grayscale pattern from a laser writer, developing the photoresist into variable thickness, and transferring the surface relief pattern from the photoresist layer onto the absorber layer by etching.
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