摘要 |
A method for printing a pattern of features including the steps of providing a substrate having a recording layer disposed thereon, providing a mask bearing a periodic pattern of features, arranging the substrate parallel to the mask and with a separation having an initial value, providing an illumination system for illuminating the mask with an intensity of monochromatic light to generate a transmitted light-field for exposing the recording layer, and illuminating the mask for an exposure time whilst changing the separation by a range having a predetermined value and varying at least one of the rate of change of separation and the intensity of illumination so that the mask is illuminated by an energy density per incremental change of separation that varies over said range, whereby the printed pattern has low sensitivity to a deviation of the range from said predetermined value or to the initial value of the separation.
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