摘要 |
A grayscale mask made from semi-transparent film layers is provided, along with an associated fabrication method. The method provides a transparent substrate, such as quartz, with a surface. A first layer of a semi-transparent film having a surface with a first surface area, is formed overlying the substrate surface. At least a second layer of the semi-transparent film having a surface with a second surface area greater than the first surface area, is formed overlying the first layer. A first vertical region is formed having a light first attenuation parameter through the combination of substrate, first layer, and second layer. A second vertical region is formed having a light second attenuation parameter through the combination of the first layer and substrate, and a third vertical region is formed having a light third attenuation parameter through the substrate.
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