The present invention describes a method for fabricating an x-ray mask tool
which is a contact lithographic mask which can provide an x-ray exposure
dose which is adjustable from point-to-point. The tool is useful in the
preparation of LIGA plating molds made from PMMA, or similar materials. In
particular the tool is useful for providing an ability to apply a graded,
or "stepped" x-ray exposure dose across a photosensitive substrate. By
controlling the x-ray radiation dose from point-to-point, it is possible
to control the development process for removing exposed portions of the
substrate; adjusting it such that each of these portions develops at a
more or less uniformly rate regardless of feature size or feature density
distribution.
