The present invention is an improvement on the LIGA microfabrication
process wherein a buffer layer is applied to the upper or working surface
of a substrate prior to the placement of a resist onto the surface of the
substrate. The buffer layer is made from an inert low-Z material (low
atomic weight), a material that absorbs secondary X-rays emissions from
the substrate that are generated from the substrate upon exposure to a
primary X-rays source. Suitable materials for the buffer layer include
polyamides and polyimide. The preferred polyimide is synthesized form
pyromellitic anhydride and oxydianiline (PMDA-ODA).