Production issues for high aspect ratio Lobster-eye optics using LIGA

We have previously considered some of the parameters for, and production issues involved in making, a useful Lobster-eye prototype using X-ray lithography. Due to the high aspect ratio and dense packing of the array features, we were unable, in our initial attempts to produce optimal Lobster-eye optics using X-ray lithography and a PMMA resist, to consistently overcome adhesion issues between the substrate and the resist. In recent work we have overcome this problem by using SU-8 as the resist instead. In the light of this advance we reconsider the relevant parameters and production issues when using SU-8 and lower-energy exposures.