E-beam application of highly sensitive positive and negative-tone resists for x-ray mask making

Resist sensitivity is one of the limiting factors in X-ray as well as e-beam lithography. To overcome the rather low sensitivities of commonly used resist like PMMA, a positiv-tone X-ray resist ("RAY-PF") has been recently developed, which makes use of the concept of chemical "amplification". Since a novolak is included as a binder matrix, development can be performed by aqueous alkaline solutions, e.g. RAZ-Developer. Replacement of the dissolution inhibitor in RAY-PF by a chemical crosslinker yields a negative-tone resist ("RAY-PN") with very similar processing. The present investigation refers to the application of both resist types, originally designed to meet the demands of X-ray mask fabrication.