X-RAY MASK DISTORTIONS DURING E-BEAM PATTERNING

The pattern placement accuracy of an x-ray lithography mask is affecte d by thermomechanical distortion induced during the electron beam patt erning process. Three-dimensional finite element models have been deve loped to simulate the response of the membrane and resist stack and id entify the in-plane distortions due to the e-beam writing. Thermal dis placements (due to the e-beam heating) and mechanical displacements (d ue to the resist in situ stress relief) were calculated for the ARPA-N IST standard x-ray mask.