Proximity correction for electron‐beam patterning on x‐ray mask blanks

TLDR: In this paper, Monte Carlo calculations and resist profile simulations show that the proximity effect can be almost entirely eliminated by using 100 keV electrons for the resist exposure, and experiments with available electron energies of 20 and 50 keV were conducted, with good agreement.

Abstract: A limiting factor in electron‐beam (e‐beam) lithography is the proximity effect. In the special case of x‐ray mask making, Monte Carlo calculations and resist profile simulations show that the proximity effect can be almost entirely eliminated by using 100 keV electrons for the resist exposure. To verify the theoretical results of the simulation, experiments with available electron energies of 20 and 50 keV were conducted, with good agreement. The poor efficiency of 100 keV electrons results in decreasing resist sensitivity. Electrons passing through the membrane hit holder parts behind it. The x‐ray radiation generated in this way was able to expose the resist from the backside of the membrane. A diffuse image of the holder parts could be seen in the resist.