Recent progress on the electron image projector

Three main aspects of the 1:1 electron image projector are considered; the economics, the ultimate resolution, and an electrostatic chuck. It is shown that the image projector is economic if more than four exposures per mask can be made; the resolution limitation due to the system is shown to be 200–300 Å, but is in practive limited by electron scattering. The effect of electron scattering can be overcome by altering dimensions in patterns down to 1 μm, but isolated windows of 0.5 μm require ’two-mode’ masks. The electrostatic chuck is shown to provide an adequate pressure to hold slices flat, and adequate heat sinking.