Ionenstrahllithographie: Entwicklung Eines 1:1 Proximity Projektionsverfahrens Auf der Basis von Channeling-Masken (Ion Beam Lithography: Development of a 1:1 Proximity Projection Method Based on Channeling Masks)

摘要

An ion-beam lithographic method, based on single-crystal silicon-foil masks, imaging on a 1:1 scale, was developed. The energy and intensity of particles transmitted through the foils were calculated and experimentally determined as a function of the type and incidence energy of the ions, as well as of the membrane thickness. Transmission values up to 90% are obtained for high energies and foil thicknesses below 10 micrometers. Contrast values higher than 1:10 can easily be obtained by a suitable adaptation of the particle energy to the thickness of the silicon mask. Higher particle energies improve the angular divergence. Factors which can cause a distortion of the structure were determined. The effect of ion scattering on foil defect can be largely eliminated by a suitable choice of the particle incidence energy. The mask manufacturing procedure was improved. The optimum range with respect to particle energy and membrane thickness was determined.