Absorber edge effect in proximity X-ray lithography

We report on the influence of the “absorber edge effect” on both the image contrast and resolution in X-ray Lithography. This effect is due to the finite absorption and the phase shift of the X photons in the absorber. Numerical simulations show that the resolution can be improved as the critical dimensions of lithography reach 50 nm. Experimental results confirm these predictions. Moreover, we use a semi-empirical model of the development to analyze our data of strongly enhanced edge effect. We also discuss the possible improvement of the simulation model.