Johannes Fielder presents at CMD29, 21-26 august 2022

Title: Impact of dispersion forces on matter-wave lithography

Johannes Fiedler

Abstract

Extreme ultraviolet lithography is the state-of-the-art tool to produce nanostructures, such as microchips. To resolve 14 nm (current limit), photons with an energy of 80 eV are required, which powerfully penetrate the substrate and result in damage. This effect causes many rejects. Further reductions in the resolution are hard a achieve because it requires high-energy photons. Current investigations to overcome these issues are performed by applying matter-wave diffraction. Due to the wave-particle duality, its theoretical resolution is in the order of a few Angstrom to nanometres. The kinetic energy of the particles dominates the transferred energy and is thus in the order of a tenth of meV. [1] However, the design of such lithography masks made of dielectric materials requires the consideration of the dispersion forces interacting between the particles and the mask. Their impacts effectively reduce the openings and imprint a spatial phase shift in the wave, bypassing the mask. [2] In this talk, we present the effective treatment of the dispersion forces and introduce the possibility of proposing mask designs to reach a wished pattern by applying a genetic algorithm approach to a neural network-based inversion. [3]

[1] T. Nesse, I. Simonsen, and B. Holst, “Nanometer-resolution mask lithography with matter waves: Near-field binary holography,” Phys. Rev. Applied 11, 024009 (2019).

[2] J. Fiedler and B. Holst, “An atom passing through a hole in a dielectric membrane: impact of dispersion forces on mask-based matter-wave lithography,” Journal of Physics B: Atomic, Molecular and Optical Physics 55, 025401 (2022).

[3] J. Fiedler, A. S. Palau, E. K. Osestad, P. Parviainen, and B. Holst, in preparation.