Numerical and experimental studies of the carbon etching in EUV-induced plasma

TL;DR

This study combines numerical modeling and experiments to analyze carbon etching mechanisms in EUV-induced plasma, revealing chemical sputtering at low pressures and reactive ion etching at higher pressures.

Contribution

It introduces a comprehensive approach integrating modeling and experimental data to distinguish etching mechanisms under different plasma conditions.

Findings

Chemical sputtering dominates at low pressure and energy.

Reactive ion etching is prevalent at high pressure and energy.

Ion fluxes correlate with observed etching rates.

Abstract

We have used a combination of numerical modeling and experiments to study carbon etching in the presence of a hydrogen plasma. We model the evolution of a low density EUV-induced plasma during and after the EUV pulse to obtain the energy resolved ion fluxes from the plasma to the surface. By relating the computed ion fluxes to the experimentally observed etching rate at various pressures and ion energies, we show that at low pressure and energy, carbon etching is due to chemical sputtering, while at high pressure and energy a reactive ion etching process is likely to dominate.