Localized Probing of Gas Molecule Adsorption Energies and Desorption Attempt Frequencies

Gas-mediated electron beam induced etching (EBIE) and deposition (EBID) are often used to measure activation energies that are interpreted as the adsorption energies of surfaceadsorbed precursor molecules. However, the measured quantities often disagree with adsorption energies measured by conventional analysis techniques such as thermally programmed desorption, and have anomalous dependencies on parameters such as the electron beam current used to perform EBID. Here, we use the theory of EBIE and EBID rate kinetics to explain this behavior and identify conditions under which the activation energies and the associated pre-exponential factors correspond to gas molecule adsorption energies and desorption attempt frequencies, respectively. Under these conditions, EBIE and EBID can be used as robust, nano-scale techniques for the analysis of adsorbates.