Monitoring damage of self-assembled monolayers using metastable excited helium atoms

• Published in: The Journal of chemical physics Vol. 154; no. 3; p. 034704
• Main Authors: Stratis, Georgios, Zesch, Jordan D, Pan, Henry S, Webb, Lauren J, Raizen, Mark G
• Format: Journal Article
• Language: English
• Published: United States 21.01.2021
• ISSN: 1089-7690
• DOI: 10.1063/5.0036827

The breaking of molecular bonds during exposure to ionizing radiation and electron beams creates irreversible damage in the molecular structure. In some cases, such as lithography, controlled damage of a molecular resist is a desirable process and is the basis for the entire semiconductor industry. In other cases, such as environmental exposure or probing of the molecular structure, the induced damage is a major problem that has limited advances in science and technology. We report here the use of an in situ probe that is minimally invasive to detect real-time damage induced in organic materials. Specifically, we use metastable excited helium atoms in the S state to characterize the damage caused by a low-energy electron beam ∼30 eV on an organic self-assembled monolayer of 11-bromo-1-undecanethiol on a gold substrate. We were able to monitor the damage caused by the electron beam without introducing any additional observed damage by the probing metastable atoms.