Measurement of Absolute Data for Electron-induced Chemical Change

• Research unit: COST
• Project number: C07.0018

Key words (English)

electron-induced chemical change; electron collisions; cross section; dissociative electron attachment; plasma technology; electron lithography; radiotherapy; ionosphere

Research programs (English)

COST-Action CM0601 - Electron Controlled Chemical Lithography - ECCL

Short description (English)

An instrument to measure quantitative data (absolute cross sections) for one aspect of electron-induced chemical change (dissociative electron attachment) will be constructed and used to characterize molecules of current interest for other participants of the COST action. The data will be combined with other quantitative data (elastic, vibrational and electronic excitation cross sections) from this laboratory and used as a basis for rationalization of results and help in understanding the mechannisms of electron-lithographic processes on surfaces. It will also be essential for validification of theoretical methods of electron-induced chemical change, ongoing within the Action.

Partners and International Organizations (English)

AT, BE, CH, CZ, DE, DK, ES, FR, IS NL, PL, PT, RS, SK, TR, UK

Abstract (English)

An instrument to measure quantitative data (absolute cross sections) for dissociative electron attachment, constructed within this project, as well as an in-house constructed electron spectrometer have been used to study a number of molecules relevant to the subject of this grant. Measurements in HCN and DCN are interest-ing for astronomy and provided impetus for improvement of theory. The measurements of dissociative attachment in diacetylene has shown that the cross section can be small in molecules which do not have a resonance at a suitable energy. The measurements of absolute values and angular distributions of the cross sections for elastic scattering and for vibrational excitation by electron impact of diacetylene revealed strong role played by symmetry. A detailed set of absolute elastic, and vibrational and electronic excitation cross sections was also measured for Pt(PF3)4. This precursor for electron-beam nanofabrication was found to have a large cross section for electronic excitation which is likely to serve as a first step in the electron-beam dissociation. The dissociative attachment cross section for the loss of one PF3 ligand is also very large. Naked platinum anion is formed with a small cross section.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C07.0018