Ion/Surface Interactions and Reaction Mechanisms
Abstract
The PI has demonstrated for the first time that hyperthermal energy atomic oxygen ions can directly abstract oxygen atoms from and deposit oxygen atoms into a silicon oxide surface. Isotopic labeling and 2-D velocity-resolved detection have allowed for the unambiguous assignment of two distinct abstraction mechanisms. In the first, an incident oxygen ion scatters from the lattice and abstracts an oxygen atom on the ion's departure from the surface. In the second mechanism, the energetic atomic oxygen ion generates an oxygen recoil, that in turn abstracts a neighboring oxygen atom from the silicon oxide lattice. In concert with the etching of oxygen from the surface, many of the incident oxygen ions become incorporated into the silicon oxide lattice. Isotopic labeling experiments have measured the cross section by which hyperthermal oxygen projectiles are incorporated into the topmost layer of the silicon oxide film. The largest rates of incorporation occur for 5 eV oxygen ions. These state-of-the-art experiments have demonstrated that the bombardment of silicon oxide with hyperthermal oxygen ions, such as in a LEO environment, can lead to changes in the gas/solid interface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2001
- Accession Number
- ADA403892
Entities
People
- Dennis C. Jacobs
Organizations
- University of Notre Dame