The National Science Foundation (NSF) doesn’t usually give grants for billiards, but the research conducted by the Lamar University Chemistry and Physics department can be loosely equated to “atomic billiards”. Faculty members in the department, Wayne Rabalais, distinguished professor, and Bogdana Bahrim, assistant professor, are the principal investigators for the NSF grant to study and understand the microscopic theory of ion-surface interactions. The $330,000 grant is shared with the University of Houston.
Beams of particles are fired at various surfaces and studied by using several methods including the scattering and recoiling imaging spectrometer (SARIS) and transmission electron microscopy (TEM) to view and map the various physical changes to the particle ions and the atoms on and beneath the surfaces being tested. Sputtering occurs when the ions from the particle beam collide with surface atoms causing them to be ejected away from the cluster, much like a cue ball crashing into a rack of billiard balls. These atoms can be captured and retained on a secondary surface in a process called ion deposition. Ion implantation occurs when some of the projectile ions embed themselves in the surface. Semiconductor manufacturers use this method to produce the semiconductors found in all modern computers.
“The technology of ion implantation is widely used, but the actual physics of the process is one of the fundamental unsolved problems in surface chemistry and physics,” said Rabalias. “Semiconductor manufacturers use a trial and error approach to manufacturing semiconductors. This is groundbreaking research and experimentation and theory that is being carried out is not being performed anywhere else in the world.”
The National Science Foundation grant is the second three-year award for the chemistry and physics department in this area of research. The research on ion-surface interactions is being performed jointly with the University of Houston. According to Rabalais, there are many instruments and techniques available to observe and study ion-surface interactions; however, each method only gives a small bit of information about the physical changes in the charge, trajectory and deposition position of the ions.
“From a theoretical standpoint,” said Bahrim, “we are trying to develop new approaches for experimenting with this type of research. New computer programs are being designed in order to provide better models to guide the experimental phase of the research.”
Several Lamar University chemistry and physics students are assisting in the ion-surface interaction research.
