Thin Film Growth Phenomena: Scaling from Angstroms to Meters, Picoseconds to Hours

Saturday, March 7, 1998 - 2:25pm - 2:50pm
Keller 3-180
Joe Greene (University of Illinois at Urbana-Champaign)
Critical phenomena which determine nanoscale chemical reactions, together with microstructural and surface morphological evolution, during thin film growth, occur over vastly different distance and time scales. Continuum modeling, necessary for describing the structure and chemistry, and hence physical properties, of macroscopic thin film systems (typical dimensions of nm to microns thick by mm to several hundred cm in diameter, i.e. 1014 to 1022 atoms requires input from kinetic equations which reliably predict surface and bulk mesoscopic-scale reactions (diffusion, surface roughening, island coalescence, grain growth, etc) that occur over times ranging from 10-9 secs. to hour. Understanding the basic physics governing these collective reactions requires probing and modeling atomic-scale interactions at surface and interfaces over times ranging from approximately 10-14 secs. to 10-6 secs. This, in turn, often necessitates ab initio or quantum chemical approaches. At all scales, experimental verification is essential.

In this talk, a few examples of microstructural and surface morphological evolution during both epitaxial and polycrystalline film growth will be briefly discussed to illustrate relationships (scaling laws) between atomic-scale interactions and macroscopic (bulk) behavior.