9307852 Cohen The aim of this research is to understand epitaxial crystal growth of thin films at the atomic level, and to develop new and more perfect thin film materials and structures. The effort will focus on understanding the fundamental processes of epitaxial growth and on developing new, controlled approaches to epitaxy. Several complementary growth monitors will be utilized in the studies; reflection high energy electron diffraction and reflection mass spectroscopy will be applied during growth to monitor the structural and chemical evolution of surfaces during molecular beam epitaxy. Scanning tunneling microscopy will be applied during growth interruptions to eliminate ambiguity in the interpretation of diffraction measurements. Initial work will focus on the role of impurities in the pinning and disordering of steps, on the structure of III- V semiconductor surfaces, and on mechanisms for strain relaxation. The research will also be extended to the growth of iron nitride, a new magnetic material. %%% The fundamental research conducted on epitaxial crystal growth is expected to improve the technology of the primary materials that are used in microelectronics and micromagnetics. Techniques to monitor the fabrication of a thin film that are sensitive enough to monitor each atomic layer as it is added to the film will be developed and used to control the fabrication process so that new and more perfect structures can be created. ***
