Area of expertise: Microelectronics materials and structures
Ph.D., Physics, 1975, University of Wisconsin, Madison, WI, United States
B.A., Physics, 1969, Johns Hopkins University, Baltimore, MD, United States
Office: 5-131 Keller Hall
Telephone: (612) 625-5517
E-mail: picohen (at) umn.edu
Personal Web Site: http://www.ece.umn.edu/~cohen/
We can now grow epitaxial films with composition control at the atomic level. Using the technique of molecular beam epitaxy, we are growing artificially structured materials to develop new device concepts and discover new materials phenomena. To do this, we monitor the epitaxial growth of semiconductor and metal films with in situ electron diffraction. Careful choice of growth procedures and parameters enables us to combine previously incompatible materials.
Once we understand the key ingredients — the role of surface structure and the kinetics of the growth process — we should be able to build semiconductors with engineered band structures for ultra-high-speed devices, as well as construct magnetic materials with BH loops and crystalline anisotropies tailored to specific device requirements. This new field is growing rapidly and is already considered state-of-the-art for the fabrication of new devices.
Held, R., G. Nowak, A. M. Dabiran, B. Ishaug, A. Parkhomovsky, P. I. Cohen, I. Grzegory, and S. Porowski. "Structure and Composition of GaN (0001) A and B Surfaces". Journal of Applied Physics, (1999).
Parkhomovsky, A., B. Ishaug, A. M. Dabiran, and P. I. Cohen. "Growth of Hf and HfN on GaN by Molecular Beam Epitaxy". Jounal of Vacuum Science Technology, (1999).
Dabiran, A. M., S. M. Seutter, S. Stoyanov, M. C. Bartelt, J. W. Evans, and P. I. Cohen. "Step Edge Barriers Versus Step Edge Relaxation in GaAs:Sn MBE". Surface Science, (1999).