9627333 Edgar This research project aims for fundamental understanding of factors controlling the polytypes and phase stability of epitaxial multilayers and alloys of SiC combined with AlN and GaN. Vapor phase epitaxy of layered structures and alloys such as SiC/AlN/SiC, (AlN)x(SiC)1-x and (GaN)x(SiC)1-x of high crystalline perfection, controlled compositions, polytypes, and interfacial quality will be studied. The approach is oriented to relating basic chemical and processing conditions associated with epitaxial growth to the multilayered structures or polytypes realized. X-ray diffraction techniques will be used to study dependence of thin film crystal quality, strain, local atomic configuration, and polytype on the processing conditions, substrate material, orientation, and composition. Additionally, thermodynamic factors stabilizing these structures and alloys, and kinetic barriers preventing decomposition to bulk stable forms will be evaluated. %%% The research will contribute basic materials science knowledge of technological relevance to advanced electronic/photonic materials synthesis and processing. Additionally, the knowledge and understanding gained from this research project is expected to contribute in a general way to improving the performance of advanced devices and circuits by providing a fundamental understanding and a basis for designing and processing more advanced materials. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***
