9504948 Smith This collaborative, interdisciplinary research project includes a comprehensive determination of detailed electronic structure of thin film refractory metal nitrides and cubic boron nitride grown by state-of-the-art cyclotron resonance-assisted MBE and ion-assisted pulsed laser deposition methods. The electronic structure of defects and dopants in these nitrides, the electronic structure of the interface between the films and their substrates, and between the films and metal overlayers will be studied. Additionally, the chemical reactivity of the films (in particular, when defective or doped) will be investigated in order to understand the nature of elementary chemical bonding and adhesion of these nitrides to both substrates and overlayers, and to understand the chemical stability of the films at elevated temperatures. The electronic structure will be studied using complementary photoemission, inverse photoemission, and soft x-ray fluorescence spectroscopies. Soft x-ray fluorescence will be further developed on the project since it has the advantage that electronic structure can be determined in the presence of external electric or magnetic fields, and at elevated temperatures. %%% The primary goal of this program is to develop a fundamental-understanding of the electronic and photonic properties and the epitaxial growth and processing of wide bandgap semiconductor materials so that they can be exploited in the realization of a variety of advanced electronic and photonic devices. An important feature of the program is the training of graduate and undergraduate students in a fundamentally and technologically significant area of materials and processing research. This research will contribute to improving the general performance of advanced devices and integrated circuits used in computing, information processing, and telecommunications. ***