CAREER: Native Oxides on the III-V Nitrides and Chemical Cleaning of the Semiconductor Surfaces

9624995 Mohney This CAREER research project addresses the formation and the chemical etching of native oxides on III-V nitride surfaces. The chemical and structural nature of intentionally and unintentionally formed oxides on the semiconductor surfaces will be studied, and chemical processing steps for the preparation of semiconductor surfaces for further devic e processing will be developed. Complementary techniques including spectroscopic ellipsometry, Auger electron spectroscopy, x-ray photoelectron spectroscopy, and conventional and high resolution transmission electron microscopy will be employed. The nature of the oxide, which is currently unknown, will strongly influence which chemical etchants w ill be most effective for removing it. Appropriate chemical treatments for removing the oxide and producing surfaces with the least residual oxygen and carbon contamination will be developed, given that many processing steps, such as the formation of ohmic contacts and Schottky barriers, are most conveniently accomplished when a brief exposure to air is allowed between chemical preparation and further processing. Comparison of the effectiveness of the chemical surface preparation procedures will be accomplished through the fabrication and characterization of non-reactive ohmic contacts and/or Schottky barriers to GaN. %%% Along with the basic research activity, this project incorporates material on surface preparation of semiconductors into an undergraduate laboratory course on electronic and photonic materials. Other educational initiatives to be undertaken include updating a senior-level laboratory course on metals science and engineering, increasing the use of c omputer modeling and visualization in the undergraduate curriculum, and increasing participation of undergraduates in research. The proposed basic investigations are expected to contribute fundamental materials science knowledge of technological relevance to advanced microelectronic devices and circuits. The knowledge and understanding gained fro m this research project is expected to contribute in a general way to improving the performance of advanced devices and circuits used in computing, information processing, and telecommunications by providing a fundamental understanding and a basis for designing and producing improved materials and processes. *** _