9521671 Adesida Over the last decade, significant improvements in the development of the epitaxial growth of wide bandgap nitrides have yielded positive results. Perhaps the most significant development in this yield has been the demonstration and commercialization of high luminosity blue LEDs. These achievements have engendered a broad spectrum of research activities in various laboratories world wide. The major emphasis of these activities continues to be on epitaxial growth. It is evident from literature that the excellent progress made in the growth of nitrides has not been accomplished by a commensurate progress in the processing methods that are required to turn these materials into devices. Some of the processing problems are sufficiently different from those of conventional III-V compound semiconductor materials, that the development of variable processing techniques for the fabrication of devices in the nitrides has become imperative . Further, it is of cardinal importance to begin training the graduate students who will constitute the human resources needed in the future to manufacture the impressive array of products that are envisaged from these materials. Our proposal research is therefore motivated by the continued improvement in the growth of GaN and related compounds and the need to develop processing methods required to turn these materials into high performance devices and circuits. The broad goals of the proposed research are to provide new insights into the etching of III-V nitrides, to develop new methodologies for the formation of ohmic and Schottky contacts on nitrides , and to develop high performance optoelectronic integrated photoreceivers operating at UV wavelengths. The specific objectives are to 1) develop and understand mechanism for highly anisotropic and "no-damage" etching processing suitable for the fabrication of laser faucets and mirrors in the nitrides; 2) develop ohmic contacts with low contact resistance and to understand the mechanism of contact formation ; 3) investigate Schottky barrier properties of refractory metals and silicides on the nitrides; and 4) fabricate and characterize metal-semiconductor-metal (MSM) photodetectors and GaN metal-semiconductor field-effect transistors (MESFETs) and to develop the technological basis for their integration. The work will be done in collaboration with Dr. M. Asif Khan of APA Optics, Minneapolis, w ho will provide the epitaxial nitrides uses in the work. ***
