UV Detector Materials Development Program

Abstract : The objective of this program is to establish the feasibility of using AlxGa1-xN as a sensor material in producing solar blind UV detectors. To achieve a solid-state blind UV detector, two major problems must be solved. First, a technique for growing AlxG1xN of controlled composition (x-value) and carrier concentration must be developed. Although AlGaN has been successfully grown over the entire range of composition, no laboratory has successfully controlled the carrier concentration in the range required for Schottky barrier formation. Our approach is to develop a new technique, metalorganic chemical vapor deposition (MO-CVD) for growing the AlGaN. As will be discussed in detail below, MO-CVD is a lower temperature growth process and utilizes less corrosive materials than other CVD processes. Hence, the prospects for achieving higher purity (lower carrier concentration) are much greater using the process than with the previously explored processes. The second major problem is developing the technology for Schottky barrier detectors. Since AlGaN has not been widely exploited for device applications, the device processing technology is not well developed. This program is the first to investigate Schottky barrier formation on AlGaN. Both the development of a controlled AlGaN growth process and Schottky barrier technology have been addressed in this program.