Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers

High quality GaN epitaxial films are one of the keys to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices. In fact, solid state lighting, high-temperature and high-power electronics, microelectronic and mechanical sensors, and high-efficiency solar cells are all poised at a new level of development. This enormous market is waiting for low-cost, high quality substrates to achieve performance and fabrication economies of scale. After achieving dislocation densities below 1E7 cm-2 in the phase I work, this NASA SBIR phase II project addresses the development of a dislocation filter that can routinely prepare low-stress GaN thin films with threading dislocation densities below 1E6 cm-2. The method relies on using a low-angle ion beam to induce both nanofilter for defect reductions and to inhibit droplet formation at low growth temperatures. Dislocation densities have so far been determined by standard etch pit densities method. The goal the project to optimize the multiple defect nanofilter with smoothening by transition layers in between filters to reduce the TD to less than 1E6 cm-2 and process, fabricate high performance HEMT for solid state high power amplifier (SSPA) applications. To obtain a more practical evaluation of the effectiveness and commercial viability of the method, heterojunction field effect transistors with high electron mobility will be fabricated in these ultra-low defect density films. These high-quality material based high electron mobility transistors (HEMTs) will enable high linearity power amplifiers with excellent thermal stability and frequency response. The proposed method to grow on low-stress, low-dislocation density films will lead to the production of electronic devices of unparalleled performance.