Combinatorial Approach to Improved P-Type Contacts via Optimal Molecular Doping

"Astralux, Inc. proposes to develop a novel and enabling p-type doping technology for the III-V nitrides with significant applications in the electronic and optoelectronic device arenas. Specifically, we will use molecular doping of magnesium (Mg) andoxygen (O) by ion implantation to improve upon the existing p-type doping technology, with the goal of significantly enhancing the dopant solubility, hole activation and hole mobility. Improved dopant solubility, hole activation and mobility will decreasethe resistivity of the p-doped GaN material. The optimum molecular doping concentrations and material annealing times will be determined by using the combinatorial chemistry approach. The fundamental improvements in p-doping technology, and resultantreduction of resistivity, will not only enable improved contact technology and thereby ease the fabrication of InGaN laser diodes (LDs), but also facilitate commercial development of high power microwave devices such as AlGaN/GaN HBTs. During phase I wewill unambiguously demonstrate the feasibility of the proposed technical approach. In the anticipated Phase II effort we will focus on a commercial HBT fabrication process with device demonstrations for this promising new technology. The Astralux teamincludes experts in wide bandgap materials and devices, as well as combinatorial chemistry. The material improvements expected from the outcome of this research should enable the AlGaN/GaN system to reach its full potential in electronic applications suchas heterojunction bipolar transistors (HBTs) and bibolar junction transistors (BJTs). Furthermore, improved p-type doping technology will lead to increasing the lifetimes of InGaN laser diodes and allow them to operate at lower bias voltages than ispossible today."