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HL: Fachverband Halbleiterphysik

HL 46: Focus Session: AlGaN Materials for UV Emitters

HL 46.1: Invited Talk

Wednesday, March 28, 2012, 09:30–10:00, ER 164

AlN-based technology for electronics and optoelectronics — •Zlatko Sitar¹, Ramon Collazo¹, Raoul Schlesser², Spalding Craft², Baxter Moody², Seiji Mita², Jinqiao Xie², Anthony Rice¹, and James Tweedy¹ — ¹MSE, North Carolina State University, Raleigh, NC, USA. — ²HexaTech, Inc., Morrisville, North Carolina, USA.

For the first time in history of III-nitrides, the availability of low defect density (<10E3 cm-2) native AlN substrates offers an opportunity for growth of AlGaN alloys and device layers that exhibit million-fold lower defect densities than the incumbent technologies and enable one to assess and control optical end electrical properties in absence of extended defects. Epi-ready AlN wafers are fabricated from AlN boules grown by physical vapor transport at temperatures between 2200 and 2300°C. Gradual crystal expansion is achieved through a scalable, iterative re-growth process in which the high crystal quality is maintained over many generations of boules. Low defect density AlN and AlGaN epitaxial films are grown upon these wafers that exhibit superior optical properties in terms of emission efficiency and line width and can be doped with an efficiency that is several orders of magnitude higher than possible in technologies using non-native substrates. UV LED structures and Schottky diodes were fabricated on these materials that exhibit low turn-on voltages and breakdown fields greater than 10 MV/cm. This presentation will review state-of-the-art of AlN-based technology and give examples of potential applications in future devices and contrast these with other wide bandgap technologies.