4-kV and 2.8-$\text{m}\Omega $ -cm² Vertical GaN p-n Diodes With Low Leakage Currents

Abstract

There is great interest in bulk GaN-based power electronics devices for applications requiring breakdown voltages greater than 3.3 kV. In this letter, the vertical GaN p-n diodes fabricated on improved bulk GaN substrates demonstrating low leakage currents (<;10 nA) and avalanche breakdown are discussed. The device layers are grown by metal-organic chemical vapor deposition on low defect density (10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ) bulk GaN substrates with improved quality and specifications that are uniquely suitable for power electronic device applications. The measured devices show breakdown voltages larger than 4 kV with an area differential specific ON-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sp</sub> ) of less than 3 mΩ-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Applications that would require such breakdown voltages, include ship propulsion, rail, wind, uninterruptable power supplies, and the power grid.