Point-defect management in homoepitaxially grown Si-doped GaN by MOCVD for vertical power devices
Shashwat Rathkanthiwar, Pegah Bagheri, Dolar Khachariya, Seiji Mita, Spyridon Pavlidis, Pramod Reddy, Ronny Kirste, James Tweedie, Zlatko Sitar, Ramón Collazo
Abstract
Abstract We demonstrate controlled Si doping in the low doping range of 5 × 10 15 –2.5 × 10 16 cm −3 with mobility >1000 cm 2 V −1 s −1 in GaN films grown by metalorganic chemical vapor deposition. The carbon-related compensation and mobility collapse were prevented by controlling the electrochemical potential near the growth surface via chemical potential control (CPC) and defect quasi-Fermi level (dQFL) point-defect management techniques. While the CPC was targeted to reduce the net C N concentration, the dQFL control was used to reduce the fraction of C atoms with the compensating configuration, i.e. <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">C</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo>.</mml:mo> </mml:math> The low compensating acceptor concentration was confirmed via temperature-dependent Hall effect analysis and capacitance–voltage measurements.