1.7 kV / 1.0 m Omega cm(2) Normally-off Vertical GaN Transistor on GaN substrate with Regrown p-GaN/AlGaN/GaN Semipolar Gate Structure


Shibata D., Kajitani R. , Ogawa M., Tanaka K., Tamura S., Hatsuda T., ...More

62nd Annual IEEE International Electron Devices Meeting (IEDM), San-Francisco, Costa Rica, 3 - 07 December 2016 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1
  • City: San-Francisco
  • Country: Costa Rica

Abstract

A normally-off vertical GaN-based transistor on a bulk GaN substrate with low specific on-state resistance of 1.0 m Omega cm(2) and high off-state breakdown voltage of 1.7 kV is presented. P-GaN/AlGaN/GaN triple layers are epitaxially regrown over V-shaped grooves formed over the drift layer. The channel utilizes so-called semi-polar face with reduced sheet carrier concentration at the AlGaN/GaN interface, which enables high threshold voltages of 2.5 V and stable switching operations. Note that formation of carbon-doped insulating GaN layer formed on p-GaN well layer underneath the channel suppresses the punch-through current at off-state between the source and drain, which enables good off-state characteristics. The fabricated high-current vertical transistor achieves successful fast switching at 400V/15A. These results indicate that the demonstrated vertical GaN transistor is very promising for future high power switching applications.