Dispersion-free AlGaN/GaN CA VET with low Ron achieved with plasma MBE regrown channel with Mg-ion-implanted current blocking layer

Srabanti Chowdhury, Man Hoi Wong, Brian L. Swenson, Umesh K. Mishra

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Scopus citations


GaN-based power transistors are rapidly developing as a contender for application in next generation high efficiency power electronics. They are either lateral devices like HEMTs or vertical devices of the form of the Current Aperture Vertical Electron Transistor (CA VET) [1, 2]. A CAVET (Fig.I) is a vertical device with source and gate on top and a current aperture that allows current to flow vertically down from the source to the drain. It has a current blocking layer (CBL) to block current flowing vertically through any other path but the aperture. The process flow for fabricating a CA VET is illustrated in figure 2. One way to achieve the current blocking layer is by implanting the layer with [Mg]-ion. However the difficulty in using a Mg-implanted barrier layer was the unintentional diffusion of the Mg into the overlying channel region (see Fig.3). This caused a significant threshold voltage shift in devices and in many cases the electrons in the channel were trapped or completely depleted by diffusing Mg acceptors. In this paper we report on successfully addressing this critical problem by using MBE to re-grow the channel containing the 2DEG on top of the n drift region that is grown by MOCVD resulting in devices free of dispersion (80μs pulse width) and Ron less than 2.5 mΩ-cm2. Here the advantages of MBE, that of a low growth temperature and hence suppressed Mg diffusion, is combined with the advantages of MOCVD, that of a high growth rate of high purity material necessary for the thick drift region to support high voltage required in power electronics.

Original languageEnglish (US)
Title of host publication68th Device Research Conference, DRC 2010
Number of pages2
StatePublished - 2010
Event68th Device Research Conference, DRC 2010 - Notre Dame, IN, United States
Duration: Jun 21 2010Jun 23 2010

Publication series

NameDevice Research Conference - Conference Digest, DRC
ISSN (Print)1548-3770


Other68th Device Research Conference, DRC 2010
Country/TerritoryUnited States
CityNotre Dame, IN

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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