Gallium nitride vertical electron transistors for high power applications
- Degree Grantor:
- University of California, Santa Barbara. Electrical & Computer Engineering
- Degree Supervisor:
- Umesh K. Mishra
- Place of Publication:
- [Santa Barbara, Calif.]
- Publisher:
- University of California, Santa Barbara
- Creation Date:
- 2013
- Issued Date:
- 2013
- Topics:
- Engineering, Materials Science, Energy, and Engineering, Electronics and Electrical
- Keywords:
- Selective Area Regrowth,
Gallium Nitride,
Buried p-GaN,
Vertical Electron Transistors,
CAVETs, and
Power Transistors - Genres:
- Online resources and Dissertations, Academic
- Dissertation:
- D.Eng.--University of California, Santa Barbara, 2013
- Description:
Lateral GaN HEMT structures have been well studied and developed for high power applications. However, for very high breakdown voltages, a vertical device design is more favorable owing to better field distribution and higher power density. Current Aperture Vertical Electron Transistors (CAVETs) benefit from the high electron mobility of the 2-dimensional electron gas (2-DEG) in the lateral direction and better field distribution in the vertical direction. Current flows laterally in the 2-DEG at the AlGaN/GaN heterojunction and is directed vertically down to the drain through an aperture. A current blocking layer (CBL) is used to define the low resistance aperture. The focus of this thesis is developing CAVETS with Mg-doped conductive p-GaN layers as the current blocking layer. Current blocking is realized by the use of a reverse biased p-n junction as opposed to an insulating layer. The p-GaN is regrown either by Ammonia MBE or MOCVD and in order to ensure that the p-GaN layer remains active, the channel regrowth is done by Ammonia-MBE. The current blocking capacity of the p-n junction has been verified in an n/p/n structure and the highest breakdown voltage recorded was 870 V. The peak electric field has been estimated to be 3.1 MV/cm, which is close to the GaN critical field. With the current blocking capacity of the active p GaN layer verified, selective area regrowth was used to define the apertures and CAVETs were fabricated. Promising transistor performance was demonstrated with a high saturation current of 10.9 kA cm-2 and low ON-resistance of 0.4 mohm cm 2.
- Physical Description:
- 1 online resource (176 pages)
- Format:
- Text
- Collection(s):
- UCSB electronic theses and dissertations
- Other Versions:
- http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqm&rft_dat=xri:pqdiss:3612053
- ARK:
- ark:/48907/f3xs5sh7
- ISBN:
- 9781303732119
- Catalog System Number:
- 990041153670203776
- Copyright:
- Ramya Yeluri, 2013
- Rights:
- In Copyright
- Copyright Holder:
- Ramya Yeluri
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