Enhancement and Depletion Mode AlGaN/GaN CAVET With Mg-Ion-Implanted GaN as Current Blocking Layer

Current aperture vertical electron transistor (CAVET) was successfully demonstrated by using Mg-implanted GaN as a current blocking layer for nonalloyed source contacts. A maximum source-drain current of (corresponding to 0.22 A/mm of source) and an extrinsic transconductance of 54 mS/mm of source were achieved. Threshold voltage as high as 0.6 V was realized by plasma exposure for 10 min, increasing the transconductance of the device to 140 mS/mm of source. Thus, a normally off CAVET was demonstrated for the first time. The increase in by plasma exposure for a given bias was due to etching of the AlGaN barrier. The shift of threshold voltage and the varied directly with the time of exposure. There was no significant dispersion in these devices.

[1]  S. Keller,et al.  High Breakdown Voltage Achieved on AlGaN/GaN HEMTs With Integrated Slant Field Plates , 2006, IEEE Electron Device Letters.

[2]  Ilesanmi Adesida,et al.  Recessed-gate enhancement-mode GaN HEMT with high threshold voltage , 2005 .

[3]  Kevin J. Chen,et al.  Self-aligned enhancement-mode AlGaN/GaN HEMTs using fluoride-based plasma treatment , 2005, 63rd Device Research Conference Digest, 2005. DRC '05..

[4]  F. Recht,et al.  Nonalloyed ohmic contacts in AlGaN/GaN HEMTs by ion implantation with reduced activation annealing temperature , 2006, IEEE Electron Device Letters.

[5]  U. Mishra,et al.  30-W/mm GaN HEMTs by field plate optimization , 2004, IEEE Electron Device Letters.

[6]  N. Fichtenbaum,et al.  Impact of CF 4 Plasma Treatment on GaN , 2007 .

[7]  Umesh K. Mishra,et al.  AlGaN/GaN current aperture vertical electron transistors with regrown channels , 2004 .

[8]  F. Recht,et al.  AlGaN/GaN HEMTs with Large Angle Implanted Nonalloyed Ohmic Contacts , 2007, 2007 65th Annual Device Research Conference.

[9]  S. Keller,et al.  Effect of ohmic contacts on buffer leakage of GaN transistors , 2006, IEEE Electron Device Letters.

[10]  Toshiaki Matsui,et al.  Non-Recessed-Gate Enhancement-Mode AlGaN/GaN High Electron Mobility Transistors with High RF Performance , 2004 .

[11]  T. Kachi,et al.  A Vertical Insulated Gate AlGaN/GaN Heterojunction Field-Effect Transistor , 2007 .

[12]  R. Coffie,et al.  AlGaN/AlN/GaN high-power microwave HEMT , 2001, IEEE Electron Device Letters.

[13]  N. Fichtenbaum,et al.  Impact of $\hbox{CF}_{4}$ Plasma Treatment on GaN , 2007, IEEE Electron Device Letters.

[14]  Michael S. Shur,et al.  Enhancement and depletion mode GaN/AlGaN heterostructure field effect transistors , 1996 .