Skip to main content Accessibility help

Analysis of Leakage Currents in AlGaN/GaN Current Aperture Vertical Electron Transistors (CAVETs)

  • Ilan Ben-Yaacov (a1), Yee-Kwang Seck (a1), Steven P. DenBaars (a1), Evelyn L. Hu (a1) and Umesh K. Mishra (a1)...


A complete analysis of leakage currents in AlGaN/GaN Current Aperture Vertical Electron Transistors (CAVETs) with regrown aperture and source regions was carried out. The total observed leakage current was found to be a combination of both gate leakage and source leakage. Two paths for source leakage have been identified; electrons passing directly through the insulating layer to the drain region as well as electrons traveling through the aperture but underneath the 2DEG at the AlGaN/GaN interface. Source leakage through the insulating layer resulted from pits formed at the onset of regrowth, as the sample was heated to growth temperature, and was successfully eliminated by optimizing regrowth conditions. Source leakage underneath the 2DEG occurred when the unintentionally doped (UID) GaN layer above the insulating layer was not fully depleted and could be eliminated by reducing the thickness of the UID GaN layer. Gate leakage has been attributed to the enhanced incorporation of n-type impurities inside as well as above the aperture region during regrowth, resulting in a narrowing ofthegateSchottkybarrier.



Hide All
[1] Wu, Y.-F., Kapolnek, D., Ibbetson, J., Zhang, N.-Q., Parikh, P., Keller, B. P., and Mishra, U. K., “High Al-content AlGaN/GaN HEMT's on SiC substrates with very high power performance,” IEDM Tech Dig., Dec. 1999, Tno. 99CH36318, pp. 925927.
[2] Eastman, L. F., Shealy, J. R., Tilak, V., Smart, J., Green, B. and Prunty, T., “AlGaN/GaN HEMT Microwave CW Power Limits,” presented at the Fourth International Conference on Nitride Semiconductors, Denver, Colorado, 2001.
[3] Limb, J. B., Xing, H., Moran, B., McCarthy, L., DenBaars, S. P., and Mishra, U. K., “High voltage operation (>80 V) of GaN bipolar junction transistors with low leakage,” Appl. Phys. Lett., vol. 76, pp. 24572459, Apr. 2000.
[4] Ambacher, O., “Growth and applications of group III-nitrides,” J. Phys. D, vol. 31, pp. 26532710, 1998.
[5] Frensley, W. R., “Power-limiting breakdown effects in GaAs MESFETs,” IEEE Trans. Electron Devices, vol. 28, pp. 962970, Aug. 1981.
[6] Zhang, N.-Q., Moran, B., DenBaars, S. P., Mishra, U. K., Wang, X.W., and Ma, T.P., “Kilovolt AlGaN/GaN HEMTs as switching devices,” phys. stat. sol. (a), vol. 188, no. 1, Nov. 2001.
[7] Ben-Yaacov, I., Seck, Y.-K., DenBaars, S. P., Hu, E. L., and Mishra, U. K., to be published.
[8] Nitta, S., Kariya, M., Kashima, T., Yamaguchi, S., Amano, H., and Akasaki, I., “Mass transport and the reduction of threading dislocation in GaN,” Appl. Surf. Sci., vol. 159, pp. 421426, June 2000.
[9] Heikman, S., Keller, S., Baars, S. P. Den, Mishra, U. K., Bertram, F., and Christen, J., submitted to Jpn. J. Appl. Phys.
[10] Heikman, S., Keller, S., DenBaars, S. P., and Mishra, U. K., submitted to phys. stat. sol.(a).


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed