Current limitation after pinch-off in AlGaN/GaN FETs


R. Dietrich, A. Wieszt, A. Vescan, H. Leier
DaimlerChrylser AG, Ulm, Germany

Joan M. Redwing, Karim S. Boutros
Epitronics/ATMI

K. Kornitzer, R. Freitag, T. Ebner, K. Thonke
Universität Ulm, Abteilung Halbleiterphysik, Germany

This article was received on Thursday, January 27, 2000 and accepted on Wednesday, March 22, 2000.

Abstract

Piezoelectric AlGaN/GaN FETs on SiC with high carrier mobility have been fabricated yielding IDS=450 mA/mm and gm=200 mS/mm. In the on-state, under UV-illumination, the devices sustain a drain voltage of VDS=49 V, corresponding to a power dissipation of 26.5 W/mm. On turn-on of the device from the pinch-off state, a significant delay in the drain current build-up is observed. This effect depends on the pinch-off time and the pinch-off voltage and can be removed by either a brief UV-illumination or a VDS>25 V applied in the on-state. The drain current transients are characterized by a relaxation time tau, which is in the order of several hundred seconds. From the temperature dependence of tau, an activation energy of about 280 meV and a capture cross section of 4.4·10-18cm2 were determined. The devices show pronounced persistent photoconductivity (PPC) and the drain current ID is sensitive to illumination.

Outline

  • Introduction
  • Device fabrication
  • Results and discussion
  • Conclusion

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    Cite this article as: MRS Internet J. Nitride Semicond. Res. 5, 2(2000).

    last updated Wednesday, March 22, 2000 12:29:59 AM.

    © 2000 The Materials Research Society MRS Internet Journal of Nitride Semiconductor Research
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