Mechanism of current collapse removal in field-plated nitride HFETs

An experimental study of the mechanism of RF current collapse removal in high-power nitride-based HFETs is presented. The results show that the conductivity of the dielectric material under the field plate plays a crucial role in the current collapse removal. Identical geometry field plated HFETs differing only in the FP dielectric conductivity show varying degree of current collapse removal. Devices with semiconducting dielectric layers exhibit perfectly linear RF power - drain bias dependence with the output powers of 20 W/mm at 55 V drain bias with essentially no current collapse. A trapped charge discharging model is presented to explain the removal of current collapse in FPd devices.

[1]  Y. Okamoto,et al.  10-W/mm AlGaN-GaN HFET with a field modulating plate , 2003, IEEE Electron Device Letters.

[2]  Shreepad Karmalkar,et al.  Enhancement of breakdown voltage in AlGaN/GaN high electron mobility transistors using a field plate , 2001 .

[3]  S. Karmalkar,et al.  RESURF AlGaN/GaN HEMT for high voltage power switching , 2001, IEEE Electron Device Letters.

[4]  Lester F. Eastman,et al.  Effect of surface passivation of AlGaN/GaN heterostructure field-effect transistor , 2002 .

[5]  Dynamic current-voltage characteristics of III-N HFETs , 2003, IEEE Electron Device Letters.

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

[7]  K. N. Bhat,et al.  Analysis and optimal design of semi-insulator passivated high-voltage field plate structures and comparison with dielectric passivated structures , 1994 .

[8]  Boris Gelmont,et al.  Theory of junction between two-dimensional electron gas and p-type semiconductor , 1992 .

[9]  G. Meneghesso,et al.  Surface-related drain current dispersion effects in AlGaN-GaN HEMTs , 2004, IEEE Transactions on Electron Devices.

[10]  Michael S. Shur,et al.  AlGaN/InGaN/GaN Double Heterostructure Field-Effect Transistor , 2001 .

[11]  C. Gaquiere,et al.  Current instabilities in GaN-based devices , 2001, IEEE Electron Device Letters.

[12]  M. Asif Khan,et al.  High electron mobility GaN/AlxGa1−xN heterostructures grown by low‐pressure metalorganic chemical vapor deposition , 1991 .

[13]  J. Li,et al.  High breakdown voltage GaN HFET with field plate , 2001 .

[14]  Michael S. Shur,et al.  Si3N4/AlGaN/GaN–metal–insulator–semiconductor heterostructure field–effect transistors , 2001 .

[15]  V. Kaper,et al.  Performance of the AlGaN HEMT structure with a gate extension , 2004, IEEE Transactions on Electron Devices.