We present experimental and modeling results on the gate-length dependence of the maximum current that can be achieved in GaN-based heterostructurefield-effect transistors(HFETs) and metal–oxide–semiconductor HFETs (MOSHFETs). Our results show that the factor limiting the maximum current in the HFETs is the forward gate leakage current. In the MOSHFETs, the gate leakage current is suppressed and the overflow of the two dimensional electron gas into the AlGaN barrier region becomes the most important factor limiting the maximum current. Therefore, the maximum current is substantially higher in MOSHFETs than in HFETs. The measured maximum current increases with a decrease in the gate length, in qualitative agreement with the model that accounts for the velocity saturation in the channel and for the effect of the source series resistance. The maximum current as high as 2.6 A/mm can be achieved in MOSHFETs with a submicron gate.
Published in Applied Physics Letters, Volume 80, Issue 17, 2002, pages 3216-3218.
©Applied Physics Letters 2002, American Institute of Physics (AIP).
Koudymov, A., Fatima, H., Simin, G., Yang, J., Khan, M. A., Tarakji, A., Hu, X., Shur, M. S., & Gaska, R. (29 April 2002). Maximum Current in Nitride-Based Heterostructure Field-Effect Transistors. Applied Physics Letters, 80 (17), 3216-3218. http://dx.doi.org/10.1063/1.1476054