Will the velocity of GaN HEMTs ever overshoot? [mm-wave frequencies]

Author

YiFeng Wu

fYear

2004

fDate

21-23 June 2004

Abstract

Summary form only given. Traditionally, the electron velocity of III-V FETs overshoots as the gate length reduces to sub-micron scale, which overcomes the higher percentage of parasitic charging times as the intrinsic input capacitance reduces. This overshoot is not yet seen in GaN HEMTs. What is worse, the f/sub t/ of these devices peaks at only 25-30% of the full-channel current and deteriorates severely at higher current levels. These problems are responsible for the measly 2-5 W/mm and 15-40% efficiency produced by GaN HEMTs at >30 GHz. This paper discusses the issues limiting the speed of GaN HEMTs at mm-wave frequencies, focusing on electron velocity overshoot effects.

Keywords

III-V semiconductors; gallium compounds; high electron mobility transistors; millimetre wave field effect transistors; wide band gap semiconductors; 15 to 40 percent; 30 GHz; GaN; HEMT speed limits; electron velocity overshoot; gate length scaling; intrinsic input capacitance; parasitic charging time; transistor turnoff frequency; Electrons; Electrostatics; Gallium nitride; HEMTs; MODFETs; Phonons; Scattering; Thermal conductivity;

fLanguage

English

Publisher

ieee

Conference_Titel

Device Research Conference, 2004. 62nd DRC. Conference Digest [Includes 'Late News Papers' volume]

Conference_Location

Notre Dame, IN, USA

ISSN

1548-3770

Print_ISBN

0-7803-8284-6

Type

conf

DOI

10.1109/DRC.2004.1367857

Filename

1367857