Title :
Temperature dependent study of the microwave performance of 0.25-μm gate GaAs MESFETs and GaAs pseudomorphic HEMTs
Author :
Feng, M. ; Scherrer, D.R. ; Apostolakis, P.J. ; Kruse, J.W.
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA
fDate :
6/1/1996 12:00:00 AM
Abstract :
We report on the noise figure, associated gain, and the current gain cutoff frequency for comparable 0.25-μm gate GaAs MESFETs and GaAs pseudomorphic HEMTs (p-HEMTs) as a function of cryogenic temperature. Contrary to previously published results which suggest that p-HEMTs should have a higher electron velocity and a lower noise figure than MESFETs due to the effects of the two-dimension electron gas (2-DEG), we have experimentally verified that this is not the case. We show clear evidence that the transport properties of the 2-DEG in p-HEMTs do not make a significant contribution to the speed enhancement and noise reduction during high-frequency operation of these devices. It is the fundamental InGaAs material properties, specifically the Γ-L valley separation in the conduction band and associated effective mass of the electron in either GaAs or InGaAs channel, which limits the high-field electron velocity and thus the speed and noise performance of the devices
Keywords :
III-V semiconductors; Schottky gate field effect transistors; cryogenic electronics; gallium arsenide; high electron mobility transistors; many-valley semiconductors; microwave field effect transistors; semiconductor device noise; Γ-L valley separation; 0.25 micron; GaAs; MESFETs; conduction band; cryogenic temperature; current gain cutoff frequency; electron effective mass; electron velocity; gain; high-field electron velocity; high-frequency operation; microwave performance; noise figure; pseudomorphic HEMTs; temperature dependence; transport properties; two-dimension electron gas; Cryogenics; Cutoff frequency; Electrons; Gallium arsenide; Indium gallium arsenide; MESFETs; Noise figure; Noise reduction; PHEMTs; Temperature dependence;
Journal_Title :
Electron Devices, IEEE Transactions on
