Enhanced DC & RF performance of InGaAs based HEMT with fully quaternary InAlGaAs as buffer and barrier layer

This paper deals with design, modeling and characterization of a 50nm InAlGaAs/InGaAs based HEMT which is compared with a 50nm InAlAs/InGaAs based HEMT. A performance evaluation is done considering the above two HEMTs and the DC and RF characteristics are compared for the same device dimension. For a InAlGaAs/InGaAs based HEMT, a maximum drain current of 331mA/mm at V
_gs
=-0.2V, a cutoff frequency of 820GHz and a maximum oscillation frequency (f
_max
) of nearly 1.4THz is obtained which is more as compared to the device parameters obtained for InAlAs/InGaAs based HEMT. This HEMT has a maximum drain current of 297 mA/mm at V
_gs
=-0.2V, a cutoff frequency of 610GHz and a maximum oscillation frequency (f
_max
) of nearly 1.3THz.