Cryogenic DC and RF characteristics of InP HEMTs with various drain-side recess lengths

Abstract

We measured the DC and RF characteristics of InP-based 75-nm-gate In_0.52Al_0.48As/In_0.63Ga_0.37As HEMTs with various drain-side recess lengths L_rd's at 300 and 16 K. The kink phenomenon was seen in the current-voltage (I-V) characteristics for all the measured HEMTs at 16 K. The peak cutoff frequency f_T decreases with increasing L_rd both at 300 and 16 K. On the other hand, the maximum oscillation frequency f_max shows very complicated behavior both at 300 and 16 K. We found that there exists the most suitable L_rd value to increase f_max at each temperature and/or drain-source voltage V_ds.