A. Mahajan et al., 0.3-MU-M GATE-LENGTH ENHANCEMENT-MODE INALAS INGAAS/INP HIGH-ELECTRON-MOBILITY TRANSISTOR/, IEEE electron device letters, 18(6), 1997, pp. 284-286
The fabrication and performance of ultra-high-speed 0.3-mu m gate-leng
th enhancement-mode high-electron-mobility transistors (E-HEMT's) are
reported, By using a buried platinum-gate technology and incorporating
an etch-stop layer in the heterostructure design, submicron E-HEMT de
vices exhibiting both high-threshold voltages and excellent threshold-
voltage uniformity have been achieved, The devices demonstrate a thres
hold voltage of +171 mV with a standard deviation of only 9 mV. In add
ition, a maximum DC extrinsic transconductance of 697 mS/mm is measure
d at room temperature. The output conductance is 22 mS/mm, which resul
ts in a maximum voltage gain (g(m)/g(0)) of 32. The devices show excel
lent RF performance, with a unity current-gain cutoff frequency (f(t))
of 116 GHz and a maximum frequency of oscillation (f(max)) of 229 GHz
. To the best of the authors' knowledge, these are the highest reporte
d frequencies for lattice-matched E-HEMT's on M.