InAlAs/InGaAs double-gate HEMTs with high extrinsic transconductance

This paper reports fabrication, DC and RF characterization of the In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As double-gate HEMTs with sub-micron gate lengths. These devices have obtained a maximum extrinsic transconductance g/sub m/ of 2650 mS/mm with a corresponding drain current I/sub d/ equal to 310 mA/mm. This extrinsic transconductance is the highest value ever reported for any transistor. Due to this high extrinsic transconductance, the ratio g/sub m//I/sub d/ is 8V/sup -1/ indicating the high charge control efficiency. Low output conductance g/sub d/ is obtained, denoting the reduction of short channel effects. The combined high transconductance and the low output conductance induce an extremely high intrinsic unloaded voltage gain (g/sub m//g/sub d/) of 87.