Design and experimental characteristics of strained In/sub 0.52/Al/sub 0.48/As/In/sub x/Ga/sub 1-x/As (x>0.53) HEMTs

Strained In/sub 0.52/Al/sub 0.48/ As/In/sub x/Ga/sub 1-x/As (x>0.53) HEMTs (high electron mobility transistors) are studied theoretically and experimentally. A device design procedure is reported that is based on band structure and charge control self-consistent calculations. It predicts the sheet carrier density and electron confinement as a function of doping and thickness of layers. The DC performance at 300 K is presented. Wafer statistics demonstrate improvement of device characteristics with excess indium in the channel (g/sub m,/ /sub intr/=500 and 700 mS/mm for x=0.60 and 0.65). Microwave characterization shows the f/sub T/ improvement (f/sub T/=40 and 45 GHz for x=0.60 and 0.65, respectively) and the R/sub ds/ limitations of the 1- mu m-long-gate HEMTs.<
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