High-performance self-aligned (Al,Ga)As/(In,Ga)As pseudomorphic HIGFETs

Transconductance as high as 676 mS/mm at 300 K was observed to 0.7*10- mu m/sup 2/ n-channel devices (HIGFETs) made on epilayers with Al/sub 0.3/Ga/sub 0.7/As insulator thickness of 200 AA and In/sub 0.15/Ga/sub 0.85/As channel thickness of 150 AA. An FET K value (K=W/sub g/U epsilon /2aL/sub g/) as large as 10.6 mA/V/sup 2/ was also measured from another device with transconductance of 411 mS/mm. The high K values are achieved under normal FET operation without hole-injection or drain-avalanche breakdown effects. These results demonstrate the promise of pseudomorphic (Al,Ga)As/(In,Ga)As HIGFETs for high-performance circuit applications.<
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