Very non linear transconductance ofhighly delta-doped multichannel HEMTs

Thispaperpresents theevolution withstructural parameters ofthelinearity ofthe transconductance ofmultichannel HEMTsmeasured underlowandmicrowave frequencies Compared totheoretical calculations, themeasured transconductance isingood agreement excepted athigh doping levels Thesediscrepancies areattributed toparasitic effects The discussion ofthedifferent possibilities brings us toconclude that thegateleakage current is mostprobably involved intheobserved phenomena