Very non linear transconductance of highly delta-doped multichannel HEMTs

This paper presents the evolution with structural parameters of the linearity of the transconductance of multichannel HEMTs measured under low and microwave frequencies. Compared to theoretical calculations, the measured transconductance is in good agreement excepted at high doping levels. These discrepancies are attributed to parasitic effects. The discussion of the different possibilities brings us to conclude that the gate leakage current is most probably involved in the observed phenomena.