J. Haruyama et al., KINK EFFECT RELATED TO THE SELF-SIDE-GATING EFFECT IN GAAS-MESFETS, I.E.E.E. transactions on electron devices, 41(10), 1994, pp. 1873-1875
A kink effect, an abrupt increase in drain current at high drain volta
ges, was observed in GaAs MESFET's with an Al0.2Ga0.8AS/GaAs heterostr
ucture buffer layer. In these MESFET's, impact ionization occurs at th
e drain side along the channel current path at high drain voltages. On
the other hand, a side-gating effect occurs when a negative voltage a
pplied to the gate pad of the MESFET (self-side-gating effect). From m
easurements of the substrate potential, we conclude that hole accumula
tion generated by the impact ionization at the channel-side GaAs/Al0.2
Ga0.8As interface cancels the drain current reduction that arises from
the self-side-gating effect. This gives rise to the kink effect we ob
serve.