Numerical analysis of kink effect in HJFET with a heterobuffer layer

The kink effect in an AlGaAs/GaAs HJFET with a heterobuffer layer is investigated using a two-dimensional device simulator with impact ionization and deep-trap models. It is confirmed that the accumulation of holes generated by impact ionization causes the kink effect. The influence of deep levels on the kink characteristics is also investigated. The kink effect is suppressed by electron traps in the channel region through the recombination of the generated holes. On the other hand, the kink effect is enhanced by hole traps, which are positively ionized by increases in hole concentration. However, excessive hole trap concentration suppresses the accumulation of holes, due to enhanced recombination with electrons. Under such conditions the kink effect vanishes.<
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