2-D SIMULATION OF KINK-RELATED SIDEGATING EFFECTS IN GAAS-MESFETS

Sidegating (backgating) effects in a planar structure with sidegate on the same side as MESFET are studied by two-dimensional simulation and the results are compared with those for a structure with a backgate o n the back side of the substrate. The kink-related sidegating is repro duced in the planar structure, too. Its mechanism is discussed and is attributed to the change of EL2's role from an electron trap to a reco mbination center by capturing holes, which are generated by impact ion ization and how into the semi-insulating substrate including EL2 (deep donor). The dependence of shallow acceptor density in the semi-insula ting substrate is also studied. It is shown that the kink-related side gating is less remarkable in the case with lower acceptor density in t he substrate. Potential dependence of sidegating effects on the sidega te (backgate) position is also discussed. Copyright (C) 1996 Elsevier Science Ltd