REGENERATIVE SWITCHING PHENOMENON OF A GRADED ALXGA1-X,AS INGAAS/GAASHETEROSTRUCTURE/

In this paper, a new regenerative switching device with a graded AlxGa 1-xAs/InGaAs/GaAs heterostructure has been fabricated and demonstrated . A thin p(+)-InGaAs quantum well (QW) is employed between n-GaAs and p(+)-GaAs layers to provide a significant confinement effect for elect rons. An interesting S-shaped multiple negative differential resistanc e (NDR) phenomenon and three operation points are observed, due to an avalanche multiplication and sequential two-stage barrier lowering eff ect resulting from the successive accumulation of holes and electrons at the p(+)-GaAs base regime and InGaAs quantum well respectively. Con sequently, with appropriate adjustments of device parameters, the prop osed heterostructure provides a good promise for multiple-valued logic circuit applications. (C) 1997 Elsevier Science S.A.