Physical Insights Into the ESD Behavior of Drain Extended FinFETs (DeFinFETs) and Unique Current Filament Dynamics

Abstract

Single and multi-Fin behavior of drain-extended FinFET (DeFinFET) devices under low and high current injection conditions is studied using detailed 3-D TCAD simulations. For completeness, electrostatic discharge (ESD) behavior of both shallow trench isolation (STI)-type and non-STI-type DeFinFET devices is studied. Under low current injection, junction breakdown, parasitic bipolar turn-on, as well as the onset of space charge modulation and its implications on high current behavior are explored. Under high current injection, the role of space charge modulation in electrothermal instability and filament formation is discussed. Unique filament spreading behavior has been discovered in DeFinFETs. Fin-based construction was found responsible for filament spreading. The interplay among bipolar turn-on, bipolar efficiency, filament density, and nature of filament spreading is explained.