Further understandings on random telegraph signal noise through comprehensive studies on large time constant variation and its strong correlations to thermal activation energies

Abstract

Comprehensive studies on random telegraph signal (RTS) noise have been done to understand carrier trapping processes, with a main focus on the large variations of time constants. It is observed that time constant distributions, as well as thermal activation energy distributions, weakly depend on the substrate doping concentrations or surface orientations. For individual traps, time constants are quite stable under strong negative bias stressing with serious interface degradation. More importantly, correlations of time constants and thermal activation energies with a narrow distribution window are experimentally observed for the first time. With further discussions, it is concluded that the activation energy variation is the main reason for large time constant distributions, and carrier trapping process is thought to be most likely from multiphonon-assisted tunneling process.