Characterizing a single hot-electron-induced trap in submicron MOSFET using random telegraph noise

Abstract

Individual interface traps generated by hot-electron stress were observed for the first time. Single trap filling and emptying can cause 0.1% step noise in drain current due to coulombic scattering. Trap location (3-10 Å from interface), time constant, energy and escape frequency are found to be very different from pre-stress (process-induced) traps. Random telegraph (RTS) noise was found to be a useful tool for studying stress-induced interface traps. It is more easily observable for stress-induced traps than process-induced traps due to the small stress area and low stress-induced trap density after light stressing. Using RTS as a characterization tool, it was found that the stress-induced traps are located closer to the interface, and therefore have a shorter time constant and much stronger influence on scattering and ΔId than process-induced traps. RTS only reveals those traps near the Fermi level, while the DC MOSFET IV degradation is also influenced by all the charged traps