RTS noise due to lateral isolation related defects in submicron nMOSFETs
The results of a systematic study of the random telegraph signal (RTS) fluctuations in submicron W-array n metal-oxide semiconductor field-effect transistors (nMOSFETs) are presented and analysed. These results include the dependency of the RTS amplitude and of the capture and emission time constants, measured both in the standard transistor and in the diode configuration, on the gate, drain and substrate voltage. For the latter configuration, the drain-substrate (or source-substrate) diode of the transistor is forward biased. Application of this technique for measuring RTS noise allows us to distinguish the drain (source) traps from the well-known channel traps. It is found that besides the classical channel-related RTSs, another type occurs which is associated with lateral isolation related (or edge-related) oxide defects, located near the drain or the source contact. As will be shown, the coulomb blockade significantly affects the capture and emission kinetics of these defects. The specific properties of such RTSs are studied in detail, as they may reveal useful information on their identification.