A unified approach to profiling the lateral distributions of both oxide charge and interface states in n-MOSFET's under various bias stress conditions

A new and accurate technique that allows the simultaneous determination of the spatial distributions of both interface states (Nit) and oxide charge (Q0x) will be presented. The gated-diode current measurement in combination with the gate-induced drain leakage (GIDL) current were performed to monitor the generation of both Nit and Qox in ra-MOSFET's. A special detrapping technique and simple calculations have been developed, from which the spatial distributions of both Nit and Qox under various bias stress conditions, such as the hot-electron stress (la,max),IB,max, and hot-hole stresses, can be determined. The calculation of gated-diode current by incorporating the extracted profiles of Nit and Qox has been justified from numerical simulation. Results show very good agreement with the experimental results. The extracted interface damages for hotelectron and hot-hole stresses have very important applications for the study of hot-carrier reliability issues, in particular, on the design of flash EPROM, E2PROM cells since the above stress conditions, such as the IG,max and hot-hole stress, are the major operating conditions for device programming and erasing, respectively.