Hot-carrier degradation monitoring in LDD n-MOSFETs using drain gated-diode measurements

We use the gated-diode configuration at small forward bias to detect hot-carrier induced defect states in n-channel LDD MOSFETs. With the aid of a 2-dimensional device simulation the measured diode current provides the spatial distribution of the defect states. The defect states are found to appear between the substrate-n^--drain and n^--n⁺-drain junctions. We investigate the dependence of the spatial defect distribution on the stress time and on the gate voltage during stress.