Hot carrier degradation for narrow width MOSFET with shallow trench isolation

Abstract

We have investigated the hot carrier reliability characteristics of narrow width MOSFET with shallow trench isolation. In the case of maximum substrate current condition, the lifetime of nMOSFET is slightly degraded by decreasing the device width. However, a significant degradation of device lifetime of the narrow width device was observed under channel hot electron condition ( V g= V d). In the case of pMOSFET, we also found enhanced degradation of narrow width device under channel hot electron condition. Enhanced degradation of MOSFETs can be explained by both the current crowding and enhanced charge trapping at the shallow trench isolation edge. Considering pass transistor in DRAM cell, the degradation of lifetime for narrow width device under high gate bias condition causes a significant impact on circuit reliability.