HCI-induced off-state I-V curve shifting and subsequent destruction in an STI-based LD-PMOS transistor

This paper describes anomalous shifts of an off-state I-V curve that are found in an STI-based LD-PMOS, which includes degradation and recovery of breakdown voltage, increase in leakage current, and subsequent destruction under HCI stressing. Our experimental results suggest that the degradation and the recovery are caused by hot electrons injected into the STI around the bottom corner and the top corner, respectively, and all these hot electrons are responsible for the increase in leakage. The recovery is not desirable because the electrons injected into gate oxide near the STI top corner potentially cause destruction by a substrate hot electron (SHE) effect. We demonstrate that these shifts are controllable, and competitive performance of Rsp-BVoff trade-off has been achieved without them.