Investigation of the Breakdown Voltage Degradation under Hot-Carrier Injection in STI-based PchLDMOS Transistors

Hot-carrier injection causes characteristics change of semiconductor devices. In this work, off-state breakdown voltage (BVdss) degradation of shallow trench isolation (STI) based PchLDMOS under drain avalanche hot-carrier (DAHC) stress has been investigated. We found that the cause of the degradation was a trapped charge at the bottom area of STI rather than STI corner. The mechanism of BVdss degradation was clarified and a tolerant LDMOS structure is proposed.