Investigation of the self-heating effect on hot-carrier characteristics for packaged high voltage devices

HVNMOS device degradation due to AC/DC hot carrier injection (HCI) stress between package level (PL) and wafer level (WL) is characterized and their relationship to the power generation is quantified. It is observed that I dlin degradation in PL is worse compared to WL during DC HCI stress due to excessive self-heating (SH) in PL compared to WL. It is also validated that SH mechanism is the dominant factor for I dlin degradation compared to HCI impact ionization during packaged HVNMOS HCI stress. A new reliability characterization methodology for HVNMOS is also proposed, which eliminates the PL SH effect and boost up the product safe-operating-area (SOA) capability.