Understanding of hot-carrier-injection induced IDLIN kink effect in sub-100nm HV NLDMOS

Hot-carrier-injection (HCI) induced effects in the electrical characteristics of high voltage n-type Lateral-Diffused-MOSFET (NLDMOS) have been studied extensively under various stress conditions. Width (W) dependent HCI induced appearance/disappearance of kink in linear drain current (I_DLIN) of NLDMOS, (i.e. kink appears after stress in large W, but it disappears after stress in narrow W, which presents initially in fresh device I_DLIN) is observed under high gate voltage (V_G) and drain voltage (V_D) stress condition. Such interesting phenomenon has never been seen during maximum substrate current (I_SUBMAX) HCI stress. TCAD simulation results revealed that enhancement in interface state generation and localized electron trapping in the gate oxide along the source side drift region are the main root causes of the appearance/disappearance of I_DLIN kink under high V_G and V_D stress. It is suspected that HCI induced I_DLIN kink may cause device reliability modeling/prediction concern, if model target is based on I_DLIN degradation.