Electrostatic discharge (ESD) protection of N-type silicon controlled rectifier with P-type MOSFET pass structure for high voltage operating I/O application

摘要

An electrostatic discharge (ESD) protection device, so called, N-type silicon controlled rectifier with P-type MOSFET pass structure (NSCR_PPS), was analyzed for high voltage I/O applications. A conventional NSCR_PPS device shows typical SCR-like characteristics with extremely low snapback holding voltage, which may cause latchup problem during normal operation. However, our modified NSCR_PPS device with proper junction/channel engineering such as counter pocket source (CPS) structure demonstrates highly latchup immune current-voltage characteristics. Methodology for the junction/channel engineering and the related operation mechanisms are discussed in terms of thermal effects incorporated device simulation results.