关键词: ESD防护, 栅接地NMOS, 抗辐射, 寄生三极管

Abstract: In electrostatic discharge (ESD) protection structures, gate grounded NMOS (GGNMOS) devices have the advantages of simple structure, fast response, and efficient discharge, and have gradually become the most commonly used devices in ESD protection structures. However, during irradiation testing, NMOS devices are affected by various radiation effects, leading to a decrease in device performance and reliability. Therefore, the design of protective structures for GGNMOS devices in radiation resistant circuits is particularly difficult. A linear regulator circuit with rasdiation resistance requirements was designed based on 0.18 μ m BCD technology. Design the ESD protection structure for the entire chip of the circuit based on the voltage and operating characteristics of each port. Through experimental analysis, identify the weak points of the GGNMOS protection structure and propose improvement solutions. According to the actual test results, the designed circuit not only meets the total dose index of 100 krad (Si), but also passes the 2.5 kV human body model ESD test. This study provides experimental basis and theoretical guidance for the design of ESD devices in future radiation resistant circuits.

Key words: ESD protection,  gate grounded NMOS, radiation-hardened, parasitic bipolar transistor