Enhance the ESD Ability of UHV 300-V Circular LDMOS Components by Embedded SCRs and the Robustness P-Body Well

Abstract

The ultra-high voltage (UHV) Lateral-diffused MOSFET (LDMOS) transistor has been widely used in power circuit applications and also used as an electrostatic discharge (ESD) self-protection device. However, the ESD ability of an UHV LDMOS is generally worse than that of low- and high-voltage (HV) devices, which means this UHV LDMOS device can be easily failed under an ESD event. Then, the method of embedded a silicon-controlled rectifier (SCR) into the HV LDMOS has been used in the HV circuit as an ESD protection technique. But when this architecture is applied to UHV devices, will its ESD capability be as good as in HV devices? A novel SCR with a P-body well architecture is proposed, which can effectively enhance the ESD ability of the UHV nLDMOS device when the drain side is embedded this new structure. The proposed structure can greatly improve the ESD capability of the device without adding any extra process step (& photomask), layout area and affecting the basic breakdown voltage. Finally, the proposed structure of the PPP-arranged type with the P-body well can greatly increase the ESD (FOM) ability which $\text{I}_{\mathrm{ t2}}$ and HBM ability can be increased by 68.7% and 22.2% (72.9%), respectively, as compared with the conventional SCR PPP-arranged type.

Keywords

• Electrostatic discharges (ESD)
• human body model (HBM)
• power MOSFET
• silicon controlled rectifier (SCR)
• transmission line pulse system
• ultra-high voltage (UHV)