Research on ESD Protection of Ultra-High Voltage nLDMOS Devices by Super-Junction Engineering in the Drain-Side Drift Region

Electrostatic discharge (ESD) transient events can often damage semiconductor components. Therefore, the ultrahigh-voltage (UHV) circular n-channel lateral diffused metal-oxide-semiconductor transistor (nLDMOS) usually used in power electronics needs to have ESD self-protection capabilities. In this paper, the geometric parameters of 300-V and 200-V UHV circular nLDMOSs were modulated using different layouts at the drain side. The high-voltage p-well (HVPW) layer was used to form various super junctions (SJs) in the drift region. The modulations were classified as SJ length, SJ concentration-gradient thickness, HVPW ring-sector, and rotated SJ concentration gradient modulations in the drift region. Various HVPWs were used to produce several SJs in the drain drift region. According to the final measurement results, all modulation processes maintained the original physical characteristics of high breakdown voltage. Devices with the SJ length and SJ concentration-gradient thickness’s modulations provided the best ESD robustness. The ESD testing value of the human-body model (HBM) will increase with the increase of the SJ length and SJ thickness modulations. The HBM value increased from the 1500 V reference to 4000V (increased by 166.66%).