Robust HV Power pLDMOS Components for ESD Protection by the Drain-side Parasitic Schottky Diode and SCR Engineering

In this paper, a TSMC 0.18-μm 70-V process is used to realize the high-voltage pLDMOS device to modulate the parasitic Schottky/SCR elements to evaluate its influence on the discharge current capability. According to the TLP measurement results, the corresponding trigger voltage (V t1 ), holding voltage (V h ) and secondary breakdown current (I t2 ) values can be obtained. In the parasitic Schottky/SCR modulations at the drain side, it can be found that the parasitic Schottky structure at the drain terminal can increase the on-resistance of the device, and the parasitic SCR device at the drain terminal will have lower V t1 and V h , but it will have excellent I t2 . If the drain terminal is parasitic vertical SCR and Schottky device structures at the same time, it will have quite good latch-up immunity and better ESD current discharge capability. Nevertheless, if only the latch-up issue is considered, it is best to change the entire drain end to the parasitic Schottky element, and the ESD capability is also slightly improved.