Low-leakage diode string designs using triple-well technologies for RF-ESD applications

This letter proposes a novel low-leakage diode string designs using triple-well technologies in 0.18-μm CMOS process for RF-electrostatic discharge (RF-ESD) applications. Based on the characteristics of the low-leakage current and low-capacitance in the triple-well diode string, it is convenient to apply it in RF-ESD (electrostatic discharge) protection circuit designs. As compared to the conventional p/sup +//n-well diode string, the substrate leakage current can be kept very small all the time before the triple-well diode string turns on. It results from the existence of the parasitic base-emitter tied p-n-p bipolar transistor in each triple-well diode.