No-Snapback Silicon-Controlled Rectifier for Electrostatic Discharge Protection of High-Voltage ICs

In this letter, we develop a no-snapback silicon-controlled rectifier (NS-SCR) in a 0.35-um BCD technology. This device is constructed by embedding in a typical SCR a p-type/intrinsic/n-type diode as the trigger element and two highly doped extension regions as parts of the bases of the parasitic bipolar transistors. These added features allow for a high electric field to be maintained at the reverse biased n/p junction in the electrostatic discharge (ESD) current path, prevent the onset of strong conductivity modulation, and result in a nosnapback transmission line pulsing I-V characteristic. Stacking the NS-SCR´s offers an ESD protection solution that is area-efficient, robust, and latch-up immune. The high temperature effect on the leakage current of NS-SCR is also studied.