Investigation of waffle structure SCR for electro-static discharge (ESD) protection

The waffle layout SCR-based ESD protection device is presented and analyzed in this paper. This waffle structure with symmetrical layout is designed to generate more current paths to distribute ESD currents better. TLP I-V measurement results show that, the stand-alone waffle layout SCR costs only 39 percent silicon area of conventional stripe layout SCR, but can achieve better ESD robustness. Results also show that the trigger voltage and current handling ability of waffle layout SCR can be adjustable to meet different operating demands by changing the device dimensions.