提出了一种用于降低触发电压的两级防护SCR(TSPSCR)。在传统LVTSCR中植入P-ESD层, 增设额外的二极管。因为P-ESD层的掺杂浓度较高, 该器件能更早发生雪崩击穿而触发第一级泄流路径, 从而开启第二级泄流路径。Sentaurus TCAD仿真结果表明, 该器件的触发电压从传统器件的10.59 V降低至4.12 V, 维持电压为1.25 V, 1 V直流电压下漏电流仅为7.85 nA。优化后的TSPSCR适用于先进1 V工作电压的电路中。

A two-stage protection SCR (TSPSCR) was proposed to reduce the trigger voltage. The P-ESD layer was implanted in the traditional LVTSCR, and an additional diode was added. Because of the higher doping concentration of P-ESD layer, the device could trigger the first-stage discharge path by avalanche breakdown earlier, thus opening the second-stage discharge path. The Sentaurus TCAD simulation results showed that compared with conventional SCRs, the device had a lower trigger voltage from 10.59 V to 4.12 V, a maintenance voltage of 1.25 V, and a leakage current of 7.85 nA at 1 V DC voltage. The optimized TSPSCR could be used in advanced circuits with 1 V operating voltage.