Application of Silicon Controlled Rectifiers in Low Power Circuits

With the advancement of microelectronics technology, the resistance of the device itself to ESD (Electrostatic Discharge) is constantly weakened, so the study of ESD is of great significance. SCR (Silicon Controlled Rectifier) has the advantages of low on-resistance and strong protection ability, but its disadvantage is that the holding voltage is low and the trigger voltage is high. This paper deals with a new type of SCR, which is based on MLSCR (Modified Lateral SCR), with an NMOS embedded in the cathode and a shallow well embedded under the N-well and P-well (SP-SN-SCR). The new structure is modeled in sentaurus TCAD and tested in simulation. The test results show that, compared with the traditional structure, the holding voltage of the SP-SN-SCR is 4.9 V, the turn-on voltage is 5.8 V, and the secondary breakdown current is also large.