A Dual Direction Silicon Controlled Rectifier

Abstract

Highly effective electrostatic discharge (ESD) protection is achieved through the use of dual-direction silicon-controlled rectifiers (DDSCRs), which offer surge channels for both positive and negative charges. However, compared to unidirectional SCRs, Due to the extended ESD surge paths, for use in low-voltage applications, DDSCRs have a high on-state resistance and a low holding voltage. On the other hand, conventional DDSCRs frequently fail. However, traditional dual-direction silicon-controlled rectifiers (DDSCRs) are unsuitable for use in integrated circuits (ICs) due to their high trigger voltage and low holding resistance. DDSCRs also exhibit increased on-state resistance compared to unidirectional SCRs due to structural factors such as additional well regions that lead to prolonged ESD surge paths. To address this issue, it is recommended to employ two additional parasitic bipolar transistors to create an innovative dual-direction silicon-controlled rectifier (DDSCR) with improved holding voltage and superior ESD surge tolerance compared to conventional low-triggering dual-direction silicon-controlled rectifiers (LTDDSCRs). This device has a P+ bridge portion to lower the high trigger voltage of the DDSCR.  A timed pulse system was employed to confirm the characteristics of the suggested ESD protection device, which was fabricated using 0.18um CMOS technology. Based on the measurement outcomes, it can be concluded that the recommended ESD protection device is dependable for low-voltage applications, featuring a substantial holding voltage and enhanced tolerance.