A High Failure-Current Gate-Controlled Dual-Direction SCR for High-Voltage ESD Protection in 0.18-μm BCD Technology

Abstract

To make a dual-direction silicon-controlled rectifier (SCR) that is highly robust in a high-voltage environment, a gate-controlled dual-direction SCR (GC-DDSCR) device is proposed. After analyzing the working principle of the device through the equivalent circuit and 2-D device simulation, the electro-static discharge (ESD) characteristics of the device are verified through the transmission line pulse (TLP) test. The failure current of the GC-DDSCR structure is greatly improved to 14.19 A compared with only 3.53 A of the same size traditional dual-direction SCR (TDDSCR) structure. The trigger voltage and the holding voltage of the GC-DDSCR are 24.23 and 20.15 V, respectively. In addition, this article explains the principle of GC-DDSCR devices with high protection capability. That is, because the device has a polysilicon gate electrode shorted to the anode (cathode), the electric field effect generated by the gate promotes carrier movement in the SCR path. Thus, the electric field force promotes the opening of the SCR path of the device and the direction of the electric field force is always consistent with the current direction. The overall failure capability of the device is effectively improved.