A Novel Dual-Directional SCR Structure With High Holding Voltage for 12-V Applications in 0.13-μm BCD Process

Abstract

This article proposes a dual-directional silicon-controlled rectifier (SCR) with a novel structure and high holding voltage to improve the electrostatic discharge (ESD) design area efficiency in high-voltage environments. In terms of structure, by decreasing the emitter injection efficiency of the p-n-p parasitic bipolar transistor formed at the bottom of the gate region, the SCR positive feedback gain is reduced, which endows the proposed device with improved snapback characteristics compared with the conventional low-voltage triggering SCR (LVTSCR) and low-trigger dual directional SCR (LTDDSCR). This article conducted 2-D and mixed-mode simulations to compare and analyze the operating principles of the proposed and traditional devices. Additionally, experimental devices were fabricated under the same conditions using the 0.13- $\mu \text{m}$ process to verify their electrical properties and latch-up immunity by measuring the transmission line pulse (TLP) and transient latch-up (TLU). This article also conducted a detailed analysis on the optimization of electrical properties for the ESD design window of the proposed device according to the design variables and application of segment topology, and also analyzed the temperature reliability using a hot chuck control system. The measurement results reveal that the proposed device is highly suitable for the 12-V-class ESD design window, has improved reliability, and can provide excellent area efficiency in related applications.