Cell-Based ESD Diodes with a Zigzag-Shaped Layout to Enhance the ESD Survival Level

Abstract

In this study, we propose cell-based diodes which are laid out with a zigzag shape as electrostatic discharge (ESD) protection elements to enhance the ESD survival level of the diodes. Generally, diodes are regarded as simple ESD protection devices in integrated circuits. During ESD events, the P–N junction of the ESD diode acts as a thermal source. In this study, we investigate a distributed layout method which relies on a cell-based ESD diode to prevent an excessive increase in the temperature at the P–N junction. However, although the distributed layout enhances the ESD survival levels of the ESD diode, the required area increases compared that of a typical layout. Thus, we propose a zigzag layout technique for the cell-based diode to reduce the area and obtain a high ESD survival level. To verify the feasibility of the zigzag layout techniques for cell-based diodes, we designed ESD diodes using 110[Formula: see text]nm RF CMOS technology. The experimental results successfully demonstrate the feasibility of the proposed method.