ESD Protection for SOI Technology Using Under-the-BOX (Substrate) Diode Structure

Abstract

This paper presents a new integrated silicon-on-insulator (SOI) substrate-diode (SUBD) structure for an electrostatic-discharge (ESD) protection of the SOI I/O circuits. The diode is built under the buried oxide, within the substrate region of the SOI wafer, without additional steps to the conventional SOI CMOS process. This paper shows that the ESD protection level can reach four times the level of the standard SOI lateral-diode structure. This paper presents the device and process simulation results to demonstrate the effect of self-heating in both the standard SOI lateral and substrate diodes, and to demonstrate how to optimize the SUBD structure using a deep n-well implant