ESD protection for SOI technology using an under-the-box (substrate) diode structure

In this paper we will present a new integrated SOI substrate diode structure for ESD protection of SOI I/O circuits that is built under the buried oxide of the SOI wafer using a standard CMOS process. We will show that the protection level can reach four times what is achieved by the standard-lateral SOI diode structure. We will also show device and process simulation results to understand the self-heating effect of both standard-SOI and substrate diodes, as well as how to optimize the structure using a deep N-well implant.