A new substrate current free nLIGBT for junction isolated technologies

Abstract

This paper presents a new lateral insulated gate bipolar transistor (LIGBT) for junction isolated technologies, the key property of which is a vertical isolation structure consisting of two buried layers on top of each other. This structure not only allows the suppression of substrate currents, it also yields an nLIGBT that can be used as a high-side switch. The proposed nLIGBT is introduced in an existing 80 V smart power technology without the costly need of defining new layers. It has a forward biased safe operating area (FBSOA) comparable to the DMOS devices in this technology and it can compete with DMOS devices when used as a large driver. Together with an equivalent circuit, two dimensional simulation has been used to verify the device's performance.