Integrated Zener Diodes for Smart Power IC

In a state of the art X-FAB XT018 smart power technology, two types of integrated Zener diodes have been successfully developed and offered: surface type and buried type, with typical Zener voltage targeting at 5.3V. The particular voltage target was selected due to 5V Gate oxide is used in this technology. In this paper, we will present the design concept of both types of Zener diode construction, the engineering trade-off between Zener voltage and leakage current, long term stability, reverse current capability and etc. Moreover, this also serves as an application guideline on how to select the right Zener diode.