Importance of Mechanical Stress Study in STI based BCD Technology

Abstract

The paper summarizes optimization of process integration in 0.25 µm modern Bipolar-CMOS-DMOS (BCD) technology with respect to a mechanical stress induced by Shallow Trench Isolation (STI) and Resurf OXide (ROX) during manufacturing. Process optimization by TCAD simulation and silicon experiments is discussed to reduce mechanical stress in the structures and improve yield by reducing leakage current of NMOS devices. Based on simulations results, two solutions to reduce mechanical stress are proposed and evaluated in silicon experiment. The impact of integration changes to other devices in the technology is evaluated as well.