Oxidation-induced substrate strain in advanced silicon integrated-circuit fabrication

Abstract

A simple model for the generation of substrate strain is developed and applied to the fabrication of advanced silicon integrated-circuit structures. These structures consist of SiO2-filled isolation trenches residing in a silicon substrate and strain is generated at elevated temperature by thermal oxidation. The high-stress behavior of the viscosity of SiO2 is considered and leads to self-limiting behavior. During the initial stages of oxidation, the strain rises rapidly and then asymptotically approaches an equilibrium level determined by the oxidation conditions and the trench geometry.