Accounting for mechanical stresses in combined dielectrics for VLSI capacitors

Abstract

A variant of a combined capacitor dielectric based on tantalum pentoxide for VLSI capacitors is proposed. To find the optimal combination of layers in which the Si—SiO₂—Ta₂O₅ system does not undergo elastic mechanical deformation, a stress model was constructed. Calculations showed that when the thickness ratio of Ta₂O₅ and SiO₂ films is 1:10, the curvature radius of the plate with formed dielectrics tends to infinity, and the curvature itself approaches zero. Elastic constants for the Ta₂O₅ film were also calculated.