Multiple material stacks with a stress relief layer between a metal structure and a passivation layer

Abstract

A structure/method for reducing the stress between a dielectric, passivation layer and a metallic structure comprising coating the metallic structure with a low stress modulus buffer material, and forming the dielectric passivation layer covering the low stress modulus buffer material. The low stress modulus buffer material is composed of a layer of a polymeric material selected from at least one of the group consisting of a hydrogen/alkane SQ (SilsesQuioxane) resin, polyimide, and a polymer resin. The dielectric, passivation layer is composed of at least one layer of a material selected from at least one of the group consisting of silicon oxide and silicon nitride. A protective layer is formed over the dielectric, passivation layer. The low stress modulus buffer material has a thermal coefficient of expansion between that of the metallic structure and that of the dielectric passivation layer. In particular, the dielectric passivation layer between the metallic structure and the low stress modulus buffer material has a thermal coefficient of expansion between about 5 ppm/° C. and about 20 ppm/° C.

Dependencies are inferred from the claim text.