Integrated circuit structure and method for preparing the same

Abstract

The present disclosure provides an integrated circuit structure with dielectric isolation structure for reducing capacitive coupling and crosstalk between conductive features and a method for preparing the same. The method includes: forming a first conductive structure over a substrate; forming a first dielectric structure over the first conductive structure; transforming a sidewall portion of the first conductive structure into a first dielectric portion; removing the first dielectric portion such that a width of the first dielectric structure is greater than a width of a remaining portion of the first conductive structure; forming an inter-layer dielectric (ILD) layer covering a sidewall of the first dielectric structure; forming a reinforcement pillar of energy removable material in the ILD layer; forming a capping dielectric layer over the reinforcement pillar; and performing a thermal process to transform the reinforcement pillar into a dielectric isolation structure including a liner layer enclosing an air gap.