Suppress copper diffusion through barrier metal-free hydrogen silisequioxane dielectrics by using NH3 plasma treatment

Abstract

a low dielectric constant material, hydrogen silisequioxane (FOx-16), can successfully suppress Cu diffusion without barrier metal by using NH3 plasma treatment. After NH3 plasma treatment, the hydrogen silisequioxane film with lower leakage current and better barrier ability was achieved. This film almost keeps the same dielectric constant after different plasma exposure times. The decrease in leakage current with more exposure time is due to dangling bonds passivated by -H bonds on porous hydrogen silisequioxane. The better barrier ability is due to a thin nitride film formed an the dielectric.