Suppression of copper diffusion through barrier metal-free hydrogen silsesquioxane dielectrics by NH3 plasma treatment

A low dielectric constant material, hydrogen silsesquioxane (FOx-16), can s uccessfully suppress Cu diffusion without barrier metal by using NH3 plasma treatment. After NH3 plasma treatment, the hydrogen silsesquioxane film wi th 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 da ngling bonds passivated by -H bonds on porous hydrogen silsesquioxane. The better barrier ability is due to a thin nitride film formed on the dielectr ic. (C) 1999 The Electrochemical Society. S1099-0062(99)06-025-3. All right s reserved.