利用NH3電漿處理來改善低介電常數材料HSQ在銅連線上的應用

Abstract

在本篇論文之中,我們主要探討低介電常數材料在無擴散障礙層時Cu導線上的應用。我們發現一種名為FOx-16的低介電常數材料在藉由NH3電漿的處理之後能夠有效的改善無擴散障礙層時銅擴散的情形。在由NH3電漿的處理之後，FOx膜將能獲得較低的漏電流以及更佳的擴散阻礙能力。而在不同的電漿處理時間之後，FOx膜幾乎擁有相同的介電常數。其中較低的漏電流乃是由於FOx膜獲得Si-H bonds 重新的鍵結以及受電漿處理後FOx膜變的較緻密的網狀結構，而較佳的擴散阻礙能力乃是由於FOx膜表面有一層氮氧化矽薄膜的形成。

In this thesis, we studied the barrier metal free low-k dielectric method for Cu metallization process. A low dielectric constant material, hydrogen silsequioxane (FOx-16), can successfully suppress Cu diffusion without barrier metal by using NH3 plasma treatment. After NH3 plasma treatment, the hydrogen silsequioxane film with lower leakage current and better barrier ability is achieved. This film almost keeps the same dielectric constant after different plasma exposure times. The decrease of leakage current with more exposure time is due to dangling bonds passivated by -H bond on porous hydrogen silsequioxane and the Fox films become dense network structure after plasma treatment. The better barrier ability is due to a thin silicon oxynitride film formed on the dielectric.