钝化剂自组装单层膜在铜铜键合工艺中的应用

Application of Self-assembled Monolayer Passivation for Cu-Cu Bonding

摘要:

解决铜铜键合工艺中的铜氧化问题对于三维集成技术具有重要意义。选用1-己硫醇做临时钝化剂, 通过自组装形式形成单层膜附着于铜表面, 以防止铜在存放时与空气接触而发生氧化, 键合前再使用乙醇等有机溶剂去除该单层膜。为了评估1-己硫醇的钝化效果, 采用接触角作为主要指标对实验结果进行评价。研究表明, 样片表面经过1-己硫醇处理后, 接触角极大增加, 并在空气中长时间保持稳定, 说明1-己硫醇具有良好的钝化效果, 采用此方法得到了高质量的铜铜热压键合样片。

Abstract:

In this paper, self-assembled monolayer of 1-hexanethiol was formed on Cu thin layer to protect its surface against excessive oxidation during storage in the atmosphere. Then the self-assembled monolayer layer is dissolved using ethyl alcohol to expose the clean surface of Cu before bonding. The contact angles of the samples are measured so as to evaluate the passivation effect. The results indicate that after dealing with 1-hexanethiol, large contact angles of the samples can be acquired and remain stable in the air for a long time. Using this method, high-quality Cu-Cu thermo-compression bonding samples are obtained.