一种对铜抛光后去除苯并三氮唑的新型清洗剂的研究

在化学机械平坦化(CMP)后,铜表面会残留一些颗粒污染(如二氧化硅)和有机物(如苯并三氮唑),这些杂质都会对集成电路造成很大的危害,因此CMP后清洗是必比不可少的过程。尤其是苯并三唑(BTA),它会和铜在其表面生成一层致密的Cu-BTA膜,使铜的表面疏水。这就要求有一种可以有效去除铜表面BTA的清洗剂。本次研究中提出的新型复合清洗剂主要来解决两个问题：一个是BTA的去除问题,另一个是清洗液对铜表面腐蚀的问题。清洗剂的主要成分有两种,一种是FA / OⅡ型碱性螯合剂,它主要用来去除BTA,另一种是FA / O I型表面活性剂,它主要用来解决铜表面的腐蚀问题。通过接触角和电化学的手段来表征BTA的去除情况。表面活性剂的抗腐蚀能力主要通过电化学实验来反映。本文提出的复合清洗剂在不腐蚀铜表面的前提下对于BTA的去除很有优势。关键词： 去除苯并三氮唑；碱性螯合剂；表面活性剂； 腐蚀抑制剂

A novel compound cleaning solution for benzotriazole removal after copper CMP

After the chemical mechanical planarization (CMP) process, the copper surface is contaminated by a mass of particles (e.g.silica) and organic residues (e.g.benzotriazole), which could do great harm to the integrated circuit, so post-CMP cleaning is essential.In particular, benzotriazole (BTA) forms a layer of Cu-BTA film with copper on the surface, which leads to a hydrophobic surface of copper.So an effective cleaning solution is needed to remove BTA from the copper surface.In this work, a new compound cleaning solution is designed to solve two major problems caused by BTA:one is removing BTA and the other is copper surface corrosion that is caused by the cleaning solution.The cleaning solution is formed of alkaline chelating agent (FA/O II type), which is used to remove BTA, and a surfactant (FA/O I type), which is used as a corrosion inhibitor.BTA removal is characterized by contact angle measurements and electrochemical techniques.The inhibiting corrosion ability of the surfactant is also characterized by electrochemical techniques.The proposed compound cleaning solution shows advantages in removing BTA without corroding the copper surface.