GLSI多层铜布线CMP后清洗BTA去除的研究

发布时间：2018-01-05 13:40

本文关键词：GLSI多层铜布线CMP后清洗BTA去除的研究　出处：《河北工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着集成电路工艺的不断发展,芯片集成度不断提高的同时器件的特征尺寸却不断减小,这样杂质对于器件的危害就显得异常突出。集成电路表面的污染物会影响器件的电学性能、成品率以及可靠性,因此清洗就成为了集成电路制造业中非常重要的环节。铜抛光后清洗是化学机械平坦化过程中至关重要的一步,抛光后铜表面会有大量的抛光液磨料(二氧化硅或氧化铝)和有机物残留,残留的有机物主要是苯并三氮唑(BTA)。BTA残留导致铜表面疏水,影响磨料的去除。影响介质经时击穿,导致器件稳定性差。本论文针对目前清洗过程去除苯并三氮唑(BTA)的问题做了详细的分析,研究BTA在铜CMP中的作用及吸附原理。BTA与Cu反应生成Cu-BTA,Cu-BTA具有复杂的结构,在铜表面难溶。本论文中提出了一种能够有效去除BTA及Cu-BTA的铜抛光后新型碱性清洗剂,并对清洗液的组分和浓度进行了研究。清洗剂主要包括碱性螯合剂和非离子表面活性剂。首先,对实验中的BTA的使用浓度及浸泡时间做了分析,通过接触角测试、金相显微镜及傅里叶红外光谱测试得出BTA最佳生长条件。然后,对BTA的去除进行螯合剂单因素实验。通过接触角测试、静态腐蚀速率电化学测试及KOH对比实验,得出螯合剂对BTA去除起主要作用,同时得出螯合剂去除BTA效果较好的浓度范围。活性剂呈弱酸性,由活性剂单因素实验得出其对BTA去除起辅助作用,去除效果通过接触角测试和静态腐蚀速率来表征。最后,清洗剂去除BTA及其他污染物的效果由接触角,静态腐蚀速率和扫描电镜测试结果表征。对于BTA的去除,酸性或碱性清洗剂比中性清洗剂更有效。本文中提出的碱性清洗剂具有pH值高,使用浓度低,不含TMAH,环保的优点。通过大量实验得出,该清洗液中螯合剂浓度不宜高于200ppm,活性剂浓度不宜高于5000ppm,具体清洗液配比还需进一步研究。
[Abstract]:With the continuous development of integrated circuit technology, the chip integration improves the feature size of the device has been reduced, so that the impurities in the device damage is very prominent. The pollutant surface of the integrated circuit will influence the electrical properties of the device, the rate of finished products and the reliability, so cleaning has become a very important integrated circuit manufacturing industry in the link. After polishing cleaning copper chemical mechanical planarization process is a crucial step, polished copper surface will have a large number of abrasive polishing liquid (silica or alumina) and organic residues, organic residues are mainly three benzo triazole (BTA).BTA residues leads to hydrophobic copper surface, abrasive effect the removal effect of medium. The breakdown leads to poor device stability. Aiming at the process of cleaning and removal of benzene three triazole (BTA) made a detailed analysis of the problems of BTA in copper CMP The effect and principle of.BTA adsorption and Cu reaction in Cu-BTA, Cu-BTA has a complex structure, difficult to dissolve in the copper surface. This paper presents a copper polishing can effectively remove BTA and Cu-BTA after alkaline cleaning agent, and the composition and concentration of cleaning liquid are studied. The cleaning agent mainly includes alkaline chelating agent and non-ionic surfactant. First of all, using concentration and soaking time on the BTA to do the analysis, contact angle test, metallographic microscope and Fourier transform infrared spectroscopy BTA tests showed that the best growth conditions. Then, by single factor experiment chelating agent on the removal of BTA. Through static contact angle measurement. The corrosion rate of electrochemical test and KOH experiment that chelating agents play a major role in the removal of BTA, at the same time that the chelator concentration range of BTA removal effect is good. The active agent was weak acidic active agent, by single factor experiment The removal of BTA play a supporting role, the removal effect is characterized by the contact angle test and static corrosion rate. Finally, the cleaning agent to remove BTA and other pollutants effect by the contact angle test results, the static corrosion rate and scanning electron microscopy. The BTA removal rate of acid or alkaline cleaning agent than neutral cleaning agent is more effective. Alkaline cleaning agent in this paper has high pH value, low concentration, does not contain TMAH, environmental advantages. Through experiments, the cleaning liquid chelating agent concentration should not be higher than 200ppm, the concentration of surfactant is higher than 5000ppm, the cleaning liquid ratio still needs further research.

【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN405.97

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