55nm CMOS金属硬质掩模铜互连技术中湿法清洗工艺的开发与改进

发布时间：2018-08-18 14:00

【摘要】：本文主要研究了55nm CMOS金属硬质掩模铜互连技术中湿法清洗工艺。在55nm工艺平台中,评估了三种清洗药液,第一种是胺基为基础的有机溶剂,第二种是半有机半水基的清洗药液,第三种是稀释的氢氟酸。通过刻蚀速率、缺陷、电学性能、许容时间等方面表现的比较,第一种胺基有机溶剂表现最优。并通过药液交换是设定的优化,使得60nm以下颗粒表现达到最优,工艺开发完成。在实际生产过程中,发现了铜腐蚀、球形缺陷、有机残留缺陷等问题。通过研究,找到了缺陷发生的原因。铜腐蚀是由于光引起的电流,在清洗过程中发生电化学腐蚀,通过保持黑暗的腔体环境能杜绝铜腐蚀问题。球形缺陷主要是设备洁净度以及药液洁净度不佳引起的,而从硅片中心聚集的特征入手,调整工艺程式喷药液的起始位置,能有效降低球形缺陷。通过增加水洗时间可以有效减少有机残留缺陷,同时不会引起额外的铜损失。通过这些改善,使得清洗工艺更加成熟、完善,缺陷降低,良率提升。同时也对金属硬质掩模铜互连中的清洗工艺的发展趋势做了一些分析。主要从设备、清洗药液等几方面入手,指出了技术节点往前时对清洗工艺的新要求。
[Abstract]:In this paper, the wet cleaning process of 55nm CMOS metal hard mask copper interconnection technology is studied. In the 55nm process platform, three kinds of cleaning solutions were evaluated, the first was amine-based organic solvent, the second was semi-organic and semi-aqueous, and the third was dilute hydrofluoric acid. Through the comparison of etching rate, defect, electrical property and volume time, the first amine organic solvent is the best. The optimal performance of the particles below 60nm was achieved by the optimization of the drug exchange, and the process development was completed. In the actual production process, copper corrosion, spherical defects, organic residual defects and other problems have been found. Through the research, the cause of the defect is found. Copper corrosion is caused by light current. Electrochemical corrosion occurs in the process of cleaning. Copper corrosion can be eliminated by keeping the dark chamber environment. The spherical defects are mainly caused by the poor cleanliness of the equipment and the cleaning degree of the medicine solution. The spherical defects can be effectively reduced by adjusting the starting position of the spray solution of the process program starting from the characteristics of the aggregation of the silicon wafer center. By increasing washing time, organic residual defects can be effectively reduced without causing additional copper loss. Through these improvements, the cleaning process is more mature, perfect, defect reduction, yield increase. At the same time, the development trend of cleaning technology in metal hard mask copper interconnection is analyzed. The new requirements for cleaning technology are pointed out from the aspects of equipment, cleaning liquid and so on.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN40

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