多层铜布线表面CMP后颗粒去除研究

针对目前清洗技术存在的问题进行了详细分析,研究了微电子材料表面污染物的来源及其危害,并介绍了表面活性剂在颗粒去除方面的作用。研究了化学机械抛光(CMP)后Cu布线片表面的颗粒吸附状态,分析了铜片表面颗粒的吸附机理。采用非离子表面活性剂润湿擦洗方法,使Cu表面的颗粒处于易清洗的物理吸附状态。利用金相显微镜和原子力显微镜(AFM)在清洗前后进行对比分析,实验采用聚乙烯醇(PVA)刷子分别对铜片和铜布线片进行清洗,发现非离子界面活性剂能够有效去除化学机械抛光后表面吸附的杂质,达到了较好的清洗效果。

Research of the Cleaning Method for Particles on the Surface of Multilevel Copper Interconnects after CMP

A detailed analysis of the problems that exist in the present cleaning technology was performed.The sources and hazards of surface contaminants of the microelectronics material were analyzed,and the effects of the surfactant in the aspects of the particle removement were introduced.The adsorption state of particles at Cu surface after chemical mechanical polishing(CMP) was researched,the adsorption mechanism of particles on Cu surface was analyzed.By using the nonionic surfactant and wetting scrubbing method,the adsorption state can be controlled as the physical sorption that is convenient to clean.The comparison and analysis for the Cu surface before and after cleaning were carried out by the metallographic microscope and atomic force microscopy(AFM),and the polyvinyl alcohol(PVA) brush was adopted for cleaning both the Cu blanket and pattern in the experiment.The results show that the nonionic surfactant can effectively remove particles after CMP,and the better cleaning effect can be achieved.