ULSI中多层Cu布线CMP表面粗糙度的分析和研究

Analysis and Research on the Surface Roughness of the Copper Multilayer Interconnection CMP in ULSI

分析介绍了Cu层表面粗糙度对器件性能的影响以及超大规模集成电路中多层Cu布线CMP的作用机理,研究分析了碱性抛光液对Cu的表面粗糙度的影响因素,如磨料、氧化剂、pH值、表面活性剂等对表面粗糙度的影响。实验证明,在一定的抛光条件下,选用SiO2为磨料、双氧水为氧化剂的碱性抛光液可以有效降低Cu层的表面粗糙度,使之达到纳米级,得到良好的抛光效果,从而解决了超大规模集成电路多层Cu布线化学机械抛光中比较重要的技术问题。

The impact of the surface roughness about copper layer on the device performance was introdueed, and interaction mechanism of the copper multilayer interconneetion CMP in ULSI was introduced.The influencing factors of alkaline slurry on the surface roughness was analyzed, such as abrasive, oxidizing agent, pH value and active agent. The experiments show that under such polishing conditions, alkaline slurry can effectively reduce the surface roughness about copper layer and makes it achieve nano-scale for getting a good polishing effect, and it solves the important technical problems of the copper muhilayer interconnection CMP in ULSI