高去除速率低碟形凹陷的铜化学机械抛光液

Cu CMP Slurry with High Throughput and Low Dishing

随着集成电路技术节点的缩小,需要开发一种具有高去除速率低碟形凹陷的铜化学机械抛光液,而且对抛光后的残留,腐蚀和微划伤等表面缺陷的要求也更严格。这是一种具有优异性能的铜化学机械抛光液。研究了抛光液配方对抛光性能包括去除速率和轮廓,静态腐蚀速率,碟形凹陷,铜残留物的清除能力和铜腐蚀状况的影响。电化学方法也被用来研究和支持这些抛光结果和性能。通过优化配方和抛光工艺,该铜化学机械抛光液能在>0.9μm/min的去除速率下获得约300?的碟形凹陷。

With the technology node shrinking, there is a need to develop a Cu slurry with fast rate for high throughput and low dishing for minimal within die and within wafer variation, and stringent defect requirement such as residue, corrosion, and micro scratches. In this paper, we introduce a high performance Cu CMP slurry to overcome these performance challenges in Cu CMP process. The impact of slurry formulation on the slurry performance will be presented under different process conditions, including blanket removal rates/profiles, static etch rates, dishing, Cu residue clearance capability and corrosion status. Electrochemical study was also conducted to support the results and performance. With the optimized formulation and polishing process, the slurry achieves about 300 ？ dishing at near 0.9 μm/min Cu removal rate.