抛光垫特性及其对300mm晶圆铜化学机械抛光效果的影响研究

利用扫描电子显微镜和接触式表面形貌仪分析了IC1000/Suba-IV和IC1010两种商用抛光垫的主要特性,并通过自行研制的超低压力化学机械抛光(CMP)试验机、四探针测试仪和三维白光干涉仪等研究了这两种抛光垫对300 mm晶圆铜互连的CMP材料去除率、片内非均匀性、碟形凹陷和腐蚀的影响规律.结果表明:IC1010比IC1000的硬度低、压缩率高、粗糙度大,IC1000为网格状沟槽、沟槽较宽、分布较稀,IC1010为同心圆沟槽、沟槽较细、分布较密;相同条件下IC1010比IC1000的材料去除率大、片内非均匀性好;在相同线宽下IC1000与IC1010的腐蚀几乎一致,IC1010的碟形凹陷比IC1000的略大.

Comparison of Polishing Pad Characteristics in Copper-interconnect Chemical Mechanical Polishing of 300 mm Wafer

A systematic study of Cu CMP for 300mm wafer in terms of the effect of polishing pad properties on the process characteristics has been performed. The properties of IC1000/Suba-IV and IC1010 polishing pads (hardness, compressibility, porosity, roughness and groove) were investigated by scanning electron microscope and stylus profile. The results show that there were significantly differences in the properties of the IC1000/Suba-IV and IC1010 pads. The IC1000/Suba-IV and IC1010 polishing pads were compared with regard to the material removal rate, non-uniformity, dishing and erosion of the CMP process for 300 mm wafer. Polishing with the IC1010 pad, a higher material removal rate, better uniformity and worse dishing were achieved. No differences in the pad influence on the erosion have been found.