300mm铜膜低压低磨料CMP表面粗糙度的研究

随着集成电路特征尺寸的减小、低k介质的引入及晶圆尺寸的增加,如何保证在低压无磨料条件下完成大尺寸铜互连线平坦化已经成为集成电路制造工艺发展的关键。采用法国Alpsitec公司的E460E抛光机在低压低磨料的条件下,研究了12英寸(1英寸=25.4 mm)无图形(blanket)铜膜CMP工艺和抛光液配比对抛光表面质量的影响。实验结果表明,在压力为0.65 psi(1 psi=6.89×103 Pa),抛光液主要成分为体积分数分别为5%的螯合剂、2%的氧化剂和3%的表面活性剂。抛光后表面无划伤,表面非均匀性为0.085,抛光速率为400 nm.min-1,表面粗糙度为0.223 nm,各参数均满足工业化生产的需要。

Study of Surface Roughness in Abrasive-Low CMP Technique for 300 mm Copper Films with Low Pressure

As the IC feature size continues to decrease,the introduction of low k medium and the increase of the wafer size,how to achieve the planarization of large size copper interconnect line with abrasive free has become the key factor to the IC manufacturing technology.This process was executed on the E460E polishing machine that made by Alpsitec company.To meet the requirements,the CMP technology and the proportion of 12 inch Blanket copper films under the condition of low pressure and without abrasive grits were studied.The results indicat that the polishing rate is 400 nm/min under the pressure of 0.65 psi.With in-wafer non-uniformity is 0.085 and surface roughness is 0.223 nm,when slurry is 5% chelating agents,2% oxidizer and 3% surfactant.The parameters meet the needs of industrial production