300mm铜膜低压CMP速率及一致性

随着铜互连结构中低k介质的应用,要求CMP抛光过程中必须将压力减小到6.89 kPa以下,传统的化学机械抛光已不符合当前的工艺要求,如何兼顾超低压力下抛光速率和速率一致性成为关键问题.对300 mm Blanket铜膜进行了低压化学机械抛光实验,分析研究了碱性抛光液组分及抛光工艺参数对铜膜去除速率及其一致性的影响.通过...

Material Removal Rate and Uniformity of CMP for 300 mm Copper Films by Low Pressure

As the low dielectric constant(low-k) materials are introduced in the copper interconnection,it is required that the working pressure must be below 6.89 kPa in chemical and mecha-nical planaration(CMP) process,and the traditional CMP technics can not satisfy current requirements.It is a key problem to balance the material removal rate under ultra low working pressure and the uniformity of the material removal rate(MRR),which is represented by the WIWNU(within wafer nonuniformity).The low working pressure investigation of CMP for 300 mm blanket copper was carried out,and then the effects of the alkaline polishing solution component and polishing parameters on MRR and WIWNU were analysed.The experiment shows that when the working pressure is 1 kPa,the flow rate is 200 mL/min,the rotate speed of the plate is 30 r/min,the oxidant volume fraction is 2%,the abrasive volume fraction is 30% and the chelating agent volume fraction is 3%.And better results indicate that the MRR is 330 nm/min,the WIWNU is 0.049,and the surface roughness after CMP is 0.772 nm.