碱性阻挡层抛光液各成分对CMP的影响

Effects of Alkaline Barrier Slurry Ingredients on the CMP

为实现图形片的全局平坦化,通过研究碱性阻挡层抛光液各成分对铜和介质(TEOS)去除速率的影响,遴选出一种碱性阻挡层抛光液。在此抛光液基础上添加不同质量分数的盐酸胍,对钽光片进行抛光,选出满足要求的抛光液,并在中芯国际图形片上验证此抛光液的修正能力。实验表明,当磨料质量分数为20%、盐酸胍质量分数为0.3%、I型螯合剂(FA/O I)体积分数为1%、非表面活性剂体积分数为3%时,钽和TEOS去除速率之和是铜去除速率的3.3倍,此种碱性阻挡层抛光液对钽的去除速率为42 nm/min,各项参数均满足工业要求。与商用酸性、碱性抛光液相比,该抛光液对碟形坑和蚀坑有更好的修正能力。

To achieve the global planarization of the pattern wafer, the effects of the alkaline barrier slurry ingredients on the removal rates of Cu and TEOS were researched, and a suitable content of the alkaline barrier slurry was selected. The guanidine hydrochloride with different mass fractions was added into the above alkaline barrier slurry to polish the tantalum wafer, and a suit able slurry satisfying the requirement was selected. Then, the correction capability of the selected slurry was verified on the pattern wafer made by SMIC. The experimental results show that when the mass fraction of the abrasive is 20%, the mass fraction of the guanidine hydrochloride is 0. 3%, the volume fraction of the chelating agent （FA/O I ） is 1% and the volume fraction of the non-ionic surfactant is 3%, the removal rate ratio of the sum of Ta and TEOS to that of Cu is 3.3 ： 1, the removal rate of the alkaline barrier slurry for tantalum is 42 nm/min, and all the parameters can satisfy the industrial requirements. The alkaline slurry has a better correction capability for the dishing and erosion compared with the commercial acidic and alkaline slurries.