非离子表面活性剂在钽基阻挡层CMP中的作用

Role of Non-Ionic Surfactant on Tantalum-Based Barrier CMP

碱性条件下,非离子型表面活性剂在阻挡层化学机械平坦化中起着重要的作用。分别对阻挡层材料Cu、Ta以及SiO2介质进行抛光,然后测量铜表面粗糙度。对含有不同浓度活性剂的抛光液进行接触角和Zeta电位的测试,并对活性剂的作用机理进行分析。活性剂体积分数达到3%时,铜表面粗糙度可达0.679nm,抛光液在铜膜表面的接触角低至10.25°,Zeta电位达到-50.2mV。实验结果表明,活性剂在减小粗糙度的同时可提高抛光液的湿润性和稳定性,便于抛光后清洗和长时间放置。

Non-ionic surfactant plays an important role in barrier chemical mechanical planarization under alkaline conditions.Copper,tantalum and SiO2 dielectric were polished,and then the copper surface roughness,contact angles and Zeta potential of slurries were measured respectively as a function of non-ionic surfactant.The mechanism of non-ionic surfactant was analyzed.The results showed that the surface roughness of copper was 0.679 nm,the contact angle of slurry was 10.25°and Zeta potential was-50.2 mV at 3% surfactant.It was demonstrated that non-ionic surfactant was beneficial to reduce the copper surface roughness and improve the wettability and stability of slurry,which was convenient for cleaning after polishing and storing for a long time.