新型碱性抛光液对300mm TaN镀膜片CMP效果评估

TaN由于其良好的性能广泛用于布线铜与介质之间的阻挡层和黏附层.在对直径为300 mm的TaN镀膜片进行化学机械抛光(CMP)后,对比并分析了两种碱性抛光液对TaN去除速率、片内非均匀性、去除速率选择性和表面粗糙度的影响.结果表明,经过自主研发且不合氧化剂的碱性阻挡层抛光液抛光后,TaN的去除速率为40.1 nm/min,片内非均匀性为3.04％,介质、TaN与Cu的去除速率之比为1.69∶1.26∶1,中心、中间以及边缘的表面粗糙度分别为0.371,0.358和0.366 nm.与商用抛光液抛光结果相比,虽然采用自主研发的抛光液抛光的去除速率低,但片内非均匀性以及选择性均满足商用要求,且抛光后TaN表面粗糙度小,易清洗,无颗粒沾污.综合实验结果表明,自主研发的高性能碱性抛光液对TaN镀膜片具有良好的抛光效果,适合工业生产.

Evaluation of Novel Alkaline Slurry for 300 mm TaN Blanket Wafer CMP Effect

TaN is widely used for barrier and adhesion layer between copper and dielectric due to its good performance.The effects of two alkaline slurry on removal rate,with in-wafer non-uniformity,removal rate selectivity and surface roughness were compared and analyzed after chemical mechanical polishing (CMP) for TaN blanket wafer with the diameter of 300 mm.The results show that after polishing with self-developed alkaline barrier slurry free of oxidant,the removal rate of TaN is 40.1 nm/min,the within-wafer non-uniformity is 3.04％,the ratio of dielectric,TaN and Cu removal rate is 1.69 ∶1.26 ∶ 1,and the surface roughnesses of center,middle and edge are 0.371,0.358 and 0.366 nm respectively.Compared with the polishing results using commercial slurry,the removal rate using self-developed slurry is lower,but the with in-wafer non-uniformity and selectivity of TaN both meet the commercial requirement.Moreover,the polished TaN surface has a lower roughness and is easy to clean,and there is no particle contamination.The whole results indicate that the self-developed and high-performance slurry has a good effect on TaN blanket wafer CMP,which is suitable for industrial production.