As the technology node of integrated circuits (ICs) shrinks down to 7nm and below, cobalt (Co) has been identified as the promising candidate for the interconnect/contact material. In this paper, colloidal silica was used as abrasive, potassium tartrate (PTH) was used as the promoter of TEOS and complexing agent of Co and titanium nitride (TiN), H2O2 was used as oxidant. The effects of PTH and H2O2 on the removal rate (RR) of Co/TiN/TEOS were studied. Polishing results showed that PTH can improve the RR of Co/TiN/TEOS effectively. The removal mechanism was revealed by X-ray photoelectron spectroscopy (XPS), electrochemical and UV-visible (UV-vis) spectroscopy measurements. It revealed that PTH can complex with Co(II)/Co(III) and TiO2+ ions produced during CMP, and formed Co(II)-PTH/Co(III)-PTH and TiO-PTH complex increases the RR of Co and TiN. The attractive force between silica abrasive and TEOS surface was improved as the concentration of PTH increased, resulting in the mechanical force increased and the RR of TEOS enhanced.

中文翻译：

---

酒石酸钾对钴“抛光步骤”化学机械平坦化 Co/TiN/TEOS 去除率选择性的影响

随着集成电路 (IC) 的技术节点缩小到 7 纳米及以下，钴 (Co) 已被确定为互连/接触材料的有希望的候选者。本文以胶体二氧化硅为磨料，酒石酸钾(PTH)为TEOS的促进剂，Co与氮化钛(TiN)的络合剂，H2O2为氧化剂。研究了 PTH 和 H2O2 对 Co/TiN/TEOS 去除率 (RR) 的影响。抛光结果表明，PTH 可以有效提高 Co/TiN/TEOS 的 RR。通过 X 射线光电子能谱 (XPS)、电化学和紫外-可见 (UV-vis) 光谱测量揭示了去除机制。结果表明，PTH 可以与 CMP 过程中产生的 Co(II)/Co(III) 和 TiO2+ 离子络合，形成的 Co(II)-PTH/Co(III)-PTH 和 TiO-PTH 络合物增加了 Co 和 TiN 的 RR .