集成电路亚14 nm节点FinFET的化学机械抛光基础研究

Fin field-effect transistor (FinFET) is the key technique to sub-14 nm technology node of ultra-large scale integrated circuit. To boost the great-leap-forward development of integrated circuit manufacturing in China, it is essential to master the FinFET processing technology. Chemical mechanical polishing (CMP) is the only enabling technology achieving global and local planarization of wafer surface, which is facing great challenges due to the complex structure, new materials and methods adopted when applied to the FinFET technology. This project targets at the CMP process of poly-Si open process (POP) and replacement metal gate (RMG), and aims to solve the technical and fundamental scientific problems. With gradually decoupling by the macro-experiments and complementing by the micro-experiments, the material removal mechanism of different materials from chemical-mechanical synergistic effect will be established. At the same time, the damages and defections on wafer surface/interface will be investigated by combining molecular dynamics simulation and CMP experiments. On this basis, the key process of CMP in FinFET manufacturing will be proposed, ensuring the precise control of gate height. The achievements in this project orient to the national strategic development and academic frontier, which will be of great value for industrial application.

鳍式场效应晶体管（FinFET）是超大规模集成电路亚14 nm节点的关键技术，掌握FinFET工艺，可以促成我国集成电路制造业的跨越式发展。化学机械抛光（CMP）是唯一可以实现晶圆表面全局和局部平坦化的一项使能技术，而FinFET的结构和制造工艺复杂、涉及众多新材料和技术的应用，因此其CMP过程面临巨大的挑战。本项目以FinFET多晶硅打开（POP）和替换金属栅（RMG）过程的CMP技术为研究对象，针对其中的技术难题和基础科学问题展开研究：采用宏观实验逐步解耦，微观实验解释补充的方法，从化学机械耦合作用角度研究异质材料的去除机理；将分子动力学模拟与CMP实验相结合，探讨表面/界面损伤和缺陷的产生机制；在此基础上，提出FinFET化学机械抛光关键工艺的实现方法，确保栅极高度的精准控制。相关研究工作面向国家战略需求和学科发展前沿，具有极大的生产应用价值。

项目针对集成电路亚14nm技术节点前段制程FinFET化学机械抛光（CMP）工艺中的技术难题和基础科学问题，以金属材料和介质材料的CMP为研究对象开展研究工作，并在以下两个方面取得突出科研成果：（1）建立了多种复杂异质材料（铜/钛/氮化钛/TEOS/硅界面、铜/钌/钽/氮化钽/BD1界面）的表/界面缺陷的产生机制，并寻求其抑制手段；（2）针对介质材料的CMP工艺，提出新型镧系金属掺杂氧化铈磨粒的制备方法，所制备的氧化铈磨粒可以显著提高介质材料在碱性抛光液种的材料去除速率和抛光后表面质量。研究成果为亚14nm技术FinFET结构化学机械抛光技术的顺利应用提供重要科学理论依据。