Effect of Different Ph in HKMG on the Selection Ratio of Al and Poly Removal Rates

When the characteristic size of integrated circuits developed to 28 nm and below according to Moore's Law, aluminum was widely used as a gate material in HKMG structures, and the CMP technology of aluminum gates was a breakthrough in the upgrading of HKMG post-gate process technology. Aluminum gate CMP requirements are much higher than aluminum wiring and Damascus wiring, the key to aluminum gate CMP is to achieve high material removal selectivity and high perfect surface. At home and abroad, the research on aluminum gate CMP is mostly concentrated on removal rate and Al-Co galvanic corrosion. This paper will explore the influence of the rate selection ratio of aluminum and polysilicon under glycine hydrogen peroxide system with different pH conditions via CMP experiments, electrochemical experiments, UV and XPS spectroscopy experiments, etc.