Ceria removal during the STI post-CMP cleaning process has recently become a serious concern in the semiconductor industry. Understanding ceria adhesion and its removal mechanism is necessary for designing a suitable post CMP cleaning methodology. Recently, colloidal ceria slurries have been heavily used due to the low defectivity factor. In this work, colloidal ceria adhesion and removal behaviors were studied as a function of particle sizes. It was found that polishing produces more contamination of ceria to oxide surface than dipping conditions and the strength of adhesion is increased with decreasing ceria size due to a higher Ce³⁺ concentration for smaller size particles resulting in more Ce-O-Si bonding. Ceria adhesion is mainly attributed to Ce-O-Si bond formation. Different cleaning methods (megasonic, brush scrubbing, SC1 (standard cleaning solution 1), DHF (diluted hydrofluoric acid) and SPM (sulfuric acid and hydrogen peroxide solution) were employed in removing these ceria particles. It was found that larger particles could be removed effectively with physical force, and smaller particles could be removed using chemicals such as DHF or SPM. Hence, it is concluded that an appropriate cleaning method should be chosen based on the size of the ceria.

最近，在STI后CMP清洗过程中去除二氧化铈已成为半导体行业中的一个严重问题。了解氧化铈粘附及其去除机理对于设计合适的CMP后清洁方法是必不可少的。最近，由于低缺陷因子，胶体二氧化铈浆料已被大量使用。在这项工作中，胶体二氧化铈的粘附和去除行为作为粒径的函数进行了研究。已发现，与浸渍条件相比，抛光会对氧化铈表面产生更多的二氧化铈污染，并且由于铈³⁺含量的增加，随着氧化铈尺寸的减小，粘合强度会增加。对于较小尺寸的颗粒，浓度较高，从而导致更多的Ce-O-Si键。二氧化铈的粘附主要归因于Ce-O-Si键的形成。使用不同的清洗方法（兆声波，刷洗，SC1（标准清洗液1），DHF（稀氢氟酸）和SPM（硫酸和过氧化氢溶液）除去这些二氧化铈颗粒，发现可以除去较大的颗粒。因此，可以得出结论：应根据氧化铈的大小选择合适的清洁方法。