Details

Autor(en) / Beteiligte

• Du, Haoyu
• Liu, Renhao
• Tan, Baimei
• Wang, Fangyuan
• Wang, Xiaolong
• Han, Xinyu
• Zhao, Xinyu
• Zhao, Jiadong

Titel

Cleaning mechanisms during post chemical mechanical polishing (CMP) using particle removal of surfactants via a citric acid-based solution

Ist Teil von

• Colloids and surfaces. A, Physicochemical and engineering aspects, 2024-09, Vol.697, p.134428, Article 134428

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• With the development of circuit integration technology, the requirements for defects in copper interconnects have become more stringent. The residual SiO2 particles on the copper surface can seriously affect circuit performance and require more efficient and thorough removal. This article investigates the effects of a novel cleaning solution composed of citric acid (CA), alkyl polysaccharide glycosides (APG1214), and dodecylbenzene sulfonic acid (LABSA), aimed at improving the removal efficiency of SiO2 and maintaining the integrity of copper surface. The optimal concentrations of APG1214 and LABSA were determined through contact angle and surface tension analysis. It was found that when APG1214 (2000 ppm) and LABSA (1000 ppm) were combined in a 3:2 vol ratio in CA solution (0.6 wt%), the highest particle removal efficiency (99.5 %) could be achieved while minimizing surface roughness. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed these findings. Combining quantum chemical calculations, new insights into the mechanism of action of different components in clean solutions have been proposed: 1. Similar to CA, LABSA and APG1214 demonstrate a strong affinity for copper, synergistically facilitating the cleavage of Cu-Si bonds. 2. Alternating adsorption of LABSA and APG1214 on free silica particles prevents their re-adsorption onto copper surfaces. 3. Furthermore, their orderly adsorption on copper mitigates the corrosive chelation effect of CA, providing a protective mechanism. These findings are pivotal for the development of advanced, multifunctional cleaning solutions. [Display omitted] •Citric acid can break the chemical bond between SiO2 and Cu.•Surfactants adsorb onto SiO2 surface to form encapsulation, changing the Zate potential and hydrophobicity of particles.•Synergistic effect of composite surfactants enhances wetting and particle removal efficiency.