Effect of Intermolecular Interaction of Compound Surfactant on Particle Removal in Post-Cu CMP Cleaning
Lijing Qu, Baohong Gao, Xuanshi Wang, Tongxi Wu, Baimei Tan
Abstract
This study focused on compound surfactant for particle removal in post CMP cleaning, including selection of surfactant to compound, compound mechanism, and particle removal efficiency of compound surfactant. The wettability and stability of surfactants with different hydrophilic and hydrophobic groups were analyzed by contact angle and surface tension comparison. AES (1000 ppm) and JFC-E (2500 ppm) were selected for compounding research. The intermolecular interaction of compound surfactant was studied by analyzing the FTIR spectrum of surfactants on copper surface and the zeta potential of the particles in the cleaning solution. The intermolecular interaction parameters βm related to surface tension, and βs related to contact angle. The particle removal efficiency is closely related to the CMC and concentration of each component, and compound AES (1000 ppm) and JFC-E (2500 ppm) at volume ratio of 2:3 achieved the best particle removal efficiency. And it has certain guiding significance for the development of cleaning solution.