Effect of surfactant on removal of particle contamination on Si wafers in ULSI
(1.Institute of Microelectronics, Hebei University of Technology, Tianjin 300130, China2.School of Information Engineering, Hebei University of Technology, Tianjin 300130, China)
Abstract: The adsorption mechanism of particle on the surface of silicon wafer after polishing or grinding whose surface force field is very strong was discussed, and the removal method of particle was studied. Particle is deposited on the wafer surface by interactions, mainly including the Van der Waals forces and static forces. In order to suppress particles depositing on the wafer surface, it is essential that the wafer surface and the particles should have the same polarity of the zeta potential. According to colloid chemistry and lots of experiments, this can be achieved by adding surfactants. Nonionic complex surfactant was used as megasonic cleaning solution, and the adsorptive state of particle on Si wafers was effectively controlled. The efficiency and effect of megasonic particle removal is greatly improved. A perfect result is also obtained in wafer cleaning.
Key words: megasonic cleaning; nonionic surfactant; particle removal; silicon wafer; adsorption