Experimental and Modeling Investigation of the Mechanism for Preventing Readhesion via Zeta Potential in the Spin-Rinse Process. (1st April 2021)

• Record Type: Journal Article
• Authors: Handa, N.; Hiyama, H.; Amagai, K.; Yano, A.
• Is Part Of: ECS journal of solid state science and technology. Volume 10:Number 4(2021)
• Publication Date: 2021-04-01
• Subjects: spin rinse process -- preventing re-adhesion of particles -- modeling -- Post-CMP Cleaning -- zeta-potential -- Near-wall hindered diffusion -- removal of detached particle via liquid flow; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2162-8777/abf16a
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : Adhesive particles on polished wafers are detached via, for example, scrubbing, and removed via liquid flow from the wafer while preventing readhesion by controlling the zeta potential. However, the effect of the zeta potential on the removal of detached particles in the spin-rinse process is yet to be quantitatively examined. Therefore, a physical model was constructed with some consideration of the zeta potential effect and was subsequently compared with the experimental results. According to the Derjaguin–Landau–Verwey–Overbeek theory, particle displacement in the direction normal to the wafer surface can be calculated from the energy that is mainly determined by the repulsive force depending on the zeta potential. Assuming that the particle displacement distribution takes the form of a Gaussian distribution, the ratio of particles present in the direction normal to the wafer surface can be expressed and the zeta potential effect could be incorporated into the model. Furthermore, assuming that the detached particles are removed from the wafer not only during the spin-rinse process but also during the spin-drying process, the model was in line with the experiment. It was found that the detached particles are removed from the wafer during both the spin-rinse process and the spin-drying process.