- Highly elastic solutions have been shown to increase contaminant removal from silicon wafers, indicating the possibility for reduced reliance upon hazardous chemicals and expensive technologies during the fabrication of semiconductor devices. The onset of this enhanced removal is explored using rinsing and siphoning experimentswith polymer fluids of high molecular weights ranging from dilute to entangled concentrations. Increases in particle removal with less than 100 ppm of polymer were observed in both experiments, with 10% more removal in the rinsing experiment and 4% more removal in the siphoning experiment relative to water. Further increases in concentration increased removal significantly, as the solutions entered the semidilute regime. Additionally, particle removal was examined as a locationally dependent parameter, showing a plateau of high removal near the radius with a sharp decrease to a constant value at distances farther away from the siphon. The increases in particle removal with solutions having nearly indistinguishable shear rheology and immeasurable extensional rheology indicates the need for more precise methods for extensional characterization of dilute polymer solutions.
- Keywords: particle removal, polymer solution, viscoelastic fluid, siphoning flow, cleaning