Semiconductor wet cleaning processes use various chemical solutions including SC1 (NH₄OH/H₂O₂/H₂O), SC2 (HCl/H₂O₂/H₂O), SPM (H₂SO₄/H₂O₂), and DHF (dilute HF). Each chemistry has specific cleaning purposes from particle removal to metal contamination control.
Dissolved oxygen concentration in these solutions directly impacts etch rates, surface roughness, and defect density. Precise DO monitoring enables tighter process control, improved yield, and reduced chemical consumption. This article explains the measurement challenges and sensor requirements for each cleaning chemistry.