Improved Methodology for Determination of Submicron Particle Concentrations in Semiconductor Process Chemicals

Improved counting methodology has been developed for measurement of submicron particle concentrations to semiconductor process chemicals. The methodology reduces counting of air bubbles and makes corrections for counter inefficiency, medium refractive index, and particle coincidence. The methodology has been used to measure bottled chemical particle concentrations and to determine filter particle removal efficiencies. Use of the methodology allows comparison of particle counts obtained in process liquid chemicals.