Electrokinetic Characteristics of Nitride Wafers in Aqueous Solutions and Their Impact on Particulate Deposition

The electrokinetic characteristics of low pressure and plasma-enhanced chemical vapor deposited silicon nitride wafers subjected to different cleaning procedures were measured using a streaming potential technique. A streaming potential cell for handling 5 in. wafers was designed and fabricated to make these measurements. The isoelectric point (IEP) of silicon nitride was dependent on the cleaning method as well as the deposition technique. X-ray photoelectron spectroscopic measurement of Si/O and Si/N ratio of films was made to explain the difference in the measured IEP values. Polystyrene latex particle deposition from aqueous solutions onto silicon nitride wafers was investigated and correlated with the electrokinetic potential data.