A New Method for Measuring Mobile Charge in SiO_2 on Si; The First Real-Time Wafer Mapping Capability

摘要

We demonstrate, for the first time, whole-wafer mapping of the mobile charge in SiO_2 on silicon. The technique uses no test structure. The measurement is done in non-contact mode in a total time of about 20 minutes per wafer. Determination of the mobile charge is based on monitoring the ion drift by measuring corresponding changes in the contact potential difference. The drift is induced by corona charge on the entire SiO_2 surface.