The correlation between the nonuniformities of plasma parameters (i.e., floating potential) and the induced charging onto the surface of oxide-covered unpatterned 4 in. Si wafers exposed toO2electron cyclotron resonance (ECR) plasma is investigated. Wafers covered with a 1000 Å oxide layer were exposed to the ECR plasma under nonuniform conditions, and the induced surface charge was mapped on the wafers using contact potential difference technique. Floating potential profiles were monitored using a Langmuir probe. Experimental data indicate that the magnitude of the surface charge is proportional to the deviation of the floating potential from its surface-averaged potential. These results were compared to location of the damage of metal-oxide-semiconductor capacitor test structures exposed to same plasmas. ©1998 American Institute of Physics.