COS-based Q-V testing: in-line options for oxide charge monitoring

The strict demands for wafer cleanliness and impurity elimination outlined in the Semiconductor Industry Association's Technology Roadmap require that new monitoring methods be developed for measurement of oxide contamination. A newly available technology is presented here that will help manufacturers achieve the goals of oxide contamination monitoring and feedforward control. The technique is based on the principles of capacitance-voltage (C-V) monitoring, but the measurements are performed in a noncontacting fashion, thus greatly speeding the return of information to the user.