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.