Implant Process Monitoring
Monitoring conventional beam-line implanters directly after the implant process is very important to prevent processing on an implant system that is not working according to its spec. Reworking is very costly and in most cases impossible.
The PVA TePla TWIN Implant monitoring technique uses the well known excitation of thermal waves with subsequent measurement of the change in reflectivity. If an implant dose or energy changes, the resulting signature of crystal damage changes the behavior if the surface reflectivity and can be seen from the result of the TWIN measurement.
The system allows various measurement modes for uniformity on monitor wafers or product wafers. The range of measurement covers 10E10 to 5E16 in dose and 1keV to 100 MeV in implant energy.
Different measurement modes allow the user to specifically analyze the entire wafer or a small area of it with high resolution, micro-scan with repetitive measurement within a few microns or frequency sweep to determine the best measurement frequency.
The latest enhancements include temperature control for chuck and calibration substrate and a software feature to compensate the self-annealing effect at room temperature.