A simplified surface photoreflectance measurement system

We present a simple and economical photoreflectance measurement methodology that can easily be adapted to conventional scanning optical microscopes. L n this design, the laser source is sine-wave modulated so that the second-h armonic modulation distortion within the optical probe beam before and afte r reflection off the sample surface can be monitored. The desired photorefl ectance measurement, which is taken as the change of reflectance as a resul t of varying the incident optical power, is then obtained from the change i n the ratio of the fundamental and second-harmonic signals. We demonstrate our set-up and technique by measuring the implantation damage in nitrogen-i mplanted silicon samples.