Multi-wavelength Reflectivity Monitoring on Growth of AlN on Si

Analysis of oscillation of reflectivity on thin film growth at a wavelength the film is transparent results in more than one solution of growth rate sometimes. Usually, the correct growth rate is chosen among the solutions with knowledge of refractive index of the film. On the other hand, if the reflectivity is monitored at two or more wavelengths, the correct solution is chosen by comparing the solutions at different wavelengths. In this report, an example of AlN growth on Si substrate is shown.