In situ determination of growth rate by pyrometric interferometry during molecular-beam epitaxy: Application to the growth of AlGaN/GaN quantum wells

In this article, we report on the application of pyrometric interferometry to monitor the growth rate of (Al)GaN in situ during molecular-beam epitaxy. Since the growth rate of III-nitrides is very sensitive to the nitrogen flux, it is important to monitor the variation in growth rate from run to run. Using this method, we grew ${\mathrm{GaN/Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ quantum-well structures with well thicknesses between 10 and 40 Å. The thicknesses of the quantum wells were confirmed by cross-sectional transmission electron microscopy measurements and found to be in good agreement with the corresponding growth rate determined in situ during the growth process.