In situ spectral reflectance monitoring of III-V epitaxy
Near normal incidence spectral reflectance was used to monitor the growth of ALAs, GaAs, and AlGaAs films by metalorganic chemical vapor deposition in real time. The simultaneous acquisition of reflectance data over a wide spectral bandwidth allows compositional discrimination between layers and greater thickness sensitivity than single wavelength measurements. The potential of this technique for application to device structures was demonstrated by moni-toring the fabrication of AlAs/AlGaAs visible distributed Bragg reflectors.