DIFFUSE-REFLECTANCE SPECTROSCOPY MEASUREMENT OF SUBSTRATE-TEMPERATUREAND TEMPERATURE TRANSIENT DURING MOLECULAR-BEAM EPITAXY AND IMPLICATIONS FOR LOW-TEMPERATURE III-V EPITAXY

We report diffuse reflectance spectroscopy (DRS) measurement of Knudse n cell induced radiative heating of the sample during molecular beam e pitaxy of GaAs at substrate temperatures between 200 and 600 degrees C . The temperature rises, as large as 12 degrees C, were observed for I n-bonded samples at a substrate temperature of 200 degrees C. As-grown GaAs layers deposited between 200 and 300 degrees C are characterized using double crystal x-ray diffraction. The onset of a distinct x-ray peak associated with the low-temperature grown GaAs layer is identifi ed, at a DRS measured temperature between 260 and 270 degrees C. (C) 1 997 American Institute of Physics.