Diffuse reflectance spectroscopy measurement of substrate temperature and temperature transient during molecular beam epitaxy and implications for low-temperature III–V epitaxy

We report diffuse reflectance spectroscopy (DRS) measurement of Knudsen cell induced radiative heating of the sample during molecular beam epitaxy of GaAs at substrate temperatures between 200 and 600 °C. The temperature rises, as large as 12 °C, were observed for In-bonded samples at a substrate temperature of 200 °C. As-grown GaAs layers deposited between 200 and 300 °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 identified, at a DRS measured temperature between 260 and 270 °C.