Molecular beam epitaxy growth of low-bandgap material thick films using a molybdenum disilicide coated backing plate for substrate temperature control

Molecular beam epitaxial (MBE) deposition allows for the epitaxial growth of materials requiring atomically precise control of nanometer thick layers. A key concern with the growth of smaller bandgap materials on larger bandgap substrates via MBE is the radiative coupling of the deposited layer with the heater, which can lead to uncontrolled increases in temperature if not properly accommodated for. In this work, we demonstrate the ability to decouple the radiative component of the heater with the substrate and layer deposition through the incorporation of a molybdenum disilicide coated molybdenum backing plate. We demonstrate that the novel coating allows for highly efficient coupling with the heater while providing improved temperature control at the growth surface, leading to stable growth conditions. We demonstrate the stable growth and film characteristics through the growth of germanium telluride thin films on (100) gallium arsenide substrates.