Molecular beam epitaxy

The molecular beam epitaxy technique (MBE) was developed initially for the crystalline growth of the semiconductors. It is an ultra-high vacuum (P Introduction chamber (1) equipped with a turbomolecular pump. Preparation chamber(2) – Gun allowing the ionic bombardment of surfaces (Ar+ ions of energy ranging between 1 and 8 keV). – Oven allowing a heating until 1800°C by combining the Joule effect until 500°C and the electronic bombardment above. The temperature is measured by a thermocouple and/or an infra-red pyrometer. – Gas introduction . – Device of low energy electron diffraction (LEED Riber). Analysis chamber (3) – Source X Riber (not monochromatic): Al (hν = 1486.6 eV) or Mg (hν = 1253,6 eV). – Detection by a hemispherical analyzer (Clam II of VG-scientific). Growth chamber(4) – Three Knudsen cells cooled by water allowing the evaporation of metals. – Gun with ions of low energy (200 to 600 eV). – Manipulator equipped to heat by Joule effect the substrate until 600°C during the deposition. The rotation of the sample holder is motorized. – Thickness measurement by a balance with Inficon quartz cooled by water. – Source of oxidation by monoatomic oxygen plasma. – Gun RHEED (Staib Instrumente) which uses electrons with a primary energy ranging between 0 and 30 keV. The diffraction pattern is observed on a fluorescent screen. The geometry of the growth chamber allows an incidence of the electrons beam about a few degrees. The images are then recorded by a camera CCD cooled by Peltier effect. The recording and the analysis of the diffraction patterns (LEED and RHEED) are done using the KSA-400 software. – quadripolar gas Analyser Inficon. – CMA Auger Spectroscopy (PHI: Physical Instruments).