| 摘要 |
PURPOSE:To restrain discharge of an N2 gas pocket or a contaminating gas molecule even if at the time of rapid rise of a thermal load by forming a cooling surface inside of a growing chamber and around an evaporation source through a cold head wherein the cooling source is an extremely low temperature refrigerator. CONSTITUTION:Ga, Al or As is heated by a molecular beam source 4 in a growing chamber 1 and the molecular beam is taken out to be irradiated on a GaAs substrate 5 for molecular beam epitaxial growth. 7 is an extremely low temperature refrigerator integrally installed on the external wall of a chamber 1a and consists of an extremely low temperature and small refrigerator 7a and a pipe 7b for liquid helium. A cold head 8 provided at the end of the pipe 7b for liquid helium is installed on the chamber 1a through a flange 1b for vacuum. A shroud 9 which thermally separates plural molecular beam sources 4 and a shroud 10 which constitutes a cooling surface provided along the inside of the chamber 1a are cooled by the cooling source of the above-mentioned extremely low temperature refrigerator 7 to a temperature of 20 deg.K and can maintain the back pressure lowly during crystal growth and also greatly reduces the rate of discharging contaminating gas molecules in a vacuum atmosphere in the growing chamber. |
