Development of High Temperature Electron Bombardment Evaporator for Ultra-High Vacuum

Abstract

To improve the techniques of molecular beam epitaxy, the electron bombardment evaporator for high temperature evaporation in ultra-high vacuum is designed, and then its performances, such as power-temperature relationship, stability of beam flux as well as molecular beam distribution, are tested by using Ag source. Through adjusting the electric current of tungsten filament can achieve the remarkable heating power in high-voltage, and the crucible temperature rises with increasing heating power, and it exceeds 1600°C at around 60W. The evaporator can reach thermal equilibrium state in a quite short time and produce a highly stable beam flux of Ag at low deposition rate. A 9mm diameter homogeneous flux platform area is obtained at the position 60mm away from the nozzle, and this area can provide high quality beam flux for molecular beam epitaxy. These results show, the electron bombardment evaporator can meet the demands for ultra-high vacuum molecular beam epitaxy growth completely.