Method for controlling the volume of a molecular beam

A molecular beam source for evaporating a material of a thin-film element and depositing the thin-film element on a film-forming surface, comprising:

• a crucible for containing the material of the thin-film element;
• a heater for heating the crucible containing the material of the thin-film element and generating molecules of the material of the thin-film element;
• a molecule discharge passage for discharging the molecules of the material of the thin-film element generated in the crucible towards the film-forming surface;
• a vacuum container having a hermetically sealed structure for receiving said crucible, said heater and said molecule discharge passage therein;
• a valve for adjusting the volume of a molecular beam discharged from the molecule discharge passage;
• a detection means for detecting the volume of the molecular beam discharged towards said film-forming surface;
• a first controller programmed to adjust the opening of the valve based on feed-back information of the detected volume of the molecules of the thin-film element material;
• an electric power source for supplying electric power to the heater;
• and
• a second controller programmed to adjust the electric power supplied to the heater based on the feedback information of the detected volume of the molecules of the thin-film element material and valve opening information and adjusting the electric power supplied to the heater when a value corresponding to the opening of the valve exceeds a predetermined upper limit or is less than a predetermined lower limit.