MECHANISM FOR CONTROLLING THE THICKNESS OF A COATING IN A VAPOR DEPOSITION APPARATUS

摘要

Apparatus for accurately determining and continuously measuring the thickness of a coating deposited on a substrate in a vacuum deposition chamber and for terminating the coating operation after the desired thickness is obtained, the apparatus utilizing a mechanical counter for determining the length of ingot fed to the crucible in combination with a precision laser device for maintaining a constant pool level in the crucible since the length of ingot fed is a direct indication of the thickness of the coating deposited.