| abstract |
The invention relates to an apparatus for coating a substrate having an evaporator source and a vapor barrier between the evaporator source and the substrate. The vapor barrier is maintained at a temperature which is at least equal to or above the vaporization temperature of the material to be vaporized. The vapor barrier is designed as a quartz valve, which contains a spherical closure part, which is connected to a movable rod. In a first position, this spherical closure member seals a steam guide tube communicating with the evaporator source, and in a second position, the spherical closure member abuts a dome sealing off a quartz tube. |