Vapor source assembly with adjustable magnetic pole pieces

A vapor source assembly for operation in vacuum, comprising:

• an electron-beam gun,
• a crucible for supporting material to be vaporized,
• a magnet,
• a pair of parallel magnetic pole plates in contact with the magnet and alligned so that the beam from the electron-beam gun is deflected through an angle in the range from 240.degree. to 300.degree. onto the crucible,
• a pole rod extending from each of the pole plates, extending into the space between them and positioned so as to be capable of altering the cross-sectional area of the beam as it impacts on the material supported by the crucible,
• a rod adjustment means for precisely adjusting the distance separating the pole rods while the vapor source is in vacuum, and
• means for measuring the deposition rate and for adjusting the separation of the pole rods in response.

A vapor source assembly for operation in vacuum, comprising:

• an electron-beam gun,
• a crucible for supporting material to be vaporized,
• a magnet,
• a pair of parallel magnetic pole plates in contact with the magnet and alligned so that the beam from the electron-beam gun is deflected through an angle in the range from 240.degree. to 300.degree. onto the crucible,
• a pole rod extending from each of the pole plates, extending into the space between them and positioned so as to be capable of altering the cross-sectional area of the beam as it impacts on the material supported by the crucible,
• a rod adjustment means for preceisely adjusting the distance separating the pole rods while the vapor source is in vacuum, and
• means for determining a parameter upon which the optimum cross-sectional area of the beam depends and for adjusting the separation of the pole rods in response.