The Boc Group, Inc.

Jersey Nuclear-avco Isotopes, Inc.

P A Smith

Ping Chang

Russell J Hill

Robert H McKoon

In a rotational rod-fed electron-beam evaporation source used with sublimating rod material, the ingot rod can be free-standing with respect to the crucible. This means that the side of the ingot rod near the tip of the rod does not contact a cooling crucible. In this way, the system can be operated in a defocused position of the electron beam, and the sweep of the electron beam can go over the edge of the ingot rod tip. Using these features, a substantially radial sweep of the tip of an ingot rod that sweeps over the edge can produce a substantially flat evaporation pattern on the ingot rod, producing a good utilization of the expensive ingot rod material.

Free-standing rotational rod-fed source

A rod-fed electron beam evaporation system having a rod-fed electron beam evaporation source for evaporating an ingot. The ingot is of rod-like configuration and has a peg-like element to self-engage a socket of a replacement ingot so that both ingot and replacement ingot are brought into alignment.

Rod-fed electron beam evaporation system

The present invention provides an electron beam gun for an electron beam evaporation source in which a beam former shields a filament from an anode such that electrons emitted from the filament are accelerated past the anode in a ribbon-like beam. The filament is connected to a split cathode block having two sides for applying an electric current through the filament. The beam former has two sections which are separately connected to the two sides of the cathode block such that the cathode block acts as a heat sink for the beam former, and a thermal gradient is not produced within the beam former that would produce warpage and movement of the beam former. Preferably, the vertical gap is about 0.254 mm. to prevent electrons emitted from the filament from arcing through the gap to the anode.

Electron beam gun for use in an electron beam evaporation source

The present invention provides an electron beam evaporation source designed so that the size of the impact area of the electron beam on an evaporant will remain essentially constant in any position of the impact area on the evaporant; and thus, the rate of evaporation will remain essentially constant. To this end, a quadrapole comprising a set of two pairs of electromagnets is used to deflect the electron beam. The quadrapoles provide a uniform magnetic deflection field to prevent distortion of the impact area. A pair of pole pieces, used in deflecting the electron beam through an arc of 270 degrees, are provided with a predetermined thickness and spacing to prevent lengthening of the impact area parallel to the pole pieces as the electron beam is deflected parallel to the pole pieces. The pole pieces, however, produce the formation of tail regions in the impact area when the impact area is positioned near the pole pieces. In order to eliminate such tail regions, a pair of surface dipoles are connected to the pole pieces at an angle of 45 degrees such that the electron beam passes between the ends of the dipoles at a near vertical location of the arc of the electron beam. The maintenance of the impact area essentially free of distortion, tail region formation, and lengthening, ensures essential consistency in the size of the impact areas.

Electron beam evaporation source

An electron-beam heated vapor source for operation in vacuum is disclosed. The source comprises a magnet and a pair of parallel pole plates for deflecting the beam from an electron-beam gun through an angle of approximately 270.degree. into a crucible containing material to be vaporized by evaporation, sublimation or other process. A pole rod extends from each of the pole plates into the space between them. A means is provided for precisely adjusting the distance separating the pole rods while the vapor source is in vacuum. This adjustment enables the impact area of the beam, and thus, the deposition rate or other impact area related parameter to be optimized while the vapor source is in operation. Preferably, each pole rod extends through a clearance hole in the pole plate and the adjustment means comprises a rack integral with the rod and a pinion which can be driven by a control means located outside the vacuum chamber.

Vapor source assembly with adjustable magnetic pole pieces

Apparatus and method for supplying feedstock to a reservoir containing material having a portion which is heated to a molten condition and vaporized by an electron beam. The electron beam is supplied from a heated filament and directed to impact on the vapor source material by electric and magnetic fields. The feedstock is suspended above a portion of the reservoir out of the path of the electron beam. Skip electrons along with some secondary electrons emitted from the surface of the material in the vicinity of the region of electron beam impact, together with radiant heating therefrom, are utilized to melt an exposed portion of the feedstock, allowing it to drip into the reservoir, and replenish the supply of material which is depleted by vaporization. Vaporization is maintained substantially uniform from the region of electron beam impact and splatter of the feedstock is largely avoided.

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San Pablo, CA, United States of America

P A Smith