Introduction
The Thermionics Laboratory e-GunTM, an electron beam evaporation source, is used to produce uniform high-purity films and optical coatings. The compact design and ease of maintenance make it useful in practically all vacuum systems and for many varied applications. It has been used to evaporate refractory and dielectric materials, as well as the more common conductive and semi-conductor materials. E-GunTM evaporation sources are reliable and simple to operate. They are equally suited for research or production applications.
Theory of Operation
Electron beam heating is an efficient way of achieving temperatures in excess of 3500°C (6300°F) for uniform thin film, optical coating and vacuum metallurgic processes The all metal sealed models are bakeable to 230°C (446°F). The e-GunTM source and companion control power supply has been designed to be part of any high or ultra-high vacuum system.
The e-GunTM source is a self-accelerated electron beam device. A beam of electrons, held at a high negative potential, is produced by the hot tungsten filament. The beam of electrons leaving the filament is magnetically focused and then deflected 270° by the integral permanent magnet. The electron beam is accelerated into the evaporant material contained within the water-cooled, grounded crucible. The beam strikes the evaporant material with a spot of approximately 1/8″ diameter and an intensity of approximately 25 kW/cm2. Sweeping the electron beam across the evaporant material contained in the crucible is performed by an electro-magnetic system, with either manual or automatic controls. Larger Thermionics e-GunTM‘s offers the sweep capability as a standard feature, 3 kW model sweep capability is available as an option.
The focused electron beam can produce temperatures over 3500°C in source materials, so virtually any material may be evaporated.
The rate at which source materials may be evaporated is dependent upon power input, charge size, charge shape, and the characteristics of the material to be evaporated. The highest evaporation rates are obtained with materials that have low evaporation temperatures and low ll1ermal conductivity.
The evaporant vapor cannot become contaminated because the focused electron beam strikes only the evaporant source material in the crucible. The beam deflection and effective shielding keeps the filament hidden from the evaporant vapor. The crucible is cooled so efficiently that its surface never gets warm enough to unite with the evaporant material.
The e-GunTM source will operate in a system base pressure as low as 5 x 1011 Torr. The magnitude of pressure, which normally increases during evaporation, depends on the pumping capacity of the system and the cleanliness of the evaporant material. This pressure increase is minimized by the high thermal efficiency of the source. There is minimal outgassing of surrounding surfaces because only the evaporant is heated.
All of Thermionics’ single , linear motion three and five position e-GunTM’s are 100% metal sealed. Thus eliminating “O” ring outgassing. Outgassing could require additional pumping capacity and sometimes result in sample contamination.
Mounting Configurations
Each gun is available in three standard mounting configurations:
- e-GunTM mounted on a PyraFlat or ConFlat metal seal type flange. which uses a standard OFE copper gasket
- e-GunTM with a 1” diameter bolt-type mount, which mounts through a 1” diameter hole, and is sealed by a compression O-ring
- e-GunTM alone with no mounting flange
Ordering Information
Please specify the mounting configuration at the time the order is placed. The prices listed may not include the bolt-type or flange-type mount.
Other mounting flanges, configuration and geometries are routinely supplied.
Custom e-GunsTM
Any e-GunTM can be designed and manufactured to fit existing or new systems.
Unique Electron Beam Heated Evaporation Sources
By means of a unique modular magnetic configuration, the Hanks HM2 e-Gun offers a more efficient electron beam heated source. It is 2/3 the size of traditional evaporation sources, yet provides the same crucible volume, evaporation rate, and power capability of physically larger guns.
The Hanks HM2 e-Gun is approximately 350% more efficient magnetically, which is reflected in its reduced physical size. It is also markedly different from other e-Guns because of the unique method used to generate the magnetic field e-Gun manufacturers that use a transverse field for beam focusing place the permanent magnet horizontally at the rear of the source and conduct the magnetic field lines through steel pole pieces. The use of th·1s system results in an inherently high magnetic leakage flux and thus, larger magnets must be used
In the Hanks HM2 e-Gun, the magnetic field generator is rotated 90˚ from a horizontal to a vertical position. It is made of two sets of number of small individual magnets arranged vertically along the two sides of the crucible and the beam path. This allows placement of the top ends of the magnets at a position slightly above the crucible top, which is the optimum position from which to deliver the flux to the desired magnetic field area This very short length path reduces leakage flux. Leakage flux is further reduced using a steel plate which connects the bottom end of the magnets to form a unitized magnetic structure. The desired changes and shaping of the magnetic gradient along the beam path are accomplished by shaping and positioning the individual magnets along the two sides of the beam path. The magnets can be either permanent magnets, electromagnets, or both, depending upon the application.
New Features and Benefits
■ Elimination of beam curl – Electrons impact the melt at a 90˚ angle providing maximum energy transfer with a minimum of energy-wasting secondary electrons. This is the result of a carefully graduated magnetic field which is stronger at the top of the crucible than at the bottom.
■ Elimination of pole pieces – Vertically mounted magnets result in less magnetic flux leakage. This improves electron capture, and it improves efficiency. Thus, the more compact a magnetic circuit is, the smaller its source footprint.
■ Easy filament alignment- Filaments are quickly, easily, and very accurately aligned by simply removing the emitter assembly from the vacuum system. An alignment tool is included with each gun.
■ More efficient electron collimation – Our new design produces a better collimated beam with fewer stray electrons.
■ Minimal filament distortion – By clamping the filament adjacent to the spiral. filament movement is held to a minimum.
■ Electron tails – Special filament shielding prevents low energy electrons from leaving the filament environment. eliminating electron tails.
■ Larger crucible size – 40cc crucible volume in a footprint 2/3 the size of traditional evaporation sources.
Hanks HM2 Hydra-2
A Breakthrough in Co-Evaporation Technology
The Hydra evaporation system is specifically designed to meet the current technological challenges posed by complex co-deposition processes and “leading-edge” materials research. The Hydra design consists of a compact array of crucibles and electron emitters which translate linearly with respect to each other to provide for the co-deposition of up to six different materials simultaneously. By the efficient utilization of space, four different combinations of six crucibles or up to forty-two permutations of two-material combinations are available for co-deposition in a single vacuum pumpdown.
Innovative technology and a creative approach to magnetic field concepts has been fostered by Thermionics to result in several new, unique electron emission configurations. The Hydra configuration eliminates adjacent source interactions without complex beam directions and bulky field shunting components. Thus. the design allows close source proximity for uniform coating and material interaction. Each source crucible is independently water cooled to prevent steam buildup. Each source crucible has separate sweep coils, ensuring the independent operational integrity of each source, and eliminating cross talk interference from any adjacent source.
UHV Compatible
Metal-sealed, fully UHV compatible, measured base pressure: 2 x 10-11 Torr.
Prices
Prices are dependent upon many factors, i.e.: system, mounting flange, and e-Gun configurations, geometries, etc. Our engineering group will work closely with you to determine your requirements, then a firm quotation can be given.
Specifications
| Power Output | 10 kW | 15 kW |
| 10 kV | 10 kV | |
| 0 to 1.0 A | 0 to 1.5 A | |
| Crucible Volume | 10/15 cc | 40 cc |
| Dimensions | 10/15 cc | 40 cc |
| 6.25” h | 6.25” h | |
| 11.0” w | 11.5” w | |
| 15” l | 15” l | |
| Filament | 12 VAC 60A | |
| Electron Beam | 270˚ deflection | |
| Evaporation Rates | 1 gm/min at 10 kW | 1.5 gm/min at 15 kW |
| 3.6 microns at 25 cm | 50,000 Å min | |
| Beam Spot Size | .25” circular (approximate) (beam can be adjusted and located electrically with beam sweep controller) | |
| Crucible | OFE copper | |
| Bakeout Temperature | 230˚C (446˚F) | |
| Water | 30 gpm (filtered) at 70 psi (each crucible has its own water supply, common return) – (3 gpm/crucible) | |
| Pressure Differential | 50 psi minimum | |
| X and Y Sweep | Hyper-Unimelt sweep (0 to above 200 Hz) | |
The Hanks HM2 Single Crucible, Single Emitter e-Gun
The Hanks HM2 e-Gun: 6, 10, 15, 20 kW
Crucible Volumes: 7, 10, 15, 40, 75,100, and 156 cc
Single Crucible Models – Single Emitter
Model Number |
Power |
Crucible Volume |
| 0607 | 6kW | 7cc |
| 0610 | 6kW | 10cc |
| 1010 | 10kW | 10cc |
| 1015 | 10kW | 15cc |
| 1540 | 15kW | 40cc |
| 1575 | 15kW | 75cc |
| 15100 | 15kW | 100cc |
| 15156 | 15kW | 156cc |
| 20156 | 20kW | 156cc |
Twin – Two Single Crucible e-Guns
Model Number |
Power |
Crucible Volume |
| D1010 | 10kW | 10cc |
| D1015 | 10kW | 15cc |
| D1540 | 15kW | 40cc |
UHV Compatible
Metal-sealed, fully UHV compatible, measured base pressure: 2 x 10-11 Torr
Specifications
| Power Output | 6 kW | 10 kW | 15 kW | 20 kW |
| 735 kV | 10 kV | 10 kV | 10 kV | |
| 0 to 800 mA | 0 to 1.0 A | 0 to 1.5 A | 0 to 2.0 A | |
| Crucible Volume | 7/10 cc | 10/15/40 cc | 40/75/100/156 cc | 156 cc |
| Dimensions | 2.50” h | 2.50” h | 2.50” h | 3.00” h |
| 3.25” w | 3.25” w | 3.50” w | 5.00” w | |
| 4.50” l | 4.50” l | 5.00” l | 6.00” l | |
| 15” l | 15” l | |||
| Weight | 5 lbs | 5 lbs | 7 lbs | 11 lbs |
| Filament | 12 VAC 60A | |||
| Electron Beam | 270˚ deflection | |||
| Evaporation Rates (for aluminum)
|
1 gm/min at 10 kW
3.6 microns at 25 cm |
1.5 gm/min at 15 kW
50,000 Å min |
||
| Beam Spot Size | .25” circular (approximate) (beam can be adjusted and located electrically with beam sweep controller) | |||
| Crucible | OFE copper | |||
| Bakeout Temperature | 230˚C (446˚F) | |||
| Water | 3.0 gpm (filtered) at 70 psi | |||
| Minimum water tube size | 3/8” dia (6/10/15 kW) | ½” dia (20 kW) | ||
| Pressure Differential | 50 psi minimum | |||
| X and Y Sweep | Hyper-Unimelt sweep (0 to above 200 Hz) | |||
Hanks HM2 Rotary Pocket e-Gun
Rotary, Multiple Crucible e-Guns
| Model Number | Power | Crucible No. | Crucible Volume |
| R0607-4 | 6 kW | 4 | 7cc |
| R0610-4 | 6 kW | 4 | 10cc |
| R0615-4 | 6 kW | 4 | 15cc |
| R1010-4 | 10 kW | 4 | 10cc |
| R1015-4 | 10 kW | 4 | 15cc |
| R1025-4 | 10 kW | 4 | 25cc |
Modular Magnets
The unique modular magnet concept is incorporated in the rotary pocket Hanks HM2 e-Gun design. This concept makes possible a very compact unit (see outline drawing). All of the Hanks HM2 unique features are incorporated in this model.
Hyper-Unimelt Sweep (Optimum Control on Low or High Rates)
High frequency sweep (0-200 Hz) provides the user with total flexibility in the operation of thee-Gun. By a twist of the knobs on the X-Y sweep controller, the beam can be varied in size to suit the material being evaporated. This is very beneficial for optical coatings and other materials, where beam size plays an important role in optimum control from 1-2 Å to very high deposition rates.
| Power Output | 6 kW | 10 kW |
| 7.5 kV | 10 kV | |
| 0 to 800 mA | 0 to 1.0 A | |
| Crucible Volume | 7/10/15 cc | 7/10/15/25 cc |
| Filament | 12 VAC 60A | |
| Electron Beam | 270˚ deflection | |
| Evaporation Rates | 1 gm/min at 10 kW
3.6 microns at 25 cm |
|
| Beam Spot Size | .25” circular (approximate) (beam can be adjusted and located electrically with beam sweep controller) | |
| Crucible | OFE copper | |
| Bakeout Temperature | 120˚C (250˚F) | |
| Water | 3.0 gpm (filtered) at 70 psi | |
| Minimum water tube size | 3/8” dia (6/10 kW) | |
| Pressure Differential | 50 psi minimum | |
| X and Y Sweep | Hyper-Unimelt sweep (0 to above 200 Hz) | |
