EFM 3T Triple Evaporator
The Highest Purity Multi-pocket Electron Beam Evaporator for Thin Film Growth
- Ultra-pure evaporation and very low back-ground pressure
- Three independent sources at once with maximum overlap
- Three flux monitors, three independent z-shifts and integrated multi-position shutter
- Rear-loading of evaporation material as rod or in crucible
- Ease-of-operation with Lab VIEW TM –based Epitass® software
- Crucible temperature display
Based on the design concept of the EFM 3 evaporators, the triple evaporator EFM 3T features three independent cells for the evaporation of a wide range of materials from wires, rods or crucibles.
The three individual cells have crossing beams at about 93 mm distance from the exit aperture (254 mm from the mounting flange) to ensure a maximum overlap of the evaporation area. Each cell is equipped with a separate filament and HV supply to prevent crosstalk. Three independent flux monitors enable the controlled stoichiometric growth of compounds. The integral multi-position shutter enables precise dosing and simultaneous or consecutive evaporation to produce e.g. super lattices or multilayers. The latter is easily accomplished by means of the optional shutter motorisation and the PC software tool Multi Epitass®. The deposition area is governed by the choice of one of three apertures. The three evaporation targets are independently mounted on three 25 mm z-shifts for alignment. This feature allows evaporation from rods with a multi-pocket instrument. The target materials can be easily refilled from the rear (3x DN 16 CF).
One power supply can operate all three cells sequentially. In case of co-evaporation each material requires a separate power supply.
The latest generation of EVC power supplies provides advanced filament control to 1 mA which allows to precisely regulate crucible temperatures down to 100 °C e.g. for evaporation of molecules. Between 100 °C and 800 °C the temperature stability is 0.1 °C or better. The crucible temperature is determined and displayed with high precision based on a proprietary algorithm using power, filament current, crucible size and position as input.
Today more than 2000 instruments are used in virtually every surface science research lab making sure that there is a set of parameters/recipes available for basically every evaporation request and compatible equipment is always at hand.
Flat Top Diameter
EFM 3: Flat top diameter 10 mm, (Nozzle - sample distance 90 mm, Mo-crucible 8 mm diameter) EFM 4: Flat top diameter 36 mm, (Nozzle - sample distance 90 mm, Mo-crucible 8 mm diameter)
Stable conditions: The EVC 300 flux monitoring system provides precise control of the evaporant flux. The regulation parameters can be adjusted to ensure excellent response even with rapid changes of the flux setting as demonstrated here.
Deposition area as a function of distance for three different standard aperture sizes for EFM 3, EFM 4 and EFM 3T.
Typical crucible temperatures (averaged) as measured for various high voltages. W-crucibles of given type were used.
(A) 3D view of the Al13Co4(100) surface dosed with 2.6 ML of Bi (300 × 300 nm2). (B) Height histogram of the Bi film showing the three specific island heights.
STM image of CuPc molecules (Copperphthalocyanine) on NaCl/Cu (100) @ 5 K. Data acquired by the group of Prof. I. Swart, Debye Institute for Nanomaterials Science, Utrecht University, the Netherlands
Sub-monolayer of CaF2 on Si(111) Imaged with STM
P. Rahe, P. Moriarty (University of Nottingham)
EVC Power Supply
The microprocessor controlled EVC power supplies in combination with the Epitass® software make the operation of all EFM-type UHV evaporators very convenient and safe. With up to 300 W power and up to 2 kV output they are sufficient for the evaporation of any desired material.
The EVC power supply provides a regulated fi lament emission current down to 1 mA in order to precisely regulate crucible temperatures down to 100°C e.g. for molecules (see front page). Between 100°C and 800°C the temperature stability is 0.1°C or better.
As a unique feature Epitass® software has a temperature display providing the actual crucible temperature.
The EVC 100 and 300-2 power supplies come with full flux regulator in addition to the emission current regulator which can be programmed for constant flux or integral flux values.
All parameters of the EVC power supplies including those for the optional motorised shutter can be set manually on the front panel or via the Lab VIEW™-based Epitass® software.
For Multilayer growth or co-evaporation from different cells several EVC power supplies need to be controlled. This functionality is provided by the MultiEpitass® software which can control up to four different cells mastering the individual Epitass® software of each EVC power supply. The MultiEpitass® is an option or part of an EFM 3T-EVC 300-2 package. All evaporators can be equipped with a motorised shutter which is either mounted at the factory or can easily be refitted by the customer.
EVC 300-2 Power Supply
The option Ion suppression adds an electrode to the EFM 3T: EFM 3Ts ,where s stands for suppression. A part of the evaporant beam in all products of the EFM-series is ionised by the electron bombardment during heating. Most of these ions are captured by the flux monitor electrode. As the evaporant is on high voltage with respect to the grounded sample the remaining ions may create defects in the substrate surface and deposit energy. To generate a 100 % neutral beam an additional voltage is applied at the suppressor electrode of the EFM 3Ts. The additional voltage is supplied by the power supply EVC 300s-2 or EVC 100s. Upgrade packages for existing EFM 3 are available on request. All other features of the EFM 3T are fully preserved.
Technical Drawing of the EFM 3Ts
The EFM e-beam evaporators originally have been designed for ultra-pure evaporation of magnetic materials such as Fe, Co, Cr, Mn and Ni as sub-monolayer and multilayer thin films. Materials like Pt, Ag, Au, Al, Ti, Ta, W and semiconductors, e.g. silicon, can be evaporated with the highest purity. Recent innovations allow using the EFM 3T for a broader range of materials than ever before. The 2 kV – now standard - for example ensures high growth rates even for materials like C, W, Ti, Ta and other elements relevant to grow 2 D materials. In order to handle larger rods an optional 50 mm z-shift is available.
Other materials are:
- Organics (down to individual molecules)
- Insulators such as CaF2
100°C - 3300°C
Rods and crucibles
Ø 8.5, 11 and 15 mm
By z-shift for each material
Integral part of base package
Up to 250°C
DN 40 CF
Co-deposition package with shutter motor and multi-pocket control
For full specifications and more information about product options, please do not hesitate to contact your local sales representative.