Sputter coater – high vacuum
Q150T series from Quorum Technologies
Sputter coaters of the Q150T series are fully automated, modular coating systems for the application of fine-grained carbon films for SEM, TEM and thin-film technology. The instrument is available in four models. Together with a variety of options, the Q150T base unit can be used as sputter coater, carbon coater or for glow discharge.
|Fully automatic coating process|
|Built-in turbo pump|
|Large chamber: 165 mm diameter|
|Suitable for noble and other metals|
|Combination of sputter coater and evaporator: Model Q150T ES|
|Combination of sputter coater and evaporator for glove box mounting: Model Q150GB|
Using the basic unit and its various options, the Q150T can be used as sputter coater, carbon coater or for glow discharge. The different head plates can easily be exchanged within seconds. The unit recognizes the replacement and the operating menu changes accordingly. A touch screen is used to enter coating parameters, display the coating sequence and show error messages. Multiple users can store their recipes including all parameters. Awarded access rights protect selected parameters against deletion and unauthorized modification. Only the administrator has access to all settings.
A number of optional sample stages ensure the efficient and repeatable coating of samples within a wide range of geometries.
Fully automatic control of the vacuum pressure for the sputtering process eliminates the need to adjust the amount of argon gas by needle valve. Depending on the preset amount of gas (vacuum) the sputter current is automatically adjusted to the desired value (mA). This enables diffuse sputtering with low sputter current for samples with a high topography.
Working principle of magnetron sputter coaters
Magnetron sputter coaters (also referred to as "Cool Sputter Coaters") are equipped with a special magnet which is located in the sputter head (cathode) in the vicinity of the target.
The benefits are:
- Electrons are available for ionization of further process gas ions and
- excessive heating is avoided.
During sputter coating, a vacuum is produced in a vacuum chamber and a process gas, preferably argon, is continuously leaked into the chamber. Argon has an optimal ion size and does not chemically react with other molecules.
Within a vacuum window from approx. 1 x 10-1 mbar to 5 x 10-3 mbar, process gas atoms are ionized in an electrical field, which creates a plasma. Positively charged argon atoms are accelerated towards the magnetron head with the target (cathode) and erode target atoms, which reach all surfaces within the vacuum chamber, including the sample to be coated.
|Specifications Q150 TS / TE / TES|
|Instrument case||585 mm W x 470 mm D x 410 mm H (total height with coating head open: 650 mm)|
|Packed dimensions||725 mm W x 660 mm D x 680 mm H (42 kg)|
|Work chamber||Borosilicate glass 150 mm ID x 127 mm H|
|Safety shield||Integral polyethylene terephthalate (PET) cylinder|
|Display||145 mm x 320 mm x 240 mm colour graphic thin film transistor (TFT) display|
|User interface||Intuitive full graphical interface with touch screen buttons, includes features such as a log of the last 10 coatings carried out and reminders for when maintenance is due|
|Sputter target||Disc style 54 mm Ø or 57 mm Ø. A 0.3 mm thick chromium (Cr) is fitted as standard. TS/TES versions only|
|Turbo-molecular pump||Internally-mounted, 70 l/sec. air-cooled turbo-molecular pump|
|Rotary pump||50 l/min. two-stage rotary pump with oil mist filter (order separately, see AG-DS102)|
|Vacuum measurement||Pirani gauge as standard. A full range gauge (10428) is available as an option|
|Typical ultimate vacuum||5x10-5 mbar|
|Sputter vacuum range||Between 5x10-3 and 5x10-1 mbar|
|Specimen stage||50 mm Ø rotation stage. Rotation speed 8-20 RPM. For alternative stages see options and Aaccessories|
|Sputtering||0–150 mA to a pre-determined thickness (with optional FTM) or by the built-in timer. The maximium sputtering time is 60 minutes (without ‘breaking’ vacuum and with built in rest periods)|
|Carbon evaporation||A robust, ripple free DC power supply featuring pulse evaporation or ensures reproducible carbon evaporation from rod or fibre sources. Current pulse: 1–90 A|
|Metal evaporation and|
aperture cleaning insert
|For thermal evaporation of metals from filaments or boats. For cleaning SEM or TEM apertures a standard molybdenum boat (supplied) can be fitted. The metal evaporation head is set up for downwards evaporation, but upward evaporation can be achieved by fitting two terminal extensions (supplied). Evaporation times: up to four minutes|
|Services and other information|
|Gases||Argon sputtering process gas, 99.999% (TS and TES versions)|
|Electrical supply||90–250 V 50/60 Hz 1400 VA including rotary pump power. 110/240 V voltage selectable|
|Conformity||CE conformity: Power factor correction. Complies with the current legislation (CE Certification) and ensures efficient use of power, which means reduced running costs|
|Options and accessories|
|10879||Carbon rod evaporation insert for 3.05 mm Ø rods (T E and T ES only). Includes manual rod shaper and 3.05mm Ø x 300 mm (pack of ten) carbon rods|
|10837||Glow discharge insert. Used to modify surface properties (eg hydrophobic to hydrophilic conversion) (R S and R ES versions only). Can be retrofitted|
|10457||Metal evaporation and aperture insert, including the ability to evaporate upwards or downwards (TE and TES version only). Supplied with a pack of 10 tungsten filaments and a molybdenum (Mo) boat|
|10455||Carbon fibre insert, supplied with 1m carbon fibre cord and 1m of standard grade carbon fibre cord. NB: For additional supplies see Carbon supplies|
|10453||Additional sputter insert for quick metal change (T E and T ES versions only). NB: This is an entire sputtering assembly; individual targets can also be purchased|
|10360||Variable angle 'Rotacota' rotary planetary specimen stage (rotational speed 8–20 RPM). 50 mm Ø specimen platform with six stub positions for 15 mm, 10 mm, 6.5 mm or 1/8" pin stubs. Stage rotation speed variable between 8–20 RPM|
|10357||Variable tilt angle specimen stage with adjustable tilt up to 90˚. 50 mm Ø specimen platform with six stub positions for 15 mm, 10 mm, 6.5 mm or 1/8" pin stubs. Stage rotation speed variable between 8–20 RPM|
|10458||Flat rotation specimen stage for 4"/100 mm wafers, includes gear box for increased coverage. Stage rotation speed variable between 8-20 RPM|
|10357||90 mm Ø specimen stage for glass microscope slides (up to two x 75 mm x 25 mm slides). Stage rotation speed variable between 8–20 RPM. Includes gear box to allow optional FTM to be used|
|10454||Film thickness monitor (FTM) attachment. Including oscillator, feed-through, quartz crystal holder and quartz crystals|
|10429||Extended height vacuum chamber (214 mm in height - the standard chamber is 127 mm high). For increased source to specimen distance and for coating large specimens|
|10422||Vacuum spigot allows more convenient connection of the vacuum hose to the rear of the Q150T when bench depth is limited|
Conductive layer deposition
Sputter coaters are used to deposit a thin metal layer on the surface of a substrate. Sputtering is used in electron microscopy to deposit an electrically conductive film on non-conductive surfaces, to prevent electrons from the microscope's electron beam from accumulating on the sample surface, causing the latter to become charged. Such a charge would prevent imaging of these surfaces with the SEM. The desired films should be extremely thin, but electrically conductive, with a thickness of 3 - 20 nm.
High-vacuum sputter coaters
Chromium or high-vacuum sputter coaters have become more and more widespread over the past few years.<br/>Their advantages are a virtually "clean" vacuum, owing to the use of a turbomolecular pump, and a powerful magnetron head for removing the oxide layer on the target material. The maximum sputter current is 150 mA and enables highly efficient removal of oxide layers by sputtering. This allows sputtering of materials where this was previously not possible with rotary pumped sputters coaters.