MultiCentre Sample Handling Systems Complete engineered solution for scientific and analytical application s High stability/precision stages Up to +/-31 mm XY motion 25 mm-1000 mm Z motion Tilt and azimuthal sample rotation 33mm Ø sample puck or stub system Failsafe hand-off to Power Probe transfer systems Heating, e-beam Heating, Cooling to LN2 and biasing options The MultiCentre provides a complete solution for sample transfer and manipulation. Typical applications include analytical instrumentation for surface analysis equipment and synchrotron end stations. MultiCentres are modular by design (as shown to the right), utilising the MultiStage range to provide X, Y and Z translations. The unique Rotatable Axis X/Y stages can also be incorporated to provide a truly eucentric stage (see page 121 for a detailed explanation). UHV Design s MagiDrive rotary feedthroughs are also utilised to provide the basic rotations. The MultiCentre range provides sample transfer pucks and sophisticated manipulator end stations / receptors with optional heating and cooling, to provide the complete sample handling solution. The MultiCentre range includes two discrete sample mounting and transfer systems. The first is based upon a large 33 mm diameter puck, whereas the second employs a sample stub (compatible with those used in the past by VG Scientific s surface analysis instrument - the ESCALAB), and wobble stick transfer fork. The general capabilities of each range are summarised below, with a more detailed section for each on the following pages. Summary table Puck system Stub system X-Y travel Z travel Polar rotation Up to +/- 29 mm 25, 50, 100, 150, 200, 300, 500, and 1000 mm +/- 200 o Azimuthal rotation Continuous or +/- 100 o with cooling N/A Maximum sample size 33 mm diameter 14 mm diameter Heating > 1000 o C > 800 o C e-beam heating > 1200 o C N/A Cooling < -150 o C < -130 o C Sample current measurement Isolation > +/- 500 V Resistance > 500 M Ohm. 116
MULTICENTRE Stacked MagiDrive rotary feedthroughs to provide polar and azimuthal rotation Heater, cooling, power and bias service collar Linear shift mechanism for Z translation MultiBase X Y stage MultiBase micrometer actuator System mounting flange Heater and sample bias wiring Heated sample holder with polar and azimuthal rotation (LN2 cooling not pictured). Tel:+44(0)1323 811188 sales@uhvdesign.com www.uhvdesign.com 117
Puck handling system To provide flexibility the sample transfer puck is larger than most competing products, at 33 mm diameter, such that a multitude of small samples can be mounted simultaneously, or a single larger sample can be mounted. A range of puck materials can be provided: 316 stainless steel is used for the basic unit Molybdenum pucks are provided when heating and heating / cooling options are selected For the best in cooling with limited heating, copper pucks can be supplied End receptors Receptors come in two basic configurations. One, providing sample tilt only (i.e. rotation about an axis lying in the plane of the sample), and one providing both tilt and azimuthal rotation (about the sample surface normal). Both receptors accept the same sample puck which is latched in place through a positive bayonet actuation. The sample is electrically isolated to 500 V to provide for sample current measurement and biasing. Cooling The Receptors can be provided with an LN2 cooling system, which employs an ingenious LN2 tank design where the LN2 is in direct thermal contact with the receptor and provides the electrical isolation. There is no need for separate electrical insulation which then also acts as a good thermal insulator. In this way even the relatively large Puck can still be cooled to LN2 temperatures quickly. K-type thermocouples are normally supplied unless there is a need for very low residual magnetic fields, in which case N type are preferred. PBN heater A 200 W PBN coated graphite disc heater is installed immediately beneath the sample puck which can rapidly heat the sample to 1000 o C. A thermocouple is located inside the Puck receptor in close proximity to the Puck to measure temperature. e-beam heating For even higher temperature flash heating of the Puck, an electrically floating filament is located immediately beneath the Puck, which when heated emits electrons that are accelerated onto the back side of the Puck. This can heat the Puck up to 1200 o C. Sample transfer Sample transfer from an entry lock for example is accomplished using a PowerProbe magnetic transfer arm (see section 4) with a puck transfer fork mounted on the end. 118
Puck handling system: General Specifications MultiCentre model MC-P14 MC-P31 XY travel +/-7 mm (+/- 9.9 mm vector) +/-20.5 mm (+/- 29 mm vector) Mounting flange options XY resolution XY Actuation Z travel Z Actuation 114 mm (4.5 ) OD CF64 with M8 straddled holes 152 mm (6 ) OD CF100 with M8 straddled holes Manual drive +/- 0.01 mm, Stepping +/- 0.0005 mm Manual via combined micrometer handwheel and linear scale. Motorised units are stepper motor driven. Z-shifts are available with following strokes as standard 25, 50, 100, 200, 400, 600, and 1000 mm. Manual handwheel actuation. Motorisation via side-mounted DC or stepper motors. 203 mm (8 ) OD CF150 with M8 straddled holes Z resolution Manual drive +/- 0.25 mm with engraved shaft, Digital linear scale +/- 0.005 mm, Stepping motor +/- 0.0005 mm. Polar rotation and resolution Maximum rotation = +/- 200 o Resolution < 1.0 o when driven from the same direction Manual and stepper motor driven actuation. Azimuthal rotation and resolution Continuous without cooling Maximum rotation = +/- 100 o with cooling Resolution< 0.5 o when driven from the same direction. Heating PBN: E-Beam: Maximum temperature measured using in-situ thermocouple at the sample puck > 1000 o C Maximum temperature measured using in-situ thermocouple at the sample puck > 1200 o C Cooling Ultimate low temperature measured using in-situ thermocouple at the sample puck < -150 o C Cool down time to ultimate < 30 min Electrical isolation Sample transfer puck :- Electrical isolation > +/- 500 V Electrical leakage resistance > 500 MOhm. Sample transfer Via UHV Design s Power Probe transfer arms Tel:+44(0)1323 811188 sales@uhvdesign.com www.uhvdesign.com 119
Stub handling system The sample transfer stub is compatible with the well known ESCALAB stub system: 316 stainless steel is used for the basic unit Molybdenum stubs are provided when heating and heating / cooling options are selected For the best in cooling with limited heating copper stubs can be supplied Standard stub sizes of 10 mm and 14 mm diameter End receptors Provide electrical isolation to 500 V for sample current measurement and biasing. Cooling The receptor can be provided with an LN2 cooling system, which employs an ingenious Cold Lance design, where the LN2 is transmitted through a co-axial tube which is docked into the receptor using an additional sprung-loaded z-shift. This has the advantage of being able to provide continuous polar rotation, when disconnected and obviates the need for coiled cooling pipes. When disengaged, heat loss to the cooling circuit is eliminated improving heating performance. K-type thermocouples are normally supplied unless there is a need for very low residual magnetic fields, in which case N-type are preferred. Heater For heating, a tantalum wire heater is installed in the end receptor which can heat the sample to 800 o C. Sample transfer from an entry lock for example, is accomplished using a our PowerProbe magnetic transfer arms (see section 4) in conjunction with our bellows sealed wobble stick. MultiCentre model MC-S14 MC-S31 XY travel +/-7 mm (+/- 9.9 mm vector) +/-20.5 mm (+/- 29 mm vector) Mounting flange options XY resolution 114 mm (4.5 ) OD CF64 with M8 straddled holes 152 mm (6 ) OD CF100 with M8 straddled holes Manual drive +/- 0.01 mm, Stepping +/- 0.0005 mm 203 mm (8 ) OD CF150 with M8 straddled holes XY Actuation Manual via combined micrometer handwheel and linear scale. Motorised units are stepper motor driven. Z travel Z-shifts are available with following strokes as standard 25, 50, 100, 200, 400, 600 and 1000 mm. Actuation Manual handwheel actuation. Motorisation via side-mounted DC or stepper motors. Z Resolution Manual drive +/- 0.25 mm with engraved shaft, with digital linear scale 0.01 mm, Stepping motor +/- 0.0005 mm Polar rotation and resolution Rotation = continuous Resolution < 1.0 o when driven from the same direction Heating Cooling Electrical isolation Sample Transfer Tantalum wire heater around the stub holder Maximum temperature measured using in-situ thermocouple at the sample stub > 800 o C Ultimate low temperature measured using in-situ thermocouple at the sample stub < -130 o C Cool down time to ultimate < 45 min Electrical isolation > +/- 500 V Electrical leakage resistance > 500 MOhm. Via UHV Design s Power Probe transfer arms 120
Eucentricity The Puck and Stub MultiCentre manipulators can be fitted with the unique Rotatable Axis MultiBase XY stage (RAMB). Using the RAMB as a platform, it is possible for the first time to configure a UHV modular MultiCentre as a truly eucentric stage. Eucentric stages are used almost exclusively for applications requiring the ultimate in alignment and analytical precision. All electron microscopes both SEMs (Secondary Electron Microscope) and TEMs (Transmission Electron Microscope) are equipped with eucentric stages for example, although these are more often than not simply O ring sealed. Eucentric stages have the lateral translations inside the tilt motion and differ quite fundamentally from a more standard configuration where the tilt is inside the translations. This is represented pictorially below. It can be seen that using a eucentric stage, once the sample is brought into focus it can be translated at will and remain in focus this is quite different to the standard configuration where tilting the sample results in a loss of focus plus an unwanted lateral translation. Tel:+44(0)1323 811188 sales@uhvdesign.com www.uhvdesign.com 121
MultiCentre Customer Questionnaire To request a quotation please fax a completed questionnaire to UHV Design on +44 (0)1323 811999. Alternatively complete our online form at http://www.uhvdesign.com/multicentre_form.htm Customer name: Company name and address: What is your application? What size are your samples? What is the size and type of your system mounting flange? What is the systems operating pressure? What is the systems ultimate pressure? Telephone Number: Fax Number: Email address: Are gases involved with your process? If so please state partial pressures of each and at what sample temperatures they will be present. Are any of the following incompatible with your process (i.e will they react):- Tantalum Molybdenum Stainless steel What Type of Thermocouple do you require? Type K Thermocouple Type N Thermocouple Other Do you wish to heat the samples? If so to what temperature? How long will the sample be heated for during a cycle? Do you wish to cool the samples? If so to what temperature? What is the maximum X motion you require (mm)? What is the maximum Y motion you require (mm)? What is the maximum Z motion you require (mm)? Do you require rotation? Azimuthal Primary Do you need to bias or electrically isolate your sample? If so to what level? Do you require rotation of the axes about the manipulator axis (R.A.M.B option)? Please indicate the actuation method for each axis of manipulation: X Motion Manual Stepper Motor DC Motor Y Motion Manual Stepper Motor DC Motor Z Motion Manual Stepper Motor DC Motor Azimuthal Manual Stepper Motor DC Motor Primary Manual Stepper Motor DC Motor R.A.M.B Manual Stepper Motor DC Motor Do you need temperature controllers and/or power supplies? Additional comments or requirements: 122
Liquid Helium Cooling A range of helium cryostats can be installed on the UHV Design XYZ MultiStage manipulators most notably those from Advanced Research Systems and Janis, although others could be considered on request. Liquid Helium Cryostats ST-400 Helitran Displex The ST-400 continuous flow crysostat from Janis provides a cost effective solution for less demanding applications. The Helitran LT-3M continuous flow cryostat from ARS offers certain unique performance advantages for demanding applications. Where continuous flow cryostats cannot be used for reasons of safety or simply cost of He consumption, we also offer a closed cycle cryostat from ARS the Displex CS202B. This unit also has two alternative heads/ expanders the DE-202AB and 202NB offering different levels of performance. Page 124 Page 125 Page 126 Tel:+44(0)1323 811188 sales@uhvdesign.com www.uhvdesign.com 123
Continuous Flow Cryostat Continuous Flow Cryostat Introduction The ST-400 is a true UHV continuous flow cryostat from Janis Research Company Inc. It is fully compatible with UHV Design s XY31- series of XYZ MultiStage manipulators (see pages 112-115 for further information), which when combined, provide +/-19.8 mm of X/Y motion (+/- 28 mm vectorial motion), up to 1 m of Z motion and 4.2 K base temperatures. Their combined use provides an economical solution to liquid helium cooling requirements. Each MultiStage / cryostat is built to order so that the cold finger length and conflat-style vacuum flange may be sized to fit the user s chamber. Features for UHV include: Bakeable to 200 C. Sample temperatures from 4.2 to 475 K standard, or > 700 K optional. Heater and temperature sensor in the cryostat helium space (not exposed to UHV environment). Electropolished stainless steel construction. Gold plated copper radiation shield and sample mount. UHV-compatible electrical feedthroughs for user wiring. Low cryogen usage @ 0.5 L/hr. Initial cool down time <15 mins. For more information and order codes please contact sales. 124
Helitran Liquid Helium Cryostat Introduction The Helitran LT-3M is a continuous flow cryostat from Advanced research Systems Inc. It is fully compatible with UHV Design s XY31- series of XYZ Multi-Stage manipulators (see pages 112-115 for further information), and can be used to accomplish +/- 14 mm X/Y motion (+/-20 mm of vectorial motion), up to 1 m of Z motion and 2K base temperatures. The Helitran LT-3M has some unique design features giving significant performance benefits, particularly in terms of low vibration, temperature stability, efficiency and cooling power:- Built-in impedance valve at the sample tip means sub 4.2 K (1.7 K operation when the He exhaust is pumped). Patented matrix heat exchanger providing high cooling power (1.5 W @ 4.2 K, 20 W @ 50 K), and very efficient heat transfer. This results in the efficient use of cryogen up to 40 times less cryogen required compared to some competitive product, and therefore also gives a concomitant reduction in operating costs. General Specification Cryo-cooler Model: L He L N2 Temperature Min Temperature Max 4.2k (<2k with pumping) 350k 77k (70k with pumping) Continuous Flow Cryostat Co-axial shielded flow transfer system, contributes to this efficiency but more importantly ensures single phase tip flow i.e. eliminates boiling. This provides excellent temperature stability, and freedom from mechanical vibration at the tip. The intrinsic vibrational stability is stated as less than 0.1 nm in STM applications. Cooling Power 4.2k Cooling Power 20k (500k or 800k available as options) 1.5 watts (2 l/hr flow) 8 watts (2 l/hr flow) An exhaust gas heater eliminates condensation and icing at the exhaust port. Cooling Power 50k 20 watts (2 l/hr flow) A flow control panel provides precise, repeatable flow / temperature control and optimisation. Cooldown time to 4.2k 20 minutes Heating and temperature control to 500 K using a Silicon diode sensor, and to 800 K using a K type thermocouple. Consumption (4k min) Orientation 0.75 l/hr. lower at higher temperatures Any Vibration at sample 0.1 Nm Tel:+44(0)1323 811188 sales@uhvdesign.com www.uhvdesign.com 125
Displex Closed Cycle Cryostat Closed Cycle Cryostat Introduction The Displex is a versatile closed cycle cryostat package from Advanced Research Systems Inc. that has many applications in ultra-high vacuum research. The system typically includes a compressor, hoses, DE-202AB expander, temperature controller / sensor and heater instrumentation. It is fully compatible with UHV Design s XY31- series of XYZ Multi-Stage manipulators (see pages 112-115 for further information), and can be used to accomplish +/- 18.8 mm X/Y motion (+/-26.5 mm of vectorial motion), up to 1 m of Z motion and 10 K base temperatures. General Specification (without options) Type DE-202AB DE-202NB Alternatively the DE-202NB is a modified version that achieves a 6.5 K bottom out temperature and higher capacity at 10 K. There are also higher speed versions for faster cool-down times, viz DE202AB(T) contact the factory for full details. The Displex Cryostats have some unique design features giving significant performance benefits which include:- Temperature range Refrigeration capacity (without attachments) Cooldown time to 20 Kelvins Lines Power requirements Weights 10 to 350 kelvin 6.5 to 350 kelvin 20 k 2.0 W @ 50 Hz 2.5 W @ 60 Hz 60 Hz - 50 minutes 50 Hz - 60 minutes 8 k 10 k 20 k 0.4 W @ 50 Hz 0.5 W @ 60 Hz 0.8 W @ 50 Hz 1 W @ 60 Hz 2 W @ 60 Hz 2.5 W @ 60 Hz 60 Hz - 65 minutes 50 Hz - 75 minutes 3 m (10ft) flexible stainless steel lines as standard 208/230 V, 50/60 Hz, 1.7 kw typical Other voltages available upon request System - 91Kg (200 lb) Compressor 80 Kg (165 lb) Expander - 7Kg (16 lb) 10 K to 350 K operation or 6.5 K to 350 K and (Options for 450 K and 800 K heating). Iron - doped gold (0.07% atomic wt. Iron) Chromel thermocouple temperature sensors, silicon diodes, or other sensors available upon request. Metallized thermofoil heater for long heater life - 36 W, 36 V resistance heater. UHV construction and instrumentation wiring. Bakeable to 200 C with displacer removed (400 C without instrumentation). Vacuum Level 1E-11 Torr. Operates in any position. The Displex is a Pneumatic Drive cryo-cooler with no mechanical drive components such as cams, push rods, and poppet valves. The motor is axial which further reduces the vibrations in the horizontal plane. The vibrations at the tip are lower than the pulse tube cryo-coolers, and lower by a factor of 4 than mechanical drive GM Cryo-coolers. Vibrations at the sample are the lowest in the class at :- +/- 15 Microns - Z +/- 5 Microns - X and Y Only two moving parts, easily maintained in the field without breaking vacuum. Requires only electricity and cooling water for operation. Note: these specifications are for the Cryocooler only. Actual performance will depend on parasitic and experimental heat loads. For more information and order codes please contact sales. 126