Instruments for Surface Science

Transcription

1 Instruments for Surface Science Page Product 2-6 RESOLVE Hemispherical Electron Energy Analyser 7 ELS100 Low Energy Electron Source 8 ELS5000 Electron Source for AES 9, 10 ISIS3000 Sample Cleaning Ion Source 11, 12 TX400 Twin anode X-ray Source for XPS 13, 14 IPES Inverse Photoemission bolt-on 15 Linear translators Sample Manipulation Electrical Feedthroughs PSP VACUUM TECHNOLOGY LTD UNIT 8 HEATHER CLOSE LYME GREEN BUSINESS PARK MACCLESFIELD, SK11 0LR, U.K. TEL: +44 (0) FAX: +44 (0) Web: pspvacuum@btconnect.com 1

2 RESOLVE Hemispherical Electron Energy Analyser RESOLVE ANALYSER CONTROL UNIT RESOLVE ANALYSER WITH MCD Large high transmission hemispherical analyser -120mm mean radius. Full 180 degree deflection angle. Fringe field correction by Jost electrodes. Fully magnetically screened -metal lined vacuum housing. Computer controlled power supply. Multi-element input lens optics. 6 selectable entrance slits / apertures to define analysed area. Single or MCD Detector options MCD version has standard / high resolution exit slits SPECTRA V8 Software for data acquisition and processing. 2

3 RESOLVE 120 Technical Specification. Mean Radius: 120mm Deflection angle: 180 deg. Lens type: Multi-element high transmission Entrance Slits: 6 sets positioned at entrance to hemispheres, used to vary analysed area at the sample (also one factor determining energy resolution) 5x10mm 2.5x10mm 1x10mm 5mmØ 2.5mmØ 1mmØ ( alternative slits / aperture sizes by special request ) Analysed area at the sample is approximately the same as the input slit size, the lens having nominal magnification of X 1 Exit slits : RESOLVE MCD5 has Standard and High resolution defining exit slit mechanism which is independent of the entrance slit mechanism) 3

4 Magnetic shielding: Fully enclosed Mu-metal internal shielding of hemispheres and lens Vacuum Housing: Stainless steel Mounting flange: DN100CF 6 / 150mm O.D. CF ( DN63CF 114mm OD CF version available ) Working distance: 40mm sample to end of lens. Sample to flange: Adaptable to suit analysis chamber. RESOLVE ELECTRONICS RESOLVE control unit. Computer controlled using SPECTRA data system (supplied). Energy range:0 to 2000eV ( 0 to 3000eV option ) (note: for electrons detection only ) Modes of operation: CPE mode (Constant Pass Energy) 0.5, 1, 2, 5, 10, 20, 50, 100eV CRR mode:(constant Retard Ratio) 2, 5, 10, 20, 50, 100 Detector Electronics: SCD Model #701 single channel pre-amp / discriminator with TTL level output to PC interface. MCD5: Model #705 five channel pre-amp/discriminator with TTL level outputs to PC interface. MCD 16: Model # 716 pre-amplifier / discriminator / counter in one. PC interface. DETECTOR OPTIONS: SCD: Single channel detector - channeltron MCD5: Five CEM electron multiplier array, low resistance high dynamic range multipliers. MCD16: Demountable 16 channel MCD using micro channel plate MCP pair and gold strip collector. TYPICAL XPS PERFORMANCE DATA SCD: 500 Kc/s on Ag 3d5/2 at 1.0eV FWHM with Mg K alpha at 300W. MCD5/16: 2,500 Kc/s on Ag 3d5/2 at 1.0eV FWHM with Mg K alpha at 300W. 4

5 DATA SYSTEM SPECTRA software v8 with SPCI721F PCI interface card. PC / Windows based COLLECT data acquisition package and PRESENTS data processing package ASCII code data storage format Mouse / menu driven. Stored / recalled Multi-region setup with software control of all analyser parameters e.g. Energy scan, Analyser Pass Energy, CPE/CRR mode, step size, repetitive scans, dwell time etc. On screen ratemeter for experimental tuning. Curve fitting, background removal, smoothing, de-spike, deconvolution, FWHM measurement. Screen shot of SPECTRA with multi-region window and FWHM window open. 5

6 XPS of Ag 3d region using RESOLVE MCD5 in mode CPE20 (Pass Energy 20eV) and TX400 X-ray source (Mg anode) Typical survey spectrum of Silver sample: RESOLVE MCD5 Analyser using TX400 X-ray source (Mg anode) 6

7 ELS100 Electron Source Low Energy Electron Gun designed for Electron Loss Spectroscopy (ELS) Beam Energy variable 5 to 100eV Low Energy Spread ~ 0.25eV FWHM using LaB6 or BaO filament 1mm typical spot size Beam current monitor with sample biasing voltage Mu-metal magnetic screen. Front Panel Control of Kinetic Energy, Filament Current, Wehnelt (Grid), Anode, Focus and Beam Deflection External Kinetic Energy sweep (e.g. by Computer Control) X-Y static deflectors for beam positioning on sample Mounting flange : 70mm (2.75 ) OD CF Manufactured to suit your chamber sample flange distance Bakeable UHV compatible construction with single multiway electrical feedthrough 7

8 ELS5000 Electron Source Ideal for Static Auger Electron Spectroscopy AES Beam Energy variable 0 to 5000eV Beam current range 10nA to 30 A Beam current monitor with sample biasing voltage Typical spot size < 50 m with 1 A beam current (measured at 2keV beam energy with a typical working distance of 50mm) Working distance 15 to 500mm X-Y static deflectors for beam positioning on sample Mounting flange : 70mm (2.75 ) OD CF Suitable for ports with sample - flange distance up to 750mm Bakeable UHV compatible construction Single multiway feedthrough with locking connector 8

9 A UHV compatible, high beam current, variable energy ion source for cleaning of sample surfaces under UHV. Supplied with Sample Current Meter Variable energy eV suitable for all types of samples. Lower beam energies are used to minimize damage to delicate sample surfaces such as single crystals. Higher beam energies are used for rapid etching of oxides and semiconductors. High beam currents available even at low energy. Used with any inert gas, which is leaked directly into the discharge chamber, no differential pumping required. Broad 10mm spot, no raster unit required to clean large area. Long working distance to avoid conflict with other instrumentation. Cost effective solution for sample cleaning under UHV. 9

10 Beam Current ( microamps ) Typical ISIS3000 Beam Current vs Beam Energy Source: The source is UHV compatible and bakeable under vacuum to 200C. Mounting Flange: 70mm OD CF port facing the sample with a sample to flange distance of up to 310mm. A spacer collar is provided to give the correct working distance of 50 to 150mm (100mm optimum) Gas Inlet Flange: 34mm OD CF, a suitable leak valve is required. Beam Energy (ev) Operating Pressure: Typically 5x10e-6 mbar of inert gas. This is dependent on the pumping speed in the vacuum chamber. Pumps should be compatible with the inert gas used. Beam Current: Typically >15 micro Amps (See chart at top of page) Filaments: Tungsten/Thoria twin filament assembly. Electronic Control Unit: Enclosure measures 483mm wide by 3U (133mm) height suitable for mounting in a standard 19-inch rack or free standing. How does it work? The ISIS3000 is an oscillating electron discharge source with electrostatic extraction and focusing lens. Inert gas is leaked directly into the discharge chamber where ions are formed at a selected energy of between 100 and 3000eV. The ions are extracted and focused into a spot of approximately 10mm diameter at the sample surface where the impact of the energetic ions physically removes surface material. What is supplied? ISIS3000 ion source, electronic control unit, sample current meter, cabling, operating manual and a spare filament assembly. Optional extras: UHV compatible leak valve. Second source, any number of sources may be supplied for individual use with one control unit. Front panel controls: Ion energy variable 0 to 3000eV Ion Energy meter Focus Potential 0 to 100% Filament Current 0-4A Filament 1, 2 or OFF switch. Filament \ Discharge current meter Anode (Discharge) Potential 0-100% Power ON/OFF illuminated switch Rear panel: Fused IEC Mains input: 100 to 240VAC selectable (50/60Hz) Single multiway cable to source electrical feedthrough. TEL: +44 (0) FAX: +44 (0) Web: pspvacuum@btconnect.com 10

11 TX400 X-ray Source for XPS Twin Anode X-ray Source Choice of Anode Materials May be differentially pumped or pumped directly through the mounting port 70mm O.D. CF mounting flange Z100 Retractor option gives 100mm retraction from sample region Insertion length made to suit your chamber at no extra cost Long life Tungsten / Thoria twin filaments Quick and reliable connections to filament, anode and water cooling Water, safety cover and pressure interlocks Aluminium foil window between source and sample Source end shaped to allow close approach to sample for optimum flux High Stability Control units supply up to 500W power

12 Mechanical Details The TX400 X-ray source has twin anodes with independent filaments to provide two separate excitation energies for X-ray Photoelectron Spectroscopy. Any anode combination from Mg, AI, Ti, Si, Ag, Zr may be chosen and it is easy to fit replacement anodes with different coatings. The X-ray exit aperture has an AI foil window, which reduces Bremsstrahlung radiation, isolates the internal volume of the source for differential pumping and prevents contamination of the sample. The source insertion length is custom made to suit your Chamber. The anode is water cooled, water pipes and flow switch are provided for connection to the water supply. (Requirement: 3 Connections to the filaments, anode and water-cooling are quick and reliable and are easily removed for bake out of the source at up to 200C. Differential Pumping The source mounts on a standard 70mm OD CF port and may be pumped directly from the chamber without the need for reentrant pumping bellows. Differential pumping may also be fitted, in which case the standard pumping holes are sealed using the barrel sleeve supplied and the 70mm OD CF pumping port on the side of the source is connected to a separate pump. Retractor Options A 100mm travel retractor may be fitted to allow close approach to the sample for maximum X-ray flux and withdrawal when not in use. Accessories: (Optional Extras) Cooling Water recirculator. Differential pumping line bellows, valve, ion pump and controller. Replacement Anodes, AI window and filament assemblies. Electronic Control Units The TX400 Control Units supply the Anode HT and Filament current to operate the source at up to 600W. The High Voltage is continuously variable from 0-15kV by front panel mounted potentiometers. The filaments may be run in current or emission stabilised mode using front panel potentiometers. Remote control facilities are also provided. The small size (total 4U, 177mm height by 483mm wide) and weight (approx. 12kg) takes up little surface or standard 19in. rack space. Safety interlocks are fitted to turn the HT off in the event of loss of water-cooling, safety cover removal or vacuum set point when connected to a suitable vacuum gauge relay. HV Specifications: Voltage regulation better than 0.005% for +/-10% input line variation. Ripple 0.1% of p-p maximum output. Stability 100ppm/hour after half hour warm up. PSP VACUUM TECHNOLOGY LTD UNIT 8 HEATHER CLOSE LYME GREEN BUSINESS PARK MACCLESFIELD, SK11 0LR, U.K. TEL: +44 (0) FAX: +44 (0) Web: pspvacuum@btconnect.com

13 INVERSE PHOTOEMISSION (IPES) IPES is used to study the empty electronic states of solids. The sample is bombarded with a beam of electrons with well defined energy and light is emitted when electrons make direct transitions into the unoccupied states. PSP manufacture an IPES electron gun and control unit, IPES photon detector with power supply and pre-amplifier / discriminator and also supply a data system. The photons are detected as a function of the kinetic energy of the incident electron beam. The data system ramps the beam energy using a DAC and recovers the CEM pulses to obtain an IPES spectrum. IPES Electron Gun. Cathode: BaO dispenser for low thermal spread. Emits at approx 1000 C. Beam energy 5 to 100eV. Sample current typically 10 µa. Electronic control unit: To allow control of cathode heater current, kinetic energy, focus voltage. Simultaneous display of beam energy, cathode heater current, sample current. The gun is supplied with Z mm linear translator.

14 IPES Detector. Photon energy filter (Fluoride window / coated Ta cone) and electron multiplier. Mounts on 70mm OD CF flange. Power supply for CEM HV, and pre-amplifier/discriminator with TTL output to recover pulses. The IPES detector is mounted on a Z mm linear translator. Courtesy of Dr Kanai, Okayama, Japan.

15 Examples : UHV Components and Accessories Linear Translator Model PZ100 70mm OD CF flanges 38mm clear bore 10 travel X,Y,Z, Motion Manipulator UHV Bakeable to 180C +/- 12 mm X,Y 50mm Z motion 70mm OD CF Flanges, 38mm bore Simple cost effective manipulator Vacuum Electrical Feedthrough Example: 12 way instrumentation feedthrough 3500V 4A 1mm dia. Contacts Supplied with locking cable end socket And in vacuum crimp connectors