Pfeiffer Vacuum QMG 422 Operating Instructions Manual
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Pfeiffer Vacuum QMG 422 Operating Instructions Manual

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Operating Instructions
Incl. Declaration of Conformity
QMG 422 Analyzers
BG 805 983 BE
(0112)
1

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Summary of Contents for Pfeiffer Vacuum QMG 422

  • Page 1 Operating Instructions Incl. Declaration of Conformity QMG 422 Analyzers BG 805 983 BE (0112)

  • Page 2: Product Identification

    The QMA 400, QMA 410 and QMA 430 Analyzers are used for gas analysis in high vacuum. They are part of the QMG 422 mass spectrometer system and may only be used in connection with equipment belonging to that system.

  • Page 3: Table Of Contents

    Contents Product Identification Validity Intended Use 1 Safety 1.1 Symbols Used 1.2 Personnel Qualifications 1.3 General Safety Instructions 1.4 Liability and Warranty 2 Description 2.1 Design 2.1.1 Ion Sources 2.1.2 Mass Filter 2.1.3 Secondary Electron Multiplier 2.2 Versions 2.2.1 Cathode Materials 2.2.2 Electron Collimation Magnet 2.2.3 90°...
  • Page 4 6 Optimization 6.1 Recommended Operating Modes 6.2 Test Gas 6.3 Ion Source Parameters 6.3.1 Emission 6.3.2 Protection 6.3.3 V1 IonRef 6.3.4 V2 Cathode 6.3.5 V3 Focus 6.3.6 V4 Field Axis 6.3.7 V5 Extraction 6.3.8 V8 Reserve 6.3.9 V9 Wehnelt 6.4 V6 / V7 Deflection 6.5 Resolution 6.6 RF Cable Polarity 7 Ion Sources...

  • Page 5: Safety

    1 Safety 1.1 Symbols Used DANGER Information on preventing any kind of physical injury. WARNING Information on preventing extensive equipment and environmental damage. Caution Information on correct handling or use. Disregard can lead to malfunctions or minor equipment damage. 1.2 Personnel Qualifications Skilled personnel All work described in this document may only be carried out by persons who have suitable technical training and the necessary experience or who have been...

  • Page 6: Liability And Warranty

    • • • • Communicate the safety instructions to all other users. instructions 1.4 Liability and Warranty Pfeiffer Vacuum assumes no liability and the warranty becomes null and void if the end-user or third parties • disregard the information in this document •...

  • Page 7: Description

    2 Description Chapter "Overview" in  [1] shows the complete system and contains short de- scriptions of the individual components. The analyzers QMA 400, QMA 410, and QMA 430 are the sensors of the QMG 422 mass spectrometer system. 2.1 Design A quadrupole analyzer consists of: •...

  • Page 8: Ion Sources

    High mechanical precision combined with optimum cooperation between the ion source and rod system, forming the ion optical unit, yield high resolution and transmission with low mass discrimination. The high resolution and wide mass range make this instrument suitable for analy- tical measurement problems.

  • Page 9: Secondary Electron Multiplier

    2.1.3 Secondary Electron The secondary ion multiplier with its 17 discrete stages and focusing dynode geometry is a fast ion current amplifier between the quadrupole filter and the Multiplier preamplifier. The high gain of the SEM allows to operate the succeeding electrometer amplifier with a lower gain.

  • Page 10: Versions

    SEV 218 The SEV 218 corresponds to the SEV 217. Additionally, it has a conversion dynode, which is separate from the dynode chain and fed by an invariable high voltage source (-6.3 kV at the CD connector of the HV 421), which is independent of the operating voltage of the secondary electron multiplier.

  • Page 11: Electron Collimation Magnet

    2.2.2 Electron Collimation The crossbeam ion source can be equipped with a magnet unit. This is recom- mended for applications in high mass ranges, for molecular beam detection, and in Magnet the QMA 410 for separating He and D The magnet increases the electron density in that part of the volume of the ion source, from which ions can be easily focused into the mass filter.

  • Page 12: Faraday Cup

    Two deflection voltages Special versions (mostly with ion optics, → enclosed diagram of the QMA). The inner deflection plate is on potential V6 "DEFI", the outer deflection plate is on potential V7 "DEFO". The Faraday cup is isolated from the deflection plate and connected to the electrometer amplifier EP1.

  • Page 13: Vacuum Annealed Qma

    2.2.6 Vacuum Annealed QMA The QMA with the vacuum annealed grid ion source has a very low degassing and desorption rate (< 10 mbar l/s). 2.2.7 Extraction Hood For extracting ions from a plasma, an extraction hood can be installed. As the versions with extraction hood are customized, a cor- responding description is enclosed with the test protocol.

  • Page 14: Technical Data

    3 Technical Data Overpressure Maximum admissible overpressure 2 bar (absolute) Maximum operating pressure Vacuum with Faraday 1×10 mbar in the ion source with SEM 1×10 mbar in the ion source Smallest detectable partial pressure Sensitivity with Faraday <10 mbar with 90° off-axis SEM and ion <10 mbar counter electronics...
  • Page 15 Rhenium >2,000 h Filament life ]10,000 h Tungsten Yttrated iridium >10,000 h mbar, emission 1 mA and electron energy ≥70 eV in a non Valid for p <10 oxidizing atmosphere → Standards 57 Declaration of conformity Dimensions and weight FARADAY 90°OFF AXIS (The illustrations are not to scale.) 90°...
  • Page 16 Ion sources Axial Crossbeam (CB) 35.5 23.5 CB gas tight 23.5 Grid 2 lens ion optics 17.5 CB with 2 lens optics 43.5 23.5 3 lens ion optics CB with 3 lens optics 23.5 With axial gas connection Without gas admission line (outer diameter of gas admission line 3 mm) Gas connections CB gas tight with 1 axial connection Bore in glass ceramic...

  • Page 17: Installation

    4 Installation 4.1 Preparation DANGER Caution: hazardous electrical voltages Hazardous voltages up to 600 V are applied to the QMA. Make sure the QMA, the vacuum chamber, and the whole system are always correctly connected to ground. If accidental contact to the QMA is possible when the vacuum system is opened, additional protective measures have to be taken, for in- stance: •...
  • Page 18 Gas inlet system Prepare the gas inlet system (if necessary) in order to ensure easy connection to the ion source. The crossbeam ion source might have to be aligned with the gas inlet system. In that case mark the correct mounting orientation (direction of the arrows) on the flange of the QMA and the system.
  • Page 19 • Using the assembling trestle Mount the assembling trestle to a stable workbench. • Insert the analyzer with the installation plate into the assembling trestle. Removing the protective tube Only for QMA 400/430 without SEM: • Remove the three screws. •...

  • Page 20: Installing The Electron Collimation Magnets

    Removing the transport Caution protection Caution: dirt sensitive area Touching the product with bare hands causes distortion of the meas- urement results. Always wear clean, lint-free gloves and use clean tools when working in this area. • Carefully remove the transport protection and keep it for later use.

  • Page 21: Installation

    Terminals Œ Position the analyzer so that the magnet unit can easily be mounted.  Unfasten the two screws without removing them. Ž Remove the magnet unit and the screws from the package.  Mount the magnet unit onto the ion source.

  • Page 22: Gas Inlet System

    Holding the seal • Hold the vertical seal stationary with a knife blade. Making the flange connection • Carefully introduce the analyzer into the vacuum system. The ion source and wiring must not touch any parts. • Insert one of the upper screws and tighten it with your fingers.

  • Page 23: Cp 400

    4.6 CP 400 Install the ion counter preamplifier CP 400 if applicable (→  [1]). Before installing the CP 400 remove the SEM connector plate of the QMA or the cover if it is not equipped with a SEM connector plate. 4.6.1 Removing / Installing the •...

  • Page 24: Operation

    5 Operation 5.1 First Time Operation • Before switching the equipment on check that all components are correctly installed and wired. DANGER Caution: hazardous electrical voltages The voltages under the connector plates are extremely hazardous. Before putting the equipment into operation make sure the protective tubes are installed.

  • Page 25: High Temperature Operation

    • If your system has been delivered as a complete assembly, the radio frequency generator has been adjusted to the analyzer at the factory (→  [2]). • Select the "Det. Type: Faraday" (except if you use only an ion counter as de- tection unit).

  • Page 26: Removing The Connector Plates

    5.3.1 Removing the Connector • If you have a 90° SEM, remove the connector plate (→ 23), however, leave Plates the three studs in place. • Remove the protective tube from the large connector plate. • Loosen the hex socket screws (size 1.5 mm) of the shielding sleeves by ½...

  • Page 27: Secondary Electron Multiplier Sem

    5.5 Secondary Electron The gain and thus the sensitivity can be roughly adjusted with the SEM high volt- age "SEM Volt". Avoid values below 1 kV as well as ion currents >1 µA for more Multiplier SEM than a few minutes, as in these ranges the gain is not stable. 5.5.1 Contamination When the gas composition is unfavorable (hydrocarbons and other organic vapors), prevent contamination of the SEM by operating it a with a low current.

  • Page 28: Surface Ions

    5.6 Surface Ions Due to electron impacts on the ion source surfaces, adsorbed contaminants are desorbed as so-called EID ions, which are represented in the spectrum, e.g. with masses 16 (O ), 19 (F ), 23 (Na ), 35/37 (Cl ) and 39/41 (K EID ions appear especially under UHV conditions.

  • Page 29: Optimization

    6 Optimization For certain applications the factory settings should be modified. The following sections explain how to determine the optimum parameter values. With increasing contamination or after revision work, the settings should be modified according to the following sections. The potentials and their denominations are listed in  [1], "Technical Data". It should be possible to measure a spectrum with the default values of the equip- ment (→...

  • Page 30: Test Gas

    • Adjust "First" so that the peaks you are interested in are in the center of the displayed range. • In the three-decade re- presentation of the ion current showed in the illustration the resolution, peak shape, and peak height are clearly visible. •...

  • Page 31: Ion Source Parameters

    6.3 Ion Source Parameters 6.3.1 Emission A typical emission "Current" is 1 mA, which is the maximum value for ion sources with yttrated cathodes. In certain cases (e.g. grid ion source) the sensitivity is higher with 2 mA. However, sometimes, the maximum sensitivity is reached at lower emission settings. E.g. for crossbeam ion sources with electron collimation magnets, volume charge effects might be expected.

  • Page 32: V2 Cathode

    6.3.4 V2 Cathode The cathode voltage determines the acceleration voltage of the electrons and thus the nominal ionization energy. The actual ionization energy deviates slightly from that value, for instance, due to the extraction field. Calibration measurements are required for applications for which the exact ionization energy has to be known. The reference data in spectra libraries are usually referenced to 70 eV.

  • Page 33: V5 Extraction

    Die deflection voltages ("Deflection", "DEFI" and "DEFO") direct the ions through the 90° deflection condensator. In the QMG 422, in Faraday operation, they are automatically switched to ground potential. The two deflection plates are on positive potential for negative ions and on negative potential for positive ions respectively.

  • Page 34: Resolution

    One deflection voltage The inner deflection plate is on potential "V6 Deflection", outer is directly connected to the Faraday cup and the electrometer amplifier EP1 and is thus on ground potential. The optimum value is determined by the ion formation potential "IonRef" and to a certain extent by the SEM voltage.

  • Page 35: Ion Sources

    7 Ion Sources 7.1 Axial Ion Source By focusing the ions in axial direction, the axial ion source supplies ions with a narrow energy distribution and a small speed component transversely to the axis so that excellent resolution, high sensitivity, and good linearity are achieved. The open design allows registration of rapid changes in the partial pressure with minimum distortion due to outgassing and surface reactions.
  • Page 36 Typical values Emission 1 mA IonREF 90 V Cathode 70 eV Focus 20 V Field Axis 10 V Deflection 300 V Wehnelt 30 V (max. 40) Protection 4.2 A -Ir / Re 3.5 A At p >5×10 mbar reduce to 0.1 mA. Before reduction of V2 to <...

  • Page 37: Crossbeam Ion Source

    7.2 Crossbeam Ion Source The open design of the crossbeam ion source allows quick reaction to changes in the gas composition. The crossbeam ion source has two filaments and has a long service life. Standard filament material: W. YO Ir also available. Molecular beams can be injected through the sensitive volume perpendicularly and parallel to the system axis.
  • Page 38 Electrode arrangement 100 V Potentials -100 V Emission 1 mA Typical values IonRef 90 V Cathode 70 eV Focus 20 V Field Axis 15 V Extraction 250 V Deflection 300 V Protection 4.2 A -Ir / Re 3.5 A With magnet 0.7 mA. / At p >5×10 mbar reduce to 0.1 mA.
  • Page 39 Adjustment without magnet Start with the values which previously yielded good results, with the values in the test protocol or otherwise with the values of the above table. Œ Increase the "Field Axis" value by 1.5 V.  Increase the "Resolution" by approx. 15%. Ž...
  • Page 40 Adjustment with magnet For analyses with different pressures we recommend removing the magnet unit or reducing the emission to 0.1 mA. For low emissions (up to 0.1 mA) follow the procedure in section "Adjustment without magnet". At a higher emission and for achieving maximum sensitivity, proceed as follows to find the best emission setting: Œ...

  • Page 41: Grid Ion Source

    7.3 Grid Ion Source Because of its open design the grid ion source has an extremely low outgassing rate and is easily degassed. It emits only a few surface ions. It is always equipped with two W filaments. • Application examples Residual gas analysis in UHV •...
  • Page 42 Emission 2 mA Typical values IonREF 120 V Cathode 100 eV Field Axis 10 V Deflection 200 V Protection 4.2 A -Ir / Re 3.5 A At p>5×10 mbar reduce to 0.2 mA. Before reducing V2 to <50 eV, reduce the "Emission" to 0.1 mA and V9 to <20 V to prevent overloading of the cathode.

  • Page 43: Two Lens Ion Optics

    7.4 Two Lens Ion Optics The two lens ion optics does not produce any ions. It transmits ions emitted else- where to the mass filter. The ions can be emitted from a flat surface (e.g. solid surface) or a small volume. The two lens optics are often combined with an isolated design.
  • Page 44 Function From the spot where they are emitted 1 (→ illustration below, e.g. solid surface), the ions to be analyzed reach the inside of the optics via the entrance orifice 2. Their shapes and potentials have a combined effect, oscillating ions are focused to the entrance orifice of the mass filter.
  • Page 45 Typical values The values and adjustment apply to ions, emitted on a target. For other applica- tions, they may be quite different. Please note the values for your individual appli- cation in the table below. IonRef 50 V / Target Lens 1 70 V Lens 2...

  • Page 46: Crossbeam Ion Source With Two Lens Ion Optics

    7.5 Crossbeam Ion Source This version offers the characteristics of the two lens ion optics combined with the features of the crossbeam ion source. It is used for detecting foreign ions and With Two Lens Ion neutral particles ionized in the crossbeam ion source. Optics The crossbeam ion source with two lens ion optics is often combined with the open design.
  • Page 47 Electrode arrangement The ion optics mode is shown here; for crossbeam operation → 37 ff. Potentials 50 V Typical values The values and adjustment apply to ions emitted on a target. For other applica- tions, they may be quite different. Please note the values for your individual appli- cation in the table below.

  • Page 48: Three Lens Ion Optics

    Adjustment Start with the values which previously yielded good results, with the values in the test protocol or otherwise with the values of the above table. Œ First optimize for crossbeam mode and use the corresponding values for V3, V4, V5. ...
  • Page 49 DANGER Caution: shock hazard The voltages of the IS 420 as well as the additional BIAS, TARGET and EXTR voltages can be extremely hazardous. Consider the technical specifications of the IS 420 (→  [1]) and use only properly made cables. Function The ions to be analyzed pass from the formation area through the entrance orifice of Lens 1.
  • Page 50 Typical values The values and adjustment apply to SIMS measurements. The values for other analyses may be quite different. Please note the values for your individual appli- cation in the table below. IonRef 50 V / Target Lens 1 70 V Field Axis Lens 2 20 V...

  • Page 51: Crossbeam Ion Source With Three Lens Ion Optics

    7.7 Crossbeam Ion Source This version combines the characteristics of the three lens ion optics with the fea- tures of the crossbeam ion source. It is used for detecting foreign ions and neutral With Three Lens Ion particles ionized in the crossbeam ion source. Optics The crossbeam ion source with three lens ion optics is often combined with the isolated design.
  • Page 52 There are three 3 SHV connectors on the AS 400 : X10 BIAS IN: Input for external voltages for biasing the whole ion source supply in ion optics mode (maximum 200 V); in crossbeam mode, the supply is on ground potential. X11 BIAS: Output with bias voltage for the "isolated design".
  • Page 53 Typical values The values and adjustment apply to SIMS measurements. The values for other applications may be quite different. Please note the values for your individual application in the table below: Operating mode SPEC+/- Emission X10 BIAS IN 0 V (shorting connector) X12 Target 80 V...

  • Page 54: Maintenance And Spare Parts

    8 Maintenance and Spare Parts →  [4] 9 Disposal DANGER Caution: contaminated parts Contaminated parts can be detrimental to health. Before beginning to work, find out whether any parts are contaminated. Adhere to the relevant regulations and take the necessary precautions when handling contaminated parts.

  • Page 55: Appendix

    Appendix Literature  [1] www.pfeiffer-vacuum.de Operating Instructions QMG 422 BG 805 981 BE Pfeiffer Vacuum GmbH, D-35614 Asslar  [2] www.pfeiffer-vacuum.de Operating Instructions QMH 400-1, -5, QMH 410-1, -2, -3 BG 805 982 BE Pfeiffer Vacuum GmbH, D-35614 Asslar  [3] www.pfeiffer-vacuum.de...

  • Page 56: Declaration Of Contamination

    Declaration of Contamination The service, repair, and/or disposal of vacuum equipment and components will only be carried out if a correctly completed declaration has been submitted. Non-completion will result in delay. This declaration may only be completed (in block letters) and signed by authorized and qualified staff. Description of product Reason for return Type...

  • Page 57: Declaration Of Conformity

    Declaration of Conformity We, Pfeiffer Vacuum, hereby declare that the products mentioned below comply with the provisions of the Directive relating to electrical equipment designed for use within certain voltage limits 73/23/EEC and the Directive relating to electromagnetic compatibility 89/336/EEC.
  • Page 58 Notes BG 805 983 BE (0112) QMA4x0.oi...
  • Page 59 Notes BG 805 983 BE (0112) QMA4x0.oi...
  • Page 60 Emmeliusstrasse 33 D–35614 Asslar Deutschland Tel +49 (0) 6441 802-0 Fax +49 (0) 6441 802-202 info@pfeiffer-vacuum.de Original: German BG 805 983 BD (0112) www.pfeiffer-vacuum.de bg805983be...

This manual is also suitable for:

Qma 400Qma 410Qma 430

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