Application
Vacuum pumps for electron microscopy
An electron microscope forms its image with an electron beam that would be scattered in air ā the column and specimen chamber are therefore under vacuum. For the CD-SEM, Pfeiffer Vacuum names 10ā»āµ to 10ā»ā· hPa, Edwards about 10 mbar for an ESEM; the backing pump maintains the backing vacuum of the turbo pump in the instrument and must not disturb the image with vibrations. Below you can see how the application works, what vacuum the manufacturers name and which of their series are intended for it ā 112 models from 4 manufacturers.
Compare 112 modelsHow it works
- 112Models
- 6Series
- 4Manufacturers
- 10ā»āµā10ā»ā· hPaCD-SEM chamber pressure (Pfeiffer Vacuum)
Touch the points: each part of the system explains itself.
In short
Electron microscopy: the key facts
- Chamber pressureFor the CD-SEM, Pfeiffer Vacuum names 10ā»āµ to 10ā»ā· hPa, Edwards about 10 mbar for an ESEM.
- Beam without scatteringEdwards and Pfeiffer Vacuum name the electron beam without scattering as the reason for the vacuum in the microscope.
- Low vibrationEdwards names low-vibration pumps, as does Pfeiffer Vacuum ā for wafer metrology with the CD-SEM.
- Pumping stationThe turbo pump sits in the instrument (Pfeiffer Vacuum HiPace Plus, Leybold TURBOVAC MAG); as the backing pump, Pfeiffer Vacuum names diaphragm, multi-stage Roots and scroll pumps, Edwards rotary vane, scroll and nXRi, Leybold ECODRY plus.
Operating principle
How it works: Electron microscopy
The drawing shows the basic principle in section. The systems and pumps of the individual manufacturers differ in detail.
- Loading the specimenThe specimen ā in the CD-SEM the wafer ā goes into the specimen chamber; the valve to the column stays closed until the chamber is sealed again.
- EvacuatingThe backing pump evacuates the chamber and then holds the backing vacuum of the turbo pump, which produces the high vacuum ā according to Pfeiffer Vacuum 10ā»āµ to 10ā»ā· hPa with the CD-SEM.
- ImagingAccording to Edwards and Pfeiffer Vacuum, the electron beam reaches the specimen without scattering; the pumps run with low vibration so that the image stays sharp.
Vacuum and sizing
Electron microscopy: how much vacuum is needed
What the manufacturers say about pressure, pumping speed and sizing.
Which vacuum
For the CD-SEM, Pfeiffer Vacuum names 10ā»āµ to 10ā»ā· hPa. For an ESEM, Edwards names about 10 mbar ā gas remains around the specimen there.
Which pumps
According to Pfeiffer Vacuum and Leybold, a turbo pump sits in the instrument (HiPace Plus, TURBOVAC MAG ā not in our range). As backing pumps, Pfeiffer Vacuum names HiScroll and ACP and, in general, diaphragm, multi-stage Roots and scroll pumps; Edwards names rotary vane, scroll and nXRi, Leybold ECODRY plus, Busch COBRA and R5.
What the manufacturers point out
Edwards: beam without scattering, low vibration. Pfeiffer Vacuum: scatter-free electron beam, low vibration ā for the CD-SEM, low-vibration wafer metrology. Busch and Leybold list electron microscopes without describing the requirements.
Technology
Electron microscopy: the vacuum pumps the manufacturers name
Listed are the series the manufacturer itself names for this application. āShow only ā¦ā sets the filter of the product overview.
Oil-lubricated rotary vane vacuum pumps
58 models Ā· 3ā1,800 mĀ³/h
Screw vacuum pumps
36 models Ā· 70ā4,652 mĀ³/h
Roots vacuum pumps
14 models Ā· 14ā120 mĀ³/h
Scroll vacuum pumps
4 models Ā· 6.1ā43 mĀ³/h
Product overview
Electron microscopy: all 112 models compared
Use the filters on the left to narrow the selection ā by manufacturer, technology and the modelsā key figures, for 50 or 60 Hz.
Busch COBRA Industry series 36 models
COBRA NS 0070 CPumping speed 70 mĀ³/h 50 Hz85 mĀ³/h 60 HzUltimate pressure 0.03 mbarRated motor power 4 kW 50 Hz4.4 kW 60 HzVariants 
COBRA NC 0100 BPumping speed 110 mĀ³/h 50 Hz130 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 3.5 kW 50 Hz4.8 kW 60 HzVariants 4
COBRA NC 0100 B ECOTORQUEPumping speed 130 mĀ³/h 50 Hz130 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 4.8 kW 50 Hz4.8 kW 60 HzVariants 
COBRA NS 0160 CPumping speed 135 mĀ³/h 50 Hz170 mĀ³/h 60 HzUltimate pressure 0.03 mbarRated motor power 5.5 kW 50 Hz6.6 kW 60 HzVariants 
COBRA NC 0200 BPumping speed 220 mĀ³/h 50 Hz265 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 6 kW 50 Hz7.6 kW 60 HzVariants 4
COBRA NC 0200 B ECOTORQUEPumping speed 265 mĀ³/h 50 Hz265 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 7.6 kW 50 Hz7.6 kW 60 HzVariants 
COBRA NC 0300 BPumping speed 320 mĀ³/h 50 Hz385 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 7.5 kW 50 Hz9.5 kW 60 HzVariants 4
COBRA NC 0400 BPumping speed 350 mĀ³/h 50 Hz420 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 7.5 kW 50 Hz9.5 kW 60 HzVariants 
COBRA NX 0450 APumping speed 350 mĀ³/h 50 Hz420 mĀ³/h 60 HzUltimate pressure 0.1 mbarRated motor power 7.5 kW 50 Hz9.5 kW 60 HzVariants 
COBRA NC 0300 B ECOTORQUEPumping speed 385 mĀ³/h 50 Hz385 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 9.5 kW 50 Hz9.5 kW 60 HzVariants 
COBRA NC 0400 B ECOTORQUEPumping speed 420 mĀ³/h 50 Hz420 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 9.5 kW 50 Hz9.5 kW 60 HzVariants 
COBRA NX 0450 A ECOTORQUEPumping speed 420 mĀ³/h 50 Hz420 mĀ³/h 60 HzUltimate pressure 0.1 mbarRated motor power 11 kW 50 Hz11 kW 60 HzVariants 
COBRA NC 0500 BPumping speed 490 mĀ³/h 50 Hz490 mĀ³/h 60 HzUltimate pressure 0.01 mbarRated motor power 9 kW 50 Hz9 kW 60 HzVariants 
COBRA NC 0630 C VRPumping speed 580 mĀ³/h 50 Hz680 mĀ³/h 60 HzUltimate pressure 25 mbarRated motor power 22 kW 50 Hz22 kW 60 HzVariants 
COBRA NS 0600 CPumping speed 600 mĀ³/h 50 Hz600 mĀ³/h 60 HzUltimate pressure 0.01 mbarRated motor power 15 kW 50 Hz15 kW 60 HzVariants 
COBRA NC 0630 CPumping speed 630 mĀ³/h 50 Hz630 mĀ³/h 60 HzUltimate pressure 0.01 mbarRated motor power 15 kW 50 Hz17 kW 60 HzVariants 
COBRA NC 0630 C ECOTORQUEPumping speed 630 mĀ³/h 50 Hz630 mĀ³/h 60 HzUltimate pressure 0.01 mbarRated motor power 17 kW 50 Hz17 kW 60 HzVariants 
COBRA DX 0650 A PLUSPumping speed 650 mĀ³/h 50 Hz650 mĀ³/h 60 HzUltimate pressure 0.1 mbarRated motor power 15 kW 50 Hz15 kW 60 HzVariants 
COBRA NX 0650 APumping speed 650 mĀ³/h 50 Hz650 mĀ³/h 60 HzUltimate pressure 0.1 mbarRated motor power 12.5 kW 50 Hz15 kW 60 HzVariants 
COBRA NX 0650 A ECOTORQUEPumping speed 650 mĀ³/h 50 Hz650 mĀ³/h 60 HzUltimate pressure 0.1 mbarRated motor power 15 kW 50 Hz15 kW 60 HzVariants 
COBRA NF 0750 APumping speed 750 mĀ³/h 50 Hz750 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 15 kW 50 Hz15 kW 60 HzVariants 
COBRA NC 1000 BPumping speed 840 mĀ³/h 50 Hz1,000 mĀ³/h 60 HzUltimate pressure 0.05 mbarRated motor power 22 kW 50 Hz25 kW 60 HzVariants 
COBRA DX 0950 A PLUSPumping speed 950 mĀ³/h 50 Hz950 mĀ³/h 60 HzUltimate pressure 0.01 mbarRated motor power 18.5 kW 50 Hz18.5 kW 60 HzVariants Busch R5 series 58 models
Edwards nXRi series 5 models
Leybold ECODRY series 5 models
Pfeiffer Vacuum ACP series 4 models
Pfeiffer Vacuum HiScroll series 4 models
No model matches these filters.
Busch COBRA Industry series 36 models
Busch R5 series 58 models
Edwards nXRi series 5 models
Leybold ECODRY series 5 models
Pfeiffer Vacuum ACP series 4 models
Pfeiffer Vacuum HiScroll series 4 models
Models a manufacturer no longer carries in its current range are listed in its āOutdated modelsā section.
Industries
Electron microscopy: where the manufacturers name it
The manufacturers list these uses on their own pages.
Research, laboratory and analytics
Busch names electron microscopes in analytics and the laboratory with COBRA and R5; Edwards names electron microscopy among its vacuum systems for analytical instruments with rotary vane, scroll and nXRi pumps (beam without scattering, low vibration, ESEM about 10 mbar); Pfeiffer Vacuum names it with diaphragm, multi-stage Roots and scroll pumps and the HiScroll.
Semiconductors, electronics and displays
Pfeiffer Vacuum names the CD-SEM for low-vibration wafer metrology at 10ā»āµ to 10ā»ā· hPa, with ACP and HiScroll as backing pumps and HiPace Plus as the turbo pump.
Frequently asked questions
Electron microscopy: frequently asked questions
Why does an electron microscope need a vacuum?
Because the electron beam would be scattered in air: Edwards names the beam without scattering, Pfeiffer Vacuum the scatter-free electron beam as the reason for the vacuum in the column and specimen chamber. For the CD-SEM, Pfeiffer Vacuum names 10ā»āµ to 10ā»ā· hPa.
How much vacuum does a scanning electron microscope need?
For the CD-SEM, a scanning electron microscope for wafer metrology, Pfeiffer Vacuum names 10ā»āµ to 10ā»ā· hPa. For an ESEM, in which gas remains around the specimen, Edwards names about 10 mbar.
Which vacuum pump for an electron microscope?
The high vacuum is produced by a turbo pump in the instrument ā Pfeiffer Vacuum names the HiPace Plus, Leybold the TURBOVAC MAG. As the backing pump, Pfeiffer Vacuum names HiScroll and ACP, Edwards rotary vane, scroll and nXRi pumps, Leybold ECODRY plus, Busch COBRA and R5.
Which backing pump for the turbo pump of an electron microscope?
Pfeiffer Vacuum names diaphragm, multi-stage Roots and scroll pumps, specifically HiScroll and ACP; Edwards names rotary vane, scroll and nXRi; Leybold the multi-stage Roots pump ECODRY plus. Edwards and Pfeiffer Vacuum both name low-vibration pumps.
Oil-free or oil-lubricated for electron microscopy?
Both are named. Edwards lists rotary vane pumps alongside scroll and nXRi, Busch the oil-lubricated R5 alongside the COBRA; Pfeiffer Vacuum names dry backing pumps (diaphragm, multi-stage Roots, scroll) and Leybold the dry ECODRY plus. For the CD-SEM in wafer production, Pfeiffer Vacuum names ACP and HiScroll, both without oil.
Why must the vacuum pump on an electron microscope be low-vibration?
Edwards names low-vibration pumps; Pfeiffer Vacuum also names low-vibration pumps and, for the CD-SEM, low-vibration wafer metrology. Vibrations of the backing pump are transmitted to the instrument and blur the image; when structures on the wafer are measured, this becomes a measurement error.
How much vacuum does an ESEM need?
For an ESEM, Edwards names about 10 mbar. Unlike in the high-vacuum scanning electron microscope, gas remains around the specimen there; the high vacuum in the column is still provided by the turbo pump.
Which vacuum pump for CD-SEM in wafer production?
For the CD-SEM, Pfeiffer Vacuum names ACP and HiScroll as backing pumps and the HiPace Plus as the turbo pump, at 10ā»āµ to 10ā»ā· hPa and low-vibration for wafer metrology. For inspection in general, Pfeiffer Vacuum names A 100/200 L, A4, ACP and TORRI.
Which scroll vacuum pump for electron microscopes?
Pfeiffer Vacuum names the HiScroll for electron microscopy and the CD-SEM; Edwards names scroll pumps alongside rotary vane and nXRi. A scroll vacuum pump runs without oil.
A single pump or a central vacuum system?
A central system in a room of its own keeps noise and heat away from production and matches its output to the demand. Central vacuum systems are planned and built by Eugen Theis Vakuum, a company of the Ehrler & Beck group ā more under Central Vacuum.
Does Ehrler & Beck also supply spare parts and service?
Yes. Ehrler & Beck offers original spare parts and accessories as well as maintenance and repair.
Which pump suits your process?
Tell us the application, the medium and the volume ā we advise you on selection, spare parts and service.
