Quanta 200 FEG Environmental SEM

Quanta 200 FEG Environmental SEM

The Quanta 200 FEG Environmental Scanning Electron Microscope (ESEM) uses a field-emission gun (FEG) electron source in an exceptionally high chamber pressure environment. 

It combines two main advantages: 

  • Nanometer resolution and a high signal to noise ratio in both regular high vacuum and environmental (wet) modes.
  • Real “wet” mode (100% humidity in the specimen chamber) and a possibility to examine specimens with a high vapor pressure in the chamber. It is provided by a differential pumping vacuum system and a series of pressure-limiting apertures in addition to a patented gaseous secondary electron detector.

By utilizing a cooling Peltier stage and a high water vapor pressure in the specimen chamber it is possible to achieve high levels of humidity. In these conditions wet or hydrated specimens (cells, plant samples, tissue, etc.) will not dry and introduce any artifacts while being examined in the SEM. Dynamic experiments such as drying or crystallization processes can be examined as well.

Low vacuum mode is very useful for observing non-conductive specimens such as paper, plastics, ceramics, fibers, fabrics, and outgassing materials.

The Quanta 200 FEG can be switched between three vacuum modes enabling the investigation of conductive, non-conductive and high-vacuum incompatible materials:

High vacuum (typically 10-5 mbar) for imaging and microanalysis of conductive and/or conventionally prepared specimens;

Low vacuum (<1.3 mbar) for imaging and microanalysis of non-conductive specimens without preparation;

ESEM mode (<26 mbar) for high-vacuum incompatible specimens, which were previously impossible to investigate with conventional SEM methods.

Electron Optics

Source: Schottky emitter field emission gun

Voltage: 200 V to 30 kV

Beam current: up to100 nA

Resolution:  ≤2 nm gold particle separation on a carbon substrate at 30 kV in high vacuum and ESEM operating modes; ≤3.5 nm at 3 kV in low vacuum mode


SE and BSE detectors:

The Quanta 200 FEG is equipped with all necessary detectors to detect secondary electrons (SE) in all vacuum modes, as follows:

High vacuum: conventional Everhart-Thornley SE detector.
Low vacuum: large-field gaseous SE detector, mounted off-axis, and with enhanced gain preamplifier suitable also for use at low voltages.
ESEM mode: axially mounted standard Gaseous SE detector.
An angular solid-state detector is used for backscattered electron (BSE) detection. It is mounted below the pole piece and is optimized for low-kV operation (down to 5 kV).
GAD low-kV, solid-state, Back-Scattered Electron (BSE) detector:
The Gaseous Analytical solid-state back-scattered electron Detector is similar to the standard low-kV, solid-state back-scattered electron detector, but features an additional X-ray cone with a 500 micron pressure limiting aperture which seals to the final lens.The cone extends the differential pumping zone to just above the sample surface, which provides the necessary gaseous analytical geometry for very small beam gas path lengths.
Two types of STEM detectors are used: one for high vacuum operation (Solid-state STEM detector), and the other for wet operation with WetSTEM detector.

Scanning transmission electron detector (STEM) allows detection of electrons transmitted through the sample. Regular kV range is from 30 kV down to around 5 kV for FEG systems. Samples can be viewed simultaneous in both Bright field (BF) and Dark field (DF) modes.

The WetSTEM provides imaging at relative humidity conditions up to 100% when cooling the samples between 0 and 10 °C.

Kammarath&Weiss Tensile stage

Additional systems operating on Quanta 200 FEG ESEM
 Kammarath&Weiss Tensile system
In-situ materials testing and continuous dynamic studies with micro-structural information are provided by the tensile stage in ESEM.

This tensile module of up to 5,000 N maximum load, works with a load cell of 5N with resolution better than 10mN and an additional load cell of 200N.

The microprocessor provides pre-selected displacement speeds over a range of 0.1µm/s to 20µm/s. The module can be operated from a microprocessor/PC combination, which displays the applied force and the actual elongation.

EBSD-EDS Oxford integrated analytical system
The electron backscattered diffraction (EBSD) detector is NORDLYS II of Oxford with integrated forescatter detectors and Aztec processing software. The EBSD detector provides texture information by performing phase identification and orientation mapping. The EBSD system is integrated with energy dispersive spectroscopy (EDS) system. The EDS uses X-Max SDD Oxford detector of 127eV resolution (at Mn) with element analysis down to Boron.
EDS-EBSD Oxford systemEDS-EBSD Oxford system
 Zyvex S100 Nanomanipulator
The Zyvex S100 system is a manipulation and testing tool. The system consists of nanomanipulator, a control cabinet housing the PC and electronics, a joystick and window based control system. The S100 features up to four positioners. It provides in- situ mechanical and electrical characterization of micro and nano device structures.
Zyvex S100 Nanomanipulator system

Additional systems for sample preparation:

Polaron E6500 evaporator
Polaron SC7640 sputter coater -  Auto/Manual Au/Pd coater
Quorum Q150T S Sputter Cr Coater

Tel Aviv University makes every effort to respect copyright. If you own copyright to the content contained
here and / or the use of such content is in your opinion infringing, Contact us as soon as possible >>