Accessories

Transmission electron microscopy is widely used in the field of Life Science or Material Engineering. Therefore TESCAN has developed an adaptor that provides a complementary method for image acquisition of the transmitted electrons - scanning transmission electron microscopy detector (STEM).

STEM detector offers great opportunity to acquire TEM comparable images with al l advantages of the scanning electron microscope.

 

• By placing the detection system below the specimen, the transmitted electron signal can be collected and used to form an image.
• Detector fits into the standard carousel placed in al l types of TESCAN chambers (SB, LM, XM, GM).
• A standard TEM grid (diameter 3,05 mm) is placed into the specimen holder of the detector.
• STEM detector consists of three semiconductor sensors for bright field and dark field imaging.
• Simultaneous bright field and dark field image acquisition or mixing of the signals is possible.
• Suitable for al l TESCAN SEMs (VEGA, VELA, MIRA, LYRA).
• MIRA3 resolution: 0.8 nm at 30 kV (Resolution according to the type of the SEM).

 

Examples of samples suitable for STEM detector:

 

• Ul trathin sections (less than 1 00nm) of biological samplesprepared as for the TEM.
• Observation of inorganic nanomaterial s (nanoparticles, nanopowders, nanowires, plastics, gel s, etc.).
• Observation of TEM lamel lae after the FIB preparation

A cathodoluminescence detector attached to a TESCAN Scanning Electron Microscope (SEM) is capable of producing high-resolution digital cathodoluminescent (CL) images of luminescent materials. 

LVSTD

The  Low Vacuum Secondary Electron TESCAN Detector is a unique solution developed and patented by TESCAN. A modified Everhart-Thornley design equipped with a YAG scintillator provides a lots of merits.

• True secondary electron imaging under low vacuum conditions
• Perfect displaying the fine surface topography
• Good-quality investigation of non-conductive materials without special preparation
• Fine imaging of the surface structure of materials with low atomic number
• Compact design of the LVSTD allowing a fast and easy interfacing to any chamber manufactured by TESCAN*

*Possible configuration must be discussed with TESCAN Brno

The new versions of the LVSTD detector

TESCAN has developed two new versions of LVSTD detector working up to 1000Pa, available as an option for VEGA microscopes with extended low vacuum mode up to 2000Pa.Benefits and Features

• Improved pumping system allows using of the LVSTD up to 1000 Pa in Low Vacuum Mode. Separate detection chamber of the LVSTD is pumped down by a turbomolecular pump. The pumping efficiency of the gas from the detector chamber is increased by a rotary pump which pre-pumps the turbomolecular pump.
• Increased detected signal in all three versions of the LVSTD detector.
• Combination of LVSTD up to 1000 Pa and Water Vapor Inlet System allows observation of hydrated samples at temperatures above zero in their natural state.

Application:

Investigation of non-conductive samples under low vacuum condition – Life science, Polymers, Textile Industry, Paper Industry, Pharmacology etc.

Investigation of hydrated samples - combination of low vacuum condition with Water Vapor Inlet System– Life science, Food Industry, Construction Industry etc.

TESCAN offers a SEM Control Panel as another option to the standard controllers like multipurpose trackball or EasySEM™ touch screen control interface. The Control Panel is designed to fully control the microscope without need to use another controlling device. Moreover, the user can work in the fullscreen image mode and operate all imaging functions simultaneously.

The Control Panel provides very fast access to the SEM functions via rotary knobs. The parameters are adjusted dynamically and their setting is optimized for maximum comfort. A small joystick precisely controls stage movements. The movement speed is relative to the current magnification.

Automatic functions, like automatic focusing or automatic signal adjustment, and a function for image acquisition are available through a 3.5 inch LCD touchscreen. The combination of the LCD touchscreen with the programmable knob-set enables the user to control advanced SEM functions and the stage movements in all directions.

Nanorobotics Manipulators forming the SEM/FIB Workbench

Nanorobotics Manipulators are optional accessory expanding the TESCAN FIB and SEMs to a material processing and analytical Workbench.

Unique Manipulator Features for easy, secure and fast usage:

• Predictable cartesian movement and automation by absolute positioning
• Automatic fast & secure tip approach with crash free movements by "Self finding tools" 
• Joint access to SEM and manipulator positions for crash free movements by "Global Coordinates"
• Simple manipulator movement without expert knowledge by "Live Image Positioning" 
• The turnkey solution from TESCAN: Automation of SEM and manipulator applications with one control.
• Plenty of unique applications become possible with one investment by this "SEM/FIB Workbench" 

Examples of SEM/FIB Workbench Applications:

• Semi-automatic partcile sorting for Material Research and Forensics 
• Scaled non-distructive Dimensional Measurements in high resolution
• Tribology test at micro- and nano-sized devices (livetime, friction, stress,...)
• The NanoFab in the SEM /FIB: nano-fabrication in automation (CNT-devices, TEM-lamellas,...)
• Fast, easy and secure Nano-probing 
• Highly automated handling and measurement tasks for Semiconductor developments

Automated Loading System for TIMA

The TESCAN Integrated Mineral Analyzer (TIMA), an automated mineralogy system, enables fast and quantitative mineral analyses of rocks, ores, concentrates, tailings, leach residues or smelter products. It combines BSE and EDX analysis for identification and measurement of mineral concentrations, particle size distribution, and liberation/locking parameters. In addition, it can provide bright particle searches for PGM, gold-silver ores, and/or REE. With the newly developed Automated Loading System (AutoLoader), the TIMA has become the first automated mineral analyzer which permits robust, continuous and unattended sample loading. With the AutoLoader (robotics) system which allows accommodation of up to 100 epoxy blocks of 25mm or 30 mm diameter at one time, the TIMA has emerged as a powerful plant support instrument. It increases the sample throughput, minimizes manual labor and enables 24/7 operations.

It can be used in daily, continuous mineralogy for mine geology/ore control, concentrators, leach operations, and smelter support. It will also increase the capabilities of technical service centers for mining companies, commercial laboratories, large drilling programs or pilot test campaigns. In combination with a highly automated sample preparation lab (sizing, potting and polishing), TIMA technology can establish high-throughput and fast-turnaround automated mineralogy lab modules for mine-site production support.

Sample magazine	Up to 100 resin blocks ø 30 mm or ø 25 mm  (the sample size must be specified at the time of placement of the order)
	Belt conveyer system easily accessible for sample loading
Sample holder	Special sample holder with an integrated BSE/EDX calibration standard and Faraday cup
Loading Mechanism and Cartridge design	Sample surface safe from scratches
	Guaranteed constant working distance for samples of various heights

The retractable STEM detector (R-STEM) is a new version of the STEM detector in addition to the fixed STEM detector version. The detector is designed with the respect to broad application range of the STEM in SEM/FIB-SEM.

 

The main features of the retractable STEM detector:

 

• Multiple samples can be observed without breaking the chamber vacuum
• Simultaneous acquisition of the Bright Field and the Dark Field signal
• The sample can be moved up and down relative to the detector to reach the best imaging conditions
• The sample can be tilted independently of the detector
• Acquisition of larger areas using Image Snapper is possible
• The detector can be fully retracted from the chamber

 

Multiple Sample Holder
The sample holder is designed for up to 8 TEM standard grids to enable quick change of the samples above the detector.

 

TEM Lamella Holder
System of exchangeable single grid holders allows easy sample handling optimized for lift out grid manipulation.

The Focused Ion Beam (FIB) and the Scanning Electron Microscopy (SEM) are essential techniques for many applications. FIB modifies the sample by the milling or, when accompanied by the Gas Injection System (GIS), by the deposition; SEM is used for imaging of resulting shapes at the high resolution, for charge compensation, or as a source of electrons for other analytical techniques. Common FIB-SEM instruments allow creation and imaging of a broad range of shapes. The most important shape is the cross section, which is used both for sectioning the sample and TEM sample preparation, by milling two cross sections at both sides of TEM sample. The high quality of the cross section surface is crucial, with no damage or artifacts. To be able to detect small  structures, it is also important to stop FIB milling at the right time, by utilizing SEM observation during the cross section polishing process.

 

The common width and depth of the cross section milled by Ga FIB are in order of several 10 μm. For larger cross sections with dimensions in order of several 100 μm, Xe plasma FIB installed on FERA3 instrument is much more efficient. As the surface milled by Xe plasma FIB is often not as smooth as the surface milled by Ga FIB, showing unpleasant curtaining artifacts, the quality has to be improved by tilting the sample and by milling from different directions.

 

This makes cross-sectioning process more difficult, time consuming and less accurate. To overcome these drawbacks, a novel method has been developed to greatly improve the surface quality, while keeping the milling process easy and accurate. Commonly used eucentric sample stages allow the tilting only around the axis perpendicular to both FIB and SEM columns. The main problem of this approach is the absence of SEM imaging during FIB milling process, in a case the sample requires milling from different directions to reduce the curtaining effect. Without the possibility of SEM imaging during the polishing process, the polishing is very difficult, as it requires pausing the polishing process and changing the stage position to check the cross section quality from time to time. This makes the polishing process less accurate, it is difficult to stop milling when desired point/structure is reached and to minimize the curtaining artifacts. The novel multi-tilt Rocking Stage enables an additional tilting also in the plane of the cross section. The proposed method (Fig. 1) enables controlling the whole milling/ tilting process by SEM imaging, which is essential for the precise end-point detection. This is illustrated on a real solder bump sample (Fig. 2).