The Advanced Microsocpy Facility houses scanning EM, FIB and other sample preparation instruments. In April 2012 we will become home to the highest resolution microscope in the world, the Hitachi HF-3300V scanning transmission electron microscope.
Hitachi S-4800 FESEM
With a cold field emission electron source for high resolution, ExB in-lens filter and a host of other features, our Hitachi S-4800 field emission scanning electron microscope is an extremely powerful and flexible tool.
Our S-4800 SEM in place
Specifications
Specifications
- 0.5 kV to 30 kV accelerating voltage
- 1 nm resolution at 15 kV, 1.4 nm at 1 kV
- Magnification from 30x to 800,000x
- Maximum specimen size = 100 mm
- Super ExB filter technology
- Dry vacuum system
- X+Y motorized eucentric stage with trackball interface (tilt and Z by manual control)
- Ring-type YAG backscatter detector
- Bruker Quantax EDS System for X-ray spectroscopy.
Instrument instructions
Instrument instructions
Sample images
Sample images
Other resources
Other resources
- Online articles, papers, and other online resources on scanning electron microscopy are here
Workshop quizzes
Workshop quizzes
Quiz questions for the workshops can be found in two ways: as PDF downloads below, or in the online quiz system.
Hitachi HF-3300V STEHM
Currently under construction, the scanning transmission electron holography microscope installation will begin in May 2012. The scanning transmission electron holography microscope (STEHM) will both achieve a STEM electron probe size and TEM spatial resolution approaching forty picometers.
Instrument specifications:
- Highest brightness and most stable cold-field electron emitter
- 60 keV to 300 keV operation
- Spherical aberration and coma corrected for TEM imaging
- Four electron biprisms for many types of electron holography
- Imaging energy filter (GIF) for energy-filtered electron holography
Rodney Herring (UVic Mechanical Engineering and Director of the Advanced Microscopy Facility) and John Braybrook (UVic Purchasing) recently travelled to Japan to sign off on the new STEHM at the Hitachi Nakaworks factory. It is currently located in Germany at CEOS, for further modifications.
Recent photographs of the STEHM
Recent photographs of the STEHM
Below are the first photographs of the STEHM, in Hitachi's Naka Works in Japan. At this time, the system had already exceeded the guaranteed resolution specification, and was on its way to Germany to get its Cs + Cc corrector for STEM and Cs + coma corrector for TEM, which will improve its resolution further.
Dr. Rodney Herring and the Hitachi HF-33XX STEHM
John Braybrook and the Hitachi HF-33XX STEHM
Below is a photograph of the STEHM in CEOS's facility in Germany, after having its correctors installed.
Rodney Herring, John Braybrook and the Hitachi HF-3300V STEHM, with correctors installed at CEOS, Germany
The best resolution microscope ever built
The best resolution microscope ever built
The Scanning Transmission Electron Holography Microscope (STEHM) will be the best high-spatial resolution microscope ever constructed and it will maintain its high position at the forefront of this rapidly moving competitive technology for many years. The STEHM will build upon the fundamentals of a standard electron microscope, which uses electrons rather than light, to give unsurpassed capabilities to see and measure the properties of a hidden world that we know exists.
The electron has a wavelength one million times smaller than light and the spatial resolution of the STEHM will approach its wavelength, i.e., approximately two picometers. The electron also carries a charge and magnetic moment, which can be used by electron holography to interrogate the electronic properties of atoms.
Opening new worlds
Opening new worlds
At the time of van Leeuwenhoek in the 1600’s, the light microscope using finely ground lenses was considered to be the highest level of technology made as it was able to resolve living cells. The STEHM is in the same league, relateively speaking, as its lenses will give direct observation of hitherto unobservable quantum phenomena by using electrons [1]. Electron holography is a special method of microscopy measuring both the amplitude and phase of a material. A hologram is created by the interference of two or more beams giving three-dimensional information at the atomic level. The phase is additional information not provided by other forms of microscopy. The phase measures the refractive index or more precisely for electrons, the mean inner potential of the specimen, which can be used to determine the specimen’s absolute composition, internal strain, electrostatic fields, magnetic fields and temperature.
A little bit about technology
A little bit about technology
Recent developments in the modularity of electron microscopes allow this first-of-a-kind microscope to be constructed. These developments, which significantly increase the STEHM’s capabilities, include:
- A cold-field emitting electron source to increase its coherence (like a laser) and to decrease the energy spread of the electron beam
- Spherical (Cs), chromatic (Cc) and coma aberration correctors to increase the microscope’s information capability
- Multiple electron biprisms to enhance the spatial resolution and to enable the creation of new forms of microscopy for new capabilities
- A large CCD detector to better measure the gray scale of fringes produced in holograms and a fine-movement specimen stage to help invent confocal electron holography
The Cs + Cc correctors improve the spatial resolution to picometers, substantially better than angstroms, which is the recent state-of-the art. The Cs corrector localizes the information in lattice images so the contrast of a lattice position in the image has a one-to-one correspondence with an atomic position, whereas without these correctors this is not possible. A Cs + Cc corrector reduces the point spread function to the dimensions of the electron probe enabling the sampling of the specimen at sub-atomic dimensions. Both aberration correctors will make it possible to see atomic columns that don’t have to be interpreted and previously hidden positions of atoms, and, when used by electron holography, measure the electron density between the atoms.
Multiple electron biprisms substantially improve the spatial resolution of holograms by separating the contrast of the fringes from the interference width of the holograms. The use of three biprisms placed below the specimen permits flexible control of all of the interference parameters, ie., the interference region, fringe spacing and fringe angle, involved in electron holography [2]. Scanning-beam electron holography is made possible by placing an additional biprism above the specimen. Multiple biprisms enable
many forms of electron holography to be possible, as envisioned by Cowley [3]. For example, holography typically reconstructs its holograms outside of the microscope using Fourier transform methods. Two electron biprisms enable the hologram to be reconstructed inside the microscope so a phase image of the specimen can be directly observed during the experiment. Multiple electron biprisms also enable the creation of confocal electron holography, which will be used to make three-dimensional measurements of the physical, electrostatic and magnetic properties of a specimen.
The cold-field emission source will make it possible to see the bandgap electrons, holes, excitons, phonons and plasmons of materials used in electronic, photonic and magnetic devices so their properties can be measured by energy-filtered electron holography. These measurements will answer many fundamental questions of science and engineering. The phase measurements of the electrostatic field strength existing between atoms provide a direct insight into the basic bonding configurations, which is information currently lacking by science.
Measuring material properties
Measuring material properties
Energy-filtered electron holography, which combines electron holography with the imaging energy filter (GIF) will make it possible to characterize the coherence properties of surface plasmons and surface phonons (two energy filters used) of carbon nanotubes (CNT) that are responsible for the observed ballistic electron mobility and excellent heat conduction.
Researchers will also use the STEHM to measure the physical properties (strength) of carbon nanotubes using a modified specimen holder. This information will help the implementation of CNTs as field emitters, heat conductors and in structural components.
Also, this configuration of the STEHM will make it possible to measure the coherence of phonons on the B planes in MgB2 and possibly Cu-O planes in high temperature superconductors that are a possible source of their superconducting properties.
Electron holography is the only means possible to measure the dimension of the electrostatic field between the source and drain of field emission transistors.
Similarly, high-resolution electron holography should be able to measure the orientation of the spinning electron’s magnetic field to characterize spintronic devices.
Other unique capabilities include the measurement of the composition and defect density of self-assembled nanodots for nanotechnology, the domain structures of magnetic materials, which when combined with the Cs + Cc correctors may be able to measure the dimension and properties of the domain boundaries and their triple points, which is now not possible by any means.
Useful to many research areas
Useful to many research areas
The new capabilities of the STEHM will make measurements to be used by researchers in engineering, physics, chemistry, materials science, biology and medical sciences. The STEHM will push the boundaries of research in nanotechnology: nanoelectronics, nanochemistry, bionanotechnology, nanophotonics, molecular devices, and diagnostics, for example.
[1] A. Tonomura, Direct observation of hitherto unobservable quantum phenomena by using electrons, Proceedings of the National Academy of Sciences of the USA, volume 102, number 42, pg 14952, 2005.
[2] K. Harada, T. Natsuda, A. Tonomura, T. Akashi, and Y. Togawa, Triple Biprism Electron Interferometry, Journal of Applied Physics, submitted.
[3] J.M. Cowley, Twenty forms of electron holography, Ultramicroscopy, volume 41, pg 335, 1992.
Hitachi FB-2100 FIB
The Hitachi FB-2100 Focused Ion Beam system is used for making TEM specimens of hard and soft materials and their combination, useful for engineers, physical scientists and life scientists, and for making TEM specimens containing different types of tissue, for example tissue growing on implants.
Our FB-2100 FIB in place
Specifications
Specifications
- 10 to 40 kV accelerating voltage
- 6 nm or better resolution
- Magnification range from 700x to 90,000x
- Maximum current of 40 nA at 40 kV
- Liquid gallium metal ion source
- 100 mm specimen diameter
- Actuated TEM holder stage
- Actuated SEM holder stage
- Actuated pick/place probe
- Tungsten deposition system
Samples can be cut using layouts created on the instrument's control computer, by importing a vector file via ftp, or by importing a bitmap image via ftp.
Hitachi High-Technologies Europe has a FB-2100 brochure, which contains a very good description of the instrument's capabilities.
Software and technical information on particle interactions with matter.
Instrument instructions
Instrument instructions
Fabrication examples
Fabrication examples
Other resources
Other resources
Downloads
Downloads
Finding sample location when switching instruments
Now available for download, an Excel spreadsheet for calculating the new coordinates of a fabrication point when you move the sample from the FIB to the SEM, or out of the FIB and then back into the FIB at a later date.
Many samples are made on gold coated glass slides, and the fabricated structure must be located far away from any reference marker. Previously, the method was to place a fine-point black Sharpie marker dot on the glass slide, and do your fabrications nearby this mark. That is not always desired. In some situations it would be ideal to place the fabricated structures out in the middle of the glass slide. This makes them very difficult to find later. Not only are the coordinate systems different in the two instruments, but chances are your sample will be rotated when you move the stub to the other instrument. To combat this problem and to allow you to find your sample point easily, use the following method:
- Place two reference marks (use a fine-point black Sharpie marker) anywhere on the glass slide prior to putting the sample into the FIB. These marks can be placed anywhere, but to reduce errors place them far apart from each other.
- Use the FIB to make a reference mark in each of the Sharpie dots. The reference mark should be a font letter A or B, and a cross marker. Record the X and Y coordinates of the cross marker at both locations A and B.
- Navigate to an arbitrary location in the glass slide where you want to fabricate your structure. Record the X and Y coordinates of this location P.
- When you move the sample to the SEM or back into the FIB at a later date, locate the cross marker at A and B, and record their coordinates.
- Input A, B, P, and the new coordinates of A' and B' into the spreadsheet. It will calculate the new location of P' where your fabrication point is located.
Finding the center point of a rotated square
For available for download, an Excel spreadsheet for calculating the center of a rotated square. Useful for finding the centerpoint of a SiN window. Simply use the FIB to navigate to the four corners of the square, record the coordinates, and enter them into the spreadsheet. The center coordinates are then computed.
Computing focus as a function of position on a plane
Now available for download, an Excel spreadsheet for calculating focus values as a function of position, on a plane. If you are fabricating on a gold-coated glass slide, it is useful to be able to move to a position or a number of positions that are distant from each other, and cut your structure without first looking at the sample to check the focus. This maintains the pristine condition of the gold coating at your structure position.
Since the glass slide is flat, but possibly tilted in three axes, it is necessary to compute the equation of the plane, where x and y are the coordinates, and z is the focus value F. To do this, go to three positions on the glass slide, and record the x, y, and focus values. Put these values into the spreadsheet as Point 1, Point 2, and Point 3. The spreadsheet will calculate the plane equation coefficients A, B, C, and D. Then enter your x and y coordinates of the point in question, and the spreadsheet will tell you the focus value at that point. Simply go into calibration mode, change the focus value to that number, register the beam, and then switch back to fabrication mode. Move the stage to the desired x and y coordinates, and then you can cut the pattern blind without looking at the sample first.
Font bitmap files
Now available for download, font bitmap files for use on the FIB. Create indicator marks, write notes on your sample, and more. Contains numerals 0 to 9, and capital letters A to Z.
Generating bitmaps
To generate bitmap images of grids of elements (such as circles, squares, rectangles, or other more complicated features) for use on the FIB, use the Matlab function makegrid.m, along with one of the helper functions plotcircle.m, plotsquare.m, plotrectangle.m, or plotantenna.m. The helper functions are provided as working samples, you can create arbitrary ones. To generate the bitmap, do the following:
- Use makegrid.m and one of the helper functions to make a figure containing the grid of elements. The function templates are:
makegrid(function_name,element_params,num_elements_x,spacing_x,num_elements_y,spacing_y)
plotcircle(X,Y,element_params) [all the helper functions have the same template]
element_params is an arbitrary length vector containing [width, height, ... ] where [...] are parameters you can use to define some arbitrary element.
Examples of use would be:
- makegrid('plotcircle',[50],5,400,10,600)
This makes a grid of 50 nm diameter circles, 5 in the horizontal direction with 400 nm center spacing, and 10 in the vertical direction with 600 nm center spacing.
- makegrid('plotsquare',[50],5,400,10,600)
This makes a grid of 50 nm x 50 nm squares, 5 in the horizontal direction with 400 nm center spacing, and 10 in the vertical direction with 600 nm center spacing.
- makegrid('plotrectangle',[50,100],5,400,10,600)
This makes a grid of 50 nm wide x 100 nm high rectangles, 5 in the horizontal direction with 400 nm center spacing, and 10 in the vertical direction with 600 nm center spacing.
- makegrid('plotantenna',[300,200,30,30],5,400,10,600)
This makes a structures that consist of an outer box and two nested interior boxes, 5 in the horizontal direction with 400 nm center spacing, and 10 in the vertical direction with 600 nm center spacing.
See documentation in the files. This makes a figure with units in nanometers.
- On the figure window, use file -> saveas and save as encapsulated postscript.
- Open this file with Photoshop. When you open it, make the height so that 1 pixel = 1 nanometer. This ensures the image is large enough so circle resolution is fairly decent. So for a 10x10 grid of 200 nm circles with 400 nm center spacing, the image size would be (10-1)*400 + 200 = 3800 px high.
- Make the image grayscale: Image -> Mode -> Grayscale.
- Make it a 1 bit image, use the Posterize function: Image -> Adjustments -> Posterize, set value to 2.
- Depending on how you write your subfunction, you may or may not have to invert the image so the elements are black and the background is white. The provided plotcircle(), plotsquare(), and plotrectangle() build arrays of filled elements on a white background. plotantenna() does not. If your subfunction makes filled elements you don't need to do anything, otherwise:
- Use paint bucket tool, and fill the space between the circles with black.
- Use: Image -> Adjustments -> Invert.
- Use the crop tool, and crop to 2000 px by 2000 px.
- Save as .bmp file format.
Workshop quizzes
Workshop quizzes
Quiz questions can be found in two ways: as PDF downloads below, or in the online quiz system.
Fischione 1010 Ion Mill
The Fischione 1010 Ion Mill is a precision ion mill and polishing system for TEM specimens.
Specifications
Specifications
- PC-controlled table top system
- Fully programmable and easy to use
- Includes liquid nitrogen specimen cooling option, and chemical etching option
Fischione 1020 Plasma Cleaner
The Fischione 1020 Plasma Cleaner is used to clean TEM and SEM specimens and specimen holders.
Specifications
Specifications
- A low energy reactive gas plasma cleans without changing the specimen's elemental composition or structural characteristics
- Removes hydrocarbons from surfaces such as electron microscopy specimens and specimen holders
- Easy to use front panel controls
Instrument use instructions
Instrument use instructions
These instructions are also available for download in pdf format.
Operating instructions:
- Open the main gas supply tank valve.
- Adjust the regulator knob so the gauge reads 10 psig.
Note: failure to turn on the supply gas at the required pressure will result in damage to the plasma cleaner.
- Ensure the unit is plugged into the wall socket.
- Turn on the unit with the small on-off switch located on the back of the instrument beside the power cable connection.
- If a sample holder or blank is installed in the plasma cleaner chamber port and the HIGH VACUUM indicator is lit, the instrument will need to be vented prior to loading your specimen:
- Press the VENT button on the front panel, wait until the ATMOSPHERE indicator is lit.
- Gently remove the specimen holder or blank from the plasma cleaner chamber port.
- Load your specimens (TEM or SEM) on the appropriate holder, re-install holder in plasma cleaner chamber port.
- Press the PUMP button on the front panel, wait until the HIGH VACUUM indicator is lit.
- Enter cleaning time in minutes:seconds using the numerical buttons on the front panel.
- Press SET to begin plasma cleaning. The minutes:seconds display will flash for a short while as the instrument starts up. Once cleaning begins the time will count down and the purple plasma glow will be visible through the glass window on the side of the instrument tower.
- Once the timer hits zero, press VENT to vent the chamber to atmospheric pressure, wait until the ATMOSPHERE indicator is lit.
- Gently remove specimen holder.
- When finished cleaning, place a specimen holder or blank into the plasma cleaner chamber port, press PUMP button on the front panel.
- Once the HIGH VACUUM indicator is lit, turn off the instrument with the small on-off switch located on the back of the instrument beside the power cable connection. The instrument will remain at high vacuum until the next use.
- Turn off the main gas supply tank valve.
Anatech Hummer VI metal sputter coater
The Anatech Hummer VI is a metal sputter coater currently setup with a Gold-Palladium target. It is used to apply a metal coating to non-conductive samples for imaging the in the SEM.
Specifications
Specifications
- Continuous and pulse modes
- Degauss function to remove static charge from samples
- Gold-Palladium alloy target
Instrument use instructions
Instrument use instructions
These instructions are also available for download in pdf format.
Notes:
- Do not over tighten the nitrogen supply needle valve, or it will be damaged. When closing this valve, once you feel resistance, STOP IMMEDIATELY.
- Do not touch anything inside the chamber without first wearing gloves.
Operating instructions:
- Ensure power switches are off.
- Put on gloves.
- Lift open chamber lid, do not shake or move top suddenly to prevent target from detaching.
- Lift off glass cylinder, place on it's side on the stand provided on top of the sputter coater.
- Place sample stub(s) inside chamber. Sample stub should be 1.5 inches from the target. If sample height needs adjusting, please consult staff.
- Replace glass cylinder, and lower chamber lid into place.
- Gently apply pressure to the chamber lid, and turn on the power switch. Once the vacuum pump starts and vacuum gauge shows vacuum, you can release pressure on the chamber lid.
- Adjust needle valve to closed position (DO NOT OVERTIGHTEN), and allow chamber to pump down to approximately 30 mTorr.
- Turn on the Argon gas valve at the top of the tank.
- Open needle valve wide to flush chamber with Argon, allow vacuum gauge to read 500 mTorr or higher. Close needle valve, and wait for chamber to pump down to approximately 30 mTorr.
- Repeat flushing of chamber once more.
- Adjust needle valve so there is between 55 mTorr to 70 mTorr of Argon in the chamber.
- Turn on high voltage control switch, and adjust voltage control knob until plasma discharge current reads 10 mA.
- It may be necessary to make slight adjustments to needle valve and voltage dial to maintain a plasma discharge current of 10 mA.
- Start your timer as soon as you see the plasma glow.
- Once your desired timer has expired, turn off the high voltage control switch, and open the needle valve wide open to flood the chamber back to atmospheric pressure.
- Lift the lid, extract your sample(s). Return lid to closed position.
- Turn off Argon gas supply valve at the top of the tank, unplug sputter coater.
Cressington 208 carbon coater
The Cressington 208carbon is used to apply a thin carbon layer to non-conductive samples prior to SEM imaging, and is suitable for imaging at higher magnifications where metal sputter coating particles become visible.
Specifications
Specifications
- Microprocessor controlled automatic mode, plus manual mode
- Continuous and pulsed mode
- Manual tilt, motorized rotating stage
- Thickness monitor
Instrument use instructions
Instrument use instructions
These instructions are also available for download in pdf format.
Notes:
- Do not touch anything inside the chamber without first wearing gloves.
- Each sharpened carbon rod will typically yield three to four runs of six seconds each. If you start the coating run and it stops before the predermined time, the rod must be replaced.
- Please ask staff for assistance in loading new carbon rods into the instrument.
Operating instructions:
- Put on gloves.
- Open top of chamber.
- Lift off cylinder and place on clean cloth.
- Put in samples and check they stay in place when stage is spinning.
- Replace glass cylinder.
- Close top.
- Turn on power switch.
- When vacuum reaches better than 10-4 (takes about five minutes), turn on rotating stage, press Auto and then press Start.
- Check thickness and repeat if necessary.