Magnetron sputter coating for ultra high resolution Scanning Electron Microscopy (Simultaneous coating of platinum and tungsten using a magnetron sputter coater)

1989 ◽  
Vol 47 ◽  
pp. 80-81
Author(s):  
K. Ogura ◽  
S. Adachi ◽  
T. Satoh ◽  
T. Watabe ◽  
M. M. Kersker
Keyword(s):  
High Resolution ◽  
Carbon Film ◽  
Metal Coating ◽  
Specimen Surface ◽  
Gas Atmosphere ◽  
Sputter Coating ◽  
Resolution Imaging ◽  
Magnetron Sputter ◽  
Ar Gas ◽  
Scanning Electron

The resolution of the SEM has been remarkably improved by means of the in-lens SEM with a field emission gun. Consequently, the thin metal coating on the specimen surface for ultra high resolution imaging has become very important. In the age of imaging with 2-3nm resolution at 100,000x magnification, a very thin platinum (Pt) coating on the specimen surface using the magnetron sputter coater has yielded successful results. However, in an ultra high resolution scanning electron microscope with better than 1nm resolution at higher than 200,000: magnification, the fine granularity of magnetron sputter coating of Inra thick Pt will be observed on the specimen surface. Therefore, a thinner metal coating with smaller grain size than that of Pt is strongly required. Recently, we tried tungsten (W) coating on many variety of specimens in argon (Ar) gas atmosphere by using a magnetron sputter coater. Using a W coated carbon film, the granularity of W was examined by both an UHR-SEM and a TEM at a minimum magnification of 250,000x.

scholarly journals High-Resolution Imaging of Dried and Living Single Bacterial Cell Surfaces: Artifact or Not?

2011 ◽  
Vol 19 (5) ◽  
pp. 22-25 ◽  
Author(s):  
Dominik Greif ◽  
Daniel Wesner ◽  
Dario Anselmetti ◽  
Jan Regtmeier
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Metal Coating ◽  
Environmental Scanning ◽  
Cell Surfaces ◽  
Critical Point Drying ◽  
Resolution Imaging ◽  
Sem Imaging ◽  
Scanning Electron

When studying highly resolved scanning electron microscope images of cell surfaces, the question arises, whether the observed patterns are real or just artifacts of the cell preparation process. The following steps are usually necessary for preparation: fixation, drying, and metal coating. Each step might introduce different artifacts. Clever techniques have been developed to dry cells as gently as possible, for example critical point drying with different organic solvents and CO2. Instrument manufacturers also have taken account of this issue, for example, through the realization of the environmental scanning electron microscope (ESEM), operating with a low-vacuum environment saturated with water so that samples might stay hydrated. Another approach is the extreme high-resolution scanning electron microscope (XHR SEM), where the electron beam is decelerated shortly before reaching the sample. This technique requires no metal coating of the sample. Cryo-SEM also may be used, where no sample preparation is required beyond freezing in a high-pressure freezer or other cryo-fixation device. Then the cell can be examined in the frozen, hydrated state using a cryostage. However, at least some kind of preparation is necessary for SEM imaging, and we wanted to find out what changes the preparation makes on the cell surface.

Reduction of contamination using a specimen heating holder in an ultra high resolution Scanning Electron Microscope

1989 ◽  
Vol 47 ◽  
pp. 724-725
Author(s):  
K. Ogura ◽  
A. Ono ◽  
M. M. Kersker
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Electron Probe ◽  
Carbon Film ◽  
Specimen Surface ◽  
Gas Molecules ◽  
Sem Imaging ◽  
Coated Carbon ◽  
Scanning Electron

In general, various improvements have been made to SEM vacuum systems, and clean high vacuum specimen chambers are now routinely available. However, in the ultra high resolution scanning electron microscope, the prevention or reduction of contamination on the specimen surface has recently become an important subject when SEM imaging is done at higher than 200,000x magnification using a very fine electron probe. Typically, the specimen carries hydrocarbon gas molecules which are the source of the contamination, into the SEM. They adhere not only to the specimen surface but may also incorporated in the specimen, most typically in biological specimens, and cannot be reduced by the anti-contamination device of the SEM. Recently, a specimen heating holder was used in a JSM-890 ultra high resolution SEM, to reduce the contamination deposition on the specimen surface during SEM imaging. Using this holder, the specimen can be heated up to 300°C inside the SEM. Images 1 to 4 in Fig. 1 are the secondary electron images showing the cone-shaped deposition of contamination on a platinum-coated carbon film at different heating temperatures. This platinum-coated film, which had been kept in wet and oily atmosphere for several weeks to insure it was well covered with hydro carbon gas molecules, was irradiated by an electron probe in a spot mode for 30sec. with 1×10−11 Amp. of probe current at 20kV. After the electron probe irradiation, the platinum-coated carbon film was tilted 45° for imaging. Image 1 in Fig. 1 shows the cone-shaped deposition of contamination when the specimen was not heated. Image 2 was at 35°C, Image 3 was at 55°C, and Image 4 in Fig. 1 was at 115°C. At higher than 120°C specimen heating temperature, the cone-shaped deposition of contamination could not be observed any more. On the other hand, we can heat up the specimen outside the SEM before we put the specimen into the SEM. Image 5 in Fig. 1 shows the results of specimen heating by a hair dryer. The same platinum- coated carbon film was heated by a hair dryer for 1 minute before it was intro- duced into the SEM, and was irradiated by the electron probe for 15, 30, and 45sec. in a spot mode. This 1 min. heating by a hair dryer shows almost same result as 55°C specimen heating in the SEM.

High-resolution scanning electron microscopy in biology

1990 ◽  
Vol 48 (3) ◽  
pp. 14-15
Author(s):  
Keiichi Tanaka
Keyword(s):  
High Resolution ◽  
Immunoglobulin M ◽  
Metal Coating ◽  
Biological Macromolecules ◽  
Ultrahigh Resolution ◽  
Preparation Methods ◽  
Low Contrast ◽  
Almost All ◽  
Charging Effect ◽  
Scanning Electron

With the development of scanning electron microscope (SEM) with ultrahigh resolution, SEM became to play an important role in not only cytology but also molecular biology. However, the preparation methods observing tiny specimens with such high resolution SEM are not yet established.Although SEM specimens are usually coated with metals for getting electrical conductivity, it is desirable to avoid the metal coating for high resolution SEM, because the coating seriously affects resolution at this level, unless special coating techniques are used. For avoiding charging effect without metal coating, we previously reported a method in which polished carbon plates were used as substrate. In the case almost all incident electrons penetrate through the specimens and do not accumulate in them, when the specimens are smaller than 10nm. By this technique some biological macromolecules including ribosomes, ferritin, immunoglobulin G were clearly observed.Unfortunately some other molecules such as apoferritin, thyroglobulin and immunoglobulin M were difficult to be observed only by the method, because they had very low contrast and were easily damaged by electron beam.

FIB Enhancement of Mechanically Polished Cross-sections

2019 ◽  
Author(s):  
Becky Holdford
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Resolution Imaging ◽  
Chemical Attack ◽  
Resolution Imaging ◽  
Scanning Electron

Abstract On mechanically polished cross-sections, getting a surface adequate for high-resolution imaging is sometimes beyond the analyst’s ability, due to material smearing, chipping, polishing media chemical attack, etc.. A method has been developed to enable the focused ion beam (FIB) to re-face the section block and achieve a surface that can be imaged at high resolution in the scanning electron microscope (SEM).

Modifications Needed for Performing High-Resolution Cryosem in a Hitachi S-4700 Fesem Using an Emitech K1250 Cryo-Preparation System

2001 ◽  
Vol 7 (S2) ◽  
pp. 720-721
Author(s):  
Ya Chen ◽  
Chris Frethem ◽  
Stanley L. Erlandsen
Keyword(s):  
High Resolution ◽  
Thermal Contact ◽  
Control Unit ◽  
Thermal Capacity ◽  
Electron Beam Evaporation ◽  
Sample Holder ◽  
Sputter Coating ◽  
Magnetron Sputter ◽  
Sample Transfer ◽  
Transfer Device

Cryo-techniques have been successfully used in scanning electron microscopy (SEM). They are especially promising for high-resolution SEM to improve specimen preservation and reduce radiation damage [1, 2]. A number of cryo-preparation systems are commercially available for SEM, however, our experience has shown that modifications are needed to perform highresolution imaging (>50,000x).Emitech K1250 system consists of a sample preparation chamber, control unit, and cryo-stage. Magnetron sputter coating is standard and electron-beam evaporation is optional. A vacuum transfer device facilitates the sample transfer between the preparation chamber and the SEM to prevent contamination. The Emitech cryo-stage replaces the Hitachi S-4700 standard stage and the cryo-stage temperature is monitored and controlled by the Emitech control unit.The specimen is mounted on a sample holder that mounts to the cryo-stage. Therefore, the distance from the specimen to cryo-stage, the thermal capacity of the sample holder, and the thermal contact between them will affect the actual temperature of the specimen.

scholarly journals High-resolution imaging by scanning electron microscopy of semithin sections in correlation with light microscopy

Microscopy ◽  
2015 ◽  
Vol 64 (6) ◽  
pp. 387-394 ◽  
Author(s):  
Daisuke Koga ◽  
Satoshi Kusumi ◽  
Ryusuke Shodo ◽  
Yukari Dan ◽  
Tatsuo Ushiki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Light Microscopy ◽  
High Resolution Imaging ◽  
Semithin Sections ◽  
Resolution Imaging ◽  
Scanning Electron

High Resolution Fesem Study of Au Particle Growth on TiO2

1997 ◽  
Vol 3 (S2) ◽  
pp. 405-406
Author(s):  
F. Cosandey ◽  
L. Zhang ◽  
T. E. Madey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Surface Science ◽  
Particle Growth ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Sensitivity And Selectivity ◽  
Resolution Imaging ◽  
Scanning Electron

Transition metals supported on oxides have important catalytic properties and are also used in chemical gas sensors for increasing sensitivity and selectivity. In order to understand growth and reactivity in the Au/TiO2 system, we have performed surface studies on a model system consisting of ultrathin, discontinuous Au films on TiO2 (110) single crystals. In this paper we are presenting results obtained by high resolution scanning electron microscopy (HRSEM) on the effects of substrate temperature and average Au thickness on particle size, density and coverage.The TiO2 (110) single crystal surfaces used in this study were prepared in UHV using surface science tools followed by in-situ Au deposition for different substrate temperatures and for various film thicknesses. After deposition, the samples were transferred in air to the Field Emission Scanning Electron microscope (LEO 982 Gemini) for high resolution imaging.Typical high resolution scanning electron microscopy (HRSEM) images of Au films deposited at 300 K are shown in Fig. 1 for two film thicknesses of 0.22 and 1.0 nm.

scholarly journals Improving the Resolution of Sputter-coated Films

2000 ◽  
Vol 8 (2) ◽  
pp. 16-17
Author(s):  
Mary Mager
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
High Resolution ◽  
Carbon Film ◽  
Metal Films ◽  
Pure Gold ◽  
High Magnification ◽  
Conducting Film ◽  
Scanning Electron

After an inquiry from the Microscopy Listserver, I went back to my 1980 copy of Scanning Electron Microscopy, volume I. Several authors had investigated the structure of thin metal films by depositing the films onto carbon-film-covered TEM grids and imaging the films at high magnification. There were several proposals for new devices that have since become standards for high-resolution coaters, but the Listserver inquiry was for a fine conducting film suitabie for high-resolution SEM from an existing sputter coater.There were several factors studied that influenced the fine structure of the films. The first was the materials sputtered: for a given set of conditions of voltage, current and time, platinum gave the finest film, 60% gold-40% palladium (Au/Pd) the next finest and pure gold the least fine.

High-Resolution Field Emission Scanning Electron Microscopy (FESEM) Imaging of Cellulose Microfibril Organization in Plant Primary Cell Walls

2017 ◽  
Vol 23 (5) ◽  
pp. 1048-1054 ◽  
Author(s):  
Yunzhen Zheng ◽  
Daniel J. Cosgrove ◽  
Gang Ning
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
High Resolution ◽  
Field Emission ◽  
Cell Walls ◽  
Cellulose Microfibrils ◽  
Critical Point Drying ◽  
Sputter Coating ◽  
Scanning Electron

AbstractWe have used field emission scanning electron microscopy (FESEM) to study the high-resolution organization of cellulose microfibrils in onion epidermal cell walls. We frequently found that conventional “rule of thumb” conditions for imaging of biological samples did not yield high-resolution images of cellulose organization and often resulted in artifacts or distortions of cell wall structure. Here we detail our method of one-step fixation and dehydration with 100% ethanol, followed by critical point drying, ultrathin iridium (Ir) sputter coating (3 s), and FESEM imaging at a moderate accelerating voltage (10 kV) with an In-lens detector. We compare results obtained with our improved protocol with images obtained with samples processed by conventional aldehyde fixation, graded dehydration, sputter coating with Au, Au/Pd, or carbon, and low-voltage FESEM imaging. The results demonstrated that our protocol is simpler, causes little artifact, and is more suitable for high-resolution imaging of cell wall cellulose microfibrils whereas such imaging is very challenging by conventional methods.

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