Development of an ultrahigh resolution objective lens pole-piece with high analytical capability for aberration corrected 300 kV microscope

2021 ◽  
Author(s):  
Ichiro Ohnishi ◽  
Keyword(s):  
Objective Lens ◽  
Pole Piece ◽  
Ultrahigh Resolution ◽  
Analytical Capability ◽  
Aberration Corrected

Development of 200kV ultrahigh-resolution analytical electron microscope

1989 ◽  
Vol 47 ◽  
pp. 108-109
Author(s):  
T. Kaneyama ◽  
M. Naruse ◽  
Y. Ishida ◽  
M. Kersker
Keyword(s):  
Electron Microscope ◽  
Optical Constants ◽  
Materials Science ◽  
Objective Lens ◽  
The Finite Element Method ◽  
Ultrahigh Resolution ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Characteristic Features ◽  
Better Than

In the field of materials science, the importance of the ultrahigh resolution analytical electron microscope (UHRAEM) is increasing. A new UHRAEM which provides a resolution of better than 0.2 nm and allows analysis of a few nm areas has been developed. [Fig. 1 shows the external view] The followings are some characteristic features of the UHRAEM.Objective lens (OL)Two types of OL polepieces (URP for ±10' specimen tilt and ARP for ±30' tilt) have been developed. The optical constants shown in the table on the next page are figures calculated by the finite element method. However, Cs was experimentally confirmed by two methods (namely, Beam Tilt method and Krivanek method) as 0.45 ∼ 0.50 mm for URP and as 0.9 ∼ 1.0 mm for ARP, respectively. Fig. 2 shows an optical diffractogram obtained from a micrograph of amorphous carbon with URP under the Scherzer defocus condition. It demonstrates a resolution of 0.19 nm and a Cs smaller than 0.5 mm.

Development of high-performance objective lens polepiece for ultrahigh resolution Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 254-255
Author(s):  
K. Fukushima ◽  
T. Kaneyama ◽  
F. Hosokawa ◽  
H. Tsuno ◽  
T. Honda ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Performance ◽  
Open Space ◽  
Materials Science ◽  
Objective Lens ◽  
Ultrahigh Resolution ◽  
Science Field ◽  
Specimen Holder ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Recently, in the materials science field, the ultrahigh resolution analytical electron microscope (UHRAEM) has become a very important instrument to study extremely fine areas of the specimen. The requirements related to the performance of the UHRAEM are becoming gradually severer. Some basic characteristic features required of an objective lens are as follows, and the practical performance of the UHRAEM should be judged by totally evaluating them.1) Ultrahigh resolution to resolve ultrafine structure by atomic-level observation.2) Nanometer probe analysis to analyse the constituent elements in nm-areas of the specimen.3) Better performance of x-ray detection for EDS analysis, that is, higher take-off angle and larger detection solid angle.4) Higher specimen tilting angle to adjust the specimen orientation.To attain these requirements simultaneously, the objective lens polepiece must have smaller spherical and chromatic aberration coefficients and must keep enough open space around the specimen holder in it.

scholarly journals Manufacturing and Investigating Objective Lens for Ultrahigh Resolution Lithography Facilities

Lithography ◽  
10.5772/8172 ◽  
2010 ◽  
Author(s):  
N.I. Chkhalo ◽  
A.E. Pestov ◽  
N. N. ◽  
Salashchenko ◽  
M.N. Toropov
Keyword(s):  
Objective Lens ◽  
Ultrahigh Resolution

Electrostatic Aberration Correction in LV-SEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 746-747 ◽  
Author(s):  
D.J. Maas ◽  
A. Henstra ◽  
M.P.C.M. Krijn ◽  
S.A.M. Mentink
Keyword(s):  
Electron Microscope ◽  
Low Voltage ◽  
State Of The Art ◽  
Spherical Aberration ◽  
Positive Definite ◽  
Ease Of Use ◽  
Objective Lens ◽  
Time Varying ◽  
Voltage Electron ◽  
Aberration Corrected

The resolution of a low-voltage electron microscope is limited by the chromatic and spherical aberration of the objective lens, see Fig. 1. The design of state-of-the-art objective lenses is optimised for minimal aberrations. Any significant improvement of the resolution requires an aberration corrector. Recently, correction of both Cc and Cs has been demonstrated in SEM, using a combination of magnetic and electrostatic quadrupoles and octupoles (Zach and Haider, 1995). The present paper presents an alternative design, which is based on a purely electrostatic concept, potentially simplifying the ease-of-use of an aberration corrected microscope.In 1936 Scherzer showed that the fundamental lens aberrations of round lenses are positive definite, in absence of time-varying fields and/or space charge. Negative lens aberrations, required for the correction of Cc and Cs, can only be obtained using non-round lenses, e.g. quadrupoles and octupoles (Scherzer, 1947).

Aberration-Corrected STEM: the Present and the Future

2001 ◽  
Vol 7 (S2) ◽  
pp. 896-897
Author(s):  
O.L. Krivanek ◽  
N. Dellby ◽  
P.D. Nellist ◽  
P.E. Batson ◽  
A.R. Lupini
Keyword(s):  
Spherical Aberration ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Objective Lens ◽  
High Angle ◽  
Successful Operation ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Full Speed ◽  
Aberration Corrected

Surprising as it may seem, aberration correction for the scanning transmission electron microscope (STEM) is now a practical proposition. The first-ever commercial spherical aberration corrector for a STEM was delivered by Nion to IBM Research Center in June 2000, and other deliveries have taken place since or are imminent. At the same time, the development of corrector hardware and software is still proceeding at full speed, and our understanding of what are the most important factors for the successful operation of a corrector is deepening continuously.Fig. 1 shows two high-angle dark field (HADF) images of [110] Si obtained with the IBM VG HB501 STEM operating at 120 kV, about 2 weeks after we fitted a quadrupole-octupole corrector into it. Fig. 1(a) shows the best HADF image that could be obtained with the corrector's quadrupoles on but its octupoles off. Sample structures were captured down to about 2.5 Å detail, easily possible in a STEM with a high resolution objective lens with a spherical aberration coefficient (Cs) of 1.3 mm. Fig. 1(b) shows a HADF image obtained after the Cs-correcting octupoles were turned on and the corrector tuned up. The resolution has now improved to 1.36 Å. This is sufficient to resolve the correct separation of the closely-spaced Si columns.

Modification of a TEM for ultra-high-vacuum reflection-EM (UHV-REM) applications

1995 ◽  
Vol 53 ◽  
pp. 582-583
Author(s):  
Tung Hsu ◽  
Min-Yi Shih ◽  
A. V. Latyshev
Keyword(s):  
Electron Microscope ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Pole Piece ◽  
High Energy Electron ◽  
Normal Position ◽  
Crystal Surfaces ◽  
Specimen Holder

A JEOL JEM-100C electron microscope was modified by adding a cryogenic UHV specimen holder for studying clean crystal surfaces with the reflection high energy electron diffraction (RHEED) and REM techniques. The Si(111) (l×l) and (7×7) phase transitions have been successfully observed (Fig. 1). Further modification is in progress for better resolution and other functions. Fig. 2.a shows the unmodified specimen holder and the objective lens of the microscope. The cryogenic holder based on the Novosibirsk design is shown in Fig. 2.b. Liquid nitrogen is continuously pumped through the shell of the holder for achieving UHV inside. The tilt/rotation controls and the current for heating of the specimen are fed through the holder. In this modification, the specimen was not placed at the normal position of the lens and therefore is not at the best position for imaging and diffraction.A new holder is shown in Fig. 2.c. This holder is inserted into the pole piece to place the specimen at the normal position.

Two “improvements” for Philips 400 series microscopes

1986 ◽  
Vol 44 ◽  
pp. 624-625
Author(s):  
A. E. Greene ◽  
J. A. Eades
Keyword(s):  
Magnetic Flux ◽  
Objective Lens ◽  
Pole Piece ◽  
Optimum Size ◽  
Lens System ◽  
Operating Characteristics ◽  
Maximum Area ◽  
Loss Of Information ◽  
Convergent Beam ◽  
Transmission Microscope

The optimum size for the disks in a convergent-beam pattern is when the disks just touch. This provides the maximum area of useful pattern indside the disks and avoids the loss of information where they overlap. In a standard transmission microscope, the size of the disk is selected by the size of the condenser aperture. This provides only a few possible settings with rather coarse steps.We have modified Philips EM420 and EM400T microscopes to provide a continuous variation of the convergence of the incident illumination. This is accomplished by adding a control to vary the ‘Mini’ lens current. The mini lens is located inside the objective lens upper pole piece and by reversal of its magnetic flux, gives the objective lens system two distinct operating characteristics.

Novel MEMS-Based Gas-Cell/Heating Specimen Holder Provides Advanced Imaging Capabilities forIn SituReaction Studies

2012 ◽  
Vol 18 (4) ◽  
pp. 656-666 ◽  
Author(s):  
Lawrence F. Allard ◽  
Steven H. Overbury ◽  
Wilbur C. Bigelow ◽  
Michael B. Katz ◽  
David P. Nackashi ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Dark Field ◽  
Objective Lens ◽  
Precise Control ◽  
Heating And Cooling ◽  
Specimen Holder ◽  
Early Results ◽  
Annular Dark Field ◽  
Electron Microscopes ◽  
Aberration Corrected

AbstractIn prior research, specimen holders that employ a novel MEMS-based heating technology (AduroTM) provided by Protochips Inc. (Raleigh, NC, USA) have been shown to permit sub-Ångström imaging at elevated temperatures up to 1,000°C duringin situheating experiments in modern aberration-corrected electron microscopes. The Aduro heating devices permit precise control of temperature and have the unique feature of providing both heating and cooling rates of 106°C/s. In the present work, we describe the recent development of a new specimen holder that incorporates the Aduro heating device into a “closed-cell” configuration, designed to function within the narrow (2 mm) objective lens pole piece gap of an aberration-corrected JEOL 2200FS STEM/TEM, and capable of exposing specimens to gases at pressures up to 1 atm. We show the early results of tests of this specimen holder demonstrating imaging at elevated temperatures and at pressures up to a full atmosphere, while retaining the atomic resolution performance of the microscope in high-angle annular dark-field and bright-field imaging modes.

Performances of an 80–200 kV microscope employing a cold-FEG and an aberration-corrected objective lens

Microscopy ◽  
2012 ◽  
Vol 62 (2) ◽  
pp. 283-293 ◽  
Author(s):  
Christian Ricolleau ◽  
Jaysen Nelayah ◽  
Tetsuo Oikawa ◽  
Yuji Kohno ◽  
Nadi Braidy ◽  
...  
Keyword(s):  
Objective Lens ◽  
Aberration Corrected
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