Resolution in the low-voltage SEM

1984 ◽  
Vol 42 ◽  
pp. 444-445
Author(s):  
David C Joy
Keyword(s):  
Spatial Distribution ◽  
High Resolution ◽  
Secondary Electron ◽  
Low Voltage ◽  
Incident Beam ◽  
Secondary Electron Image ◽  
Electron Image ◽  
Integrated Intensities

The resolution of a secondary electron image is determined by the spatial distribution of the secondaries leaving the surface. This distribution results from two components, SE1 which are the secondaries generated by the incident beam and which carry the high resolution information, and SE2 which are the secondaries produced by exiting electrons and which carry information mimicing that in the backscattered signal. The integrated intensities of these two components are comparable, but their spatial characteristies are quite different. In order to study the factors which limit resolution it is therefore necessary to model the events which give rise to the two groups of secondaries.

Image Formation With Upper and Lower Secondary Electron Detectors in the Low Voltage Field-Emission SEM

1998 ◽  
Vol 4 (S2) ◽  
pp. 260-261
Author(s):  
J. Liu
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Secondary Electron ◽  
Low Voltage ◽  
Incident Beam ◽  
Sample Surface ◽  
Backscattered Electrons ◽  
Sample Chamber ◽  
Scale Surface ◽  
Short Working

High-resolution secondary electron (SE) imaging was first demonstrated at 100 kV in the STEM a decade ago. High-resolution SE imaging is now routinely obtainable in field-emission SEMs. Although nanometer-scale surface features can be examined at low incident beam voltages we still do not fully understand the factors that affect the contrast of low voltage SE images. At high incident beam voltages, SE1 (SEs generated by the incident probe) and SE2 (SEs generated by backscattered electrons at the sample surface) can be spatially separated. SE1 carries high-resolution detail while SE2 contributes to background. At low incident beam voltages, however, the interaction volume of the incident electrons shrinks rapidly with decreasing incident beam voltage. Thus, both the SE1 and SE2 signals carry high-resolution information. At low incident beam voltages, SE3 (SEs generated by backscattered electrons impinging on the sample chamber, pole pieces and etc.) also carries high-resolution detail and contributes significantly to the collected signal, especially for high atomic number materials and at short working distances.

Single-Pole Objective Lens for Low-Voltage SEM High Resolution Wafer Observation

1990 ◽  
Vol 48 (1) ◽  
pp. 396-397
Author(s):  
Akira Yonezawa ◽  
Yukio Takeuchi ◽  
Takeshi Kano ◽  
Hiroshi Ishijima
Keyword(s):  
High Resolution ◽  
Secondary Electron ◽  
Low Voltage ◽  
Objective Lens ◽  
Magnetic Lens ◽  
Large Size ◽  
Specimen Holder ◽  
Electron Image ◽  
Working Distance ◽  
Etch Residue

The low-voltage in-lens FE-SEM can observe a 10nm diameter pinhole on Si polycrystal film and etch residue which cannot be observed by a typical SEM. However,this in-lens SEM cannot observe a large size specimen such as a wafer. A new single pole objective lens was recently designed for this purpose. Because of the small bore diameter (2∼3mm),when using this lens,a negative potential must be given to the specimen holder to improve the efficiency of the secondary electron detection.From researching of a single pole magnetic lens system used for observing a wafer with high resolution, we obtained the secondary electron image. Fig.1 shows the single pole objective lens mounted on the specimen chamber. L is the distance between the pole face and the opposite iron wall,R is the radius of the outer yoke,and WD is the working distance. The design features are as follows:

Ultra-high resolution SEMI-in-lens type FE-SEM, JSM-6320F, with strong magnetic-field lens with built-in secondary-electron detector

1994 ◽  
Vol 52 ◽  
pp. 484-485
Author(s):  
T. Miyokawa ◽  
H. Kazumori ◽  
S. Nakagawa ◽  
C. Nielsen
Keyword(s):  
High Resolution ◽  
Secondary Electron ◽  
Spherical Aberration ◽  
Incident Beam ◽  
Chromatic Aberration ◽  
Magnetic Flux Density ◽  
Objective Lens ◽  
Electron Detector ◽  
High Resolution Images ◽  
Working Distance

We have developed a strongly excited objective lens with a built-in secondary electron detector to provide ultra-high resolution images with high quality at low to medium accelerating voltages. The JSM-6320F is a scanning electron microscope (FE-SEM) equipped with this lens and an incident beam divergence angle control lens (ACL).The objective lens is so strongly excited as to have peak axial Magnetic flux density near the specimen surface (Fig. 1). Since the speciien is located below the objective lens, a large speciien can be accomodated. The working distance (WD) with respect to the accelerating voltage is limited due to the magnetic saturation of the lens (Fig.2). The aberrations of this lens are much smaller than those of a conventional one. The spherical aberration coefficient (Cs) is approximately 1/20 and the chromatic aberration coefficient (Cc) is 1/10. for accelerating voltages below 5kV. At the medium range of accelerating voltages (5∼15kV). Cs is 1/10 and Cc is 1/7. Typical values are Cs-1.lmm. Cc=l. 5mm at WD=2mm. and Cs=3.lmm. Cc=2.9 mm at WD=5mm. This makes the lens ideal for taking ultra-high resolution images at low to medium accelerating voltages.

Studies of Supported Metal Catalysts Using Low Voltage Biased Secondary Electron Imaging in a JSM-6320f Fe-SEM

1997 ◽  
Vol 3 (S2) ◽  
pp. 1223-1224
Author(s):  
J. Liu ◽  
R. L. Ornberg ◽  
J. R. Ebner
Keyword(s):  
Secondary Electron ◽  
Low Voltage ◽  
Supported Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Incident Beam ◽  
Active Species ◽  
Supported Metal Catalysts ◽  
Active Components ◽  
Electron Imaging

Many industrial catalysts have a complex geometric structure to enable reacting gases or fluids to reach as much of the active surface of the catalyst as possible. The catalyzing surface frequently consists of a complex chemical mixture of different phases produced by an evolved chemical process. The active components are often very small particles dispersed on high-surface-area supports. The catalytic properties of this type of catalyst depend on the structure, composition, and morphology of the active species as well as the supports. TEM/STEM and associated techniques have been used extensively to characterize the structure and composition of supported catalysts. Surface morphology of supported catalysts is generally examined by secondary electron imaging, especially at low incident beam energies. It is, however, frequently found that small metal particles are not usually seen in SE images because of the complication of support topography

Analysis on Resistance Change Mechanism of NiO-ReRAM Using Visualization Technique of Data Storage Area With Secondary Electron Image

2010 ◽  
Vol 1250 ◽  
Author(s):  
Kentaro Kinoshita ◽  
Tatsuya Makino ◽  
Yoda Takatoshi ◽  
Dobashi Kazufumi ◽  
Kishida Satoru
Keyword(s):  
Data Storage ◽  
Secondary Electron ◽  
High Resistance State ◽  
Secondary Electron Image ◽  
Resistance Change ◽  
Force Microscopy ◽  
Electron Image ◽  
Storage Area ◽  
Resistance State ◽  
Pt Films

AbstractBoth a low resistance state and a high resistance state which were written by the voltage application in a local region of NiO/Pt films by using conducting atomic force microscopy (C-AFM) were observed by using scanning electron microscope (SEM) and electron probe micro analysis (EPMA). The writing regions are distinguishable as dark areas in a secondary electron image and thus can be specified without using complicated sample fabrication process to narrow down the writing regions such as the photolithography technique. In addition, the writing regions were analyzed by using energy dispersive X-ray spectroscopy (EDS) mapping. No difference between the inside and outside of the writing regions is observed for all the mapped elements including C and Rh. Here, C and Rh are the most probable candidates for contamination which affect the secondary electron image. Therefore, our results suggested that the observed change in the contrast of the second electron image is related to the intrinsic change in the electronic state of the NiO film and a secondary electron yield is correlated to the physical properties of the film.

The darkening effects of secondary electron image due to superconductivity in Y1BA2CU3O7-xfilms

1992 ◽  
Vol 128 (1) ◽  
pp. 243-248 ◽  
Author(s):  
Ludmila Kokhanchik ◽  
Alexey Nikulov ◽  
Anatoly Chernykh
Keyword(s):  
Secondary Electron ◽  
Secondary Electron Image ◽  
Electron Image
Sign in / Sign up

Export Citation Format

Share Document