Voltage and Dopant Concentration Measurements of Semiconductors using a Band-Pass Toroidal Energy Analyzer Inside a Scanning Electron Microscope

2015 ◽  
Vol 21 (4) ◽  
pp. 910-918 ◽  
Author(s):  
Avinash Srinivasan ◽  
Anjam Khursheed
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Dopant Concentration ◽  
High Signal ◽  
Energy Analyzer ◽  
Order Of Magnitude ◽  
Band Pass ◽  
Concentration Measurements ◽  
Scanning Electron ◽  
Better Than

AbstractThis paper presents experimental results obtained from a scanning electron microscope (SEM) second-order focusing toroidal electron energy analyzer attachment. The results demonstrate that the analyzer can be used to obtain high signal-to-noise voltage and dopant concentration measurements on semiconductors in the presence of different electric field conditions at the sample. The experimentally calculated relative error of measurement typically varies from 31 to 63, corresponding to secondary electron (SE) signal mean shifts of 9–18 mV. The millivolt accuracy of these results is over one order of magnitude better than earlier quantitative dopant concentration measurements made by a retarding field analyzer.

Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

Morphology of Ground and Lapped Surfaces of Ferrite and Metal

1987 ◽  
Vol 109 (2) ◽  
pp. 83-86 ◽  
Author(s):  
S. Chandrasekar ◽  
M. C. Shaw ◽  
B. Bhushan
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Stress ◽  
Ground Surface ◽  
Residual Surface Stress ◽  
Deformed Layer ◽  
Order Of Magnitude ◽  
Metal Chips ◽  
Steel Surfaces ◽  
Scanning Electron

Scanning electron microscope pictures of ground and lapped ferrite (sinfered magnetic ceramic) and steel surfaces and chips are studied and compared. These reveal considerably more plastic action associated with the formation of metal chips in fine grinding than for ferrite chips. Individual chips are an order of magnitude larger for metals than for ferrites. These results are consistent with the much greater specific grinding energy for metals than for ferrites. The depth of the plastically deformed layer beneath a ground surface revealed by etching corresponds closely with the depth of residual surface stress.

scholarly journals Preparo inicial em periodontia: avaliações perfilométricas e microscópias pós-remoção de excesso cervicais de restaurações

2021 ◽  
pp. 73-80
Author(s):  
Raul G. Caffesse ◽  
José D. Freitas Vale
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Class Ii ◽  
Measuring Instrument ◽  
Combined Use ◽  
The Mean ◽  
Amalgam Restorations ◽  
Scanning Electron ◽  
Better Than

Forty recently extracted teeth with Class II amalgam restorations with overhangs were divided in four groups of ten teeth each. The overhangs were removed using one of the following instruments in each gruop: trimmer, chisel, surgical blade and reciprocating.motor.driven diamond tip. Instrumentation was performed until no irregularity could be detected clinically with a nº 3 explorer. The tooth.amalgam interfaces were examined by combined use of a surface measuring instrument and a scanning electron microscope. Four tracings from each specimen were recorded and the vertical discrepancy at the tooth.restoration interfaces measured. The mean score for tooth was determined, and the results were photographed aí 140 magnification with the SEM. The results indicated that all instruments tested were effective in removing overhangs, since none of the discrepancies registered after instrumenntation exceeded 4 Um. The surgical blade, and especially the reciprocting-motor.driven diamond tip eliminated overhangs better than the chisel. Both SEM photographs and the profilometric tracing revealed gaps at the tooth amalgam interface, rancing from 10 t o 50 Um in width.

The JSM-890 ultra high resolution Scanning Electron Microscope

1989 ◽  
Vol 47 ◽  
pp. 88-89
Author(s):  
M. Kersker ◽  
C. Nielsen ◽  
H. Otsuji ◽  
T. Miyokawa ◽  
S. Nakagawa
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Morphological Changes ◽  
High Current Density ◽  
High Signal ◽  
Extensive Experience ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron

Historically, ultra high spatial resolution electron microscopy has belonged to the transmission electron microscope. Today, however, ultra high resolution scanning electron microscopes are beginning to challenge the transmission microscope for the highest resolution.To accomplish high resolution surface imaging, not only is high resolution required. It is also necessary that the integrity of the specimen be preserved, i.e., that morphological changes to the specimen during observation are prevented. The two major artifacts introduced during observation are contamination and beam damage, both created by the small, high current-density probes necessary for high signal generation in the scanning instrument. The JSM-890 Ultra High Resolution Scanning Microscope provides the highest resolution probe attainable in a dedicated scanning electron microscope and its design also accounts for the problematical artifacts described above.Extensive experience with scanning transmission electron microscopes lead to the design considerations of the ultra high resolution JSM- 890.

scholarly journals Evaluating the Emergence and Biochemical Changes of Primed Seeds in Proso Millet (Panicum miliaceum L.)

2019 ◽  
pp. 1-7
Author(s):  
R. Sridevi ◽  
V. Manonmani
Keyword(s):  
Cell Proliferation ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Pseudomonas Fluorescens ◽  
Biochemical Parameters ◽  
Free Sugars ◽  
Proso Millet ◽  
Scanning Electron ◽  
Better Than

The present study aimed in exploring the performance of primed seeds in enhancing the quality of proso millet. The primed seeds along with nonprimed seeds were evaluated for emergence, cell proliferation in radicle cells using scanning electron microscope and biochemical parameters. Seeds primed with Pseudomonas fluorescens 20% possessing higher germination and anatomical changes observed through scanning electron microscope revealed more cell proliferation which was found to show rapid cell elongation and cell division of the radicle when compared to nonprimed seeds. The biochemical causes responsible for higher invigorative effect were identified as enhanced enzyme activity recorded through α-amylase content, dehydrogenase activity, protein content, lipase activity, antioxidative enzymes like catalase activity, peroxidase activity and superoxide dismutase with lower electrical conductivity, free amino acid and free sugars of the seed leachate. It is concluded in this study that primed seeds of Pseudomonas fluorescens 20% performed better than other treatments through their exhibition of higher emergence, more cell proliferation and enhanced biochemical parameters.

scholarly journals Limits of SEM Resolution

1996 ◽  
Vol 4 (5) ◽  
pp. 10-11
Author(s):  
David C. Joy
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Mechanical Stability ◽  
Electron Sources ◽  
The Past ◽  
Probe Size ◽  
Order Of Magnitude ◽  
Imaging Mode ◽  
Scanning Electron

Over the past decade the achievable resolution of the scanning electron microscope (SEM) in secondary electron (SE) imaging mode has improved by about one order of magnitude. In fact, instruments capable of demonstrating a resolution of one nanometer and exhibiting a probe size of less than 0.6 nm are not available. Continued improvements in electronoptics, electron sources, and in electronic and mechanical stability promise even smaller probe sizes that still contain adequate current for imaging, it is therefore relevant to consider what resolution might ultimately be achievable with an SEM in SE mode.

scholarly journals A Parallel Radial Mirror Energy Analyzer Attachment for the Scanning Electron Microscope

2015 ◽  
Vol 21 (S4) ◽  
pp. 142-147 ◽  
Author(s):  
Kang Hao Cheong ◽  
Weiding Han ◽  
Anjam Khursheed ◽  
Karuppiah Nelliyan
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Analyzer ◽  
Scanning Electron

High Resolution Scanning Electron Microscope Using Lathanum Hexaboride Cathode Electron Gun

1968 ◽  
Vol 26 ◽  
pp. 372-373
Author(s):  
A. N. Broers
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Spherical Aberration ◽  
Lanthanum Hexaboride ◽  
Electron Gun ◽  
Maximum Brightness ◽  
Working Distance ◽  
Scanning Electron ◽  
Better Than

A new scanning electron microscope has been built which uses a lanthanum hexaboride cathode electron gun. The microscope has three magnetic lenses which are prealigned in the electron optical column to better than 20 micron. The final lens has a design spherical aberration of 1.8 cm for a 6 mm working distance. The pole-pieces of the final lens have been machined round within 0.25 micron and are aligned with respect to the axis of the lens to better than 10 micron. The electron gun which has been described previously uses a lanthanum hexaboride rod cathode. The cathode has approximately two orders of magnitude longer life than a 5 mil tungsten hairpin and is capable of producing an electron beam with a maximum brightness of 5.6 x 105 A/cm2 /ster at 12 KV. This brightness is approximately five times greater than that produced by a 5 mil tungsten hairpin under similar conditions.

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