On the Chromatic Field Aberration of the Magnetic Electron Lens in the Electron Microscope

A silicon microfabrication technique has been applied toward the development of a Miniature Scanning Electron Microscope (MSEM). The fabrication technology is not only precise but is inexpensive compared to conventional methods of electron microscope construction and is easily extended to the construction of arrays of MSEMs for applications in high throughput e-beam lithography and wafer inspection.An electrostatic electron lens consists of a series of planar electrodes with central apertures that are precisely aligned to and electrically isolated from one another. This structure is fabricated using silicon as the electrode material and Pyrex optical fibers as the insulators. The electrodes are fabricated on four inch (100) orientation silicon wafers that are patterned on both sides and anisotropically etched to form four orthogonal v-grooves and an open diaphragm with a circular aperture in the center. The apertures are formed by reactive ion etching. The wafers are then diced to create approximately 100 7 mm by 9 mm electrodes.

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On the magnetic electron lens of minimum sphrical aberration

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107265 ◽

1978 ◽

Vol 36 (1) ◽

pp. 24-25

Author(s):

S. Suzuki ◽

A. Ishikawa

Keyword(s):

Spherical Aberration ◽

Resolving Power ◽

Objective Lens ◽

Lens Design ◽

Magnetic Lens ◽

Initial Voltage ◽

Path Distance ◽

Electron Lens ◽

Image Position ◽

Magnetic Electron

For the development of the electron microscope, in which high resolving power is demanded, it is important to construct an electron objective lens with minimum spherical aberration.In 1943, one of the authors published the paper on the approximate calculation of the electromagnetic field to give a minimum spherical aberration and also published the papers on small spherical aberration lens design based on this calculation.We will speak a comparison between the experimental results and the numerical calculations in practical cases.The following line shows the method to get more strictly minimum spherical aberration of magnetic lens.In a space charge free electron optical system, where a pure magnetic lens is concerned, differential equation for paraxial electron path is given byU being the initial voltage applied to the electron beam and γ the path distance from the optical axis Z.

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IMPROVED POLE PIECE CONSTRUCTION OF THE OBJECTIVE LENS OF A MAGNETIC ELECTRON MICROSCOPE

Canadian Journal of Research ◽

10.1139/cjr40a-017 ◽

1940 ◽

Vol 18a (11) ◽

pp. 175-177 ◽

Cited By ~ 3

Author(s):

Albert Prebus

Keyword(s):

Electron Microscope ◽

Objective Lens ◽

Pole Piece ◽

University Of Toronto ◽

New Form ◽

The University ◽

Magnetic Electron

The paper is a description of a new form of pole piece devised for the electron microscope developed at the University of Toronto.

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Colloidal Carbon as Revealed by the Electron Microscope

Rubber Chemistry and Technology ◽

10.5254/1.3543152 ◽

1942 ◽

Vol 15 (3) ◽

pp. 664-671

Author(s):

William B. Wiegand ◽

William A. Ladd

Keyword(s):

Electron Microscope ◽

Surface Area ◽

Ohio State University ◽

Theory And Practice ◽

Critical Conditions ◽

State University ◽

New Approach ◽

Synthetic Rubber ◽

Electron Lens ◽

First Time

Abstract The electron microscope of today may be said to rest on the pioneer work of three outstanding physicists. J. J. Thompson, in 1897, discovered electrons under the name of negative corpuscles. De Broglie, about 1922, established the wave characteristics of electrons. In 1926 Busch established the electron lens. In 1935, E. F. Burton, following a visit to Germany, envisaged the enormous potentialities of the electron microscope and began a program at Toronto designed to eliminate the serious defects of early German instruments. In 1938, this program culminated in the construction of a new and superior instrument by two of his graduate students, A. Prebus and J. Hillier. The publication of their results early in 1939 aroused the immediate interest of the Columbian Carbon Company which later established a Fellowship at Toronto under Professor Burton's direction. In 1940, A. Prebus, assisted by W. A. Ladd, working in Toronto, secured for Columbian the first perfect pictures of Micronex, from which accurate data as to mean surface area and as to particle shape were obtained. Public release followed in June, 1940. Prebus is now Professor at Ohio State University and is pursuing the theoretical side. Hillier is at R. C. A., where instruments, of essentially Toronto design, are being developed commercially, and Ladd has joined the Columbian Carbon Research Laboratories, for the two-fold purpose of further improving the microscope and of applying it to the problems of natural and synthetic rubber reënforcement. This work of Professor Burton and his pupils is of importance under present critical conditions since the replacement of natural by synthetic rubber necessitates a new approach to the theory and practice of rubber reënforcement. With the aid of the electron microscope, it is now for the first time possible to evaluate the role played by surface area in carbon-rubber reënforcement.

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