Evaluation of a 100 kV thermal field emission electron-beam nanolithography system

Bright and coherent electron beams have been opening new frontiers in science and technology. So far, we have developed several field-emission transmission electron microscopes (FE-TEM) with increasing accelerating voltages to provide higher beam brightness. By using a 200-kV FE-TEM and electron holography techniques, we directly confirmed the Aharonov-Bohm effect. A 350-kV FE-TEM equipped with a low-temperature specimen stage enabled us to observe moving vortices in superconductors.2 Most Recently, we have developed a new 1-MV FE-TEM with a newly designed FE gun to obtain an even brighter and more coherent electron beam.Electron beam brightness, Br, defined in Figure 1, is suitable for measuring the performance of electron guns, since both lens aberrations and mechanical/electrical vibrations contribute to a decrease in beam brightness, and beam coherency is proportional to (Br)1/2. Therefore, we optimized design of the illuminating system and its operation by maximizing the electron beam brightness.

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Fabrication and beam characteristics of an ultra-sharp electrode for field emission electron beam

10.1117/12.577601 ◽

2004 ◽

Author(s):

Seong-Soo Kim ◽

Jong-Hang Lee ◽

Youn-Chan Yim ◽

Jung-Woo Hyun ◽

Cheol-Woo Park ◽

...

Keyword(s):

Electron Beam ◽

Field Emission ◽

Emission Electron ◽

Beam Characteristics

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MEBES IV thermal-field emission tandem optics for electron beam lithography

Journal of Vacuum Science & Technology B Microelectronics Processing and Phenomena ◽

10.1116/1.585632 ◽

1991 ◽

Vol 9 (6) ◽

pp. 2949 ◽

Cited By ~ 3

Author(s):

M. Gesley

Keyword(s):

Electron Beam ◽

Field Emission ◽

Electron Beam Lithography ◽

Thermal Field

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Holographic contrast transfer theory

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100129553 ◽

1992 ◽

Vol 50 (2) ◽

pp. 984-985

Author(s):

R. Plass ◽

L. D. Marks

Keyword(s):

Electron Beam ◽

Transfer Function ◽

Field Emission ◽

Electron Holography ◽

Contrast Transfer Function ◽

Beam Focusing ◽

Emission Electron ◽

Transmission Electron ◽

Electron Microscopes ◽

Image Position

With the advent of reliable cold field emission transmission electron microscopes there is substantial interest in using the amplitude and phase information recorded in electron holograms to optically or numerically correct for the coherent aberrations of transmission electron microscopes. However electron holography cannot compensate for incoherent aberrations. The derivation of the contrast transfer function for off axis electron holography in this paper shows there is no fundamental improvement in resolution for electron holography over conventional transmission electron microscopy.Evaluating the contrast transfer function involves mathematically following an electron beam through a field emission electron microscope set up for off axis electron holography. Due to the high coherence of the field emission electron beam coherent aberrations caused by the pre-specimen beam focusing system must be accounted for. Starting with a spacial frequency distribution, C(v), for the electron beam leaving the gun, the electron beam is limited by the condenser aperture and coherently aberrated by the condenser lens and objective pre-field as it passes to the specimen region:

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