High frequency ion sources for ion implanters-theoretical and practical comparison

This paper describes recent results obtained with a compact 2.45 GHz ECR Ion Source at the ECR ion sources test bench. The source was tested for production of helium and hydrogen ions with different configurations of Ultra High Frequency (UHF) coupler, UHF power and frequency. At the extraction voltage about of 10 kV and UHF power about of 100 W more than 500 µA of He + ions were produced with the extraction hole of 3 mm in diameter that corresponds to the current density of 7.5mA/cm2. The future possible upgrades of the ion source are also discussed.

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High-frequency ion sources of inert and chemically active gases

Journal of Surface Investigation X-ray Synchrotron and Neutron Techniques ◽

10.1134/s1027451012080034 ◽

2012 ◽

Vol 6 (4) ◽

pp. 693-698 ◽

Cited By ~ 8

Author(s):

V. K. Abgaryan ◽

H. V. Loeb ◽

V. A. Obukhov ◽

I. I. Shkarban

Keyword(s):

High Frequency ◽

Ion Sources

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The Microstructure of Steatite (Protoenstatite)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118102 ◽

1985 ◽

Vol 43 ◽

pp. 236-237

Author(s):

W. E. Lee ◽

A. H. Heuer

Keyword(s):

High Frequency ◽

Glass Ceramics ◽

Magnesium Silicate ◽

Beam Current ◽

Glassy Matrix ◽

Angle Of Incidence ◽

X Ray ◽

Mechanical And Electrical Properties ◽

Argon Ions ◽

High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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Simulations of high-resolution images of amorphous silicon films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014419x ◽

1986 ◽

Vol 44 ◽

pp. 544-545

Author(s):

G. Y. Fan ◽

J. M. Cowley

Keyword(s):

Electron Microscope ◽

High Frequency ◽

Fourier Transformation ◽

Amorphous Materials ◽

Low Frequency ◽

Chromatic Aberration ◽

Structure Information ◽

Frequency Components ◽

High Resolution Images ◽

Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

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