Synthesis of electrostatic focusing and deflection systems

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

In this article, we present synthesis of an ion beam column as a single entity, based on combined focusing and deflection (CFD). We present seven cases as examples of designing CFD systems by synthesis. Four of those are examples resulting from the a priori given multielectrode approach using a multipurpose multipole system with nine or five units. In these cases, the units have short cylindrical rings or disks cut into segments with geometrically octupole symmetry. In one example we are using the cubic spline method. The other two cases are examples obtained by using both methods in the case of a separate group of axially symmetric electrostatic lenses and electrostatic postlens deflectors. By using a sequential optimization technique combined with the gradient method and the Hooke-Jeeve's method for a multipurpose multipole system with nine units, our calculations show that one can produce a beam spot radius less than 7 nm and current density of 614 A/cm2, scanned over a 2-mm-square field for a field ionization source. We also present comparison of our CFD system with other published data. The results display substantial improvements, especially for a field ionization source with smaller energy spread ΔU = 1 eV and higher acceptance half-angle γ0 = 2.3 mrad. A sensitivity analysis is given, and the optimum working distances of a given CFD system are presented for the minimum beam spot radius.

Original languageEnglish (US)
Pages (from-to)1971-1982
Number of pages12
JournalJournal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
Volume15
Issue number6
StatePublished - Nov 1997

Fingerprint

Ion sources
deflection
Electrostatics
Electrostatic lenses
electrostatics
Gradient methods
synthesis
Splines
Ion beams
multipoles
Sensitivity analysis
Current density
ionization
radii
deflectors
sensitivity analysis
splines
acceptability
ion beams
lenses

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)
  • Surfaces and Interfaces

Cite this

Synthesis of electrostatic focusing and deflection systems. / Szilagyi, Miklos N; Cho, H.

In: Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures, Vol. 15, No. 6, 11.1997, p. 1971-1982.

Research output: Contribution to journalArticle

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