Field Emission from W Tips Sharpened by Field-Assisted Nitrogen and Oxygen Etching

Onoda, Jo; Rahman, F.; Mizuno, Seigi

doi:10.1380/ejssnt.2008.152

Cited by 11 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the field-assisted nitrogen etching process, a specific nanoprotrusion was formed on the tip-apex to obtain a higher angular current density. We performed a modified method based on a field-assisted nitrogen etching, which was reported by Rezeq et al and Onoda et al in detail [5,6]. The nanoprotrusion with a hemispherical shape even along ⟨111⟩ direction could be formed on the tip-apex with a significantly large radius of curvature by the modified field-assisted nitrogen etching process.…”

Section: Methodsmentioning

confidence: 99%

“…In order to more improve the angular current density of GFIS we have developed tungsten emitter-tips with a specific nanoprotrusion on the tip-apex by using a modified field-assisted oxygen etching, followed by a field evaporation process to fabricate a trimer on the nanoprotrusion [4]. Whereas, nitrogen etching process, in which a subnanometric protrusion such as a single tungsten atom could be formed on ⟨110⟩-or ⟨111⟩-oriented crystalline tungsten emitter-tips [5,6].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stability Measurement of Ion Beam Current from Argon Field Ion Source

Okawa

Morikawa

Nagai

et al. 2011

e-J. Surf. Sci. Nanotechnol.

View full text Add to dashboard Cite

We have been developing a next generation finely focused ion beam (FIB) system with noble gas field ion source (GFIS), which could reduce the contamination of irradiated ion species. Ion current stability of GFIS is one of the most fundamental factors for FIB applications. In this study, we report a preliminary measurement of current stability of field-ionized Ar + ions from a tungsten emitter-tip which has a specific nanoprotrusion terminated by a trimer on the tip-apex. As a measure of long-term stability of Ar + ion beam, current fluctuation of ∼5% for 1800 seconds was typically obtained at the beam current of 1.3 pA and the argon gas pressure of 5×10 −3 Pa. Furthermore it was found in argon-GFIS that the spike-like current fluctuation was correlated with the trimer-dimer transformation in a tungsten trimer-tip.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stability Measurement of Ion Beam Current from Argon Field Ion Source

Okawa

Morikawa

Nagai

et al. 2011

e-J. Surf. Sci. Nanotechnol.

View full text Add to dashboard Cite

show abstract

“…It was described that if the taper angle of emitter-shank becomes smaller, then a larger ion current could be obtained. Onoda et al reported field-assisted oxygen etching as a fabrication method for field electron emitter tips terminated by a single-atom [6][7][8]. In this study, to focus more effectively an ion beam, we modified the field-induced oxygen etching method to optimize the shape of field ion emitter tip with a nanoprotrusion.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Gas Field Ion Emitter by Field Induced Oxygen Etching Method

Sugiura

Liu

Iwata

et al. 2011

e-J. Surf. Sci. Nanotechnol.

View full text Add to dashboard Cite

Focused ion beam system with a liquid metal ion source has a serious problem which is the pollution of samples due to irradiated ion species. To solve the problem, we have developed a noble gas field ion source which scarcely gives rise to the pollution. In this case, a key issue for the field-ion emitter is the shape of tip-apex to obtain a higher angular current density. Better performance is expected for a shape of tip-apex having a nanoscale-protrusion on the emitter tip with large radius of curvature. For realization of such a shape of tip-apex, field-induced oxygen etching method, which was reported by Onoda et al., was modified and applied to a sharpened tungsten wire which was electrolitically polished. Observation of formed emitter tips by transmission electron microscopy revealed that a nanoprotrusion having a shape of truncated cone with ∼5 nm in diameter and ∼4 nm in height was formed at the center of an emitter tip with ∼90 nm in radius of curvature.

show abstract

“…Recently, to obtain an emitter tip with a better emission property, a method of preparing an emitter tip having a nanoprotrusion terminated by a single atom or a trimer has been actively investigated. 2,3 For this situation, the helium ion microscope as a powerful apparatus for surface analysis was developed by ALIS corporation in 2006 by using a trimer-terminated W ͑111͒ emitter tip. 4 However, the shape of the emitter shank still remains as a subject of investigation for obtaining an ion beam with a higher dI / d⍀.…”

Section: Introductionmentioning

confidence: 99%