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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Field emitter array</span></span>

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<p>A <b>field emitter array</b> (FEA) is a particular form of <a href="Field_electron_emission" title="Field electron emission">large-area field electron source</a>. FEAs are prepared on a silicon substrate by lithographic techniques similar to those used in the fabrication of integrated circuits. Their structure consists of many individual, similar, small-field electron emitters, usually organized in a regular two-dimensional pattern. FEAs need to be distinguished from "film" or "mat" type large-area sources, where a thin film-like layer of material is deposited onto a substrate, using a uniform deposition process, in the hope or expectation that (as a result of statistical irregularities in the process) this film will contain a sufficiently large number of individual emission sites.

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<div class="mw-heading mw-heading2"><h2 id="Spindt_arrays">Spindt arrays</h2></div>

<p>The original field emitter array was the <i>Spindt array</i>, in which the individual field emitters are small sharp molybdenum cones. Each is deposited inside a cylindrical void in an oxide film, with a counterelectrode deposited on the top of the film. The counterelectrode (called the "gate") contains a separate circular aperture for each conical emitter. The device is named after Charles A. Spindt, who developed this technology at <a href="SRI_International" title="SRI International">SRI International</a>, publishing the first article describing a single emitter tip microfabricated on a wafer in 1968.<sup id="cite_ref-SpindtArticle_3-0" class="reference"><a href="#cite_note-SpindtArticle-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>

Spindt, Shoulders and Heynick filed a U.S. Patent <sup id="cite_ref-SpindtPatent_4-0" class="reference"><a href="#cite_note-SpindtPatent-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> in 1970 for a vacuum device comprising an array of emitter tips.

</p><p>Each individual cone is referred to as a <i>Spindt tip</i>. Because Spindt tips have sharp apices, they can generate a high local electric field using a relatively low gate voltage (less than 100 V). Using lithographic manufacturing techniques, individual emitters can be packed extremely close together, resulting in a high average (or "macroscopic") current density of up to 2×10<sup>7</sup> A/m<sup>2</sup> . Spindt-type emitters have a higher emission intensity and a more narrow angular distribution than other FEA technologies.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>

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<div class="mw-heading mw-heading2"><h2 id="nano-Spindt_arrays">nano-Spindt arrays</h2></div>

<p>Nano-Spindt arrays represent an evolution of the traditional Spindt-type emitter. Each individual tip is several orders of magnitude smaller; as a result, gate voltages can be lower, since the distance from tip to gate is reduced. In addition, the current extracted from each individual tip is lower, which should result in improved reliability.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup>

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<div class="mw-heading mw-heading2"><h2 id="Carbon_Nanotube_(CNT)_arrays">Carbon Nanotube (CNT) arrays</h2></div>

<p>An alternative form of FEA is fabricated by creating voids in an oxide film (as for a Spindt array) and then using standard methods to grow one or more <a href="Carbon_nanotube" title="Carbon nanotube">carbon nanotubes</a> (CNTs) in each void.

</p><p>It is also possible to grow "free-standing" CNT arrays.

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<div class="mw-heading mw-heading2"><h2 id="Applications">Applications</h2></div>

<p>Essentially very small electron beam generators, FEAs, have been applied in many different domains. FEAs have been used to create flat panel displays (where they are known as <a href="Field_emission_display" class="mw-redirect" title="Field emission display">field emission displays</a> (or "nano-emissive displays"). They may also be used in microwave generators, and in RF communications, where they could serve as the cathode in <a href="Traveling-wave_tube" title="Traveling-wave tube">traveling-wave tubes</a> (TWTs).

</p><p>Recently, there has been renewed interest in using field effect arrays as <a href="Cold_cathode" title="Cold cathode">cold cathodes</a> in <a href="X-ray_tubes" class="mw-redirect" title="X-ray tubes">X-ray tubes</a>. FEAs offer a number of potential advantages over conventional <a href="Thermionic_cathode" class="mw-redirect" title="Thermionic cathode">thermionic cathodes</a>, including low power consumption, instantaneous switching, and independence of current and voltage.

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<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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</style><cite id="CITEREFswenson2013" class="citation web cs1">swenson (2013-03-05). <a rel="nofollow" class="external text" href="https://www.nist.gov/news-events/news/2013/03/new-player-electron-field-emitter-technology-makes-better-imaging-and">"New Player in Electron Field Emitter Technology Makes for Better Imaging and Communications"</a>. <i>NIST</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2021-08-21</span></span>.</cite></span>

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<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.nist.gov/image/siliconcarbidefieldemitterjpg">"Silicon Carbide Field Emitter"</a>. <i>NIST</i>. 5 March 2013<span class="reference-accessdate">. Retrieved <span class="nowrap">2021-08-21</span></span>.</cite></span>

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<li id="cite_note-SpindtArticle-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-SpindtArticle_3-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFSpindt1968" class="citation journal cs1">Spindt, C. A. (1968). "A Thin-Film Field-Emission Cathode". <i>Journal of Applied Physics</i>. <b>39</b> (7). AIP Publishing: <span class="nowrap">3504–</span>3505. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1063%2F1.1656810">10.1063/1.1656810</a>. <a href="ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0021-8979">0021-8979</a>.</cite></span>

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<li id="cite_note-SpindtPatent-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-SpindtPatent_4-0">^</a></b></span> <span class="reference-text">U.S. Patent 3,755,704 granted on August 28, 1973</span>

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<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><cite id="CITEREFSpindtBrodieHumphreyWesterberg1976" class="citation journal cs1">Spindt, C. A.; Brodie, I.; Humphrey, L.; Westerberg, E. R. (1976). "Physical properties of thin-film field emission cathodes with molybdenum cones". <i>Journal of Applied Physics</i>. <b>47</b> (12). AIP Publishing: <span class="nowrap">5248–</span>5263. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1063%2F1.322600">10.1063/1.322600</a>. <a href="ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0021-8979">0021-8979</a>.</cite></span>

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<li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><cite id="CITEREFScadutoLubinskyRowlandsKenmotsu2014" class="citation conference cs1">Scaduto, David A.; Lubinsky, Anthony R.; Rowlands, John A.; Kenmotsu, Hidenori; Nishimoto, Norihito; et al. (2014-03-19). "Investigation of spatial resolution and temporal performance of SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) with integrated electrostatic focusing". In Whiting, Bruce R.; Hoeschen, Christoph (eds.). <i>Medical Imaging 2014: Physics of Medical Imaging</i>. Vol. 9033. SPIE. p. S-1. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1117%2F12.2043187">10.1117/12.2043187</a>.</cite></span>

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<ul><li><a href="Field_emission_display" class="mw-redirect" title="Field emission display">Field emission display</a></li>

<li><a href="Field_electron_emission" title="Field electron emission">Field electron emission</a></li>

<li><a href="Vacuum_tube#Vacuum_tubes_using_field_electron_emitters" title="Vacuum tube">Vacuum tubes using field electron emitters</a></li>

<li><a href="Cold_cathode" title="Cold cathode">Cold cathode</a></li></ul></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-02-13" href="https://en.wikipedia.org/wiki/?title=Field_emitter_array&oldid=1275499770">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

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