Reliability tests of gated silicon field emitters for use in space

Aplin, Karen; Collingwood, Cheryl; Kent, B. J.

doi:10.1088/0022-3727/37/14/018

Cited by 29 publications

(13 citation statements)

References 20 publications

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“…According to the earlier literatures 13 14 , ion bombardment is the main concern for running the field emission devices in a relatively lower vacuum level ( i.e. , 10 −4 Pa).…”

Section: Resultsmentioning

confidence: 99%

Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes

Huang

Deng

Wang

et al. 2015

Sci Rep

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Nano-scale vacuum channel transistors possess merits of higher cutoff frequency and greater gain power as compared with the conventional solid-state transistors. The improvement in cathode reliability is one of the major challenges to obtain high performance vacuum channel transistors. We report the experimental findings and the physical insight into the field induced crystalline-to-amorphous phase transformation on the surface of the Si nano-cathode. The crystalline Si tip apex deformed to amorphous structure at a low macroscopic field (0.6~1.65 V/nm) with an ultra-low emission current (1~10 pA). First-principle calculation suggests that the strong electrostatic force exerting on the electrons in the surface lattices would take the account for the field-induced atomic migration that result in an amorphization. The arsenic-dopant in the Si surface lattice would increase the inner stress as well as the electron density, leading to a lower amorphization field. Highly reliable Si nano-cathodes were obtained by employing diamond like carbon coating to enhance the electron emission and thus decrease the surface charge accumulation. The findings are crucial for developing highly reliable Si-based nano-scale vacuum channel transistors and have the significance for future Si nano-electronic devices with narrow separation.

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“…According to the earlier literatures 13 14 , ion bombardment is the main concern for running the field emission devices in a relatively lower vacuum level ( i.e. , 10 −4 Pa).…”

Section: Resultsmentioning

confidence: 99%

Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes

Huang

Deng

Wang

et al. 2015

Sci Rep

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“…Researchers have found some ways to minimize damage to the emitters [10], and they have also found more sputterresistant longer-life emitter materials [8,[11][12][13]. However, all electron field emitters become damaged over time [14,15]; it is just a matter of how much time it will take. Some of the mechanisms that cause damage to field emitters include arcing between the emitter and the extraction electrode, localized heating causing emitter tip melting/destruction, and sputtering of the sharp emitter tips.…”

Section: Introductionmentioning

confidence: 99%

Regenerable Field Emission Cathodes: Surface Morphology and Performance

Makela

Washeleski

King

2011

Journal of Propulsion and Power

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This paper reports on a field-emission cathode for use in electric propulsion that has the potential for very long lifetime due to its ability to be regenerated when the emitter tip(s) become damaged. The field-emitting tips were formed by applying an ion-extracting electric potential to a heated indium-coated tungsten needle, known as a liquidmetal ion source. The liquid-metal ion source was then cooled, freezing in a solid nanotip at the apex. When the modified emitter was then subjected to electron-extracting potentials, stable and long-lived electron emission was observed. The first goal of this investigation was to operate and quench a liquid-metal ion source at ion emission currents from 1 to 30 A to acquire micrographs of the surface morphology as a function of the ion emission current at quench. Micrographs of the quenched emitter tips revealed Taylor-cone-shaped structures. Some of the quenched emitters exhibited multiple nanoprotrusions on the tapered surface of the microscale Taylor cone, which were capable of electron field emission. The second goal of this investigation was to compare regenerable field emitters with single-needle tungsten field emitters. Each type of emitter was used to obtain electron emission at a vacuum chamber pressure of 10 8 Torr, and then the emitters were exposed to increased pressure, up to 10 5 Torr, to observe how long they could sustain emission. In all cases, emission from the regenerable emitters lasted 10s of hours longer at increased pressure, and it was demonstrated that the tungsten emitters would eventually permanently fail, whereas the regenerable emitters could be repaired when they became damaged. Nomenclature a = Fowler-Nordheim empirical relation b 0 = Empirical relation between tip radius and gap spacing k = Fowler-Nordheim field-voltage proportionality factor m = slope r t = emitter tip radius s m = standard error t e = elapsed time = Fowler-Nordheim image-correction factor ' = work function

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“…Critical reliability issues have been pointed out (see for instance Aplin et al (2004) for silicon field emitters) originating from various phenomena as degradation due to ion bombardment, arcing, or thermal breakdown due to electromigration. The present study was conducted with 1 cm 2 Mo tips cathodes containing 14400 tips.mm −2 and delivering a 25mA nominal current.…”

Section: Introductionmentioning

confidence: 99%

Physical characterization of molybdenum microtips field emitter arrays

Cipriani¹,

Leblanc²,

Illiano³

et al. 2010

J. Phys. D: Appl. Phys.

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We used a dedicated hemispherical energy analyzer to measure energetic and angular distributions of electrons emitted from Molybdenum microtips integrated in a 1 cm 2 Field Emitter Array designed by the CEA/LETI laboratory. Such cathodes typically deliver about 25mA at an extraction voltage of 100V, and are studied in order to replace heated wires as electron sources for space applications. We find that the energy distribution of the beam strongly depends on the extraction voltage, and is therefore expected to vary across the emission life time of the device, at a rate depending both on the alteration of the resistive structure with time, and on the fate of adsorbed contaminants at the tip surface. A semi-empirical model of the emitters is proposed and used to determine parameters of energetic and angular distributions. The energy dispersion of the beam is found to increase from 2eV±20% up to 9eV±20% eV, for extraction voltages varying from 40 to 100 V. The mean angular dispersion of the beam is found to be 42 • ±20% when a null electric field is set at the grid extraction surface.

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Reliability tests of gated silicon field emitters for use in space

Cited by 29 publications

References 20 publications

Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes

Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes

Regenerable Field Emission Cathodes: Surface Morphology and Performance

Physical characterization of molybdenum microtips field emitter arrays

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