摘要:

Degradation of electron emission characteristics in single-crystalline and polycrystalline silicon field emitter arrays and its mechanism have been studied. A critical biasing timetcat which the emission current started to be degraded dominantly was observed at a pressure of5×10−7 Torr.Thetcis shortened as the emission current increases. Also, the emission current repeatedly measured withintcwith a complete relaxation after each measurement would not be degraded even though the total biasing time exceeded the critical time. The experimental results indicate that the degradation in silicon field emitters mainly originates from thermal instability of the silicon tips, especially a decrease in the effective emitting area rather than changes in the work function and geometrical factor.

ISSN:1071-1023    

DOI:10.1116/1.589912

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

A metal–oxide–semiconductor (MOS) electron tunneling cathode usingn- and heavily dopedp-type Si substrates were fabricated and their characteristics were measured. Two energy peaks in the energy distributions of emitted electrons from then-type cathode with the gate oxide thickness of 8.5 nm and thep-type cathode with the gate oxide thickness of 8.9 nm were observed. This article discusses the experimental results to make a conduction mechanism clear and shows that a part of electrons tunnel through the oxide barrier from the valence band of Si substrate and are emitted into vacuum in the MOS electron tunneling cathode.

ISSN:1071-1023    

DOI:10.1116/1.589913

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

GaN field emission pyramids are grown by self-limiting, selective-area metalorganic chemical vapor deposition. The self-limitation provides the potential of high uniformity of the pyramids and the selective-area growth allows one to define regular arrays of GaN pyramids for field emitter arrays (FEAs). Fabrication of an integrated anode lowered the operating voltage of the FEAs by narrowing the anode-cathode distance compared to devices with an external anode. A maximum emission current of 0.15 μA/tip has been observed for voltages of 570 V with an emitter-anode separation of 2 μm.

ISSN:1071-1023    

DOI:10.1116/1.589914

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

A two by two electron microcolumn array aligned with field emission array (FEA) was fabricated based on our electron-beam simulation. The spherical and chromatic aberrations, that affect the spot size of the e-beam, are highly dependent on the alignment of the electrostatic microlenses. A laser micromachining technique was used for making a self-aligned microcolumn. A FEA with a designed size and spacing was aligned and bonded to the microcolumn. TheI–Vand current stabilities of the microcolumn were measured and the field emission pattern of highly focused e-beam was obtained. The application of focused electron beam or ion beam for lithography and miniaturized scanning electron microscopy are suggested.

ISSN:1071-1023    

DOI:10.1116/1.589915

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

ZrN thin film field emitter arrays were fabricated by the ion beam assisted deposition technique. The work function of ZrN is controlled by the selection of the deposition parameters. We investigated the relationship between the work function and the emission stability, and the influence of the ambient gas on the emission stability by introducing the gases ofN2andO2into the measurement chamber. It was found that the emission stability depended on the work function: the emitters with a lower work function were more stable than those with a higher work function. The dependence is explained qualitatively by the analysis of the Fowler–Nordheim equation. Emission noise increased with the increase of the ambient gas pressure. However, difference in the increase of noise betweenN2gas andO2gas was seen.O2gas severely affected the emission stability of the ZrN emitter.

ISSN:1071-1023    

DOI:10.1116/1.589916

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

Selective area growth technique has been used to fabricate field emitter arrays of GaN. Uniform micro-sized hexagonal pyramids of Si-doped GaN were obtained on dot-patterned GaN(0001)/sapphire substrates using metalorganic vapor phase epitaxy at atmospheric pressure, and the tip radius of the pyramids was less than 100 nm. Measurement of the emission was performed at the pressure of10−7 Parange. The Fowler–Nordheim plot obtained from current–voltage characteristics shows a linear relationship, indicating that the emitted current is apparently due to field emission.

ISSN:1071-1023    

DOI:10.1116/1.590220

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

Diamonds grown by chemical vapor deposition and high-pressure high-temperature processes were mass analyzed by a newly developed scanning atom probe. The mass analysis of the diamonds revealed that the diamonds contain a large amount of hydrogen not only in the surface layer but also in the deep underlying layers and that carbon atoms form the clusters,C3,C5,C8,andC16.The clustering carbon atoms could be strongly bound in the diamond structure. The detection of a large number of neutral particles indicates that most cluster ions were decomposed into a positive ion and a neutral particle immediately after field evaporation. The interesting finding is that most carbon atoms are field ionized as multi-ionized ions such asC2+,C3+,andC4+and/orCH2+,CH3+,andCH4+with the mass peak ofH+,while the major mass peaks areC+and/orCH+when no hydrogen peak is found. This may suggest that the binding state of carbon atoms in the diamonds varies with the binding state with hydrogen atoms.

ISSN:1071-1023    

DOI:10.1116/1.589917

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

We report results on the field emitters’ electrical properties uniformity, directly measured by an electrostatic-lens projector apparatus. First, we describe the experimental setup and its resolution capability. Then, we present the emission characteristics of two1 mm2microtip arrays measured in ultrahigh vacuum and we compare these characteristics to the results of a numerical approach by taking into account a Gaussian distribution of β (the tip sharpness). From these experimental data, fitted by a numerical description of the probably emitting tips, it is possible to deduce the mean and the standard deviation of tip sharpness in our samples. A comparison between these experiments and microtip atomic force microscopy characterizations coupled to field-emission simulations, shows a good agreement. Finally, we show the effect of hydrogen on the tips’ emissive properties by using the standard Fowler–Nordheim analysis and we explore the induced changes on their statistical emission characteristics. All these results show that the probability density function of the emitting tips with respect to the applied voltage is uniform and very close to a top-hat function.

ISSN:1071-1023    

DOI:10.1116/1.590221

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

An 8-nm-thick epitaxialCaF2layer grown on ann+-Si substrate was used as the insulator in a metal–insulator–semiconductor cathode with a10 μm2emitter region. The fabricated cathodes exhibited two different types ofI–Vcharacteristics. The first type showed conventional tunnel emission current of 22 pA at an emitter current of 2.4 mA and an emitter voltage of 7 V. The emitter with the other type of characteristics showed an emission current of 5.6 nA at an emitter current of 2.2 mA and an emitter voltage of 4.5 V but it showed current instability.

ISSN:1071-1023    

DOI:10.1116/1.589918

出版商:American Vacuum Society    

年代:1998

数据来源: AIP

摘要:

The feasibility of using Ce-doped silicates as an alternative to the P22 blue phosphor (ZnS:Ag) was investigated for low voltage field emission displays (FEDs). Silicates of various composition were evaluated based on their chromaticity, intrinsic efficiency, and brightness saturation behavior. The influence of silicate composition and particle morphology on the cathodoluminescence properties was also assessed. Saturation measurements indicated that the high saturation resistance of the Ce-doped samples can yield better performance than ZnS:Ag when operating at low voltages. The silicates are also attractive for their stability in a FED environment.

ISSN:1071-1023    

DOI:10.1116/1.589919

出版商:American Vacuum Society    

年代:1998

数据来源: AIP