Discontinuous Au films on NaCl substrates

Articles you may be interested inAnalysis of temperature dependent current-conduction mechanisms in Au/TiO2/n-4H-SiC (metal/insulator/semiconductor) type Schottky barrier diodes Hydrogen interaction with platinum and palladium metal-insulator-semiconductor devices J. Appl. Phys. 98, 014505 (2005); 10.1063/1.1953866Metal-insulator-semiconductor emitter with an epitaxial CaF 2 layer as the insulator J.The flat metal-insulator-semiconductor ͑MIS͒ electron emitter is a simple design, allowing easy manufacture. The emitters are relatively insensitive to environment, allowing them to operate in poorer vacuum conditions than are necessary for oxide thermionic or microtip field emitters. In most literature reports, MIS and metal-insulator-metal devices are limited in emission current ͑Ͻ0.001 A / cm 2 ͒ by their low efficiencies ͑Ӷ0.1%͒. We have observed emission currents as high as 2-10 A/cm 2 at efficiencies from 3 % -10%. Our best results are from emitters comprised of 5 -7.5 nm gold/ 15 nm SiO 2 / 100 nm polysilicon/n ++ doped silicon substrate. The roles of each component of the flat emitter were investigated. The polysilicon serves a dual role: Bumps on its surface act as field-enhanced emission sites while the bulk of the film behaves as a self-adjusting ballast resistor preventing run away emission from any one emission site. The thin gold layer self-assembles into a nanomesh with Ͼ400 pores/ m 2 through which electrons are emitted. Energy distribution and angular divergence of emitted electrons were measured. A coherent explanation of emission including the origination of the divergence is presented. Pros and cons of the MIS emitter and potential application are discussed.

show abstract

“…23,24 Nonuniform thin film coverage may explain the observed anomaly. 23,24 Nonuniform thin film coverage may explain the observed anomaly.…”

Section: Thin Metalmentioning

confidence: 96%

Polysilicon metal-insulator-semiconductor electron emitter

Govyadinov

Novet

Pidwerbecki

et al. 2005

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

show abstract

“…Most coated the DMTF with carbon and floated samples off the substrate in water, aided by the surface tension. But this turned out to be impossible for areas immediately adjacent to the contacts, with the only solution to use a soluble substrate [40]. The net effect has been that published structures have been from the center of the films while (it will be argued below) the structure determining electrical properties is that at the contacts.…”

Section: Electrostatically Activated Tunnelingmentioning

confidence: 99%

Electron transport in discontinuous metal thin films

Morris

2022

Nano Ex.

View full text Add to dashboard Cite

The structure and basic experimental electrical properties of vacuum evaporated discontinuous (island) metal thin films of discrete metal nanoparticles on insulating substrates are briefly reviewed. Then the widely accepted Neugebauer and Webb (N&W) electrostatically activated electron tunneling conduction model is covered (with enhancements) before the numerous discrepancies between this model and experimental observations are identified, e.g. minimal substrate bias effect, non-linear field distribution, anomalous AC effects, asymmetrical contact effects, and switching. A modified model, based on contact electron injection and extraction, and computer simulations are introduced which explain these discrepancies at a qualitative level. However, quantitative experimental verification of the model is not possible without stable, reproducible films of known structures. The paper concludes with a review of possible preparation techniques which could yield satisfactory samples, especially self-assembly of organically protected metal nanoparticles. One of these has already demonstrated electrostatically activated conduction.

show abstract