Dual mechanical behaviour of hydrogen in stressed silicon nitride thin films

Volpi, F.; Braccini, Alessandro de Lucca e; Devos, Arnaud; Raymond, G.; Pasturel, A.; Morin, Pascal

doi:10.1063/1.4887814

Cited by 6 publications

(2 citation statements)

References 39 publications

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“…For the mechanical model, the cantilever or beam is attached to a 500 nm wide frame with the outside edges assumed to be rigidly clamped. The SiN x has elastic modulus E SiNx =220 GPa, Poisson ratio ν =0.2, and density ρ =2,200 kg·m −3 , consistent with values reported in the literature for plasma-enhanced chemical vapour deposition grown films3031.…”

Section: Methodssupporting

confidence: 87%

Nanomechanical motion transduction with a scalable localized gap plasmon architecture

Roxworthy

Aksyuk

2016

Nat Commun

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Plasmonic structures couple oscillating electromagnetic fields to conduction electrons in noble metals and thereby can confine optical-frequency excitations at nanometre scales. This confinement both facilitates miniaturization of nanophotonic devices and makes their response highly sensitive to mechanical motion. Mechanically coupled plasmonic devices thus hold great promise as building blocks for next-generation reconfigurable optics and metasurfaces. However, a flexible approach for accurately batch-fabricating high-performance plasmomechanical devices is currently lacking. Here we introduce an architecture integrating individual plasmonic structures with precise, nanometre features into tunable mechanical resonators. The localized gap plasmon resonators strongly couple light and mechanical motion within a three-dimensional, sub-diffraction volume, yielding large quality factors and record optomechanical coupling strength of 2 THz·nm−1. Utilizing these features, we demonstrate sensitive and spatially localized optical transduction of mechanical motion with a noise floor of 6 fm·Hz−1/2, representing a 1.5 orders of magnitude improvement over existing localized plasmomechanical systems.

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Section: Methodssupporting

confidence: 87%

Nanomechanical motion transduction with a scalable localized gap plasmon architecture

Roxworthy

Aksyuk

2016

Nat Commun

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“…Therefore, to a first approximation, hydrogen content plays a direct role in determining thin-film density because of both its low atomic number (Z ¼ 1), which decreases the average atomic mass of the constituents, and its coordination number of 1, which decreases the average network coordination and consequently increases the free volume in the solid. 98 Relatively small (0.40 to 0.69 nm), isolated pores are also observed in the films, with the pore diameter appearing to trend with hydrogen content/density [ Fig. 9(b)].…”

Section: A Atomic Composition Physical Structure and Mechanical Prmentioning

confidence: 99%

The influence of hydrogen on the chemical, mechanical, optical/electronic, and electrical transport properties of amorphous hydrogenated boron carbide

Nordell

Karki

Nguyen

et al. 2015

Journal of Applied Physics

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Because of its high electrical resistivity, low dielectric constant (j), high thermal neutron capture cross section, and robust chemical, thermal, and mechanical properties, amorphous hydrogenated boron carbide (a-B x C:H y) has garnered interest as a material for low-j dielectric and solid-state neutron detection applications. Herein, we investigate the relationships between chemical structure (atomic concentration B, C, H, and O), physical/mechanical properties (density, porosity, hardness, and Young's modulus), electronic structure [band gap, Urbach energy (E U), and Tauc parameter (B 1/2)], optical/dielectric properties (frequency-dependent dielectric constant), and electrical transport properties (resistivity and leakage current) through the analysis of a large series of a-B x C:H y thin films grown by plasma-enhanced chemical vapor deposition from ortho-carborane. The resulting films exhibit a wide range of properties including H concentration from 10% to 45%, density from 0.9 to 2.3 g/cm 3 , Young's modulus from 10 to 340 GPa, band gap from 1.7 to 3.8 eV, Urbach energy from 0.1 to 0.7 eV, dielectric constant from 3.1 to 7.6, and electrical resistivity from 10 10 to 10 15 X cm. Hydrogen concentration is found to correlate directly with thin-film density, and both are used to map and explain the other material properties. Hardness and Young's modulus exhibit a direct power law relationship with density above $1.3 g/cm 3 (or below $35% H), below which they plateau, providing evidence for a rigidity percolation threshold. An increase in band gap and decrease in dielectric constant with increasing H concentration are explained by a decrease in network connectivity as well as mass/electron density. An increase in disorder, as measured by the parameters E U and B 1/2 , with increasing H concentration is explained by the release of strain in the network and associated decrease in structural disorder. All of these correlations in a-B x C:H y are found to be very similar to those observed in amorphous hydrogenated silicon (a-Si:H), which suggests parallels between the influence of hydrogenation on their material properties and possible avenues for optimization. Finally, an increase in electrical resistivity with increasing H at <35 at. % H concentration is explained, not by disorder as in a-Si:H, but rather by a lower rate of hopping associated with a lower density of sites, assuming a variable range hopping mechanism interpreted in the framework of percolation theory. V

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