Amorphous Dielectric Thin Films with Extremely Low Mechanical Loss

Amorphous Dielectric Thin Films with Extremely Low Mechanical Loss

The ubiquitous low-energy excitations are one of the universal phenomena of amorphous solids. These excitations dominate the acoustic, dielectric, and thermal properties of structurally disordered solids. One exception has been a type of hydrogenated amorphous silicon ( -Si:H) with 1 at.% H. Using l...

Full description

Saved in:
Bibliographic Details
Published in:Archives of metallurgy and materials Vol. 60; no. 1; pp. 359 - 363
Main Authors: Liu, X., Queen, D.R., Metcalf, T.H., Karel, J.E., Hellman, F.
Format: Journal Article
Language:English
Published: Warsaw De Gruyter Open 01-04-2015
Polish Academy of Sciences
Subjects:
Amorphous silicon
Amorphous structure
Dielectric properties
elastic modulus
Electron beams
Electrons
Energy
Excitation
Friction
Hydrogenation
Internal friction
Low temperature
Silicon
speed of sound
Temperature
Thermal measurement
Thermodynamic properties
Thin films
tunneling systems
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The ubiquitous low-energy excitations are one of the universal phenomena of amorphous solids. These excitations dominate the acoustic, dielectric, and thermal properties of structurally disordered solids. One exception has been a type of hydrogenated amorphous silicon ( -Si:H) with 1 at.% H. Using low temperature elastic and thermal measurements of electron-beam evap-orated amorphous silicon ( -Si), we show that TLS can be eliminated in this system as the films become denser and more structurally ordered under certain deposition conditions. Our results demonstrate that TLS are not intrinsic to the glassy state but instead reside in low density regions of the amorphous network. This work obviates the role hydrogen was previously thought to play in removing TLS in -Si:H and favors an ideal four-fold covalently bonded amorphous structure as the cause for the disappearance of TLS. Our result supports the notion that -Si can be made a “perfect glass” with “crystal-like” properties, thus offering an encouraging opportunity to use it as a simple crystal dielectric alternative in applications, such as in modern quantum devices where TLS are the source of dissipation, decoherence and 1/f noise.
ISSN:2300-1909
1733-3490
2300-1909
DOI:10.1515/amm-2015-0059