Mechanical stiffness and dissipation in ultrananocrystalline diamond microresonators

Loading...
Thumbnail Image
Penn collection
Departmental Papers (MSE)
Degree type
Discipline
Subject
resonators
ultrananocrystalline diamond
dissipation
modulus
poisson's ratio
Condensed Matter Physics
Materials Science and Engineering
Funder
Grant number
License
Copyright date
Distributor
Related resources
Author
Sumant, A V
Suresh, S
Gudeman, C
Auciello, O
Carlisle, J A
Contributor
Abstract

We have characterized mechanical properties of ultrananocrystalline diamond UNCD thin films grown using the hot filament chemical vapor deposition HFCVD technique at 680 °C, significantly lower than the conventional growth temperature of 800 °C. The films have 4.3% sp2 content in the near-surface region as revealed by near edge x-ray absorption fine structure spectroscopy. The films, 1 m thick, exhibit a net residual compressive stress of 3701 MPa averaged over the entire 150 mm wafer. UNCD microcantilever resonator structures and overhanging ledges were fabricated using lithography, dry etching, and wet release techniques. Overhanging ledges of the films released from the substrate exhibited periodic undulations due to stress relaxation. This was used to determine a biaxial modulus of 8382 GPa. Resonant excitation and ring-down measurements in the kHz frequency range of the microcantilevers were conducted under ultrahigh vacuum UHV conditions in a customized UHV atomic force microscope system to determine Young’s modulus as well as mechanical dissipation of cantilever structures at room temperature. Young’s modulus is found to be 79030 GPa. Based on these measurements, Poisson’s ratio is estimated to be 0.0570.038. The quality factors Q of these resonators ranged from 5000 to 16000. These Q values are lower than theoretically expected from the intrinsic properties of diamond. The results indicate that surface and bulk defects are the main contributors to the observed dissipation in UNCD resonators.

Advisor
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Publication date
2009-06-02
Journal title
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
Copyright 2009 American Physical Society. Reprinted from: Mechanical stiffness and dissipation in ultrananocrystalline diamond microresonators. V. P. Adiga, A. V. Sumant, S. Suresh, C. Gudeman3, O. Auciello, J. A. Carlisle, and R. W. Carpick. Phys. Rev. B 79, 245403 (2009) Publisher URL: http://link.aps.org/doi/10.1103/PhysRevB.79.245403 DOI: 10.1103/PhysRevB.79.245403
Recommended citation
Collection