Picosecond ultrasonic study of surface acoustic waves on titanium nitride nanostructures

Journal Article · Sat Mar 07 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4914048· OSTI ID:22413229

Bjornsson, M. M.; Connolly, A. B.; Mahat, S.; Rachmilowitz, B. E.; Daly, B. C. ^[1]; Antonelli, G. A. ^[2]; Myers, A.; Singh, K. J.; Yoo, H. J.; King, S. W. ^[3]

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1. Vassar College, Physics and Astronomy Department, Poughkeepsie, New York 12604 (United States)
2. Antonelli Research and Technology LLC, Portland, Oregon 97202 (United States)
3. Intel Corporation, Logic Technology Development, Hillsboro, Oregon 97124 (United States)

We have measured surface acoustic waves on nanostructured TiN wires overlaid on multiple thin films on a silicon substrate using the ultrafast pump-probe technique known as picosecond ultrasonics. We find a prominent oscillation in the range of 11–54 GHz for samples with varying pitch ranging from 420 nm down to 168 nm. We find that the observed oscillation increases monotonically in frequency with decrease in pitch, but that the increase is not linear. By comparing our data to two-dimensional mechanical simulations of the nanostructures, we find that the type of surface oscillation to which we are sensitive changes depending on the pitch of the sample. Surface waves on substrates that are loaded by thin films can take multiple forms, including Rayleigh-like waves, Sezawa waves, and radiative (leaky) surface waves. We describe evidence for detection of modes that display characteristics of these three surface wave types.

• OSTI ID: 22413229
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
GHZ RANGE
NANOSTRUCTURES
OSCILLATIONS
SILICON
SUBSTRATES
SURFACES
THIN FILMS
TITANIUM
TITANIUM NITRIDES
TWO-DIMENSIONAL SYSTEMS
ULTRASONIC WAVES
WAVE PROPAGATION