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Title: Picosecond ultrasonic study of surface acoustic waves on titanium nitride nanostructures

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.
Authors:
; ; ; ;  [1] ;  [2] ; ; ; ;  [3]
  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)
Publication Date:
OSTI Identifier:
22413229
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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