TY - JOUR
T1 - Thermal Conductivity of Aluminum Scandium Nitride for 5G Mobile Applications and beyond
AU - Song, Yiwen
AU - Perez, Carlos
AU - Esteves, Giovanni
AU - Lundh, James Spencer
AU - Saltonstall, Christopher B.
AU - Beechem, Thomas E.
AU - Yang, Jung In
AU - Ferri, Kevin
AU - Brown, Joseph E.
AU - Tang, Zichen
AU - Maria, Jon Paul
AU - Snyder, David W.
AU - Olsson, Roy H.
AU - Griffin, Benjamin A.
AU - Trolier-Mckinstry, Susan E.
AU - Foley, Brian M.
AU - Choi, Sukwon
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation, as part of the Center for Dielectrics and Piezoelectrics under grant nos. IIP-1361571, IIP-1361503, IIP-1841453, and IIP-1841466. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. G.E. would like to gratefully thank Sara Dickens and Joseph Michael at Sandia for conducting EBSD analysis. Sandia National Laboratories is a multimission laboratory managed and operated by the National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE’s National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government.
Publisher Copyright:
©
PY - 2021/4/28
Y1 - 2021/4/28
N2 - Radio frequency (RF) microelectromechanical systems (MEMS) based on Al1-xScxN are replacing AlN-based devices because of their higher achievable bandwidths, suitable for the fifth-generation (5G) mobile network. However, overheating of Al1-xScxN film bulk acoustic resonators (FBARs) used in RF MEMS filters limits power handling and thus the phone's ability to operate in an increasingly congested RF environment while maintaining its maximum data transmission rate. In this work, the ramifications of tailoring of the piezoelectric response and microstructure of Al1-xScxN films on the thermal transport have been studied. The thermal conductivity of Al1-xScxN films (3-8 W m-1 K-1) grown by reactive sputter deposition was found to be orders of magnitude lower than that for c-axis-textured AlN films due to alloying effects. The film thickness dependence of the thermal conductivity suggests that higher frequency FBAR structures may suffer from limited power handling due to exacerbated overheating concerns. The reduction of the abnormally oriented grain (AOG) density was found to have a modest effect on the measured thermal conductivity. However, the use of low AOG density films resulted in lower insertion loss and thus less power dissipated within the resonator, which will lead to an overall enhancement of the device thermal performance.
AB - Radio frequency (RF) microelectromechanical systems (MEMS) based on Al1-xScxN are replacing AlN-based devices because of their higher achievable bandwidths, suitable for the fifth-generation (5G) mobile network. However, overheating of Al1-xScxN film bulk acoustic resonators (FBARs) used in RF MEMS filters limits power handling and thus the phone's ability to operate in an increasingly congested RF environment while maintaining its maximum data transmission rate. In this work, the ramifications of tailoring of the piezoelectric response and microstructure of Al1-xScxN films on the thermal transport have been studied. The thermal conductivity of Al1-xScxN films (3-8 W m-1 K-1) grown by reactive sputter deposition was found to be orders of magnitude lower than that for c-axis-textured AlN films due to alloying effects. The film thickness dependence of the thermal conductivity suggests that higher frequency FBAR structures may suffer from limited power handling due to exacerbated overheating concerns. The reduction of the abnormally oriented grain (AOG) density was found to have a modest effect on the measured thermal conductivity. However, the use of low AOG density films resulted in lower insertion loss and thus less power dissipated within the resonator, which will lead to an overall enhancement of the device thermal performance.
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U2 - 10.1021/acsami.1c02912
DO - 10.1021/acsami.1c02912
M3 - Article
C2 - 33851815
AN - SCOPUS:85105049124
SN - 1944-8244
VL - 13
SP - 19031
EP - 19041
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 16
ER -