@article{7d4938d3ac194513b73f6ae9b1fb3ca2,
title = "Thermal conductivity of crystalline AlN and the influence of atomic-scale defects",
abstract = "Aluminum nitride (AlN) plays a key role in modern power electronics and deep-ultraviolet photonics, where an understanding of its thermal properties is essential. Here, we measure the thermal conductivity of crystalline AlN by the 3ω method, finding that it ranges from 674 ± 56 Wm-1 K-1 at 100 K to 186 ± 7Wm-1 K-1 at 400 K, with a value of 237 ± 6 Wm-1 K-1 at room temperature. We compare these data with analytical models and first-principles calculations, taking into account atomic-scale defects (O, Si, C impurities, and Al vacancies). We find that Al vacancies play the greatest role in reducing thermal conductivity because of the largest mass-difference scattering. Modeling also reveals that 10% of heat conduction is contributed by phonons with long mean free paths (MFPs), over ∼7 μm at room temperature, and 50% by phonons with MFPs over ∼0.3 μm. Consequently, the effective thermal conductivity of AlN is strongly reduced in submicrometer thin films or devices due to phonon-boundary scattering.",
author = "Xu, {Runjie Lily} and {Mun{\~o}z Rojo}, Miguel and Islam, {S. M.} and Aditya Sood and Bozo Vareskic and Ankita Katre and Natalio Mingo and Goodson, {Kenneth E.} and Xing, {Huili Grace} and Debdeep Jena and Eric Pop",
note = "Funding Information: This work was supported in part by the National Science Foundation (NSF) DMREF program through Grant Nos. 1534279 and 1534303, by the NSF Engineering Research Center for Power Optimization of Electro-Thermal Systems (POETS) with Cooperative Agreement (No. EEC-1449548), and by the Stanford SystemX Alliance. This work was also supported by ASCENT, one of six centers in JUMP, a SRC program sponsored by DARPA. The experiments were performed in part at the Stanford Nanofabrication Facility and the Stanford Nano Shared Facilities, which receive funding from the NSF as part of the National Nanotechnology Coordinated Infrastructure Award (No. ECCS-1542152). A.K. and N.M. acknowledge support from the Air Force Office of Scientific Research through Grant No. FA9550615-1-0187 DEF. A.K. also acknowledges DST-INSPIRE Grant, India (Grant No. IFA17-MS122). R.L.X. and M.M.R. gratefully acknowledge technical discussions with C. Dames, V. Mishra, and W. Hodges. Publisher Copyright: {\textcopyright} 2019 Author(s).",
year = "2019",
month = nov,
day = "14",
doi = "10.1063/1.5097172",
language = "English (US)",
volume = "126",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "18",
}