Thermal conductivity of GaN, 
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, and SiC from 150 K to 850 K

Zheng, Qiye; Li, Chunhua; Rai, Akash; Leach, J. H.; Broido, David

doi:10.1103/physrevmaterials.3.014601

Cited by 107 publications

(79 citation statements)

References 123 publications

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“…In comparison, previous experimental efforts only reported a small to moderate isotope effect on other materials. For example, the effect was P ≈ 10% for Si (23), 20% for Ge (24), 5% for GaAs (25), 15% for GaN (26), and 50% for diamond (27). We note that isotope effects of 43% and 58% were measured for hBN (28) and graphene (29), respectively.…”

Section: Main Textmentioning

confidence: 71%

Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride

Chen

Song

Ravichandran

et al. 2020

Science

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225

127

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Materials with high thermal conductivity (κ) are of technological importance and fundamental interest. We grew cubic boron nitride (cBN) crystals with controlled abundance of boron isotopes and measured κ greater than 1600 watts per meter-kelvin at room temperature in samples with enriched 10B or 11B. In comparison, we found that the isotope enhancement of κ is considerably lower for boron phosphide and boron arsenide as the identical isotopic mass disorder becomes increasingly invisible to phonons. The ultrahigh κ in conjunction with its wide bandgap (6.2 electron volts) makes cBN a promising material for microelectronics thermal management, high-power electronics, and optoelectronics applications.

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Section: Main Textmentioning

confidence: 71%

Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride

Chen

Song

Ravichandran

et al. 2020

Science

Self Cite

225

127

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“…Ceramic and ceramic composite materials are under intensive investigation for HTHX and other industrial thermal devices due to their creep resistance, intrinsically higher κ and lower CTE . For example, κ of bulk crystals of 4H and 6H SiC is about 400 W m −1 K −1 at room temperature and is expected to be above 70 W m −1 K −1 at 1000 K, while CTE of 4H SiC is (3–5) × 10 −6 K −1 from room temperature to 1000 °C . However, when the ceramic materials are processed into HTHXs, their κ is generally substantially lower than the single crystal values due to the grain boundaries and impurities presented in the sintered materials (e.g., κ of sintered SiC is ≈100 W m −1 K −1 at room temperature and ≈40 W m −1 K −1 at 1000 °C ).…”

Section: Introductionmentioning

confidence: 99%

Advanced Materials for High‐Temperature Thermal Transport

Shin

Wang

Luo

et al. 2019

Adv Funct Materials

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High temperature processes are widely used in a variety of existing and emerging industrial and aerospace applications. The thermal properties of high‐temperature materials thus play an important role in controlling the thermal energy, as highlighted by successful applications of thermal barrier coating and aerogels. While thermal transport processes at room and low temperature have witnessed tremendous progress in the past two decades, particularly on the fronts of understanding basic heat transfer properties at the micro‐ and nanoscale, the understanding at high temperature is still at the nascent stage, owing to several unique features at high temperature, such as the dominant Umklapp scattering effect that can render a crystalline material amorphous‐like thermal properties, and the important radiation contribution at high temperature. This lack of systematic understanding, coupled with the challenges in maintaining high‐temperature stability in a large number of materials, has limited the development of materials to meet the thermal transport properties pertaining to several current and emerging high‐temperature applications. This Review is aimed at providing an overview of the basic mechanisms governing thermal transport processes at high temperature, to identify their unique features and challenges, and to explore opportunities in material research for high‐temperature thermal materials.

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“…800 nm layer GaN is 150 W/m-K. 26,35 Figure 5(b) shows the max temperature of the device with a heating source width of 4 μm, a heating source length of 500 μm, and gate-gate spacing of 50 μm. The thermal conductivity of SiC and diamond used in the modeling are 380 W/m-K and 2000 W/m-K, respectively 32,42. The max temperature of GaN devices on a diamond substrate is much lower than that on a SiC substrate, indicating the advantage of using diamond substrates.…”

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confidence: 99%

Interfacial Thermal Conductance across Room-Temperature-Bonded GaN/Diamond Interfaces for GaN-on-Diamond Devices

Cheng

Yates

et al. 2020

ACS Appl. Mater. Interfaces

146

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The wide bandgap, high-breakdown electric field, and high carrier mobility makes GaN an ideal material for high-power and high-frequency electronics applications such as wireless communication and radar systems. However, the performance and reliability of GaN-based high electron mobility transistors (HEMTs) are limited by the high channel temperature induced by Joule-heating in the device channel. High thermal conductivity substrates (e.g., diamond) integrated with GaN can improve the extraction of heat from GaN-based HEMTs and lower the device operating temperature. However, heterogeneous integration of GaN with diamond substrates is not trivial and presents technical challenges to maximize the heat dissipation potential brought by the diamond substrate. In this work, two modified room-temperature surface-activated bonding (SAB) techniques are used to bond GaN and single crystal diamond with different interlayer thicknesses. Time-domain thermoreflectance (TDTR) is used to measure the thermal properties from room temperature to 480 K. A relatively large thermal boundary conductance (TBC) of the GaN-diamond interfaces with a ~4-nm interlayer (~90 MW/m 2 -K) was observed and material characterization was performed to link the structure of the interface to the TBC. Device modeling shows that the measured GaN-diamond TBC values obtained from bonding can enable high power GaN devices by taking the full advantage of the high thermal conductivity of single crystal diamond and achieve excellent cooling effect. Furthermore, the room-temperature bonding process in this work do not induce stress problem due to different coefficient of thermal expansion in other high temperature integration processes in previous studies. Our work sheds light on the potential for room-temperature heterogeneous integration of semiconductors with diamond for applications of electronics cooling especially for GaN-on-diamond devices.

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Thermal conductivity of GaN, GaN71 , and SiC from 150 K to 850 K

Cited by 107 publications

References 123 publications

Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride

Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride

Advanced Materials for High‐Temperature Thermal Transport

Interfacial Thermal Conductance across Room-Temperature-Bonded GaN/Diamond Interfaces for GaN-on-Diamond Devices

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