High Thermal Boundary Conductance across Bonded Heterogeneous GaN-SiC Interfaces

Fengwen Mu, Zhe Cheng, Jingjing Shi, Seongbin Shin, Bin Xu, Junichiro Shiomi, Samuel Graham, Tadatomo Suga

Research output: Contribution to journalArticlepeer-review

47 Citations (Scopus)


High-power GaN-based electronics are limited by high channel temperatures induced by self-heating, which degrades device performance and reliability. Increasing the thermal boundary conductance (TBC) between GaN and SiC will aid in the heat dissipation of GaN-on-SiC devices by taking advantage of the high thermal conductivity of SiC substrates. For the typical growth method, there are issues concerning the transition layer at the interface and low-quality GaN adjacent to the interface, which impedes heat flow. In this work, a room-temperature bonding method is used to bond high-quality GaN to SiC directly, which allows for the direct integration of high-quality GaN with SiC to create a high TBC interface. Time-domain thermoreflectance is used to measure the GaN thermal conductivity and GaN-SiC TBC. The measured GaN thermal conductivity is larger than that of grown GaN-on-SiC by molecular beam epitaxy. High TBC is observed for the bonded GaN-SiC interfaces, especially for the annealed interface (∼230 MW m-2 K-1, close to the highest value ever reported). Thus, this work provides the benefit of both a high TBC and higher GaN thermal conductivity, which will impact the GaN-device integration with substrates in which thermal dissipation always plays an important role. Additionally, simultaneous thermal and structural characterizations of heterogeneous bonded interfaces are performed to understand the structure-thermal property relation across this new type of interface.

Original languageEnglish
Pages (from-to)33428-33434
Number of pages7
JournalACS applied materials & interfaces
Issue number36
Publication statusPublished - 2019 Sep 11


  • GaN-on-SiC
  • interface
  • room-temperature bonding
  • thermal boundary conductance
  • time-domain thermoreflectance

ASJC Scopus subject areas

  • Materials Science(all)


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