Kumar Nitish, Barry Matthew C, Kumar Satish
G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, United States of America.
J Phys Condens Matter. 2021 Dec 24;34(10). doi: 10.1088/1361-648X/ac413e.
Phonon transport in-GaOthin films and metal-oxide field effect transistors (MESFETs) are investigated using non-gray Boltzmann transport equations (BTEs) to decipher the effect of ballistic-diffusive phonon transport. The effects of domain size, and energy dissipation to various phonon modes and subsequent phonon-phonon energy exchange on the thermal transport and temperature distribution is investigated using non-gray BTE. Our analysis deciphered that domain size plays a major role in thermal transport in-GaObut energy dissipation to various phonon modes and subsequent phonon-phonon energy exchange does not affect the temperature field significantly. Phonon transport in-GaOMESFETs on diamond substrate is investigated using coupled non-gray BTE and Fourier model. It is established that the ballistic effects need to be considered for devices with-GaOlayer thickness less than 1 m. A non-gray phonon BTE model should be used near hotspot in the thin-GaOlayer as the Fourier model may not give accurate temperature distribution. The results from this work will help in understanding the mechanism of phonon transport in the-GaOthin films and energy efficient design of its FETs.
使用非灰玻尔兹曼输运方程（BTEs）研究了氧化镓（In-GaO）薄膜和金属氧化物场效应晶体管（MESFETs）中的声子输运，以解读弹道-扩散声子输运的影响。使用非灰BTE研究了畴尺寸以及向各种声子模式的能量耗散和随后的声子-声子能量交换对热输运和温度分布的影响。我们的分析表明，畴尺寸在氧化镓（In-GaO）的热输运中起主要作用，但向各种声子模式的能量耗散和随后的声子-声子能量交换对温度场的影响并不显著。使用耦合的非灰BTE和傅里叶模型研究了金刚石衬底上的氧化镓（In-GaO）MESFETs中的声子输运。结果表明，对于氧化镓（In-GaO）层厚度小于1μm的器件，需要考虑弹道效应。在氧化镓（In-GaO）薄层的热点附近应使用非灰声子BTE模型，因为傅里叶模型可能无法给出准确的温度分布。这项工作的结果将有助于理解氧化镓（In-GaO）薄膜中的声子输运机制及其场效应晶体管的节能设计。
