【Device Papers】Crystal orientation dependence of thermal conductivity and phonon transport mechanism at β-Ga₂O₃/Si heterointerface

      Researchers from Xi'an Shiyou University‌ have published a dissertation titled "Crystal orientation dependence of thermal conductivity and phonon transport mechanism at β-Ga₂O₃/Si heterointerface" in 《物理学报》。

Abstract

      β-Ga₂O₃ possesses advantages such as an ultra-wide bandgap and high breakdown field strength, presenting broad application potential in the field of high-voltage and high-power electronic devices. However, its low thermal conductivity can easily lead to self-heating effects in devices. β-Ga₂O₃/Si hetero-integration provides a feasible approach for the compatibility of β-Ga₂O₃ devices with Si-based process platforms, with interfacial thermal resistance being a key factor affecting its thermal management performance. To reveal the influence of crystal plane orientation on the thermal transport of β-Ga₂O₃/Si hetero-interfaces, models of β-Ga₂O₃/Si hetero-interfaces with (100), (010), and (001) crystal planes were constructed, and the interfacial thermal conductivity of the system was calculated using non-equilibrium molecular dynamics. The results indicate that at 300 K, the (010) crystal plane exhibits the highest interfacial thermal conductivity, approximately 288 MW·m^-2·K^-1; followed by the (001) crystal plane, with a value of approximately 242 MW·m^-2·K^-1; and the (100) crystal plane has the lowest, approximately 122 MW·m^-2·K^-1. Analysis of phonon density of states and spectral decomposition thermal conductivity reveals that the differences in interfacial thermal conductivity among different crystal planes primarily stem from the mismatch of phonon spectra on both sides of the interface and the varying transmission abilities of mid- and low-frequency phonons, with phonons below 20 THz making a dominant contribution. An increase in temperature generally enhances interfacial thermal conductivity, but does not alter the dependence on crystal plane orientation. These findings suggest that crystal plane orientation is a crucial factor in regulating the thermal transport performance of β-Ga₂O₃/Si hetero-interfaces, providing a theoretical reference for the interfacial thermal management and crystal plane selection in β-Ga₂O₃/Si hetero-integrated devices.

Link：

https://kns.cnki.net/kcms2/article/abstract?v=gvg-iIm8s3MChGrspfyX-zkhwWc-ocO9NLP7AYiko10-6K3_Ul4ot7q-8GYhvspa_5mHUAJTChw8VWowwpxKLSA2CaCLPucENKOnAZ4ar6Z21GdEX2hv6Z8r4kEgzK_xeDQJWdMhm39cJ4CFOx-FSWrF1JEdxdGqTsNuceKNybjXfzxTlp5kqw==&uniplatform=NZKPT&language=CHS