Abstract
In this work, a thin layer of hexagonal boron nitride (h-BN) or HfO2 serves as an adhesion layer between the ultrathin atomic-layer-deposited (ALD) indium oxide (In2O3) channel and a sapphire substrate to enhance the thermal interfacial conductance. A thermo-reflectance (TR) measurement system with high spatial resolution is introduced to experimentally demonstrates the improvement. With the thin h-BN or HfO2 interlayer, the temperature elevation ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta {T}$ </tex-math></inline-formula> ) induced by self-heating effect (SHE) is decreased by roughly 9% or 27%, respectively. To quantify the improvement of the interfacial heat transfer, a steady-state thermal diffusion model with a finite-element method is combined with the experimental TR observation to extract the effective thermal boundary conductance (TBC) values in each case. It is shown that the effective TBC is ameliorated by a factor of 2 or 7 with the h-BN or HfO2 interlayer, which is responsible for the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta {T}$ </tex-math></inline-formula> reduction. Furthermore, phonon density of states (PDOS) distribution mismatch implies that the intersection over union (IOU) ratio in the acoustic phonon region of In2O3 with h-BN or HfO2 is roughly 3 or 11 times higher than that directly with sapphire, which is responsible for the profound TBC enhancement. Based on this, ultrahigh maximum drain current of 2.4 mA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> is achieved with 2.1-nm-thick In2O3 channel on a sapphire substrate with an HfO2 interlayer in between due to the alleviated SHE.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
