Showing papers by "Samuel Graham published in 2020"

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

Abstract: 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. Integration of GaN with high thermal conductivity substrates can improve the heat extraction from GaN-based HEMTs and lower the operating temperature of the device. However, heterogeneous integration of GaN with diamond substrates presents technical challenges to maximize the heat dissipation potential brought by the ultrahigh thermal conductivity of diamond substrates. In this work, two modified room-temperature surface-activated bonding (SAB) techniques are used to bond GaN and single-crystal diamond. 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/(m2 K)) was observed and material characterization was performed to link the interfacial structure with the TBC. Device modeling shows that the measured TBC of the bonded GaN/diamond interfaces can enable high-power GaN devices by taking full advantage of the ultrahigh thermal conductivity of single-crystal diamond. For the modeled devices, the power density of GaN-on-diamond can reach values ∼2.5 times higher than that of GaN-on-SiC and ∼5.4 times higher than that of GaN-on-Si with a maximum device temperature of 250 °C. 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.

Thermal Transport across Ion-Cut Monocrystalline β-Ga2O3 Thin Films and Bonded β-Ga2O3–SiC Interfaces

Abstract: The ultrawide band gap, high breakdown electric field, and large-area affordable substrates make β-Ga2O3 promising for applications of next-generation power electronics, while its thermal conductiv...

Integration of polycrystalline Ga2O3 on diamond for thermal management

Abstract: Gallium oxide (Ga2O3) has attracted great attention for electronic device applications due to its ultra-wide bandgap, high breakdown electric field, and large-area affordable substrates grown from the melt. However, its thermal conductivity is significantly lower than that of other wide bandgap semiconductors such as SiC, AlN, and GaN, which will impact its ability to be used in high power density applications. Thermal management in Ga2O3 electronics will be the key for device reliability, especially for high power and high frequency devices. Similar to the method of cooling GaN-based high electron mobility transistors by integrating it with high thermal conductivity diamond substrates, this work studies the possibility of heterogeneous integration of Ga2O3 with diamond for the thermal management of Ga2O3 devices. In this work, Ga2O3 was deposited onto single crystal diamond substrates by atomic layer deposition (ALD), and the thermal properties of ALD-Ga2O3 thin films and Ga2O3–diamond interfaces with different interface pretreatments were measured by Time-domain Thermoreflectance. We observed a very low thermal conductivity of these Ga2O3 thin films (about 1.5 W/m K) due to the extensive phonon grain boundary scattering resulting from the nanocrystalline nature of the Ga2O3 film. However, the measured thermal boundary conductance (TBC) of the Ga2O3–diamond interfaces is about ten times larger than that of the van der Waals bonded Ga2O3–diamond interfaces, which indicates the significant impact of interface bonding on TBC. Furthermore, the TBC of the Ga-rich and O-rich Ga2O3–diamond interfaces is about 20% smaller than that of the clean interface, indicating that interface chemistry affects the interfacial thermal transport. Overall, this study shows that a high TBC can be obtained from strong interfacial bonds across Ga2O3–diamond interfaces, providing a promising route to improving the heat dissipation from Ga2O3 devices with lateral architectures.

Experimental observation of high intrinsic thermal conductivity of AlN

Abstract: Wurtzite AlN is an ultrawide bandgap semiconductor that has been developed for applications including power electronics and optoelectronics. Thermal management of these applications is the key for stable device performance and allowing for long lifetimes. However, the intrinsic high thermal conductivity of bulk AlN predicted by theoretical calculations has not been experimentally observed because of the difficulty in producing high-quality materials. This work reports the growth of thick (g15 \ensuremath{\mu}m) AlN layers by metal-organic chemical vapor deposition and experimental observation of intrinsic thermal conductivity from 130 to 480 K that matches density-functional-theory calculations for single crystal AlN, producing some of the highest values ever measured. Detailed material characterizations confirm the high quality of these AlN samples with one or two orders of magnitude lower impurity concentrations than commercially available bulk AlN. The thermal conductivity of these commercially available bulk AlN substrates are also measured as comparison. To interpret the reduced thermal conductivity, a simple Callaway model is built. This work demonstrates the possibility of obtaining theoretically high values of thermal conductivity in AlN and will impact the thermal management and reliability of future electronic and optoelectronics devices.

Modeling and analysis for thermal management in gallium oxide field-effect transistors

Abstract: Increased attention has been paid to the thermal management of β-Ga2O3 devices as a result of the large thermal resistance that can present itself in part due to its low intrinsic thermal conductivity. A number of die-level thermal management approaches exist that could be viable for thermal management. However, they have not been assessed for β-Ga2O3 devices exclusively. Here, we explore the limits of various die level thermal management schemes on a β-Ga2O3 metal–semiconductor field-effect transistor using numerical simulations. The effects of the various cooling approaches on the device channel temperature were comprehensively investigated, along with guidance for material selection to enable the most effective thermal solutions. Among various cooling strategies, double side cooling combined with a heat spreader used in the active region of the device can suppress the device thermal resistance to as low as 11 mm °C/W, achieving a maximum dissipated power density as high as 16 W/mm for a junction temperature limit of 200 °C. A multi-finger transistor thermal model was also developed to assess the potential of β-Ga2O3 devices for higher output power applications. Overall, this numerical study shows that it is possible to achieve high power β-Ga2O3 device operation with appropriate die-level thermal management solutions.

Thermal boundary conductance across epitaxial metal/sapphire interfaces

Abstract: As electronic devices shrink down to their ultimate limit, the fundamental understanding of interfacial thermal transport becomes essential in thermal management. However, a comprehensive understanding of phonon transport mechanisms that drive interfacial thermal transport is still under development. The thermal transport across interfaces can be strongly affected by factors such as crystalline structure, surface roughness, chemical diffusion, etc. These complications lead to a significant quantitative uncertainty between experimentally measured thermal boundary conductance (TBC) across real material interfaces and theoretically calculated TBCs that are often predicted on structurally and/or chemically ideal interfaces. In this paper, we report on the thermal conductance across interfaces between various epitaxially grown metal films (Co, Ru, and Al) and $c$-plane sapphire substrates via time-domain thermoreflectance over the temperature range of \ensuremath{\sim}80 to \ensuremath{\sim}500 K. The room-temperature interface conductances of Al/sapphire, Co/sapphire, and Ru/sapphire are all $\ensuremath{\sim}350\phantom{\rule{0.16em}{0ex}}\mathrm{MW}\phantom{\rule{0.16em}{0ex}}{\mathrm{m}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ despite the phonon spectra differences among the metals. We compare our results to predictions of TBC using atomistic Green's function calculations and the modal nonequilibrium Landauer method with transmission from the diffuse mismatch model. We found a consistent quantitative agreement between the experimentally measured TBCs and the predictions using the modal nonequilibrium Landauer model for the $\mathrm{Al}/{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$, $\mathrm{Co}/{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$, and $\mathrm{Ru}/{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ interfaces. This result suggests that interfacial elastic phonon thermal transport dominates TBC for the various epitaxial metal/sapphire combinations of interest in this work, while other mechanisms are negligible.

Bulk-like Intrinsic Phonon Thermal Conductivity of Micrometer-Thick AlN Films.

Abstract: Aluminum nitride (AlN) has garnered much attention due to its intrinsically high thermal conductivity. However, engineering thin films of AlN with these high thermal conductivities can be challenging due to vacancies and defects that can form during the synthesis. In this work, we report on the cross-plane thermal conductivity of ultra-high-purity single-crystal AlN films with different thicknesses (∼3-22 μm) via time-domain thermoreflectance (TDTR) and steady-state thermoreflectance (SSTR) from 80 to 500 K. At room temperature, we report a thermal conductivity of ∼320 ± 42 W m-1 K-1, surpassing the values of prior measurements on AlN thin films and one of the highest cross-plane thermal conductivities of any material for films with equivalent thicknesses, surpassed only by diamond. By conducting first-principles calculations, we show that the thermal conductivity measurements on our thin films in the 250-500 K temperature range agree well with the predicted values for the bulk thermal conductivity of pure single-crystal AlN. Thus, our results demonstrate the viability of high-quality AlN films as promising candidates for the high-thermal-conductivity layers in high-power microelectronic devices. Our results also provide insight into the intrinsic thermal conductivity of thin films and the nature of phonon-boundary scattering in single-crystal epitaxially grown AlN thin films. The measured thermal conductivities in high-quality AlN thin films are found to be constant and similar to bulk AlN, regardless of the thermal penetration depth, film thickness, or laser spot size, even when these characteristic length scales are less than the mean free paths of a considerable portion of thermal phonons. Collectively, our data suggest that the intrinsic thermal conductivity of thin films with thicknesses less than the thermal phonon mean free paths is the same as bulk so long as the thermal conductivity of the film is sampled independent of the film/substrate interface.

Thermal conductance across harmonic-matched epitaxial Al-sapphire heterointerfaces

Abstract: A unified fundamental understanding of interfacial thermal transport is missing due to the complicated nature of interfaces Because of the difficulty to grow high-quality interfaces and lack of materials characterization, the experimentally measured thermal boundary conductance (TBC) in the literature are usually not the same as the ideally modelled interfaces This work provides a systematic study of TBC across the highest-quality (atomically sharp, harmonic-matched, and ultraclean) epitaxial (111) Al||(0001) sapphire interfaces to date The comparison of measured high TBC with theoretical models shows that elastic phonon transport dominates the interfacial thermal transport and other mechanisms play negligible roles This is confirmed by a nearly constant transmission coefficient by scaling the TBC with the Al heat capacity and sapphire heat capacity with phonon frequency lower than 10 THz Finally, the findings in this work will impact applications such as electronics thermal management, thermoelectric energy conversion, and battery safety The mechanism of thermal transport at solid interfaces depends on many parameters in particular the quality of the interface Here, the authors compare experimental and calculated thermal boundary conductance across high-quality harmonic-matched epitaxial Al-sapphire interfaces and find that elastic phonon processes dominate the ultra-clean interfaces

Heteroepitaxial growth of β-Ga2O3 films on SiC via molecular beam epitaxy

Abstract: β-Ga2O3 is a promising ultrawide bandgap semiconductor for next generation radio frequency electronics. However, its low thermal conductivity and inherent thermal resistance provide additional challenges in managing the thermal response of β-Ga2O3 electronics, limiting its power performance. In this paper, we report the heteroepitaxial growth of β-Ga2O3 films on high thermal conductivity 4H-SiC substrates by molecular beam epitaxy (MBE) at 650 °C. Optimized MBE growth conditions were first determined on sapphire substrates and then used to grow β-Ga2O3 on 4H-SiC. X-ray diffraction measurements showed single phase ( 2 ¯ 01 ) β-Ga2O3 on (0001) SiC substrates, which was also confirmed by TEM measurements. These thin films are electrically insulating with a ( 4 ¯ 02 ) peak rocking curve full-width-at-half-maximum of 694 arc sec and root mean square surface roughness of ∼2.5 nm. Broad emission bands observed in the luminescence spectra, acquired in the spectral region between near infrared and deep ultraviolet, have been attributed to donor-acceptor pair transitions possibly related to Ga vacancies and its complex with O vacancies. The thermal conductivity of an 81 nm thick Ga2O3 layer on 4H-SiC was determined to be 3.1 ± 0.5 W/m K, while the measured thermal boundary conductance (TBC) of the Ga2O3/SiC interface is 140 ± 60 MW/m2 K. This high TBC value enables the integration of thin β-Ga2O3 layers with high thermal conductivity substrates to meliorate thermal dissipation and improve device thermal management.

Thermal Performance of GaN/Si HEMTs Using Near-Bandgap Thermoreflectance Imaging

Abstract: Superlattice (SL) structures have been used to reduce the stress in the GaN epilayer of high-electron-mobility transistors (HEMTs). This has led to an improvement in their properties such as the breakdown voltage. The increase in thermal resistance associated with these structures, however, causes elevated device temperatures which may outweigh the benefits of this approach. To verify this, the thermal performance of SL structures on HEMTs must, thus, be accurately characterized. Transient thermoreflectance imaging (TTI) is an optical technique that can map the temperature distribution across a surface. For materials, such as gold, TTI shows a high spatial and temporal resolution. Consequently, the technique has been primarily used to monitor the gate metal temperature distribution in HEMTs. The origin of the localized heating in HEMTs, however, is known to be in the active GaN layer and, thus, accurate thermal characterization of the channel is necessary. Using a UV LED excitation source with a wavelength near the bandgap of GaN, TTI of GaN channels in HEMTs is presented and verified by comparing the gate metal temperature. To ensure a strong thermoreflectance signal from the GaN surface, the importance of using an excitation wavelength near the bandgap of the GaN channel is highlighted. The effect of the bandgap on the magnitude and the linearity of the thermoreflectance coefficient is presented and discussed. Overall, the improvements to TTI discussed in this article make the technique an accurate method to measure the temperature distribution in GaN HEMT SL structures.

Guidelines for Reduced-Order Thermal Modeling of Multifinger GaN HEMTs

Abstract: The increasing demand for tightly integrated gallium nitride high electron mobility transistors (HEMT) into electronics systems requires accurate thermal evaluation. While these devices exhibit favorable electrical characteristics, the performance and reliability suffer from elevated operating temperatures. Localized device self-heating, with peak channel and die level heat fluxes of the order of 1 MW cm−2 and 1 kW cm−2, respectively, presents a need for thermal management that is reliant on accurate channel temperature predictions. In this publication, a high-fidelity multiphysics modeling approach employing one-way electrothermal coupling is validated against experimental results from Raman thermometry of a 60-finger gallium nitride (GaN) HEMT power amplifier under a set of direct current (DC)-bias conditions. A survey of commonly assumed reduced-order approximations, in the form of numerical and analytical models, are systematically evaluated with comparisons to the peak channel temperature rise of the coupled multiphysics model. Recommendations of modeling assumptions are made relating to heat generation, material properties, and composite layer discretization for numerical and analytical models. The importance of electrothermal coupling is emphasized given the structural and bias condition effect on the heat generation profile. Discretization of the composite layers, with temperature-dependent thermal properties that are physically representative, are also recommended.

Substrate dependent resistive switching in amorphous-HfOx memristors: an experimental and computational investigation

Abstract: While two-terminal HfOx (x < 2) memristor devices have been studied for ion transport and current evolution, there have been limited reports on the effect of the long-range thermal environment on their performance. In this work, amorphous-HfOx based memristor devices on two different substrates, microscopic glass (∼1 mm) and thin SiO2 (280 nm)/Si, with different thermal conductivities in the range from 1.2 to 138 W m−1 K−1 were fabricated. Devices on glass substrates exhibit lower reset voltage, wider memory window and, in turn, a higher performance window. In addition, the devices on glass show better endurance than the devices on the SiO2/Si substrate. These devices also show non-volatile multi-level resistances at relatively low operating voltages which is critical for neuromorphic computing applications. A multiphysics COMSOL computational model is presented that describes the transport of heat, ions and electrons in these structures. The combined experimental and COMSOL simulation results indicate that the long-range thermal environment can have a significant impact on the operation of HfOx-based memristors and that substrates with low thermal conductivity can enhance switching performance.

Impact of the thermal environment on the analog temporal response of HfOx-based neuromorphic devices

Abstract: Filamentary adaptive oxide devices based on HfOx are a promising technology for neuromorphic computing applications. The resistance of these devices depends on the concentration of oxygen vacancies in the filament region. A local temperature rise from joule heating plays a significant role in the movement of oxygen ions, making thermal management crucial to reliable performance. In this work, the role of the substrate thermal conductivity on the analog performance was investigated at biologically realistic pulse widths. Au/Ti/HfOx/Au adaptive oxide devices were fabricated on substrates with two orders of magnitude difference in thermal conductivity. A lower thermal conductivity substrate dissipates heat more slowly, resulting in a large initial change in resistance from a single operation pulse, which is detrimental to the desired analog behavior. The results were validated by a COMSOL Multiphysics® model that models the flow of heat in both samples.

Understanding Phonon Transport Properties Using Classical Molecular Dynamics Simulations

Abstract: Predictive modeling of the phonon/thermal transport properties of materials is vital to rational design for a diverse spectrum of engineering applications. Classical Molecular Dynamics (MD) simulations serve as a tool to simulate the time evolution of the atomic level system dynamics and enable calculation of thermal transport properties for a wide range of materials, from perfect periodic crystals to systems with strong structural and compositional disorder, as well as their interfaces. Although MD does not intrinsically rely on a plane wave-like phonon description, when coupled with lattice dynamics calculations, it can give insights to the vibrational mode level contributions to thermal transport, which includes plane-wave like modes as well as others, rendering the approach versatile and powerful. On the other hand, several deficiencies including the lack of vibrationally accurate interatomic potentials and the inability to rigorously include the quantum nature of phonons prohibit the widespread applicability and reliability of Molecular Dynamics simulations. This article provides a comprehensive review of classical Molecular Dynamics based formalisms for extracting thermal transport properties: thermal conductivity and thermal interfacial conductance and the effects of various structural, compositional, and chemical parameters on these properties. Here, we highlight unusual property predictions, and emphasize on the needs and strategies for developing accurate interatomic potentials and rigorous quantum correction schemes.

Monitoring the Joule heating profile of GaN/SiC high electron mobility transistors via cross-sectional thermal imaging

Abstract: The development of high-quality gallium nitride (GaN) high electron mobility transistors (HEMTs) has provided opportunities for the next generation of high-performance radio frequency and power electronics. Operating devices with smaller length scales at higher voltages result in excessively high channel temperatures, which reduce performance and can have detrimental effects on the device's reliability. The thermal characterization of GaN HEMTs has traditionally been captured from either the top or bottom side of the device. Under this configuration, it has been possible to map the lateral temperature distribution across the device with optical methods such as infrared and Raman thermometry. Due to the presence of the gate metal, however, and often also the addition of a metal air bridge and/or field plate, the temperature of the GaN channel under the gate is typically inferred by numerical simulations. Furthermore, measuring the vertical temperature gradient across multiple epitaxial layers has shown to be challenging. This study proposes a new cross-sectional imaging technique to map the vertical temperature distribution in GaN HEMTs. Combining advanced cross-sectioning processing with the recently developed near bandgap transient thermoreflectance imaging technique, the full transient thermal distribution across a GaN HEMT is achieved. The cross-sectional thermal imaging of the GaN channel is used to study the effects of biasing on the Joule heating profile. Overall, the direct measurement of the GaN channel, capturing both the vertical and lateral gradient, will provide deeper insight into the device's degradation physics and supply further experimental data to validate previously developed electrothermal models.

Experimental and computational analysis of thermal environment in the operation of HfO2 memristors

Abstract: Neuromorphic computation using nanoscale adaptive oxide devices or memristors is a very promising alternative to the conventional digital computing framework. Oxides of transition metals, such as hafnium (HfOx), have been proven to be excellent candidate materials for these devices, because they show non-volatile memory and analog switching characteristics. This work presents a comprehensive study of the transport phenomena in HfOx based memristors and involves the development of a fully coupled electrothermal and mass transport model that is validated with electrical and thermal metrology experiments. The fundamental transport mechanisms in HfOx devices were analyzed together with the local and temporal variation of voltage, current, and temperature. The effect of thermal conductivity of substrate materials on the filament temperature, voltage ramp rate, and set/reset characteristics was investigated. These analyses provide insight into the switching mechanisms of these oxides and allow for the prediction of the effect of device architecture on switching behavior.

Diamond Seed Size and the Impact on Chemical Vapor Deposition Diamond Thin Film Properties

Abstract: Diamond seeds were assessed for their role in the heterogeneous nucleation for diamond films deposited on silicon using chemical vapor deposition. Two diamond seed sizes – 4 nm and 20 nm – were studied. The study revealed that the larger seed size, even when with a smaller seed density, produces a larger grain size near the interface region, and led to a higher in-plane thermal conductivity as measured by Raman thermography. By fine control of the seed size and density, thermal conductivity near the nucleation region can therefore be improved. This demonstrates that the seeding condition is critical to diamond film growth for thermal applications in electronic devices.

Simultaneous Evaluation of Heat Capacity and In-plane Thermal Conductivity of Nanocrystalline Diamond Thin Films

Abstract: As wide bandgap electronic devices have continued to advance in both size reduction and power handling capabilities, heat dissipation has become a significant concern. To mitigate this, chemical vapor deposited (CVD) diamond has been demonstrated as an effective solution for thermal management of these devices by directly growing onto the transistor substrate. A key aspect of power and radio frequency (RF) electronic devices involves transient switching behavior, which highlights the importance of understanding the temperature dependence of the heat capacity and thermal conductivity when modeling and predicting device electrothermal response. Due to the complicated microstructure near the interface between CVD diamond and electronics, it is difficult to measure both properties simultaneously. In this work, we use time domain thermoreflectance (TDTR) to simultaneously measure the in plane thermal conductivity and heat capacity of a 1 um thick CVD diamond film, and also use the pump as an effective heater to perform temperature dependent measurements. The results show that the in plane thermal conductivity varied slightly with an average of 103 W per meter per K over a temperature range of 302 to 327 K, while the specific heat capacity has a strong temperature dependence over the same range and matches with heat capacity data of natural diamond in literature.

Mechanical Deformation Study of Flexible Leadset Components for Electromechanical Reliability of Wearable Electrocardiogram Sensors

Abstract: The focus of this paper is to study the reliability of a wearable electrocardiogram sensor leadset under tight bending conditions using numerical simulations and experiments. In these simulations, appropriate material models are selected and fitted for each material layer, including a hyperelastic model for TPU, an elastic-plastic model for PET, and linear elastic models for the silver ink, carbon ink, and dielectric layers. The results from the numerical simulations are compared and validated using an analytical model as well as experimental data. Recommendations are made for acceptable operating conditions of the leadset.

Thermal Conductivity of β-Ga 2 O 3 Thin Films Grown by Molecular Beam Epitaxy

Abstract: β-Ga 2 O 3 is considered as a promising material for future power electronic applications. In this work, we used time-domain thermoreflectance to measure the thermal conductivity and thermal boundary conductance (TBC) of thin films of β-Ga 2 O 3 grown using molecular beam epitaxy (MBE) on c-Al 2 O 3 (sapphire) and 4H-SiC substrates. One sample was 119 nm thick on sapphire, while the other sample was 81 nm thick on 4H-SiC. The Ga 2 O 3 layer on c-sapphire presented a through-plane thermal conductivity of 3.2 ± 0.3 W/m-K with a Ga 2 O 3 /sapphire TBC of 155.6 ± 65.3 MW/m2-K. The thermal conductivity of the Ga 2 O 3 layer on 4H-SiC was measured as 3.1 ± 0.5 W/m-K with a Ga 2 O 3 /SiC TBC of 141.8 ± 63.8 MW/m2-K. When compared with the thermal conductivity of films grown using pulsed-laser deposition from a previous study, thermal conductivity of layers grown by MBE show higher values, which suggests that the films grown by epitaxial method such as MBE can improve the thermal conductivity of thin films.

Impact of interface materials on side permeation in indirect encapsulation of organic electronics

Abstract: This work demonstrates the impact of the contact interface between barrier films and adhesives on the side permeation of moisture into packaged devices. When barrier films are brought into contact with the adhesive layer during indirect encapsulation, permeation along defects at this interface can occur due to the imperfect nature of contact, resulting in the formation of pores. The connected network of pores can act as capillaries and be an alternative pathway for water permeation as opposed to the bulk of the adhesive or edge seal materials used for barrier attachment to the package. The rate of water permeation through the capillaries is governed by surface energies of the materials at the interfaces. Experimental results demonstrate that the rate of water permeation is significantly lowered by using materials with higher contact angles at the interface.

Wafer-scale Heterogeneous Integration of Monocrystalline \b{eta}-Ga2O3 Thin Films on SiC for Thermal Management by Ion-Cutting Technique

Abstract: The ultra-wide bandgap, high breakdown electric field, and large-area affordable substrates make \b{eta}-Ga2O3 promising for applications of next-generation power electronics while its thermal conductivity is at least one order of magnitude lower than other wide/ultrawide bandgap semiconductors. To avoid the degradation of device performance and reliability induced by the localized Joule-heating, aggressive thermal management strategies are essential, especially for high-power high-frequency applications. This work reports a scalable thermal management strategy to heterogeneously integrate wafer-scale monocrystalline \b{eta}-Ga2O3 thin films on high thermal conductivity SiC substrates by ion-cutting technique. The thermal boundary conductance (TBC) of the \b{eta}-Ga2O3-SiC interfaces and thermal conductivity of the \b{eta}-Ga2O3 thin films were measured by Time-domain Thermoreflectance (TDTR) to evaluate the effects of interlayer thickness and thermal annealing. Materials characterizations were performed to understand the mechanisms of thermal transport in these structures. The results show that the \b{eta}-Ga2O3-SiC TBC values increase with decreasing interlayer thickness and the \b{eta}-Ga2O3 thermal conductivity increases more than twice after annealing at 800 oC due to the removal of implantation-induced strain in the films. A Callaway model is built to understand the measured thermal conductivity. Small spot-to-spot variations of both TBC and Ga2O3 thermal conductivity confirm the uniformity and high-quality of the bonding and exfoliation. Our work paves the way for thermal management of power electronics and \b{eta}-Ga2O3 related semiconductor devices.