Achieving high thermal conductivity from AlN films deposited by high-power impulse magnetron sputtering

Aissa, K. Ait; Semmar, Nadjib; Achour, Amine; Simon, Quentin; Petit, Agnès; Camus, J.; Boulmer‐Leborgne, Chantal; Djouadi, M. A.

doi:10.1088/0022-3727/47/35/355303

Cited by 32 publications

(19 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These include diamond, silicon, , arsenides (e.g., BAs, − AlAs, GaAs, , and InAs), nitrides (e.g., BN, AlN, GaN, − and InN), silicon carbide SiC, oxides (e.g., BeO and MgO), phosphides (e.g., BP, GaP, and InP), and antimonides (e.g., GaSb , and InSb). (b) Comparison of the selected highest room-temperature thermal conductivity of diamond, − AlN, − GaN, , and Si thin films as a function of their characteristic size. All of the open symbols are based on the literature value, while the filled symbols are based on the present effort.…”

Section: Introductionmentioning

confidence: 99%

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

Koh

Cheng

Mamun

et al. 2020

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 99%

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

Koh

Cheng

Mamun

et al. 2020

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…The lattice thermal conductivity (κ l ) of the AlN films were calculated using eq and fitted with modified Callaway model as described below where t tot is the thickness of AlN film and amorphous like layer between the interface of Si/AlN, κ l is lattice thermal conductivity, κ eff is the effective thermal conductivity determined from the differential 3ω measurement for the two AlN samples, and R Si/AlN is the thermal boundary resistance between the Si and AlN thin film. The thermal boundary resistance of 1 × 10 –8 m 2 K/W was used to calculate the intrinsic thermal conductivity of our films. , …”

Section: Resultsmentioning

confidence: 99%

“…The thermal boundary resistance of 1 × 10 -8 m 2 K/W was used to calculate the intrinsic thermal conductivity of our films. 31,32 The reduced thermal conductivity of AlN thin films, is due to increased phonon scattering rate at the grain boundaries among others, impurity scattering, and micro-structural defects. To quantify the true contribution of the various phonon scattering parameters we used the Callaway/Klemens' formulation 5,33 derived from Boltzmann transport equation used previously 34,35 which was modified and discussed in detail below.…”

Section: Thermal Conductivity and Callaway Modelmentioning

confidence: 99%

Using Mosaicity to Tune Thermal Transport in Polycrystalline Aluminum Nitride Thin Films

Singh

Shervin

Sun

et al. 2018

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 vs 8.09 W/mK are measured for samples with tilt angles of 10° versus 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

show abstract

“…The applied voltage was -1 kV, with a pulse width of 28 µs, and frequency of 300 Hz. The experimental details are fully described in our previous works [16].…”

Section: Methodsmentioning

confidence: 99%

AlN films deposited by dc magnetron sputtering and high power impulse magnetron sputtering for SAW applications

Aissa¹,

Achour²,

Elmazria³

et al. 2015

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

In this work, AlN films were deposited on silicon substrates buffered by epitaxial AlN thin film for surface acoustic wave (SAW) applications. The films were deposited by dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) deposition techniques. The structural properties of AlN films were investigated using X-ray diffraction (XRD), Raman spectroscopy and atomic force microscopy. In both cases of films deposited by dcMS and HiPIMS, the XRD results showed that the obtained films are oriented, with a full width at half maximum rocking curves of around 1°. Raman spectroscopy revealed higher residual stress relaxation in the AlN epilayers grown by HiPIMS compared to AlN grown by dcMS, highlighted by a blue shift in the E2(high) Raman mode. The SAW measurements indicated an insertion loss of AlN/Si -SAW devices of about 53 and 35 dB for the AlN films deposited by dcMS and HiPIMS respectively. The relation between the 2 structural properties of AlN and the characteristics of AlN-SAW devices were correlated and discussed.

show abstract

Achieving high thermal conductivity from AlN films deposited by high-power impulse magnetron sputtering

Cited by 32 publications

References 24 publications

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

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

Using Mosaicity to Tune Thermal Transport in Polycrystalline Aluminum Nitride Thin Films

AlN films deposited by dc magnetron sputtering and high power impulse magnetron sputtering for SAW applications

Contact Info

Product

Resources

About