Thermal boundary conductance of transition metals on diamond

Journal of Applied Physics

Weber

2013

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The effect of diamond surface treatment on the Thermal Boundary Conductance (TBC) between Al and diamond is investigated. The treatments consist in either of the following: exposition to a plasma of pure Ar, Ar:H and Ar:O, and HNO3:H2SO4 acid dip for various times. The surface of diamond after treatment is analyzed by X-ray Photoelectron Spectroscopy, revealing hydrogen termination for the as-received and Ar:H plasma treated samples, pure sp2 termination for Ar treated ones and oxygen (keton-like) termination for the other treatments. At ambient, all the specific treatments improve the TBC between Al and diamond from 23 ± 2 MW m–2 K–1 for the as-received to 65 ± 5, 125 ± 20, 150 ± 20, 180 ± 20 MW m–2 K–1 for the ones treated by Ar:H plasma, acid, pure Ar plasma, and Ar:O plasma with an evaporated Al layer on top, respectively. The effect of these treatments on temperature dependence are also observed and compared with the most common models available in the literature as well as experimental values in the same system. The results obtained show that the values measured for an Ar:O plasma treated diamond with Al sputtered on top stay consistently higher than the values existing in the literature over a temperature range from 78 to 290 K, probably due a lower sample surface roughness. Around ambient, the TBC values measured lay close to or even somewhat above the radiation limit, suggesting that inelastic or electronic processes may influence the transfer of heat at this metal/dielectric interface.

Section: Influence Of Deposition Techniquesupporting

confidence: 87%

Section: B Time Domain Thermoreflectancementioning

confidence: 99%

Influence of diamond surface termination on thermal boundary conductance between Al and diamond

Journal of Applied Physics

Weber

2013

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“…Experiment a. Experimental setup The experimental setup used in this paper is a coaxial two tints pump/probe experiment 34 and has been described in detail previously 19,35 .…”

Section: Methodsmentioning

confidence: 99%

Qualitative link between work of adhesion and thermal conductance of metal/diamond interfaces

Journal of Applied Physics

Schusteritsch

Kaxiras

et al. 2014

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We report Time-Domain ThermoReflectance experiments measuring the Thermal Boundary Conductance (TBC) of interfaces between diamond and metal surfaces, based on samples consisting of [111] diamond substrates with hydrogen or with sp 2 carbon surface terminations created using plasma treatments. In a concurrent theoretical study, we calculate the work of adhesion between Ni, Cu and diamond interfaces with [111] surface orientation, with or without hydrogen termination of the diamond surface, using first-principles electronic structure calculations based on density functional theory (DFT).We find a positive correlation between the calculated work of adhesion and the mea-sured conductance of these interfaces, suggesting that DFT could be used as a screening tool to identify metal/dielectric systems with high TBC We also explain the negative effect of hydrogen on the thermal conductance of metal/diamond interfaces. a) Corresponding author,

“…The experimental setup used for the following experiments is a coaxial two tints pump/probe experiment [31] and has already been described in detail [15]. In a nutshell, this setup uses a Spectra Physics Tsunami femtosecond laser working at 80 MHz repetition rate, the beam of which is split into two parts, one used to heat up the sample surface (the pump), and one to test the reflectivity of the sample surface (the probe).…”

Section: Time Domain Thermoreflectance 221 Experimental Setupmentioning

confidence: 99%

“…While concomitance between good adhesion and high TBC is generally observed (e.g. [4,14,15]), some groups have pushed the analogy farther by invoking that the Al/diamond TBC is anisotropic in such composites, and thus estimated the effect of diamond shape (i.e. proportions of [111] to [100] faces) on the composite thermal conductivity [16,17].…”

Section: Introductionmentioning

confidence: 99%

Effect of diamond surface orientation on the thermal boundary conductance between diamond and aluminum

Diamond and Related Materials

Weber

2013

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Abstract[100] and [111] oriented diamond substrates were treated using Ar:H and Ar:O plasma treatments, and 1:1 HNO 3 :H 2 SO 4 heated at 200˚C. Subsequent to these treatments, an aluminum layer was either evaporated or sputtered on the substrates. The Thermal Boundary Conductance (TBC) as well as the interfacial acoustical reflection coefficient between this layer and the diamond substrate was then measured using a Time Domain ThermoReflectance (TDTR) experiment. For the Ar:H plasma treated surfaces the [111] oriented faces exhibited conductances 40 % lower than the [100] oriented ones, with the lowest measured TBC at 32±5 MWm −2 K −1 . The treatments that led to oxygen-terminated diamond surfaces (i.e. acid or Ar:O plasma treatments) showed no TBC anisotropy and the highest measured value was 230±25 MWm −2 K −1 for samples treated with Ar:O plasma with a sputtered Al layer on top. Sputtered layers on oxygen-terminated surfaces showed systematically higher TBC than their evaporated counterparts. The interfacial acoustic reflection coefficient correlated qualitatively with TBC when comparing samples with the same type of surface terminations (O or H), but this correlation failed when comparing H and O terminated interfaces with each other.