Regulated Interfacial Thermal Conductance between Cu and Diamond by a TiC Interlayer for Thermal Management Applications

Abstract

The metal/diamond interface consisting of two highly dissimilar materials is widely present in high-power microelectronic devices using a diamond film as a heat spreader or using a metal matrix/diamond filler composite as a heat sink for thermal management applications. To improve the interfacial thermal conductance (G), a common method is to add an appropriate interlayer in between the two materials; however, the effect of the interlayer on G is still not clear. In this work, we prepare a Cu/TiC/diamond structure by magnetron sputtering to detect how the crystallinity, grain size, and thickness of the TiC interlayer influence G between Cu and diamond. We characterize in detail the interface by transmission electron microscopy and X-ray photoelectron spectroscopy and measure experimentally G by the time-domain thermoreflectance technique. The results indicate that the higher crystallinity and thinner interlayer are both beneficial to the improvement of G between Cu and diamond, but the G is insensitive to the grain size of TiC. An increase of G between Cu and diamond as much as 48% can be reached by a highly crystallized 10 nm thick TiC interlayer. The microscopic characteristics of the TiC interlayer have played a decisive role for G between Cu and diamond. While an inserted interlayer in principle has a potential to enhance G between two dissimilar materials, the low crystallinity and large thickness of the interlayer will weaken the enhancement or even reverse this positive effect. The G of a sandwiched structure can be regulated in a wide range by the microscopic characteristics of the interlayer, which provides guidelines for preparation of metal/nonmetal interfaces with high interfacial thermal conductance for thermal management applications.

Enhanced strength of nano-polycrystalline diamond by introducing boron carbide interlayers at the grain boundaries

“…5,31 A higher binding energy peak was found at 289.25 eV from C-O bonds. 4,37,38 Fig. 6 XPS spectra of B 1s, C 1s, and O 1s core levels, respectively.…”

High thermal conductive copper/diamond composites: state of the art

“…As analyzed above, the induction of electrons adds extra complexity in the case of copper/diamond composites, because of the interaction between phonons and electrons. Many works on copper/diamond composites ignore the contribution of electrons but focus on phonons, and the predictions of thermal conductivity do have discrepancy compared to the experimental results [50,80]. Sadasivam uses the Atomic green function method and integrates the electron-phonon coupling effect in the function to deal with metal-semiconductor thermal boundary conductance problems [81].…”

“…TDTR technique is just applied for investigating the interface thermal conductance problem of copper/diamond composites recently [80,87,110]. The general principle is that the interface scenario in the copper/diamond composites can be physically simulated through creating a Ti layer by magnetron sputtering onto a diamond substrate, as shown in Fig.…”

“…32, and this facilitates more phonon transmission. This method has been experimentally applied and demonstrated in copper/diamond composites [80,114].…”

Production and Heat Properties of an X-ray Reflective Anode Based on a Diamond Heat Buffer Layer

“…Figure 1 shows the composition of the diamond composite anode, which was produced through the following steps and methods. Based on the high thermal conductivity (TC = 1500-2000 W/m K) [12][13][14] of diamond, materials containing diamond are widely used in high-power microelectronic devices as a heat dissipator [15,16]. In order to improve the thermal conductivity of composite materials, a method for mixing diamond particles with a metal, and a method for plating a diamond film were proposed [17,18].…”