Anisotropic thermal conductivity in chemical vapor deposition diamond

Abstract

The thermal conductivity of thick-film diamond prepared by chemical vapor deposition (CVD) has been measured with heat flowing in a direction perpendicular to the plane of the film. A laser flash technique with fast infrared detection has been devised for measurement of thin samples with high conductivity. The conductivity perpendicular to the plane is observed to be at least 50% greater than with heat flowing parallel to the plane. This anisotropy is attributed to low-quality grain boundaries in the columnar microstructure. The observed dependence of the thermal conductivity on microstructure has important implications for thermal management of microelectronic devices with CVD diamond.

Theory of Heat Transport in a Dielectric Slab and Its Applications to CVD Diamond Films

“…and k jj data of the same sample are available, anisotropy effects are observed [12,[15][16][17][18]22]. These effects are mainly due to the film layer close to the substrate (or bottom) side: when the film is removed from the substrate, the above layer presents a random distribution of grains of the order of a few mm.…”

“…So far, to the present author's knowledge, measurements of k ? have been confined to room temperature [15][16][17] or to the narrow interval 25-125 C [12,18]. Conductivity curves from low to high temperatures, at various values of the film thickness, have only been determined for k jj [11,14,19,20].…”

Evaluation of thermal conductivity of the constituent layers in TRISO particles using Raman spectroscopy

“…Thermal conductivity of carbon is significantly influenced by the texture [16,17]. Therefore, the texture of the PyC layers should be identified.…”

“…A 3D model of the localized temperature rise induced by laser irradiation was proposed to determine the thermal conductivity. In addition, as the thermal conductivity of carbon is significantly influenced by the texture [16,17], polarized Raman spectroscopy was employed to determine the texture of the PyC layers. The uncertainty of the Raman spectra measurements was also discussed.…”

Experimental Investigation on Thermoresistance between AlN, Bi-2223 and OFHC in High Tc- Direct Cooling Technology

“…Despite numerous investigations on the thermal characteristics of AlN at normal and high temperatures [5] , little has been done in learning about AlN material application in the . The high heat conductivity and electrically insulating AlN has become one of the acknowledged materials for devices using in HTS direct cooling technology.…”