Document Type

Article

Publication Date

2015

Publication Source

Journal of Applied Physics

Abstract

The characterization of Cu/diamond interface thermal conductance (hc) along with an improved understanding of factors affecting it are becoming increasingly important, as Cu-diamond composites are being considered for electronic packaging applications. In this study, ∼90 nm thick Cu layers weredeposited on synthetic and natural single crystal diamond substrates. In several specimens, a Ti-interface layer of thickness ≤3.5 nm was sputtered between the diamond substrate and the Cu top layer. The hc across Cu/diamond interfaces for specimens with and without a Ti-interface layer was determined usingtime-domain thermoreflectance. The hc is ∼2× higher for similar interfacial layers on synthetic versus natural diamond substrate. The nitrogen concentration of synthetic diamond substrate is four orders of magnitude lower than natural diamond. The difference in nitrogen concentration can lead to variations in disorder state, with a higher nitrogen content resulting in a higher level of disorder. This difference in disorder state potentially can explain the variations in hc.

Furthermore, hc was observed to increase with an increase of Ti-interface layer thickness. This was attributed to an increased adhesion of Cu top layer with increasing Ti-interface layer thickness, as observed qualitatively in the current study.

Inclusive pages

074305-1 to 074305-8

ISBN/ISSN

0021-8979

Document Version

Published Version

Comments

This document is provided for download in compliance with the publisher's policy on self-archiving. Permission documentation is on file.

Publisher

AIP Publishing

Volume

117

Peer Reviewed

yes

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