Effects of disorder state and interfacial layer on thermal transport in copper/diamond system
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 were deposited 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 using time-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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 19, 2015
- Source ID
- 10.1063/1.4906958
Entities
People
- Christopher Muratore
- J. E. Spowart
- J. J. Gengler
- V. Sinha
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory
- University of Dayton