Thermal conductivity of fully and partially coalesced lateral epitaxial overgrown GaN/sapphire (0001) by scanning thermal microscopy

Florescu, D. I.; Florescu, D.I.; Asnin, V. M.; Asnin, V.M.; Pollak, Fred H.; Jones, A. M.; Jones, A.M.; Ramer, J. C.; Ramer, J.C.; Schurman, M. J.; Schurman, M.J.; Ferguson, I.
September 2000
Applied Physics Letters;9/4/2000, Vol. 77 Issue 10
Academic Journal
We have measured high spatial/depth resolution (∼2-3 μm) thermal conductivity (κ) at 300 K of both fully and partially coalesced GaN/sapphire (0001) samples fabricated by lateral epitaxial overgrowth. On the fully coalesced sample we found 1.86W/cm K<κ<2.05 W/cm K over a distance of approximately 50 μm. One of the partially coalesced samples had 2.00 W/cm K<κ<2.10 W/cm K on the overgrown regions, as identified by atomic force microscopy imaging. These latter results are the highest thermal conductivity values reported on GaN material. A correlation between low threading dislocation density and high thermal conductivity values was established. © 2000 American Institute of Physics.


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