Growth and thermal conductivity analysis of polycrystalline GaAs on chemical vapor deposition diamond for use in thermal management of high-power semiconductor lasers

• Published in: Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena Microelectronics and nanometer structures processing, measurement and phenomena, 2011-05, Vol.29 (3)
• Main Authors: Clark, S. P. R., Ahirwar, P., Jaeckel, F. T., Hains, C. P., Albrecht, A. R., Rotter, T. J., Dawson, L. R., Balakrishnan, G., Hopkins, P. E., Phinney, L. M., Hader, J., Moloney, J. V.
• Format: Article
• Language: English
• ISSN: 1071-1023; 2166-2746; 1520-8567; 2166-2754
• DOI: 10.1116/1.3565054

The authors demonstrate the growth of polycrystalline GaAs thin films on polycrystalline chemical vapor deposition (CVD) diamond by low-temperature molecular beam epitaxy. The low-temperature GaAs (LT-GaAs) layer is easily polished compared to the CVD diamond, and this process results in a reduction of rms surface roughness from > 50 to < 5   nm . This makes the LT-GaAs on diamond layer an ideal wafer-bonding interface for high-power semiconductor devices. The samples were grown at 0.2   μ m / h with a substrate temperature of 250   ° C and a 1:8 III/V beam equivalent pressure ratio. The samples were analyzed by x-ray powder diffraction, atomic force microscopy for surface roughness, and in situ reflective high-energy electron diffraction during molecular beam epitaxy growth. The authors also measure the thermal conductivity of the GaAs layer on CVD diamond using pump-probe time domain thermoreflectance.