AlN-AlN Layer Bonding and Its Thermal Characteristics

Homogeneous bonding was successfully demonstrated on 150 mm Si wafers by face-to-face direct dielectric bonding of clean and smooth aluminum nitride (AlN) layers. Characterization result from XPS confirms the layer composition and reveals that approximately 5 nm of the layer surface was partially oxidized during processing. After activation, substoichiometric nitrogen bound to aluminum, Al-O and Al-OH bonds were found at the thin film surface. The as-bonded wafer pairs are nearly void and particle free with a high bonding strength of 1527.8 +/- 272.2 mJ/m(2), enabling them to withstand the subsequent process steps. In addition, experimental results have indicated that the AlN-AlN bonded wafers can achieve a 23 and 16% improvement respectively in terms of heat dissipation compared with those using SiO2 and Al2O3 as the bonding layer. It is concluded that this AlN-AlN bonded wafer pairs can exhibit a better heat dissipation capability than other bonded counterparts. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/),which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.