High-kappa Al2O3 material in low temperature wafer-level bonding for 3D integration application

作者：Fan, J.^*; Tu, L. C.; Tan, C. S.

来源：AIP Advances, 2014, 4(3): 031311.

DOI：10.1063/1.4867089

• Ambient conditions
• Conductivity analysis
• Experimental approaches
• Four-point bending method
• Helium bomb tests
• Interfacial adhesion energy
• Mechanical support
• Surface activation

This work systematically investigated a high-kappa Al2O3 material for low temperature wafer-level bonding for potential applications in 3D microsystems. A clean Si wafer with an Al2O3 layer thickness of 50 nm was applied as our experimental approach. Bonding was initiated in a clean room ambient after surface activation, followed by annealing under inert ambient conditions at 300 degrees C for 3 h. The investigation consisted of three parts: a mechanical support study using the four-point bending method, hermeticity measurements using the helium bomb test, and thermal conductivity analysis for potential heterogeneous bonding. Compared with samples bonded using a conventional oxide bonding material (SiO2), a higher interfacial adhesion energy (similar to 11.93 J/m(2)) and a lower helium leak rate (similar to 6.84 x 10(-10) atm.cm(3)/sec) were detected for samples bonded using Al2O3. More importantly, due to the excellent thermal conductivity performance of Al2O3, this technology can be used in heterogeneous direct bonding, which has potential applications for enhancing the performance of Si photonic integrated devices.

• 出版日期2014-3
• 单位华中科技大学; 南阳理工学院