Design and Engineering of Gibbs Free Energy for Heterostructure Nano-Bonding™ of Piezo-Electric Crystals to Si-based materials at T < 500 K
ORAL
Abstract
Forming heterostructures between piezo-electrics such as LiTaO3 and LiNbO3 with Si-based materials is limited by the mismatch of their lattice constants and thermal expansion.
This work uses RT Nano-Bonding™ [1] to bond piezo-electrics to Si via Surface Energy Engineering (SEE). SEE modifies synergistically Surface Energies (SE) and hydro-affinity to far-from-equilibrium states create reactive 2D Precursor Phases (2D PP) on each surface of the pair. 2D PPs react in air at RT when contacted by water vapor catalysis.
The △GPiezo-Si-H2O for each pair is computed from SE measured via Three Liquid Contact Angles to see whether it favors Nano-Bonding™. The △GPiezo-Si-H2O for ‘as received’ (AR) LiTaO3, with ‘after SEE’ Si and α-quartz SiO2 is -0.1 mJ/m2 and -16.8 mJ/m2. For or AR LiNbO3, with ‘after SEE’ Si and α-q SiO2 it is -13.4 mJ/m2 and -28 mJ/m2, thus all < 0.
Nano-Bonding™ of AR hydrophobic piezo-electrics with ‘after SEE’ hydrophilic Si/ SiO2 is thus favored in the presence of atmospheric moisture.
Experimentally, 2D PP generated by SEE are indeed found to activate Nano-Bonding™, at RT in 25 % RH.
[1] Nano-Bonding™, Herbots, et al. U.S. Pat. # 9,018,077 (2015), 9,589,801(2017), pend. (2020)
This work uses RT Nano-Bonding™ [1] to bond piezo-electrics to Si via Surface Energy Engineering (SEE). SEE modifies synergistically Surface Energies (SE) and hydro-affinity to far-from-equilibrium states create reactive 2D Precursor Phases (2D PP) on each surface of the pair. 2D PPs react in air at RT when contacted by water vapor catalysis.
The △GPiezo-Si-H2O for each pair is computed from SE measured via Three Liquid Contact Angles to see whether it favors Nano-Bonding™. The △GPiezo-Si-H2O for ‘as received’ (AR) LiTaO3, with ‘after SEE’ Si and α-quartz SiO2 is -0.1 mJ/m2 and -16.8 mJ/m2. For or AR LiNbO3, with ‘after SEE’ Si and α-q SiO2 it is -13.4 mJ/m2 and -28 mJ/m2, thus all < 0.
Nano-Bonding™ of AR hydrophobic piezo-electrics with ‘after SEE’ hydrophilic Si/ SiO2 is thus favored in the presence of atmospheric moisture.
Experimentally, 2D PP generated by SEE are indeed found to activate Nano-Bonding™, at RT in 25 % RH.
[1] Nano-Bonding™, Herbots, et al. U.S. Pat. # 9,018,077 (2015), 9,589,801(2017), pend. (2020)
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Presenters
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Mohammed Sahal
- Physics, Arizona State University
- SiO2 Innovates LLC
- Dpt of Physics/Eyring Materials Center, Arizona State University
- Physics Dpt/Eyring Materials Cr, Arizona State University
- SiO2 Innovates, LLC