TY - JOUR
T1 - Room-temperature transfer bonding of lithium niobate thin film on micromachined silicon substrate with Au microbumps
AU - Takigawa, Ryo
AU - Higurashi, Eiji
AU - Suga, Tadatomo
AU - Kawanishi, Tetsuya
PY - 2017/9/1
Y1 - 2017/9/1
N2 - This paper introduces a room-temperature transfer bonding method for a future integration of LiNbO3 thin-film device with a micromachined Si platform. A single-crystal LiNbO3 thin film (5 μm thickness) prepared by mechanical polishing was successfully transfer-bonded onto a micromachined Si substrate with Au microbumps in ambient air using surface activated bonding. Tensile testing showed the strong bond strength between the Au thin film and the Au microbumps, which was sufficient for device applications. An air/LiNbO3 thin film/air structure was demonstrated on a Si substrate using the proposed method. In addition, our simulation and experimental results showed that room-temperature bonding was essential to overcome the large coefficient of thermal expansion mismatch between LiNbO3 and Si. We expect that this technology can be utilized to realize new configurations of highly-functional integrated microelectromechanical systems, including Si-based high-density integrated photonic devices.
AB - This paper introduces a room-temperature transfer bonding method for a future integration of LiNbO3 thin-film device with a micromachined Si platform. A single-crystal LiNbO3 thin film (5 μm thickness) prepared by mechanical polishing was successfully transfer-bonded onto a micromachined Si substrate with Au microbumps in ambient air using surface activated bonding. Tensile testing showed the strong bond strength between the Au thin film and the Au microbumps, which was sufficient for device applications. An air/LiNbO3 thin film/air structure was demonstrated on a Si substrate using the proposed method. In addition, our simulation and experimental results showed that room-temperature bonding was essential to overcome the large coefficient of thermal expansion mismatch between LiNbO3 and Si. We expect that this technology can be utilized to realize new configurations of highly-functional integrated microelectromechanical systems, including Si-based high-density integrated photonic devices.
KW - Hetero-integration
KW - LiNbO thin film
KW - LiNbO/Si structure
KW - Optical microsystem
KW - Room-temperature transfer bonding
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U2 - 10.1016/j.sna.2017.08.015
DO - 10.1016/j.sna.2017.08.015
M3 - Article
AN - SCOPUS:85027589280
VL - 264
SP - 274
EP - 281
JO - Sensors and Actuators A: Physical
JF - Sensors and Actuators A: Physical
SN - 0924-4247
ER -