TY - JOUR
T1 - Chemical bonding at room temperature via surface activation to fabricate low-resistance GaAs/Si heterointerfaces
AU - Ohno, Yutaka
AU - Liang, Jianbo
AU - Shigekawa, Naoteru
AU - Yoshida, Hideto
AU - Takeda, Seiji
AU - Miyagawa, Reina
AU - Shimizu, Yasuo
AU - Nagai, Yasuyoshi
N1 - Funding Information:
A part of this work is supported by JST/CREST, Japan , Grant No. JPMJCR17J1 (2017-2023) , and JSPS/KAKENHI, Japan , Grant No. 18K05009 (2018-2021) . Specimen preparations by LT-FIB and CMP are, respectively, supported at the Oarai Center and at the Laboratory of Alpha-Ray Emitters, under the GIMRT Program in IMR, Tohoku University, Japan (Proposal Nos. 19M0037 and 19M0404 ). X-STEM is performed at “Network Joint Research Center for Materials and Devices: Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials” in ISIR, Osaka University, Japan (Proposal No. 20191240 ). SRIM calculations are assisted by Dr. Sosuke Kondo in IMR, Tohoku University, Japan.
Funding Information:
A part of this work is supported by JST/CREST, Japan, Grant No. JPMJCR17J1 (2017-2023), and JSPS/KAKENHI, Japan, Grant No. 18K05009 (2018-2021). Specimen preparations by LT-FIB and CMP are, respectively, supported at the Oarai Center and at the Laboratory of Alpha-Ray Emitters, under the GIMRT Program in IMR, Tohoku University, Japan (Proposal Nos. 19M0037 and 19M0404). X-STEM is performed at ?Network Joint Research Center for Materials and Devices: Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials? in ISIR, Osaka University, Japan (Proposal No. 20191240). SRIM calculations are assisted by Dr. Sosuke Kondo in IMR, Tohoku University, Japan.
Publisher Copyright:
© 2020 The Author(s)
PY - 2020/9/30
Y1 - 2020/9/30
N2 - Bonding mechanism at room temperature (RT) in GaAs/Si heterointerfaces fabricated by surface-activated bonding (SAB) is examined using cross-sectional scanning transmission electron microscopy combined with low-temperature focused ion beam and time-of-flight secondary ion mass spectrometry. In the bonding process at RT, atomic intermixing at the interfaces, presumably due to the transient enhanced diffusion assisted by the point defects introduced in the surface activation process, is confirmed. The defect-assisted atomic diffusion at the interfaces, as well as the formation of atomically clean and activated surfaces, would be the key concept of SAB, by which we can create tough heterointerfaces at RT. Meanwhile, the defects on the activated surfaces would degrade the interface resistance. The degraded properties can be recovered by an appropriate annealing after the SAB processes, although the atomistic structure around the heterointerfaces would be modified during the annealing. By controlling SAB and subsequent annealing conditions, we can obtain low-resistance heterointerfaces via the optimization of the trade-off relationship between the chemical bonding strength and the electronic properties, determined by the activated surfaces before bonding.
AB - Bonding mechanism at room temperature (RT) in GaAs/Si heterointerfaces fabricated by surface-activated bonding (SAB) is examined using cross-sectional scanning transmission electron microscopy combined with low-temperature focused ion beam and time-of-flight secondary ion mass spectrometry. In the bonding process at RT, atomic intermixing at the interfaces, presumably due to the transient enhanced diffusion assisted by the point defects introduced in the surface activation process, is confirmed. The defect-assisted atomic diffusion at the interfaces, as well as the formation of atomically clean and activated surfaces, would be the key concept of SAB, by which we can create tough heterointerfaces at RT. Meanwhile, the defects on the activated surfaces would degrade the interface resistance. The degraded properties can be recovered by an appropriate annealing after the SAB processes, although the atomistic structure around the heterointerfaces would be modified during the annealing. By controlling SAB and subsequent annealing conditions, we can obtain low-resistance heterointerfaces via the optimization of the trade-off relationship between the chemical bonding strength and the electronic properties, determined by the activated surfaces before bonding.
KW - Heterointerfaces
KW - Low-temperature direct wafer bonding
KW - Low-temperature focused ion beam
KW - Scanning transmission electron microscopy
KW - Surface activation
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U2 - 10.1016/j.apsusc.2020.146610
DO - 10.1016/j.apsusc.2020.146610
M3 - Article
AN - SCOPUS:85084459165
VL - 525
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
M1 - 146610
ER -