Study of LiTaO3/ST-quartz Bonding with Amorphous Interlayer Assisted by VUV/O3 Treatment for SAW Device

Haruka Suzaki, Hiroyuki Kuwae, Akiko Okada, Shuichi Shoji, Jun Mizuno

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Development of surface acoustic wave (SAW) devices has been getting attention to achieve next fifth generation (5G) mobile communications. We had previously proposed a temperature compensated SAW substrate, LiTaO3 (LT: lithium tantalate)/ST-cut quartz (ST-quartz), with which directly combined piezoelectric single crystals using amorphous intermediate bonding (AIB) method. In this paper, we investigate bonding characteristics using different amorphous layers with the object of improving bonding of piezoelectric single crystals for future SAW devices. We applied amorphous Al2O3 (α-Al2O3) as intermediate layers as well as previously reported amorphous SiO2 (α-SiO2) to the bonding interface of LT and ST-quartz, since a-Al2O3 has high water corrosion resistance against to the hydrophilic treatment. The substrates with both of the amorphous intermediate layers were successfully bonded assisted with vacuum ultraviolet irradiation in the presence of oxygen gas (VUV/O3). Especially, the substrate with the a-Al2O3 layer achieved the dominant highest bonding strength of 10.5 MPa, which is approximately three times stronger than the substrate with the α-SiO2 layer. These results indicate that the α-Al2O3 layer is preferable to improve effects of VUV/O3 hydrophilic treatment and fabricate LT/ST-quartz substrate. To investigate the amorphous interlayers can be promising for making piezoelectric single crystals bonding enough strong to fabricate the future SAW devices.

Original languageEnglish
Title of host publication11th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2016 - Proceedings
PublisherIEEE Computer Society
Pages239-242
Number of pages4
ISBN (Electronic)9781509047697
DOIs
Publication statusPublished - 2016 Dec 27
Event11th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2016 - Taipei, Taiwan, Province of China
Duration: 2016 Oct 262016 Oct 28

Other

Other11th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2016
CountryTaiwan, Province of China
CityTaipei
Period16/10/2616/10/28

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ASJC Scopus subject areas

  • Hardware and Architecture
  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this

Suzaki, H., Kuwae, H., Okada, A., Shoji, S., & Mizuno, J. (2016). Study of LiTaO3/ST-quartz Bonding with Amorphous Interlayer Assisted by VUV/O3 Treatment for SAW Device. In 11th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2016 - Proceedings (pp. 239-242). [7799986] IEEE Computer Society. https://doi.org/10.1109/IMPACT.2016.7799986