A novel temperature compensation method for SAW devices using direct bonding techniques

Onishi, K.; Namba, Akihiko; Sato, Hisanao; Ogura, Tetsuyoshi; Seki, S.; Taguchi, Yutaka; Tomita, Yoshihiro; Kawasaki, Osamu; Eda, Kazuo

doi:10.1109/ultsym.1997.663015

Cited by 22 publications

(16 citation statements)

References 10 publications

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“…When a stiff material with small CTE is chosen as the base substrate, the bonding suppresses the thermal expansion of the top surface where SAW propagates. Various bonding technologies such as fusion [20][21][22]28], room temperature [25][26][27][28] and adhesive [23,30,31] ones, have been investigated. Although the adhesive one seems most cost-effective, it is not clear whether the adhesive is stable during and after the device fabrication.…”

Section: B Wafer Bondingmentioning

confidence: 99%

“…As the base-substrate, Si [21][22][23]28,30,31], glass (fused quartz) [21][22][23][24][29][30][31], and sapphire [25][26][27] have been tested. Sapphire is most appropriate for the TCF improvement, but expensive.…”

Section: B Wafer Bondingmentioning

confidence: 99%

“…In contrast, usual materials including LN and LT become soft with T, and their intrinsic TCE and TCV are negative [19,20]. Another strategy is use of the wafer bonding of a single crystal LN/LT with a stiff substrate with small CTE [21][22][23][24][25][26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

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Recent development of temperature compensated SAW Devices

Hashimoto

Kadota

Nakao

et al. 2011

2011 IEEE International Ultrasonics Symposium

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Section: B Wafer Bondingmentioning

confidence: 99%

Section: B Wafer Bondingmentioning

confidence: 99%

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Recent development of temperature compensated SAW Devices

Hashimoto

Kadota

Nakao

et al. 2011

2011 IEEE International Ultrasonics Symposium

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“…Figure 2 shows the thinningpolishing procedure of the layered substrate. Firstly a heat treatment process after initial bonding [8] is applied to directly bonded thick substrates (in this paper, the initial thicknesses of LiTaO? and Glass # l substrates were 1 mm These processes were required to obtain high bonding strength.…”

Section: Fabrication Process Of Thesawdevicementioning

confidence: 99%

“…[8] In this method, since the difference in TECs exetts thermal stress on the surface ofthe piezoelectric substrate, the temperature Characteristics of the SAW devices can be controlled.…”

Section: Introductionmentioning

confidence: 99%

Temperature stable SAW devices using directly bonded LiTaO/sub 3//glass substrates

Sato

Onishi²,

Shimamura³

et al.

1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102)

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We have developed temperamre stable SAW devices by using a direct-bonding technique, Temperature stability approximating that of quartz was achieved by thinning a 36" Y-X LiTaO3 substrate to 30 pm on a glass substrate.The temperature compensated SAW devices were fabricated using a stacking procedure based on the direct bonding of a piezoelectric single crystalline layer onto a glass substrate. Because the thermal expansion coefficient (TEC) of the glass substrate is smaller than that of the piezoelectric layer, the piezoelectric layer experiences thermal seess. As a result, the temperature dependence of the SAW devices could be improved.By using a glass substrate with small TEC and minimizing the LiTaO3/glass thickness ratio, the temperature coefftcient of frequency (TCF) of the SAW devices was maintained at approximately -6 ppm/"C from -30 "C to 80 "C. The SAW propagation characteristics (velocity and electromechanical coupling factor) and the frequency response of the SAW devices were almost the same as those of SAW devices using a 36" Y-X LiTaO3 substrate.

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