Study on Bonding Technology of Silicon-Based Lithium Tantalate Heterogeneous Wafers

Abstract

Abstract: The development of 5G mobile communication imposes requirements of high frequency, miniaturization, and integration on surface acoustic wave devices. Compared with traditional piezoelectric bulk single crystal material, surface acoustic wave filters fabricated with silicon-based piezoelectric single crystal film materials exhibit advantages such as high frequency, low insertion loss, high temperature stability and so on, making silicon-based piezoelectric single crystal film material prime foundation material. Smart-Cut^TM is the universal method for preparing silicon-based piezoelectric single crystal film materials, and bonding process is one of the most essential procedures. Bonding quality determines the quality of piezoelectric single crystal film and ultimately affects the performance of the devices. In this work, high-quality heterogeneous silicon-based LiTaO₃ wafers with the bonding strength up to 1.84 J/m²and bonding area over 99.9% were achieved through optimizing low-temperature direct bonding process, which includes plasma activation, megasonic cleaning, pre-bonding, and thermal treatment.

Key words: silicon-based lithium tantalate, low-temperature direct bonding, plasma activation, megasonic cleaning, pre-bonding, thermal treatment, surface acoustic wave filter

CLC Number:

CHEN Zheming, DING Yuchong, ZOU Shaohong, LONG Yong, SHI Zibin, MA Jinyi. Study on Bonding Technology of Silicon-Based Lithium Tantalate Heterogeneous Wafers[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(4): 634-640.

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