Wafer bonding of SiC-AlN at room temperature for all-SiC capacitive pressure sensor

Fengwen Mu, Yang Xu, Seongbin Shin, Yinghui Wang, Hengyu Xu, Haiping Shang, Yechao Sun, Lei Yue, Tatsurou Tsuyuki, Tadatomo Suga, Weibing Wang, Dapeng Chen

Research output: Contribution to journalArticle

Abstract

Wafer bonding of a silicon carbide (SiC) diaphragm to a patterned SiC substrate coated with aluminum nitride (AlN) film as an insulating layer is a promising choice to fabricate an all-SiC capacitive pressure sensor. To demonstrate the bonding feasibility, a crystalline AlN film with a root-mean-square (RMS) surface roughness less than ~0.70 nm was deposited on a SiC wafer by a pulsed direct current magnetron sputtering method. Room temperature wafer bonding of SiC-AlN by two surface activated bonding (SAB) methods (standard SAB and modified SAB with Si nano-layer sputtering deposition) was studied. Standard SAB failed in the bonding, while the modified SAB achieved the bonding with a bonding energy of ~1.6 J/m2. Both the microstructure and composition of the interface were investigated to understand the bonding mechanisms. Additionally, the surface analyses were employed to confirm the interface investigation. Clear oxidation of the AlN film was found, which is assumed to be the failure reason of direct bonding by standard SAB.

Original languageEnglish
Article number635
JournalMicromachines
Volume10
Issue number10
DOIs
Publication statusPublished - 2019 Oct 1

Keywords

  • All-silicon carbide (SiC)
  • Aluminum nitride (AlN) film
  • Capacitive pressure sensor
  • Interface
  • Room temperature wafer bonding

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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  • Cite this

    Mu, F., Xu, Y., Shin, S., Wang, Y., Xu, H., Shang, H., Sun, Y., Yue, L., Tsuyuki, T., Suga, T., Wang, W., & Chen, D. (2019). Wafer bonding of SiC-AlN at room temperature for all-SiC capacitive pressure sensor. Micromachines, 10(10), [635]. https://doi.org/10.3390/mi10100635