Wafer-Level Fabrication of FAIMS Chips Based on TGV Technology

By introducing the strengths of the vertical interconnection of TGV (Through Glass Via) technology into FAIMS (high-Field Asymmetric waveform Ion Mobility Spectrometry) chip manufacturing, we propose a wafer-level TGV-MS (multi-stack) FAIMS chip manufacturing method and achieve the wafer-level fabrication of 14 chips on a 6-inch glass wafer for the first time. The test results demonstrate that the TGV wafer manufactured based on this method shows excellent airtightness, electrical properties, and consistency with a leakage rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.94\times 10 ^{-11}$</tex-math> </inline-formula> Pa<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot $</tex-math> </inline-formula>m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>/s, a resistivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.92\times 10 ^{-4}~\Omega \cdot $</tex-math> </inline-formula>cm. A single FAIMS chip volume is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.8\times 1.6 \times 0.16$</tex-math> </inline-formula> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, weight is 2.28 g, the relative thickness error is less than 0.3%, and the parallelism error is less than 0.01°. Meanwhile, typical volatile organic compounds benzene and toluene were selected as samples to test the separation performance of the FAIMS chip, and the detection spectra under different gas concentrations and voltages were obtained. The experimental results show that the wafer-level FAIMS chip has a good resolution for benzene and toluene, and the linear detection range for the two samples is 0.1 ppm to 2 ppm (linear fitting coefficients 98.9%, 99.5%). The detection limit for benzene and toluene is 77 ppb. This paper solves the problem that microfluidic structures with electrodes cannot be manufactured at the wafer level due to side planar electrode leads, greatly simplifies the structure of the chip, realizes the mass production of FAIMS chips, and provides a technical reference for the wafer-level manufacturing of analysis sensors such as microfluidic chips with electrode structures and MEMS mass analyzers. [2024-0229]