A Film Bulk Acoustic Resonator-Based Sensor with AlN Piezoelectric Material for Detecting Ethanol and Acetone

Figure 3

The illustration of fabrication protocol for FBAR chip. The upper electrode is Ni/Au, the bottom electrode is Mo. The piezoelectric material of the sensor is AlN. (b) Is for the photolithography and etching of the front side, (c) is for the SiO₂ deposition, (d) is for upper electrode deposition, (d) is for back etch.

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