D15-mode ferroelectric single crystal film piezoelectric vibration sensor and preparation method thereof

Abstract

The invention provides a d15-mode ferroelectric single crystal film piezoelectric vibration sensor and a preparation method thereof, and the method comprises the steps: bonding a bottom electrode / a silicon dioxide layer / a silicon substrate with a lithium niobate wafer, and sequentially carrying out the thinning, chemical mechanical polishing and cleaning, thereby obtaining a lithium niobate single crystal film; the method comprises the following steps: preparing an alignment mark and a surface electrode on the surface of a wafer by adopting magnetron sputtering and ion beam etching stripping processes, then etching a lithium niobate single crystal film by adopting an ion beam etching method to pattern the lithium niobate single crystal film, etching a silicon dioxide layer by adopting a reactive ion etching method to pattern the silicon dioxide layer, and then etching a bottom electrode by adopting an ion beam etching method to pattern the bottom electrode, thereby obtaining the lithium niobate single crystal film. And finally preparing the cantilever beam and the mass block from the front surface of the silicon substrate by adopting a deep silicon etching process, and completing the release of the device from the back. According to the invention, the ferroelectric single crystal lithium niobate film and the silicon wafer can be well bonded, a standard MEMS process is adopted to prepare the sensing device on the basis, the process feasibility and the repetition rate are high, and the prepared device has a broadband and a very high output voltage.

Description

technical field [0001] The application belongs to the technical field of MEMS structure process preparation, and in particular relates to a d 15 Mode ferroelectric single crystal thin film piezoelectric vibration sensor and preparation method thereof. Background technique [0002] Vibration signal is the main monitoring parameter of monitoring system. In a variety of vibration environments, effectively extracting and monitoring vibration signals poses severe challenges to traditional vibration sensors. Piezoelectric vibration sensors based on piezoelectric materials have become the main development of future vibration sensors. direction. At present, there are five main types of piezoelectric materials, such as piezoelectric crystals, piezoelectric ceramics, piezoelectric polymers, piezoelectric composite materials and piezoelectric films. Although piezoelectric crystals, piezoelectric ceramics, piezoelectric polymers and piezoelectric composites all have their excellent pr...

AI Technical Summary

Problems solved by technology

Most cantilever vibration sensors usually use a d of the upper and lower electrodes 31 mode, while the piezoelectric coefficient d 31 Smaller, which in turn affects the output voltage, corresponding sensitivity and device performance

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