Study On Structure Design And Fabrication Of Film Bulk Acoustic Wave Biochemical Sensor With Acoustic Energy Compensation

Film bulk acoustic wave biochemical sensor has a wide application prospect in biochemical detection, clinical medicine detecting, environmental monitoring, food safety analysis etc., because of its advantages such as fast testing, non-labeling, easy integration and high sensitivity. It has become on of the focuses of biochemical sensors research based on MEMS technology. The resolution of existing film bulk acoustic wave biochemical sensors are not high enough, which confine their application in detecting of low concentration, small molecular such as drug screening. The research of the method and mechanism of improving resolution to enlarge the application range of film bulk acoustic wave sensor is very important.In order to improve the resolution of film bulk acoustic wave sensor, one new mechanism with acoustic energy compensation is put forward in this paper. There is another piezoelectric layer under the conventional piezoelectric layer, which can compensate the energy loss which happens when the sensor is working, and increase improve the resolution while increase the quality factor of sensor.The main research contents including:①Based on the analysis of domestic and international research status of the film bulk acoustic wave sensor, a scheme of sensor with active energy compensation is put forward.②Mathematical model of sensor is established from the continuum theory, new method to improve the resolution of film bulk acoustic wave sensor is further verified.③By using the FEM simulation software,the effect of difference of structure parameters such as thickness of piezoelectric layer, thickness and width of electrode to the resonant characteristics of device is analyzed. Vibration of thickness shear mode is excited by staggered electrodes.④Sensors with differrent shape and dimension are designed, and the layout of sensors is designed.⑤The micromachining process of the film bulk acoustic wave sensor is developed and the sensor chip is fabricated. The first frequency of single piezoelectric layer sensor is 1.5~2.3GHz.