The Design And Preparation Of MEMS Vector Hydrophone For The Integration Of Silicon Cilium/ Nano-membrane

The vector hydrophone is especially suitable for sonobuoy because of its small size,light weight and convenient layout.In view of the poor consistency and alignment accuracy in the adhering process of the cilia,hydrophone cilia adhesive,the integration process of silicon cilia is put forward,.Specifically,the back of the SOI substrate is deep etched,to form silicon silicon cilia cylinder structure,where the consistency and alignment accuracy is guaranteed by the fabrication process,In view of the problem of hydrophone chip size,sensitive silicon nanometer membrane is put forward.In the case of ensuring sensitivity and frequency response,the cross beam structure size could be decreased,Meanwhile,the overall size of hydrophone chip could be dramatically reduced due to the introduce of silicon cilia.This paper firstly introduces the research background and the research status at home and abroad of MEMS two-dimensional vector acoustic sensor,and analyzes the working principle of the vector hydrophone.On this basis,this paper puts forward the MEMS two-dimensional vector hydrophone structure based on silicon cilium / nano-membrane,the majority carrier concentration distribution is analyzed in the condition of completely exhausted,the relationship between the surface potential and silicon nano-membrane conductivity is derived,the huge pressure resistance model based on surface depletion mechanism is built.In this paper,the integrated preparation method of MEMS two-dimensional vector hydrophone is studied,and the integrated preparation of silicon cilium,silicon dioxide four beam structure and silicon nano-membrane sensitive cell are realized.The fabrication process of preparing MEMS two-dimensional vector hydrophone is established.The structure of silicon cilium and silicon nano membrane was prepared.The reasons of the problems in the preparation process were analyzed and the single step process verification was carried out.Finally,the structure of vector hydrophone was characterized by scanning electron microscope.The resistive and pressure-sensitive properties of the pressure resistance were tested by using the normal temperature probe,and the i-v curve was obtained,which proved that the prepared resistance had good pressure-sensitive properties.