Study On The MEMS Pressure-Sensitive Si-based Diaphragm With Complex Structure And Its Application

Micro Electro Mechanical System (MEMS) technology has rapidly developed in recent decades and has become an important field of modern science and technology development. MEMS is a brand new high-tech with many outstanding characteristic, such as miniaturization, integration, mass production and multidisciplinary etc. With the rapid development of MEMS technology in recent years, MEMS devices have wide application prospect in the national economy and military defense. Thus, more and more researchers all over the world pay great attention to design and process of MEMS devices.We make a further research on silicon MEMS Si-based devices’design and processing technology. Meanwhile, we designed and fabricated a pressure-sensitive corrugated silicon nitride diaphragm. With respect to the common flat film, the corrugated silicon nitride diaphragm has the characteristics of small internal stress, high elastic modulus, high strength and good stability. The corrugated silicon nitride diaphragm has important applications in the field of optical sensing, acting as high-performance pressure and vibration sensing diaphragm.In the first chapter, we firstly introduce the research status, basic characteristics and technical classification of MEMS technology, and discuss the development trend of MEMS technology. Then, we put forward the main research content and purposes of this paper.In the second chapter, we mainly introduce and analyze the photolithography process of MEMS, from four aspects, including photolithography principle, photo mask, and photoresist, photolithography equipment. Meanwhile, we summarize and analyze the various problems encountered in experiments, in order to troubleshoot problems and optimize MEMS process.In the third chapter, we intensively introduce the etching process in MEMS device fabrication, including wet etching (silicon isotropic etching and anisotropic etching) and dry etching (ion beam sputtering etching, plasma etching and reactive ion etching).In the fourth chapter, we focus on the fabrication of a pressure-sensitive corrugated silicon nitride diaphragm, based on the design and manufacture of MEMS devices. From early mask layout to the exploration of experimental data, we obtain a set of relatively suitable process parameters through a large number of confirmatory experiments, aiming to achieve corrugated silicon nitride diaphragm.In the fifth chapter, we firstly summarize the total work of this paper, and discuss and analyze some shortcomings in this paper. In addition, we put forward suggestions and prospect for the further research in this paper.