Study On Vacuum Microelectronic Pressure Sensor

Pressure is the most important parameter in the five-parameter in autocontrol procedure. As the pressure information-acquiring device; the pressure sensor is the necessary device being used in the field of oil industry, chemical industry, metallurgical industry, electrical power industry, instruments and meters industry, automobile industry, smart structure, aerospace, defense. And its quantity is greatly demanded. It is one of the important parts of the modern information technology. With the development of Micro-Electro-Mechanical-Systems (MEMS) from the end of 80s in last century, the basic idea of designing and fabricating pressure sensors has changed greatly. These changes pave the way to realizing micromation, integration and intelligence of pressure sensors. And the MEMS technology provides new measurement in the design and fabrication. The worldwide research on pressure sensors focuses on integration, new principle, new structure, new function and high performance.Our research is supported by the Fifteen-Project of Chongqing municipality. In the paper, we put forward the combination of micro electronic technology, MEMS technology and vacuum micro electronic technology to develop a micro electronic pressure sensor with overload protection. The pressure sensor consists.of elastic anode membrane, isolation layer, vacuum micro cavity and field emission catelectrode tip array with overload protection. Such pressure sensor has many advantages, such as high temperature stability, radiation resistance, fast response, high sensitivity, small volume, simple secondary instruments and bulk production. ;The research items are listed as bellow.1. The structures and fabrication technology of different pressure sensors are analyzed after carefully studying the relevant documents.2. After studying the relevant basic theories, the relationship between the field emission current and the work function of semiconductor and the temperature is analyzed.3. The mechanical property and electricity property of the vacuum micro electronic pressure sensor is studied and relevant computation and simulation are carried out.4. The design of overload protection is put forward in the vacuum micro electronic pressure senor.5. Study is carried out to develop the relevant technology design and technology research. A prototype of such sensor is fabricated. The density of its field emission catelectrode tip is about 24000tip/mm2, the onset emission voltage is 0.5 ~ IV, the backward voltage is larger than 25V, the current of single tip is 0.2nA, the sensitivity is 98.5mV/bar. 6. The testing and calibrating method is studied and the testing result is analyzed.