The Research On Development Technology Of Polysilicon Pressure Sensor

Pressure sensors have lots of application fields. Polysilicon pressure sensor's research and development widely promote its application. First, the research status on several kinds of high-temperature pressure sensors is introduced in the thesis.The principle and design of the poiysilicon pressure sensor is discussed in detail in the thesis. The poiysilicon high temperature pressure sensor's temperature stability is greatly improved by depositing a poly-silicon film on the layer of SiO2, which has both good mechanics of silicon and excellent insulation property between piezo-resistors and substrate. Compared with doped mono-crystalline silicon pressure sensor, poiysilicon pressure sensor shows great advantages in 200℃ operating temperature. Because of the simple manufacture technique, compatible with the integrated circuit fabrication, and low cost, the sensor can be easily mass-produced. In the research and development, we obtained the better process, fabrication condition and parameters for the sensor chip making.The encapsulation technology of the high temperature poiysilicon pressure sensor is discussed in detail. The static electricity bonding and silicon oil infilling setups were designed and fabricated. By adoptingreasonable structure and material, and chip mounting process, the miniature solid-state encapsulation technology for the high temperature polysilicon pressure sensor is obtained. Experiments show that the sensor developed has good sensitivity, high accuracy and excellent temperature stability.The effects of temperature on polysilicon resistor high temperature pressure sensors are analyzed. Several methods for improving the temperature effects to the sensor are presented.The design and making of the test system of polysilicon pressure sensor satisfy the characteristics testing requirement. The problems of precisely testing pressure sensor's thermal zero shift; thermal sensitivity shift, and non-linearity hysteretic repeatability, in different temperature condition are solved.Finally, the pressure sensor application and its intelligentization are introduced...