Design And Fabrication Of SOI High Temperature Pressure Sensor

In high temperature harsh environment, due to the mechanical structure’s degradationand the metal leads’ invalidation, the real-time dynamic measurement of of pressure sensor isunable to carry out. It is necessary to design the high temperature pressure sensor, using thematerial remains stable in high temperature, from the sensitive chip to metal leads and to thepackage tube. Hence overall the design, high-temperature resistant structure must befabricated to ensure that the pressure sensor is capable of operating stably in high temperatureharsh environmentThe problem, the reverse of PN junction, caused by the intrinsic excitation of thesemiconductor in high temperature, was solved using the SOI material. Then the stability ofthe mechanical properties and reliability of the mechanical structure of sensitive head isguaranteed with the MEMS fabrication process. Through high temperature metal materialsas the metal wire material, the packaging of the pressure sensor can withstand hightemperature in the harsh environment. And using the ceramic which thermal expansioncoefficient is similar to the sensor of sensors as the package tube, thepressure sensor’s thermal stress is reduced,and the stability of pressure sensor is improvedin high temperature harsh environment.With to the high temperature pressure sensor designing principles above, parallelingtheoretics with simulation, and studying the various structure part of the sensor, the designwas worked out for the various parts of the sensor in harsh environment. After the MEMSfabrication process and packaging, the prototype of high temperature pressure sensors wasfabricated. And the performance parameters and operation maximum temperature of the SOIhigh temperature pressure sesor in this paper were obtained according to the test results.Thiswork provided reference for the design of more high temperature pressure sensor.