Research On Thin Film Type Micro Gas Sensor

In order to fulfill different industrial requirements on detecting specified gas particles in air environment, Detecting principle, design method, producting technology and packaging technology of micro gas sensor were studied in this article based on the national basic study project (973 project) "Numerical principle and method of producing high performance IC product"(project number:2003CB716200). Finally the vacuum evaporating deposition technology and the method of making thin film highly sensitive to ethonal vapor has been studied. one type of self-made micro ethonal vapor sensor has been discussed. Firstly the author introduces the detecting principle of some gas sensors including semiconduct type, electrochemistry type. According to the industrial develop trend of making the sensor size smaller and smaller, semiconducting type gas sensor for ethonal vapor by using Mems technics was chosen as the study direction. Secondly the method of making highly sensitive thin film was studied. It is shown that highly sensitive thin film to ethanol vapor can be produced by using SnO2 as sensing material. the sensitivity of the thin film can be enhanced greatly By adding Fe2O3 as katalyst. Thirdly the MEMS technology were studied. two designs of the ethanol vapor sensor were present based on these study. After analyze and compare the two models by using the MemsPro software analyzing tools. The proper design has been chosen as the final decision. Finally the ethanol vapor sensor prototype was produced and its working condition and surface morphology was studied in detail. The sensor's packaging and circuit has also been specified.