| Field emission array (FEA) pressure sensor Is a new type sensor, which has many advantages such as high sensibility, high temperature stability and lower volume, is developed with the improvement of vacuum microelectronic technique in recent years. A novel PEA pressure sensor is mainly discussed In this thesis. The methods of designation, fabrication as well as the experiment results are given iii five chapters respectively In details.In the first part of the thesis the current study status of the pressure sensor and the techmniques of the MEMS arc sunintarizcd.The properties of several pressure sensors are compared. MEMS is system which has composed the techinique of microelectronics and the technique of precious mcchachtinc fatbrication.Thie current study status and the technique subjects of the MEMS are analysed.The field emission theory and the cht:iraictcristics of hydrogen naiio-crystahlinc silicon filni(uic桽i:li) arc studied iii the second chuptcr. The field emission study of silicon materials is based on the study of metal materials. Fowler and Norderhelm first got the field emission cqLlation. Many limctors affecting the field emission characteristics of semiconductors such as tcmJ)cratllrc and surface phase are in yes tig a te(l.Methods of the (Iesign of the novel FEA pressure scitsor are l)tlt Iorwar(l by systematically studying the ol)cration l)rincil)lc of FEA pressure sensor. According to this desigtm, cathode instead ci ano(lc is devised as the pressure sensing film and tic?Si:!! flit, is (leposltc(l on hc FEA. The d illicit lties at n(l the cotnplica tions of time fabrication of the sensor are reduced by this (lesign and with time (hiSposltion of the ttc桽i:H fihtti ott the cathode time emission characteristic of the FEA is improved also.Besides, detailed 5) CCSS flow is given Out. Time main tcchmfli(511Cs of time micromachine fabrication arc represented firstly. 憀抙tcn the etching of FEA is introduced purticuila ny. 憀抙mc etching of FEA is one of the most important I)arts of the process, by severn I timcs of groping we get the proper distribution of time etching solution and lie etch lug time. Five masks an re uise(l tin rough on t I lie flow.Experiment results arc h)reseumtc(I. Tine l?V characteristic of the sensor ismeasured. The silicon tip which has been sharpened by oxidation and which has not been sharpened sire observed by the SEM. The height of the tip before sharpening is about 2.l7prn and Is 1.71~.tm after sharpening. The curvature radius of the tip is 40桽Onm. Deformation characteristics of the FEA acting as the pressure sensing film of the sensor are investigated using the finite element analysis method also.Conclusions and Improvements arc rChIrcSCfltC(l sit Istst. |
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