| As the third-generation infrared detector based on Micro-Electro-Mechanical-System (MEMS) technology, uncooled infrared detector/microbolometer has a very wide application prospects in the many fields of industry, agriculture, defence, medical, transportation and environmental protection, owing to the advantages of small volume, light weight, low power consumption, portability and less expensive, etc. Improving the sensitivity and performance of uncooled infrared detectors is the goal that all researchers who engages in this aera keep pursuing. This thesis focuses on the key technologies of one kind of microbolometer based on vanadium dioxoide sensitive thin film. A series of intensive researches have been made including working principle, structural design, simulation and analysis, materials preparation, device fabrication and performance testing of the microbolometer. Bolometer performance has been improved by micromachining technology-the preparation and integration of high temperature coefficient of resistance (TCR) VOx, nitrogen-doped vanadium oxide and gold black of high infrared absorption, respectively. The main contents and achievements are summarized as follows:(1) The electrical and optical property of nickel chromium oxide-NiCr2O4thin film has been explored and prepared by using pulsed-dc magnetron sputtering method. The characteristic of NiCr2O4prepared by this method is different from those of material prepared under the conditions of high pressure oxidation. It's been found that this thin film from room temperature to100degrees Celsius has properties of semiconductor-insulator electrical phase transition and good infrared absorption between3μm and5μm of high temperature infrared spectrum. It has potential application in the field of infrared market.(2) The thermal sensitive material and device of vanadium oxide thin film have been studied. The vanadium oxide thin film has high temperature coefficient of resistance at near room temperature which is prepared by ion beam sputtering. The properties of this film-surface morphology, grain size and other attributes are revealed by XRD, SEM and AFM technology.64×2array bolometer based on porous silicon sacrificial layer is designed and fabricated. The optical, mechanical, thermal and electrical performances of the detector are simulated and analyzed by the film matrix method and the finite element method. Finally, the detector system test is carried out.(3) Gold black thin film of high infrared absoption is prepared by resistive evaporation method. The surface morphology and reflectivity is measured. The optical property of gold black material is simulated by numerical computation by establishing model of gold black chain structure which is equivalent to the equivalent circuit of Drude-Zener model. Gold black film is integrated into vanadium oxide microbolometer as infrared absorber. Comparing with bolometer without gold black, this bolometer with gold black has a better detection.(4) In the preparation process of nitrogen-doped vanadium oxide thin film by introducing a small amount of nitrogen gas is put forward as a way to improve TCR. Nitrogen-doped vanadium oxide thin film of high TCR is prepared by pulsed-dc magnetron sputtering method.64×2array nitrogen-doped vanadium oxide microbolometer based on surface sacrificial layer technology is designed and fabricated. The optical, mechanical, thermal and electrical performances of the detector are simulated and analyzed by the film matrix method and the finite element method. The detector system testing shows that the detectivity of this bolometer has reached1.399×109cmHz1/2/W.
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