红外微测辐射热计用纳米氧化钒薄膜的制备和性能研究

Fabrication and Property Study of Vanadium Oxide Thin Films with Nanostructure for Infrared Microbolometer Application

具有优异热敏性能的氧化钒薄膜材料是红外测辐射热计的首选热敏电阻材料,合适的薄膜电阻及高温度电阻系数的氧化钒薄膜的制备是实现高探测率红外测辐射热计的保证．利用新型对靶反应磁控溅射工艺制备了具有纳米颗粒的氧化钒薄膜材料,确定了最佳工艺参数．对其组成、结构和性能进行了分析,原子力显微镜AFM形貌分析表明薄膜具有均匀致密的表面,X射线光电子能谱分析XPS确定了其组成成分主要为V_2O_5、VO_2和少量的V_2O_3．在常用作微测辐射热计结构层材料的氮化硅基底上,该薄膜材料在室温附近具有合适的薄膜电阻(大约为每方14 kΩ)以及高的温度电阻系数(-3．17%/℃),有望适用于非致冷红外测辐射热计探测器．

Vanadium oxide with outstanding thermal sensing property is an ideal thermistor material for bolometer application and the fabrication of vanadium oxide thin film with high TCR and suitable film resistance are the base of high detectivity of microbolometer. Vanadium oxide thin film with nanostructrue was deposited by novel facing targets d.c. reactive sputtering technique using V metal as target and a new deposition parameter was defined. X-ray photoelectron spectroscopy analysis revealed the vanadium oxygen state of the film, which included V2O5, VO2 and a few V2O3. Atomic force microscopy surface morphology indicated a planar and compact film surface. The temperature coefficient of resistance （TCR） of vanadium oxide film as-deposited on Si3 N4 substrate, which is a common MEMS structure material in microbolometer use, was high up to -3.17%/℃ and the sheet resistance was about 14kΩ/square around room temperature, implied promising application in uncooled microbolometer infrared （IR） detectors.