【作者】 孙鹏；

【导师】 胡明；

【作者基本信息】 天津大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 随着工业和日常生活向空气中排放的污染气体越来越多,新型高性能低功耗的气敏传感器越来越受到人们的关注。本文主要针对多孔硅基氧化钨气敏薄膜以及传感器的电学特性和气敏特性进行了研究。首先,通过双槽电化学腐蚀法制备介孔硅基底。选取40,60和80mA/cm²三种腐蚀电流密度,得到不同孔隙结构参数的介孔硅样品,对样品进行了孔隙率、SEM、I-V特性等各种测试,分析了介孔硅的材料参数、微观形貌和电学特性等。用静态配气法对一定浓度的NH₃、C₂H₅OH和NO₂进行了气敏特性测试。结果显示:腐蚀电流密度为80mA/cm²的介孔硅样品具有较好的气敏特性。随后,在制备的介孔硅基底上溅射氧化钨薄膜以及Pt电极,形成介孔硅基氧化钨薄膜气敏传感器。通过对氧化钨薄膜溅射时间的选取,得到不同膜厚的样品,对样品进行了SEM、阻温特性等各种测试,分析了介孔硅基氧化钨薄膜的材料参数、微观形貌和电学特性等。用静态配气法对一定浓度的NH₃和NO₂进行了气敏特性测试。研究表明:溅射氧化钨薄膜的时间为5分钟的样品具有较好的气敏特性。虽然器件在常温下具有较高的灵敏度,但器件的响应较慢,迫切需求制备一种大孔硅基底,以制备更高性能的大孔硅基氧化钨薄膜气敏传感器。最后,实验提出了大孔硅的制备方法,并对大孔硅的表面形貌,腐蚀深度,孔隙率和气敏特性进行了测试,并且测试了大孔硅基氧化钨气敏薄传感器的气敏特性,为下一步制备更高性能的多孔硅基氧化钨气敏传感器奠定了基础。更多还原

【Abstract】 With more and more contaminated gas emissions from industry and daily life, novel high-performance and low-power gas sensors has attracted increasing attention. This paper mainly studies silicon electrical properties and gas sensitivity of the porous tungsten oxide gas sensors.First of all, by the method of double-tank cell electrochemical corrosion meso-porous silicon substrate is fabricated, on whose surface tungsten oxide and metal electrodes thin film is deposited through the magnetron sputtering. With 80, 40 and 60 mA/cm² corrosion current density respectively, different parameters of pore structure of mesoporous silicon samples are attained. In addition, we tested the porosity of samples, SEM, IV and other characteristics and analyst material parameters. In a certain concentration of NH₃, C₂H₅OH and NO₂ made by static state analytical method,gas sensitive characteristics of the samples are tested. It is showed that: the sample prepared with 80mA/cm² corrosion current density has the best gas-sensing properties.Subsequently, tungsten trioxide thin film is deposited on the samples through magnetron sputtering as the sensitive material of gas sensor. Depending on the different sputtering time, tungsten trioxide thin films were formed with different thickness. The properties of thin film were tested and analyst, including SEM, resistance-temperature characteristics, the material parameters, microstructure and electrical properties of tungsten trioxide thin-film based on mesoporous silicon substate. Similarly, in a certain concentration of NH₃, C₂H₅OH and NO₂ made by static state analytical method,gas sensitive characteristics of the samples are tested. The result shows that: tungsten trioxide thin film for 5 minutes sputtering time has the best gas-sensitive properties. Although the device at room temperature has high sensitivity, the responding time is long. there is an urgent demand for the preparation of a macroporous silicon substrate in order to prepare more high-performance macroporous silicon-based tungsten oxide thin film gas sensors.Finally, the experiments put forward the fabrication method of macroporous silicon and test the samples for surface morphology, corrosion depth, porosity and gas sensitivity. At the same time, we carried out test for the gas sensitivity of WO3 thin film gas sensor based on macroporous silicon. These lay foundation for the next high-performance WO₃ thin film gas sensor based on macroporous silicon.更多还原