低功耗微热板ZnO甲烷传感器仿真及性能研究

Simulation and performance study of low-power magnetron sputtered ZnO methane sensor

随着微机电系统(MEMS)的发展,运用该技术的半导体传感器也跟着迅速发展,逐渐走向微型化、集成化和智能化.基于MEMS的微加热板(MHP)的金属氧化物甲烷传感器具有功耗小、响应快等优点,广泛应用于甲烷检测.其中,氧化锌(ZnO)甲烷敏感材料因其灵敏度高、中毒效应小、工作温度低等优点,广受关注.但是,该敏感材料制备的传感器响应性能依然受加热温度及热量分布的强烈影响.使用有限元分析(FEA)软件COMSOL中的Multiphysics模块对物理场中的温度进行仿真分析与比较,揭示了在相同工作条件下加热电极结构对温度分布的影响,优选的微加热板达到300℃时需要75 mW左右的功率.在商用微加热板的叉指电极上采用无遮挡全表面溅射氧化锌敏感材料构建ZnO薄膜甲烷传感器,并使用合肥微纳公司HIS9010测试了气体传感器的响应.采用静态测量的方法向1 L的气体腔内注射甲烷气体,经过测试,与现在不同形貌的ZnO相比,本课题组使用的磁控溅射制备的氧化锌薄膜气体传感器,在(1000~10000)×10^(-6)甲烷浓度区间内响应线性度比较好,对浓度为10000×10^(-6)的甲烷响应值达到了30.与国内外商用甲烷传感器的甲烷响应性能进行了对比,结果表明本课题组制作传感器响应更高,更具有应用优势.

With the development of the industry of semiconductor integrated circuits,microelectromechanical system(MEMS)products have made rapid progress.The development of MEMS and the combination of sensor technology have yielded compact sensors with increased functions and intelligence levels.MEMS-based microhotplate(MHP)-type metal oxide methane sensors have the advantages of low power consumption and fast response and have been widely used in methane detection applications.In particular,ZnO methane-sensitive materials have attracted significant attention due to their high sensitivity,small poisoning effect,and low operating temperature.Notably,the response performance of sensors prepared from these sensitive materials is still significantly affected by the heating temperature and thermal distribution of the MEMS-based MHP.The purpose of our experiment is to optimize the heat generation of the heating electrodes of MHP,optimize the thermal distribution of MHP,and further reduce the power consumption of MHP sensors.The heating electrodes of MHP are made of platinum materials that have high thermal conductivity and stable performance.In this study,we use the Multiphysics module in the finite element analysis software COMSOL to simulate and analyze the temperature in the physical field for the two structures of serpentine platinum heating electrodes of MHP.By comparison,the structure of the heating electrodes affects the temperature distribution under the same working conditions.The structure with a larger width in the middle of the heating plate electrode and gradually narrowing to both sides generates more heat than that with the same width.When the heating plate reaches300℃,it needs about 75 mW of power.Next,ZnO thin film methane sensors were constructed by sputtering ZnO methane-sensitive materials on the interdigital electrode of a commercial MHP,and the response of the gas sensor was tested using the HIS9010 of Hefei Micro-Nano Company.The static measurement method was used to inject methane gas into a 1-L gas chamber.In order to verify the superior response of our sensor,it has been compared that performance of commercial methane sensors and ZnO methane sensors made by.The response linearity in the interval is relatively good,and the response value for 10000×10^(-6) methane reaches 30.The response of our fabricated sensor is higher than those of existing domestic and foreign commercial methane sensors,showing significant potential in related applications.