海洋温盐深高精度测量集成微纳传感器制备及测试

Fabrication and test of integrated micro-nano sensors for high precision measurement of ocean temperature-salinity-depth

海洋传感器技术在海洋军事作战领域发挥着重要的作用,随着人类探索海洋的未知领域,海洋传感器技术逐渐发展,但现阶段发展不完全,主要依赖进口,国产化率低.海水的温度、盐度、深度(温盐深)是海洋环境测量的基本参数,目前国内温盐深三参数传感器体积大、设备复杂、集成度低,难以满足实时在线检测的需求.本文基于微机电系统(MEMS)技术,制备了一批用于海洋温度、电导率和压力检测的温盐深集成微纳传感器,其中温度测量采用PT8000铂电阻传感器,盐度测量采用四电极法电导率传感器,深度测量采用压阻式压力传感器,通过离子注入工艺控制掺杂浓度形成压力敏感电阻,硅片下表面经过湿法腐蚀工艺形成压力形变所需的空间,最后键合硅片和玻璃制备出压力传感器,三参数传感器的制备工艺全兼容,具有较高的批量一致性.对于压力传感器,利用COMSOL仿真软件确定合适的传感器参数,得到0∼10 MPa下的宽范围量程,以满足1000 m水深检测的需求.利用嵌入式系统原理开发了针对制备的温盐深传感器的采样和读出电路,其中温度传感器的电阻为8231±100Ω,灵敏度为32.101Ω/℃,测量准确度达到±0.01℃;电导率传感器的电导池参数为2.594 cm^(−1),测量准确度为±0.05 mS/cm,与温度传感器联合测量消除了温度对电导率的影响;压力传感器的压敏区域构成了惠斯通(Wheatstone)电桥模型,消除了温度对压敏电阻的影响,采用矩形形变膜片,提高了压力线性度,传感器的测量准确度达到0.01 MPa,非线性误差为0.366%,重复性误差为0.376%,迟滞性误差为0.188%.结果表明,本文制备的温盐深传感器精度高、尺寸小、集成度高、可批量制造,适用于海洋温盐深参数精确定点测量的需求.

Ocean sensor technologies play important roles in the analysis of seawater properties.They have been used in the exploration of unknown ocean areas;ocean temperature-salinity-depth are basic parameters in marine environment measurements.Presently,Chinese researchers mainly rely on imported ocean sensors;the locally available three-parameter sensors for ocean temperature-salinity-depth are bulky,complex,and difficult to use;therefore,they do not meet the needs of realtime and online analysis.In this paper,a number of integrated nanoand microsensors for temperature-salinity-depth were prepared using micro-electromechanical systems(MEMS)technology for the determination of ocean temperature,conductivity,and pressure.The developed PT8000 platinum resistance,four-electrode conductivity,and piezoresistive pressure sensors were used for the determination of temperature,salinity,and depth.The doping concentration was controlled by an ion implantation process to form a pressure-sensitive resistant sensor.The space required for pressure deformation was formed on the lower surface of a silicon wafer by a wet etching process.Finally,the pressure sensor was fabricated by bonding a silicon wafer and glass.The preparation process of the proposed three-parameter sensor was fully compatible with highly acceptable batch consistency.For the pressure sensor,COMSOL simulation software was used to determine the appropriate sensor parameters,which are applicable for a wide range of pressures(i.e.,0–10 MPa)and water depth of 1000 m during measurements.Based on the principle of an integrated system,the sampling and readout circuit for both the temperature-salinity-depth sensors were developed.The resistance of the temperature sensor was 8231±100Ω with sensitivity and measurement accuracy of 32.101Ω/℃ and ±0.01℃,respectively.The conductivity cell parameter and measurement accuracy of the conductivity sensor were 2.594 cm^(−1) and ±0.05 mS/cm,respectively.Meanwhile,the pressure-sensitive area of the pressure sensor utilized a Wheatstone bridge model,which eliminated the influence of temperature on the varistor.Additionally,the rectangular deformation diaphragm was used to improve the pressure linearity.The measurement accuracy of the sensor reached 0.01 MPa with nonlinear,repeatability,and hysteresis errors of 0.366%,0.376%,and 0.188%,respectively.The proposed small-sized and integrated sensor showed high precision and can be easily manufactured in batches.Furthermore,the proposed sensor meets the requirements for realtime measurements of ocean temperature-salinitydepth.