【作者】 李振宇；

【导师】 周治平；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 以硅为主要材料（包括二氧化硅、氮化硅等）的微环谐振腔是一类非常重要的光学器件。微环谐振腔具有较高的品质因数,由此能够获得较高的灵敏度和较低的探测极限。同时,微环谐振腔的制作工艺与当前的微电子工艺完全兼容,使其可以实现大批量生产,降低成本。此外,它还具有尺寸小、易于集成等优点。本文就是利用微环谐振腔的上述优点,将其用于生物传感,初步实现免标记生物检测。本文在国家自然科学基金的资助下,对基于微环谐振腔的免标记生物传感器进行了研究,获得了以下成果:在理论上,本文重点对单直波导微环谐振腔的工作原理、耦合模型进行了研究;给出了自耦合因子和传输因子越接近1时,场增强因子越大的物理解释;用耦合相位模型解释了临界耦合时,直波导输出端的光功率为零的现象。在制作工艺上,对光刻、刻蚀等微电子工艺进行了学习与掌握。通过实验摸索,对工艺参数与器件性能之间的关系有了较好的理解。通过优化工艺参数,制作了具有较小表面粗糙度和较好侧壁垂直度的微环谐振器。由于器件尺寸在微纳米量级,使得对器件性能的测试有别于一般的光学测试。为此,构建了高精度的光学测试平台,并建立了完善的测试流程。在此过程中,解决了红外CCD聚焦的问题,提出了快速确定器件谐振特性的方法。通过测试,获得了器件的特征参数,其品质因数可达25000以上。用不同浓度的乙醇溶液进行测试,获得了器件对溶液折射率的探测灵敏度（108.9336nm/RIU）和探测极限(1.836×10^-4RIU)。用不同浓度的单链DNA分子进行测试,实验结果表明,器件能够检测出nmol/L的分子溶液的浓度变化。更多还原

【Abstract】 Due to its naturally high Q factor, microring resonator has become an important optical sensing device with high sensitivity and low detection limit. The microring resonator is based on silicon, SiO2 and Si3N4 materials and can be realized with high-mass production and low costs because its fabrication process is fully compatible with the micro-electronics processing technology. In addition, it has other advantages such as small size, easy integration and so on. With its unique sensing mechanism, it can be used as biosensor to realize label-free detection.Supported by National Natural Science Fund, microring resonator based label-free biosensor is studied and following results are obtained:Theory of operating principle, coupling model of microring resonator coupled with single straight waveguide is studied. Physical interpretation is given on the phenomenon that field enhancement factor becomes larger as self-coupling factor and transmission factor getting close to 1; coupling phase model is used to explain the zero output optical power from straight waveguide on critical coupling condition.Micro-electronic technology such as lithography, etching are studied. By optimization of process parameters, microring resonator with small surface roughness and vertical sidewall is obtained.High-precision optical testing platform is set up to satisfy the requirement of device testing which is different from traditional optical testing platform due to the small size of device. Comprehensive testing procedure is established. In the process, problem of focusing infrared CCD is solved and method to quickly determine the resonant characteristics of device is proposed.Performance of device is measured, which shows quality factor up to 25,000. Detection sensitivity of 108.9336nm/RIU and detection limit of 1.836×10^-4RIU are demonstrated by using various concentrations of ethanol solution as analytes. With different concentrations of single-stranded DNA molecules solution for testing, experimental results show that the device can detect concentration changes of nmol/L.更多还原