新型薄膜体声波谐振器（FBAR）技术研究

发布时间：2018-05-01 02:15

本文选题：薄膜体声波谐振器(FBAR) + 石墨烯　；参考：《浙江大学》2017年硕士论文

【摘要】：近些年来,新兴消费电子的巨大需求带动了基于半导体微纳加工技术的MEMS产业的蓬勃发展,薄膜体声波谐振器(FBAR)作为MEMS领域增长飞快的产品正在受到广泛的关注与研究。FBAR具有尺寸小(μm级)、谐振频率高(GHz)、品质因数高(1000)、功率容量大、滚降效应好等优良特性,其滤波器正在逐步取代传统的声表面波(SAW)滤波器和陶瓷滤波器,在无线通信射频领域发挥巨大作用,其高灵敏度的优势也能应用到生物、物理、医学等传感领域。本文基于FBAR的基本结构,优化了背刻蚀型FBAR的工艺流程,以石墨烯作为电极制备新型的FBAR,器件具有优异的谐振性能,并以PI为基底制备了 FBAR磁性传感器,还在柔性玻璃上实现了 FBAR的柔性透明化。主要的研究内容和成果如下:1、研究了背刻蚀FBAR的工艺与不同器件结构。在硅基底上制备了高c轴生长的氧化锌薄膜,表征其薄膜质量,优化刻蚀工艺提高了 FBAR背刻蚀器件的成品率。在薄氧化硅的硅片上制备了金为电极的FBAR器件,通过优化电极形状提升了器件性能,所制备的FBAR器件谐振频率为1.672GHz,Q值优化到1672的超高值。同时在厚氧化硅硅片上制备了铝为电极的FBAR器件,与薄氧化层器件相比具有谐振性能较好的两个谐振峰。2、制备了基于石墨烯电极的FBAR。进行理论仿真分析了石墨烯电极的优势。在背刻蚀器件的基础上,将上电极替换为石墨烯,优化转移工艺与制备流程,实现了多层石墨烯及石墨片作为FBAR电极的新型器件结构,其中6-8层石墨烯器件谐振频率1.277GHz,Q值高达650,优于铝电极器件,石墨片器件谐振频率1.398GHz,Q值为350,与ITO为电极的器件性能相当。3、获得了 PI型的磁性FBAR传感器。运用COMSOL有限元仿真验证了 PI型FBAR的理论可能性,实验中用镍为电极制备了 FBAR磁性传感器,其在磁场下谐振频率有7kHz左右的上升,提出了磁致伸缩的传感机理并通过Mason模型进行ADS电路仿真加以验证。4、以willow glass为衬底制备了柔性透明FBAR。研究了在柔性玻璃上的FBAR制备工艺,制备的器件在弯曲后仍有谐振性能,谐振频率为1.77GHz,Q值为443,优于PET与纸衬底的柔性FBAR性能,在施加压力下,谐振频率会有1MHz左右的较大偏移。
[Abstract]:In recent years, the huge demand of emerging consumer electronics has led to the vigorous development of the MEMS industry based on semiconductor micro-nano processing technology. Thin film bulk acoustic resonator (FBA), as a rapidly growing product in the field of MEMS, is receiving extensive attention and research. FBAR is characterized by its small size (渭 m level), high resonant frequency, high quality factor, high power capacity, good rolling effect and so on. Its filters are gradually replacing the traditional saw filters and ceramic filters, which play a great role in the radio frequency field of wireless communication. Its high sensitivity advantages can also be applied to the biological, physical, medical and other sensing fields. In this paper, based on the basic structure of FBAR, the process of back etching FBAR is optimized. The novel FBAR is fabricated with graphene as the electrode. The device has excellent resonance performance, and the FBAR magnetic sensor is fabricated on Pi substrate. The flexible transparency of FBAR is also realized on the flexible glass. The main research contents and results are as follows: 1. The technology and structure of FBAR are studied. Zinc oxide thin films with high c-axis growth were prepared on silicon substrates. The quality of ZnO films was characterized and the yield of FBAR back etching devices was improved by optimizing the etching process. Gold electrode FBAR devices were fabricated on silicon wafers with thin silicon oxide. By optimizing the electrode shape, the device performance was improved. The resonant frequency of the fabricated FBAR devices was optimized to a high value of 1672, with a resonant frequency of 1.672 GHz. At the same time, FBAR devices with aluminum as electrode were fabricated on thick silicon oxide wafer. Compared with thin oxide devices, there were two resonance peaks of the devices with better resonance performance. FBA based on graphene electrode was prepared. The advantage of graphene electrode was analyzed by theoretical simulation. On the basis of the back etching device, the upper electrode was replaced with graphene, and the transfer process and preparation process were optimized. The multilayer graphene and graphite sheet were realized as the new device structure of FBAR electrode. The resonant frequency of 6-8 layer graphene device is as high as 650, which is higher than that of aluminum electrode device. The resonant frequency of graphite chip device is 350, which is equivalent to that of ITO. A Pi type magnetic FBAR sensor is obtained. The theoretical possibility of Pi type FBAR is verified by COMSOL finite element simulation. In the experiment, the FBAR magnetic sensor is fabricated with nickel electrode. The resonance frequency of the sensor increases with the increase of 7kHz in the magnetic field. The sensing mechanism of magnetostriction is proposed and verified by ADS circuit simulation with Mason model. The flexible transparent FBA is fabricated on willow glass substrate. The fabrication process of FBAR on flexible glass is studied. The resonant frequency is 1.77 GHz / Q = 443, which is superior to the flexible FBAR performance of PET and paper substrate. Under the applied pressure, the resonant frequency of the device has a large deviation of 1MHz or so.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN751.2

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