新型声波谐振器及其传感应用研究

发布时间：2018-02-28 18:35

  本文关键词： 氧化锌 柔性器件 声表面波 薄膜体声波谐振器 传感器　出处：《浙江大学》2015年博士论文　论文类型：学位论文

【摘要】：得益于材料科学和先进微纳米加工工艺的进步,近年来柔性电子发展迅速。柔性电子不仅弥补了传统固体电子的不足,同时其也是电子学一个新兴的重要分支,有助于拓展整个电子学的应用范围。学术界陆续报导了许多柔性电子的应用,但目前为止,有关柔性微机电系统一(MEMS)的报导还很少。在众多的MEMS器件中,声表面波(SAW)器件是最简单的一种MEMS器件,它与另一类MEMS器件一薄膜体声波谐振器(FBAR)一起,常用作传感器来使用。本文研究了在柔性聚酰亚胺(PI)和聚对苯二甲酸乙二酯(PET)上通过磁控溅射方法沉积具有大晶粒尺寸且具有良好(0002)晶体取向的ZnO薄膜的制备方法,研究了该种ZnO薄膜的特性。并成功地在ZnO/PI和ZnO/PET复合基板上制备出高性能的柔性SAW器件。所制备的柔性SAW器件具有两个主要的谐振模态,分别对应于广义兰姆波(Lamb Wave)的0阶对称和反对称模态。论文探讨了ZnO薄膜厚度、器件波长和叉指电极间距对这种柔性器件的影响。由于制备在柔性基板上,该种器件可以弯折,在最大应变量为2500με的情况下,其可弯曲次数超过100次,这表面该种器件可作为柔性器件来使用。同时本文还研究了这种器件在温度、湿度、紫外光和应变传感等领域的应用,器件对这些外部参数反应敏感,其特性不逊于类似的固体基板上的SAW传感器。初步揭示了柔性SAW器件在传感领域的应用前景。本文还研究了另一类高频声波器件FBAR,所研究的FBAR器件制备于硅衬底上,采用体硅背面刻蚀型结构。由于使用Si02作为支撑层,所制备的器件呈现两个主要的谐振频率。在这一基板结构的基础上,本文提出一种带密封腔的新型FBAR压强传感器结构,这主要通过用硅片密封器件背面沟槽来实现。本文研究了这种带密封腔的FBAR传感器在不同温度和压强下的响应,其两个谐振频率随温度和压强变化呈线性变化。这说明可以使用单一FBAR器件来同时测量温度和压强。这种双模态FBAR器件结构简单、造价低廉且无需特殊封装,具有广泛的应用前景。
[Abstract]:Thanks to the progress of material science and advanced micro-nano processing technology, flexible electrons have developed rapidly in recent years. Flexible electrons not only make up for the shortcomings of traditional solid electrons, but also become an important branch of electronics. The academic circles have reported many applications of flexible electronics, but so far, there are few reports on flexible MEMS applications. Among many MEMS devices, Surface acoustic wave (saw) devices are one of the simplest MEMS devices, along with the thin film bulk acoustic resonator (FBA), another kind of MEMS device. ZnO thin films with large grain size and good crystal orientation have been deposited on flexible polyimide (Pi) and poly (ethylene terephthalate) (PET) by magnetron sputtering. The characteristics of the ZnO thin film are studied, and the high performance flexible SAW devices are successfully fabricated on the ZnO/PI and ZnO/PET composite substrates. The fabricated flexible SAW devices have two main resonant modes. The effects of the thickness of ZnO film, the wavelength of the device and the interDigital electrode spacing on this kind of flexible device are discussed in this paper. The device can be bent because it is fabricated on a flexible substrate, which corresponds to the 0-order symmetric and antisymmetric modes of the generalized Lamb wave wave, and the effect of the thickness of the ZnO film, the wavelength of the device and the interDigital electrode spacing on the device is discussed. When the maximum strain is 2500 渭 蔚, the number of bending is more than 100 times. The device can be used as a flexible device on this surface. The applications of the device in temperature, humidity, ultraviolet light and strain sensing are also studied in this paper. The device is sensitive to these external parameters, Its characteristics are not inferior to those of SAW sensors on similar solid substrates. The application prospects of flexible SAW devices in the field of sensing are preliminarily revealed. Another kind of high frequency acoustic devices, FBA, is studied in this paper. The FBAR devices studied are fabricated on silicon substrates. A novel FBAR pressure sensor structure with sealed cavity is proposed in this paper, which is based on the bulk silicon back etching structure. Because of the use of Si02 as the supporting layer, the fabricated device presents two main resonant frequencies, and based on the substrate structure, a new type of FBAR pressure sensor structure with sealed cavity is proposed in this paper. In this paper, the response of the FBAR sensor with seal cavity at different temperatures and pressures is studied. The two resonant frequencies vary linearly with temperature and pressure. This shows that a single FBAR device can be used to measure temperature and pressure simultaneously. This dual-mode FBAR device has simple structure, low cost and no special package. It has wide application prospect.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN65
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本文编号：1548464