State Key Laboratory of Precision Measuring Technology & Instruments, College of Precision Instrument and Optoelectronics Engineering, Tianjin University , Tianjin 300072, China.
ACS Appl Mater Interfaces. 2015 Jan 14;7(1):950-8. doi: 10.1021/am507640g. Epub 2014 Dec 22.
In this work, a new method to tune the resonant frequency of microfabricated resonator using molecular layer-by-layer (LbL) self-assembly approach is demonstrated. By simply controlling the polymer concentration and the number of layers deposited, precisely tuning the frequency of microfabricated resonators is realized. Due to its selective deposition through specific molecular recognitions, such technique avoids the high-cost and complex steps of conventional semiconductor fabrications and is able to tune individual diced device. Briefly, film bulk acoustic resonator (FBAR) is used to demonstrate the tuning process and two types of LbL deposition methods are compared. The film thickness and morphology have been characterized by UV-vis reflection spectra, ellipsometer and AFM. As a result, the maximum resonant frequency shift of FBAR reaches more than 20 MHz, meaning 1.4% tunability at least. The minimum frequency shift is nearly 10 kHZ per bilayer, indicating 7 ppm tuning resolution. Pressure cooker test (PCT) is performed to evaluate the reliability of LbL coated FBAR. Furthermore, applications for wireless broadband communication and chemical sensors of LbL coated FBAR have been demonstrated.
在这项工作中，展示了一种使用分子层层自组装方法来调整微制造谐振器的谐振频率的新方法。通过简单地控制聚合物浓度和沉积的层数，可以精确地调整微制造谐振器的频率。由于其通过特定分子识别进行选择性沉积，因此该技术避免了传统半导体制造的高成本和复杂步骤，并且能够调整单个切割器件。简而言之，薄膜体声波谐振器（FBAR）用于演示调谐过程，并比较了两种类型的 LbL 沉积方法。通过紫外-可见反射光谱、椭偏仪和 AFM 对薄膜厚度和形貌进行了表征。结果表明，FBAR 的最大谐振频率偏移超过 20 MHz，这意味着至少有 1.4%的调谐性。最小频率偏移接近每双层 10 kHz，表明调谐分辨率为 7 ppm。进行压力蒸煮器测试（PCT）以评估 LbL 涂层 FBAR 的可靠性。此外，还展示了 LbL 涂层 FBAR 在无线宽带通信和化学传感器中的应用。
