Chu Sheng-Yuan, Water Walter, Liaw Jih-Tsang
Department of Electrical Engineering, National Cheng Kung University, 1 University Road, Tainan, Taiwan, ROC.
Ultrasonics. 2003 Mar;41(2):133-9. doi: 10.1016/s0041-624x(02)00430-4.
Love mode acoustic devices are very promising as biosensors in liquid environments because of their high sensitivity. An experimental study of Love mode sensors based on ZnO/90 degrees rotated ST-cut quartz structure with different sputtering conditions to deposit ZnO films is presented. In order to achieve sensor with higher sensitivity, the effects of sputtering substrate temperatures to deposit ZnO films on the sensitivity of viscosity and conductivity were investigated. Phase velocity, sensitivity and temperature coefficient of frequency (TCF) of Love wave devices have been studied. The Love wave sensor has higher sensitivity as sputtering ZnO films on the unheated substrate than that of on the heated substrate. The maximum sensitivity up to -18.77 x 10(-8) m(2) s kg(-1) of ZnO film with thickness of 1.8 microm for a wavelength of 40 microm is much bigger than SiO(2)/quartz structure. In this research, we report ZnO/90 degrees rotated ST-cut quartz structure of Love wave sensors with high sensitivity of viscosity and conductivity in liquid circumstance and TCF of quartz is compensated by ZnO film.
由于其高灵敏度，洛夫模声学器件作为液体环境中的生物传感器非常有前景。本文展示了基于具有不同溅射条件以沉积ZnO薄膜的ZnO/90度旋转ST切割石英结构的洛夫模传感器的实验研究。为了获得具有更高灵敏度的传感器，研究了溅射衬底温度对沉积ZnO薄膜的粘度和电导率灵敏度的影响。研究了洛夫波器件的相速度、灵敏度和频率温度系数（TCF）。与在加热衬底上溅射ZnO薄膜相比，洛夫波传感器在未加热衬底上溅射ZnO薄膜时具有更高的灵敏度。对于波长为40μm、厚度为1.8μm的ZnO薄膜，最大灵敏度高达-18.77×10⁻⁸ m² s kg⁻¹，远大于SiO₂/石英结构。在本研究中，我们报道了在液体环境中具有高粘度和电导率灵敏度且石英的TCF由ZnO薄膜补偿的洛夫波传感器的ZnO/90度旋转ST切割石英结构。
