Novel AlN/Pt/ZnO Electrode for High Temperature SAW Sensors

Xingpeng Liu; Bin Peng; Wanli Zhang; Jun Zhu; Xingzhao Liu; Meng Wei

doi:10.3390/ma10010069

Novel AlN/Pt/ZnO Electrode for High Temperature SAW Sensors

Materials (Basel). 2017 Jan 16;10(1):69. doi: 10.3390/ma10010069.

Authors

Xingpeng Liu¹, Bin Peng², Wanli Zhang³, Jun Zhu⁴, Xingzhao Liu⁵, Meng Wei⁶

Affiliations

¹ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. tadyliu@outlook.com.
² State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. bpeng@uestc.edu.cn.
³ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. wlzhang@uestc.edu.cn.
⁴ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. junzhu@uestc.edu.cn.
⁵ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. xzliu@uestc.edu.cn.
⁶ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. wm2lzx1314@hotmail.com.

Abstract

In order to develop a film electrode for the surface acoustic wave (SAW) devices working in high temperature, harsh environments, novel AlN/Pt/ZnO multilayers were prepared using pulsed laser deposition (PLD) systems on langasite (LGS) substrates. The AlN film was used as a protective layer and the ZnO buffer layer was introduced to improve the crystal quality of Pt films. The results show that the resistances of Pt and AlN/Pt film electrodes violently increase above 600 °C and 800 °C, respectively, while the resistances of AlN/Pt/ZnO electrodes have more stable electrical resistance from room temperature to 1000 °C. The AlN/Pt/ZnO electrode, where the ZnO film was deposited at 600 °C, has the best temperature stability and can steadily work for 4 h at 1000 °C. The mechanism underlying the stable resistance of the AlN/Pt/ZnO electrode at a high temperature was investigated by analyzing the microstructure of the prepared samples. The proposed AlN/Pt/ZnO film electrode has great potential for applications in high temperature SAW sensors.

Keywords: SAW sensor; electrical resistance; high temperature electrode; langasite.