Preparation of piezoelectric ZnO thin films by target-facing-type sputtering method

✍ Scribed by Ken-ya Hashimoto; Syotaro Ogawa; Akinori Nonoguchi; Tatsuya Omori; Masatsune Yamaguchi

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 231 KB
• Volume: 84
• Category: Article
• ISSN: 8756-663X
• DOI: 10.1002/1520-6432(200101)84:1<48::aid-ecjb6>3.0.co;2-3

✦ Synopsis

This paper describes the deposition of high-quality zinc oxide (ZnO) thin film by reactive dc target-facing-type sputtering (DC-TFTS) using an arc killer that periodically applies a positive pulse to the negative dc discharge current. High-speed deposition of high-quality thin film, which is a merit of TFTS, is possible because this method can neutralize the electric charge on the target surface without degrading the plasma convergence. The relationship of the crystallographic and ultrasonic characteristics of the thin films fabricated by this method was studied in detail, and the conditions for optimum sputtering were studied. Based on the conditions obtained, an excellent film was realized with a standard deviation of the c-axis orientation in the X-ray diffraction rocking curve of 0.22° and resistivity of 10 12 Wcm. We also fabricated a ZnO-glass composite structure surface acoustic wave delay line, evaluated its characteristics in detail, and demonstrated the effectiveness of the proposed method as a ZnO thin-film fabrication technique for high-frequency ultrasonic devices.