AVS 45th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoP

Paper TF-MoP17
Characterization of YSZ(Yttria-Stabilized Zirconia) Thin Films Prepared by RF-Magnetron Sputtering for Oxygen Gas Sensor

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Thin Films Poster Session
Presenter: J.W. Bae, Sungkyunkwan University, Korea
Authors: J.W. Bae, Sungkyunkwan University, Korea
J.Y. Park, Sungkyunkwan University, Korea
G.Y. Yeom, Sungkyunkwan University, Korea
K.D. Kim, Korea Gas Corporation
Y.A. Cho, Korea Gas Corporation
J.S. Jeon, Korea Gas Corporation
D.S. Choi, Korea Gas Corporation
Correspondent: Click to Email
Yttria-stabilized zirconia(YSZ), a well known oxygen ion conductor, is one of the many solid state ionic materials utilized in the variety of electrochemical devices including fuel cells, oxygen pumps, and chemical gas sensors. Commercial YSZ oxygen gas sensors rely on the traditional bulk ceramic fabrication and require temperatures above 600 @degree@C to achieve sufficient ionic conductivity. However, if the YSZ could be applied as a thin film, it would offer many advantages including compact dimensions with smaller power consumption, reduced ohmic losses, and lower operating temperatures. In this experiment, yttria-stabilized zirconia(YSZ) films(0.5­1.5µm) were deposited on Pt/NiO-Ni mixed reference layer/SiO@sub 2@ substrates to characterize films properties using an RF-magnetron sputter deposition system and zirconia stabilized with 8mol% yttria(Y@sub 2@O@sub 3@) was used as a sputter target. The plasma atmospheres were pure Ar or mixtures of Ar and O@sub 2@. We employed X-ray diffraction to study the structure of YSZ films and scanning electron microscopy(SEM) to examine the film surface morphologies. Analyses by Auger electron spectroscopy(AES) and X-ray photoelectron spectroscopy(XPS) were performed to examine Zr, Y, and oxygen compositions in YSZ thin films and the uniformity in compositions. Transmission electron microscopy(TEM) was employed to examine the microstructural details and crystallography of the films. Gas-sensing test was carried out for Pt/YSZ/Pt/NiO-Ni/SiO@sub 2@ film structures exposed to an atmosphere of oxygen controlled composition. The deposition rates of YSZ thin films increased with increasing rf power and total pressure, and decreased with increasing O@sub 2@ concentration. The preferred orientation of deposited YSZ films changed from (111) to (220) with increasing thickness. O/Zr ratio analyzed by XPS was increased from 1.94 to 2.4 with increasing O@sub 2@/(Ar+O@sub 2@) ratio. But yttria atomic percentage in the YSZ films were not changed. More detailed physical and chemical characteristics of YSZ thin films and their relations to gas-sensing properties will be discussed in the presentation.