Plasma parameter analysis of Ag sputter deposition using cathodes with different magnetic flux densities

• Published in: Vacuum Vol. 86; no. 10; pp. 1435 - 1439
• Main Authors: Kato, Kazuhiro, Omoto, Hideo, Takamatsu, Atsushi, Yonekura, Masaaki
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 27.04.2012
• Subjects: Cathodes; Density; Electrical resistivity; Electron density; Electron energy; Kinetic energy; Langmuir probe; Magnetic flux; Magnetic flux density; Magnetron sputtering; Silver; Thin film; Langmuir probe; Magnetic flux density; Magnetron sputtering; Ag; Thin film
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2012.02.007

The effects of the magnetic flux density of the Ag sputter target surface on plasma parameters were investigated using the Langmuir probe system in this work. It was found that the electron energy and electron density near the substrate clearly decreased at a high magnetic flux density. In addition, the difference between plasma potential and floating potential (Vp−Vf) decreased at the high magnetic flux density relative to the potentials at the low magnetic flux density. The changes in plasma parameters could be interpreted as the result of many electrons being trapped in the neighborhood of the target surface (cathode sheath) at the high magnetic flux density; hence, the number of electrons in the space near the substrate is reduced. The Ag thin films exhibited low resistivity at a high magnetic flux density. The reduction in resistivity was attributed to the following factors: the low electron energy and electron density near the substrate; the low kinetic energy of positive argon ions; the low kinetic energy of argon atoms backscattered onto the target surface. ► Effect of magnetic flux density of Ag sputter target on plasma parameters was studied. ► Langmuir probe system was used for the evaluation. ► The electron energy and density of plasma decreased using high magnetic flux density. ► The resistivity of Ag thin films decreased using high magnetic flux density. ► This resistivity improvement related to the plasma parameter changes.