Determining Emission Lines for in situ Compositional Analysis of Sputter-deposited MgO Films Using Optical Emission Spectroscopy

• Published in: E-journal of surface science and nanotechnology Vol. 23; no. 1; pp. 29 - 35
• Main Author: Imashuku, Susumu
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Society of Vacuum and Surface Science 01.03.2025; 公益社団法人 日本表面真空学会; Japan Science and Technology Agency
• Subjects: Composition; In situ analysis; Magnesium oxide; Metal oxide film; Metal oxides; MgO; Optical emission spectroscopy; Oxide coatings; Spectrum analysis; Sputter deposition; Zinc oxide
• ISSN: 1348-0391; 1348-0391
• DOI: 10.1380/ejssnt.2025-009

In situ elemental analysis is required to improve the yield and quality of sputter-deposited metal oxide films by detecting the films whose compositions are deviated from the required compositions. In this study, the author proposed a method to determine the MgO film composition by measuring the intensities of the Mg emission lines and O I 777.3 nm line during sputter deposition. Linearity (R2 value) between the emission intensity ratios of the Mg lines to the O I 777.3 nm line and Mg/O atomic ratio in the films was investigated. The Mg I 518.4 and 517.3 nm lines exhibited R2 values higher than 0.80, and showed the properties that (1) they did not overlap with other emission lines and (2) their intensities exhibited a dependence on the input power to the MgO target and chamber pressure, similar to that of the O I 777.3 nm line, which were consistent with the properties of the Zn emission lines that can accurately determine the ZnO films compositions. Therefore, searching emission lines that satisfy the two properties is a powerful approach for the in situ elemental analysis of sputter-deposited metal oxide films.