Investigation of TiN thin film oxidation depending on the substrate temperature at vacuum break

• Published in: Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vol. 34; no. 5
• Main Authors: Piallat, Fabien, Gassilloud, Remy, Caubet, Pierre, Vallée, Christophe
• Format: Journal Article
• Language: English
• Published: United States 01-09-2016
• Subjects: ATMOSPHERES; CHEMICAL VAPOR DEPOSITION; ENGINEERING; LAYERS; OXIDATION; OXYGEN; SUBSTRATES; SURFACES; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0400-1000 K; THICKNESS; THIN FILMS; TITANIUM NITRIDES; X-RAY PHOTOELECTRON SPECTROSCOPY
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.4960648

Due to the reduction of the thickness of the layers used in the advanced technology nodes, there is a growing importance of the surface phenomena in the definition of the general properties of the materials. One of the least controlled and understood phenomenon is the oxidation of metals after deposition, at the vacuum break. In this study, the influence of the sample temperature at vacuum break on the oxidation level of TiN deposited by metalorganic chemical vapor deposition is investigated. TiN resistivity appears to be lower for samples which underwent vacuum break at high temperature. Using X-ray photoelectron spectrometry analysis, this change is correlated to the higher oxidation of the TiN layer. Moreover, angle resolved XPS analysis reveals that higher is the temperature at the vacuum break, higher is the surface oxidation of the sample. This surface oxidation is in turn limiting the diffusion of oxygen in the volume of the layer. Additionally, evolution of TiN layers resistivity was monitored in time and it shows that resistivity increases until a plateau is reached after about 10 days, with the lowest temperature at vacuum break resulting in the highest increase, i.e., the resistivity of the sample released to atmosphere at high temperature increased by a factor 1.7 whereas the resistivity of the sample cooled down under vacuum temperature increased by a factor 2.7.