Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates
Ti-Al thin films with a thickness of 200 nm were prepared either by co-sputtering from elemental Ti and Al targets or as Ti/Al multilayers with 10 and 20 nm individual layer thickness on thermally oxidized Si substrates. Some of the films were covered with a 20-nm-thick SiO<inline-formula> <...
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2020-04-01
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| Online Access: | https://www.mdpi.com/1996-1944/13/9/2039 |
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| author | Marietta Seifert Eric Lattner Siegfried B. Menzel Steffen Oswald Thomas Gemming |
| author_facet | Marietta Seifert Eric Lattner Siegfried B. Menzel Steffen Oswald Thomas Gemming |
| author_sort | Marietta Seifert |
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| description | Ti-Al thin films with a thickness of 200 nm were prepared either by co-sputtering from elemental Ti and Al targets or as Ti/Al multilayers with 10 and 20 nm individual layer thickness on thermally oxidized Si substrates. Some of the films were covered with a 20-nm-thick SiO<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>2</mn> </msub> </semantics> </math> </inline-formula> layer, which was used as an oxidation protection against the ambient atmosphere. The films were annealed at up to 800 °C in high vacuum for 10 h, and the phase formation as well as the film architecture was analyzed by X-ray diffraction, cross section, and transmission electron microscopy, as well as Auger electron and X-ray photoelectron spectroscopy. The results reveal that the co-sputtered films remained amorphous after annealing at 600 °C independent on the presence of the SiO<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>2</mn> </msub> </semantics> </math> </inline-formula> cover layer. In contrast to this, the <inline-formula> <math display="inline"> <semantics> <mi>γ</mi> </semantics> </math> </inline-formula>-TiAl phase was formed in the multilayer films at this temperature. After annealing at 800 °C, all films were degraded completely despite the presence of the cover layer. In addition, a strong chemical reaction between the Ti and SiO<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>2</mn> </msub> </semantics> </math> </inline-formula> of the cover layer and the substrate took place, resulting in the formation of Ti silicide. In the multilayer samples, this reaction already started at 600 °C. |
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| language | English |
| last_indexed | 2024-03-10T20:11:04Z |
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| spelling | doaj.art-0e83a17a2e5845a0873a32fad7b82a102023-11-19T22:52:57ZengMDPI AGMaterials1996-19442020-04-01139203910.3390/ma13092039Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si SubstratesMarietta Seifert0Eric Lattner1Siegfried B. Menzel2Steffen Oswald3Thomas Gemming4Leibniz IFW Dresden, Helmholtzstraße 20, 01069 Dresden, GermanyLeibniz IFW Dresden, Helmholtzstraße 20, 01069 Dresden, GermanyLeibniz IFW Dresden, Helmholtzstraße 20, 01069 Dresden, GermanyLeibniz IFW Dresden, Helmholtzstraße 20, 01069 Dresden, GermanyLeibniz IFW Dresden, Helmholtzstraße 20, 01069 Dresden, GermanyTi-Al thin films with a thickness of 200 nm were prepared either by co-sputtering from elemental Ti and Al targets or as Ti/Al multilayers with 10 and 20 nm individual layer thickness on thermally oxidized Si substrates. Some of the films were covered with a 20-nm-thick SiO<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>2</mn> </msub> </semantics> </math> </inline-formula> layer, which was used as an oxidation protection against the ambient atmosphere. The films were annealed at up to 800 °C in high vacuum for 10 h, and the phase formation as well as the film architecture was analyzed by X-ray diffraction, cross section, and transmission electron microscopy, as well as Auger electron and X-ray photoelectron spectroscopy. The results reveal that the co-sputtered films remained amorphous after annealing at 600 °C independent on the presence of the SiO<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>2</mn> </msub> </semantics> </math> </inline-formula> cover layer. In contrast to this, the <inline-formula> <math display="inline"> <semantics> <mi>γ</mi> </semantics> </math> </inline-formula>-TiAl phase was formed in the multilayer films at this temperature. After annealing at 800 °C, all films were degraded completely despite the presence of the cover layer. In addition, a strong chemical reaction between the Ti and SiO<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mn>2</mn> </msub> </semantics> </math> </inline-formula> of the cover layer and the substrate took place, resulting in the formation of Ti silicide. In the multilayer samples, this reaction already started at 600 °C.https://www.mdpi.com/1996-1944/13/9/2039TiAlthin filmssurface acoustic waveshigh-temperature stabilityphase formation |
| spellingShingle | Marietta Seifert Eric Lattner Siegfried B. Menzel Steffen Oswald Thomas Gemming Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates Materials TiAl thin films surface acoustic waves high-temperature stability phase formation |
| title | Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates |
| title_full | Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates |
| title_fullStr | Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates |
| title_full_unstemmed | Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates |
| title_short | Phase Formation and High-Temperature Stability of Very Thin Co-Sputtered Ti-Al and Multilayered Ti/Al Films on Thermally Oxidized Si Substrates |
| title_sort | phase formation and high temperature stability of very thin co sputtered ti al and multilayered ti al films on thermally oxidized si substrates |
| topic | TiAl thin films surface acoustic waves high-temperature stability phase formation |
| url | https://www.mdpi.com/1996-1944/13/9/2039 |
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