High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD
The gas sensitivity and structural properties of TiO<sub>2</sub> thin films deposited by plasma-enhanced atomic layer deposition (ALD) were examined in detail. The TiO<sub>2</sub> thin films are deposited using Tetrakis(dimethylamido)titanium(IV) and oxygen plasma at 300 °C o...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/14/10/1875 |
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| author | Aleksei V. Almaev Nikita N. Yakovlev Dmitry A. Almaev Maksim G. Verkholetov Grigory A. Rudakov Kristina I. Litvinova |
| author_facet | Aleksei V. Almaev Nikita N. Yakovlev Dmitry A. Almaev Maksim G. Verkholetov Grigory A. Rudakov Kristina I. Litvinova |
| author_sort | Aleksei V. Almaev |
| collection | DOAJ |
| description | The gas sensitivity and structural properties of TiO<sub>2</sub> thin films deposited by plasma-enhanced atomic layer deposition (ALD) were examined in detail. The TiO<sub>2</sub> thin films are deposited using Tetrakis(dimethylamido)titanium(IV) and oxygen plasma at 300 °C on SiO<sub>2</sub> substrates followed by annealing at temperatures of 800 °C. Gas sensitivity under exposure to O<sub>2</sub> within the temperature range from 30 °C to 700 °C was studied. The ALD-deposited TiO<sub>2</sub> thin films demonstrated high responses to O<sub>2</sub> in the dynamic range from 0.1 to 100 vol. % and low concentrations of H<sub>2</sub>, NO<sub>2</sub>. The ALD deposition allowed the enhancement of sensitivity of TiO<sub>2</sub> thin films to gases. The greatest response of TiO<sub>2</sub> thin films to O<sub>2</sub> was observed at a temperature of 500 °C and was 41.5 arb. un. under exposure to 10 vol. % of O<sub>2</sub>. The responses of TiO<sub>2</sub> thin films to 0.1 vol. % of H<sub>2</sub> and 7 × 10<sup>–4</sup> vol. % of NO<sub>2</sub> at a temperature of 500 °C were 10.49 arb. un. and 10.79 arb. un., correspondingly. The resistance of the films increased due to the chemisorption of oxygen molecules on their surface that decreased the thickness of the conduction channel between the metal contacts. It was suggested that there are two types of adsorption centers on the TiO<sub>2</sub> thin films surface: oxygen is chemisorbed in the form of O<sup>2–</sup> on the first one and O<sup>–</sup> on the second one. |
| first_indexed | 2024-03-10T21:02:18Z |
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| id | doaj.art-1b8aedb470ef4bc6beea055e84203124 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T21:02:18Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
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| series | Micromachines |
| spelling | doaj.art-1b8aedb470ef4bc6beea055e842031242023-11-19T17:24:07ZengMDPI AGMicromachines2072-666X2023-09-011410187510.3390/mi14101875High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALDAleksei V. Almaev0Nikita N. Yakovlev1Dmitry A. Almaev2Maksim G. Verkholetov3Grigory A. Rudakov4Kristina I. Litvinova5Research and Development Center for Advanced Technologies in Microelectronics, National Research Tomsk State University, 634050 Tomsk, RussiaResearch and Development Center for Advanced Technologies in Microelectronics, National Research Tomsk State University, 634050 Tomsk, RussiaResearch and Development Center for Advanced Technologies in Microelectronics, National Research Tomsk State University, 634050 Tomsk, RussiaResearch and Development Center for Advanced Technologies in Microelectronics, National Research Tomsk State University, 634050 Tomsk, RussiaInstitute of Nanotechnology of Microelectronics of the Russian Academy of Sciences, 119991 Moscow, RussiaInstitute of Nanotechnology of Microelectronics of the Russian Academy of Sciences, 119991 Moscow, RussiaThe gas sensitivity and structural properties of TiO<sub>2</sub> thin films deposited by plasma-enhanced atomic layer deposition (ALD) were examined in detail. The TiO<sub>2</sub> thin films are deposited using Tetrakis(dimethylamido)titanium(IV) and oxygen plasma at 300 °C on SiO<sub>2</sub> substrates followed by annealing at temperatures of 800 °C. Gas sensitivity under exposure to O<sub>2</sub> within the temperature range from 30 °C to 700 °C was studied. The ALD-deposited TiO<sub>2</sub> thin films demonstrated high responses to O<sub>2</sub> in the dynamic range from 0.1 to 100 vol. % and low concentrations of H<sub>2</sub>, NO<sub>2</sub>. The ALD deposition allowed the enhancement of sensitivity of TiO<sub>2</sub> thin films to gases. The greatest response of TiO<sub>2</sub> thin films to O<sub>2</sub> was observed at a temperature of 500 °C and was 41.5 arb. un. under exposure to 10 vol. % of O<sub>2</sub>. The responses of TiO<sub>2</sub> thin films to 0.1 vol. % of H<sub>2</sub> and 7 × 10<sup>–4</sup> vol. % of NO<sub>2</sub> at a temperature of 500 °C were 10.49 arb. un. and 10.79 arb. un., correspondingly. The resistance of the films increased due to the chemisorption of oxygen molecules on their surface that decreased the thickness of the conduction channel between the metal contacts. It was suggested that there are two types of adsorption centers on the TiO<sub>2</sub> thin films surface: oxygen is chemisorbed in the form of O<sup>2–</sup> on the first one and O<sup>–</sup> on the second one.https://www.mdpi.com/2072-666X/14/10/1875TiO<sub>2</sub> filmsatomic layer depositiongas-sensitive propertiesoxygen sensorssensory effect |
| spellingShingle | Aleksei V. Almaev Nikita N. Yakovlev Dmitry A. Almaev Maksim G. Verkholetov Grigory A. Rudakov Kristina I. Litvinova High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD Micromachines TiO<sub>2</sub> films atomic layer deposition gas-sensitive properties oxygen sensors sensory effect |
| title | High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD |
| title_full | High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD |
| title_fullStr | High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD |
| title_full_unstemmed | High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD |
| title_short | High Oxygen Sensitivity of TiO<sub>2</sub> Thin Films Deposited by ALD |
| title_sort | high oxygen sensitivity of tio sub 2 sub thin films deposited by ald |
| topic | TiO<sub>2</sub> films atomic layer deposition gas-sensitive properties oxygen sensors sensory effect |
| url | https://www.mdpi.com/2072-666X/14/10/1875 |
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