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- Konofaos, N., et al.
(författare)
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Electrical characterisation of SrTiO3/Si interfaces
- 2002
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Ingår i: Journal of Non-Crystalline Solids. - 0022-3093 .- 1873-4812. ; 303:1, s. 185-189
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of SrTiO3 (STO) thin films by ultra-high vacuum rf magnetron sputtering was performed in order to produce high-quality STO/p-Si (1 0 0) interfaces and STO insulator layers with high dielectric constants. The deposition temperatures were in the range from room temperature to 550 °C. Capacitance-voltage (C-V) and conductance-frequency measurements showed that the dielectric constant of the films ranges from 55 to 120. C-V measurements on Al/STO/p-Si structures clearly revealed the creation of metal-insulator-semiconductor diodes. The interface state densities (Dit) at the STO/p-Si interfaces were obtained from admittance spectroscopy measurements. The samples deposited at lower temperatures revealed values of Dit between 2 × 1011 and 3.5 × 1012 eV-1 cm-2 while the higher temperature deposited samples had a higher Dit ranging between 1 × 1011 and 1 × 1013 eV-1 cm-2. The above results were also well correlated to X-ray diffraction measurements, Rutherford backscattering spectroscopy, and spectroscopic ellipsometry. © 2002 Elsevier Science Ltd. All rights reserved.
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| 2. |
- Konofaos, N., et al.
(författare)
-
Properties of Al-SrTiO3-ITO capacitors for microelectronic device applications
- 2004
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Ingår i: IEEE Transactions on Electron Devices. - 0018-9383 .- 1557-9646. ; 51:7, s. 1202-1205
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Tidskriftsartikel (refereegranskat)abstract
- Growth of SrTiO3 (STO) thin films on indium tin oxide (ITO) substrates took place by RF magnetron sputtering under various deposition conditions. Subsequent AI metallization created metal-insulator-metal (MIM) capacitors. The properties of such capacitors were investigated by means of structural and electrical measurements, revealing the films transparency, the dielectric constant, the switching time characteristics, and the trapped charges density. Dielectric constant values as high as 120 were obtained for low frequencies of around 2 kHz, the switching time was found to be 3.2 µs and the trapped charges were found equal to 2.9 nCcm-2. The results showed that the films were suitable for use in electronic devices where high capacitance is required and for potential applications in optical devices. © 2004 IEEE.
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| 3. |
- Wang, Z., et al.
(författare)
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Characteristics of SrTiO3 thin films deposited on Si by rf magnetron sputtering at various substrate temperatures
- 2002
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Ingår i: Philosophical Magazine B. - : Informa UK Limited. - 1364-2812 .- 1463-6417. ; 82:8, s. 891-903
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Tidskriftsartikel (refereegranskat)abstract
- SrTiO3 (STO) thin films were deposited on p-type Si(100) substrates by rf magnetron sputtering at various substrate temperatures, and their structural and electrical properties were investigated without post-deposition annealing. The thickness of the films was in the range from 300 to 500 nm while the deposition temperature was varied between room temperature and 550°C. Compositional and structural characterizations included X-ray diffraction, Rutherford back-scattering spectroscopy and variable-angle spectroscopic ellipsometry. Metal-insulator-semiconductor diodes with the configuration of Al/STO/p-Si/Al were fabricated and characterized by capacitance-voltage, current voltage and admittance spectroscopy measurements. Depending on the substrate temperatures, the dielectric constant of the films varied between 60 and 120 and the loss factor between 0.019 and 0.051 at 100 kHz. All films showed high charge storage capacity, varying between 1.9 and 3 µm cm-2. However, the films deposited at 200°C showed the lowest density of bulk trapped charges (150nC cm-2) and interface states ((1.2-6.1) × 1011 cm-2 eV-1), and are therefore considered to be the most suitable for device applications.
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| 4. |
- Wang, Z., et al.
(författare)
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Electrical properties of SrTiO3 thin films on Si deposited by magnetron sputtering at low temperature
- 2001
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 79:10, s. 1513-1515
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of SrTiO3 (STO) thin films by radio-frequency magnetron sputtering in an ultrahigh vacuum system at a low substrate temperature (~200°C) was performed in order to produce high-quality STO/p-Si (100) interfaces and STO insulator layers with dielectric constants of high magnitude. The STO films were identified as polycrystalline by x-ray diffraction, and were approximated with a layered structure according to the best fitting results of raw data from both Rutherford backscattering spectroscopy and variable angle spectroscopic ellipsometry. Room-temperature current-voltage and capacitance-voltage (C-V) measurements on Al/STO/p-Si diodes clearly revealed metal-insulator-semiconductor behavior, and the STO/p-Si interface state densities were of the order of 1011 eV-1 cm-2. The dielectric constant of the STO film was 65, and the dielectric loss factor varied between 0.05 and 0.55 for a frequency range of 1 kHz-10 MHz. For a 387 nm thick STO film, the dielectric breakdown field was 0.31 MV cm-1, and the charge storage capacity was 2.1 µC cm-2. These results indicate that STO films are suitable for applications as insulator layers in dynamic random access memories or as cladding layers in electroluminescent devices. © 2001 American Institute of Physics.
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