| 1. |
- Hourahine, B., et al.
(författare)
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Evidence for H2* trapped by carbon impurities in silicon
- 2001
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Ingår i: Physica. B, Condensed matter. - 0921-4526 .- 1873-2135. ; 308, s. 197-201
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Tidskriftsartikel (refereegranskat)abstract
- Local mode spectroscopy and ab initio modelling are used to investigate two trigonal defects found in carbon-rich Si into which H had been in-diffused. Isotopic shifts with D and 13C are reported along with the effect of uniaxial stress. Ab initio modelling studies suggest that the two defects are two forms of the CH2* complex where one of the two hydrogen atoms lies at an anti-bonding site attached to C or Si, respectively. The two structures are nearly degenerate and possess vibrational modes in good agreement with those observed.
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| 2. |
- Murin, L.I., et al.
(författare)
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Early stages of oxygen clustering in hydrogenated Cz-Si : IR absorption studies
- 2001
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Ingår i: Physica. B, Condensed matter. - 0921-4526 .- 1873-2135. ; 302-303, s. 180-187
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The formation kinetics of small oxygen clusters in hydrogenated Si has been studied by means of infrared absorption measurements. Hydrogen was introduced into the crystals by in-diffusion from H2 gas at 1200-1300°C. The samples were heated at temperatures in the range of 280-370°C for different durations. At initial stages of heat-treatment, enormous generation rates of the oxygen dimer have been observed in hydrogenated samples. This indicates highly enhanced diffusion of the interstitial oxygen atoms. The maximum achievable concentration of the dimers is found to be limited by their dissociation rate even at temperatures of about 300°C, while in as-grown crystals the capture processes are known to be dominant in this temperature region. An explanation of this phenomenon is presented. © 2001 Published by Elsevier Science B.V.
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| 3. |
- Markevich, V.P., et al.
(författare)
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Local vibrational mode bands of V-O-H complexes in silicon
- 1999
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Ingår i: Physica. B, Condensed matter. - 0921-4526 .- 1873-2135. ; 273-274, s. 300-304
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Tidskriftsartikel (refereegranskat)abstract
- H2 molecules, which are introduced into moderately doped silicon crystals by high-temperature in-diffusion from H2 gas ambient followed by fast cooling to room temperature, are found to interact effectively with the defects induced by irradiation of the crystals with fast electrons. In Czochralski-grown silicon crystals, the interaction of the mobile H2 molecules with vacancy-oxygen defects (A centers) leads to the creation of V-O-H2 complexes. This complex gives rise to infrared (IR) absorption lines at 943.5, 2126.4, and 2151.5 cm-1. Ab initio calculations showed that the most stable configuration of V-O-H2 consists of one oxygen and two hydrogen atoms sharing a vacancy site. It is suggested that the interaction of the V-O-H2 complexes with interstitial oxygen atoms results in the formation of V-O2-H2 complexes, which are responsible for the IR absorption line at 891.5 cm-1.
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| 4. |
- Markevich, V. P., et al.
(författare)
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Observation and theory of the V-O-H2 complex in silicon
- 2000
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 61:19, s. 12964-12969
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Tidskriftsartikel (refereegranskat)abstract
- The interaction of hydrogen with radiation-induced defects (RD's) in Czochralski-grown silicon crystals has been studied by infrared-absorption spectroscopy and ab initio modeling. Hydrogen and/or deuterium was introduced into the crystals by indiffusion from H2 (D2) gas at 1200-1300 °C. The samples were subsequently irradiated with fast electrons (E=2-4 MeV) and annealed in the temperature range of 100-600 °C. The centers produced by the irradiation were the same in both the untreated and treated cases, namely the A-center, Ci-Oi complex, and divacancy. A heat treatment of the H-treated samples resulted in the enhanced loss of these centers and the formation of centers containing hydrogen. The disappearance of the A centers in the temperature range of 100-150 °C is correlated with the appearance of three local vibrational modes (LVM's) at 943.5, 2126.4, and 2151.5 cm-1. The isotopic shifts of these lines were obtained from measurements on the samples doped with hydrogen and deuterium. The lines are identified as related to stretching vibrational modes of a complex that consists of one oxygen and two hydrogen atoms sharing a vacancy site (V-O-H2 complex). Ab initio calculations are used to explore the structures and properties of this defect. The origin of other LVM bands, which were observed upon annealing, is discussed.
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| 5. |
- Markevich, VP, et al.
(författare)
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Stable hydrogen pair trapped at carbon impurities in silicon
- 2003
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Ingår i: Defect and Diffusion Forum. - 1012-0386 .- 1662-9507. ; 221-2, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Local mode spectroscopy and ab initio modeling are used to investigate two trigonal defects found in carbon rich Si into which H had been in-diffused. Isotopic shifts with D and C-13 are reported along with the effect of uniaxial stress. Ab-initio modeling studies suggest that the two defects are two forms of the CH2* complex where one of the two hydrogen atoms lies at an anti-bonding site attached to C or Si respectively. The two structures are nearly degenerate and possess vibrational modes in good agreement with those observed experimentally. The defects are energetically favorable in comparison with separated C-s and H-2 in Si and may represent aggregation sites for hydrogen.
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