| 1. |
- Hallén, Anders., et al.
(author)
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Annealing of Al implanted 4H silicon carbide
- 2006
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In: Physica Scripta. - 0031-8949 .- 1402-4896. ; T126, s. 37-40
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Journal article (peer-reviewed)abstract
- Al ions were implanted with multiple energies up to 250 keV at elevated temperatures in n-type 4H SiC epitaxial layers to reach a surface concentration of 1 x 10(20) cm(-3). These samples were then annealed at temperatures between 1500 and 1950 degrees C. A similar 4H SiC epitaxial sample was implanted by MeV Al ions to lower doses and annealed only at 200 and 400 degrees C. After annealing, cross-sections of the samples were characterized by scanning spreading resistance microscopy (SSRM). The results show that the resistivity of high-dose Al implanted samples has not reached a saturated value, even after annealing at the highest temperature. For the MeV Al implanted sample, the activation of Al has not yet started, but a substantial annealing of the implantation induced damage can be seen from the SSRM depth profiles.
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| 2. |
- Karpus, V., et al.
(author)
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Mg 2p shallow core-level and local atomic structure of i-ZnMgRE quasicrystals
- 2006
-
In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 252:15, s. 5411-5414
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Journal article (peer-reviewed)abstract
- We present a detailed analysis of the Mg 2p shallow core-levels measured on icosahedral single-grain ZnMgY, ZnMgHo, and ZnMgEr quasicrystals during a photoelectron microscopy study. The synchrotron radiation photoemission measurements were performed on in situ cleaved samples at a pressure of 10(-10) mbar and at low temperature, typically 90-150 K. The Mg 2p photoemission lines are essentially broadened as compared to those of the Mg 2p spin-orbit doublet recorded on the Zn2Mg crystalline Laves phase. The broadening is associated to the coordination shifts of the Mg 2p level due to the inequivalent magnesium sites in the quasicrystalline lattice. The coordination shifts are calculated on the basis of i-ZnMg(Ho, Y) atomic structure data, recently determined from the pair distribution function analysis. The coordination shifts obtained are up to 0.2 eV. The Mg 2p experimental spectral intensity is nicely reproduced by a superposition of coordination-shifted Mg 2p spin-orbit doublets.
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| 3. |
- Karpus, V., et al.
(author)
-
Photoemission spectroscopy study of si-ZnMgHo quasicrystals
- 2008
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In: Optical materials (Amsterdam). - : Elsevier BV. - 0925-3467 .- 1873-1252. ; 30:5, s. 690-692
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Journal article (peer-reviewed)abstract
- The results of photoemission spectroscopy of the simple-icosahedral single-grain ZnMgHo quasicrystals are presented. Synchrotron radiation photoemission measurements were performed on in situ cleaved samples at 10(-10) mbar pressure and low, 160 K, temperature. The valence band photoemission spectra measured reveal a simple metal type valence band with a distinct Fermi edge and a sharp pseudogap feature, which originates from the van Hove singularities in the density of states. The photoemission spectra of the Mg 2p core level show the coordination shifts of Mg 2p, spin-orbit doublet due to inequivalent Mg sites in the quasicrystalline lattice.
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| 4. |
- Suchodolskis, Arturas, et al.
(author)
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Photoemission studies of Mg and Rb layers on Zn(0001)
- 2004
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 137-40, s. 189-192
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Journal article (peer-reviewed)abstract
- The electronic structure of the clean Zn(0 0 0 1) surface is studied by angle resolved photoemission. An earlier detected surface state at the surface Brillouin zone centre is confirmed and a new surface state is found at the surface Brilluoin zone boundary. The surface electronic structure of Zn is found to be similar to the that of Cd. Evaporation of thin films of Mg and Rb onto the Zn(0 0 0 1) surface quenches the emission from both surface states and reduces the intensity of the bulk related structures.
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| 5. |
- Suchodolskis, Arturas, et al.
(author)
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Scanning spreading resistance microscopy of shallow doping profiles in silicon
- 2006
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In: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 253:02-jan, s. 141-144
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Journal article (peer-reviewed)abstract
- We demonstrate the application of scanning spreading resistance microscopy (SSRM) for characterization of shallow highly-conductive layers formed by boron implantation of lowly doped n-type silicon substrate followed by a post-implantation annealing. The electrically active dopant concentration versus depth was obtained from a cross-section of freshly cleaved samples where the Si-surface could be clearly distinguished by depositing a SiO2-layer before cleavage. To quantify free carrier concentration we calibrated our data against samples with implanted/annealed boron profiles established by secondary ion mass spectrometry (SIMS). A good fit of SSRM and SIMS data is possible for free carrier concentrations lower than 10(20) cm(-3), but for higher concentrations there is a discrepancy indicating an incomplete activation of the boron.
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