| 1. |
- Popok, Vladimir, 1966, et al.
(författare)
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Complex crater formation on silicon surfaces by low-energy Ar cluster ion implantation
- 2004
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Ingår i: Surface Science. - : Elsevier BV. - 0039-6028. ; 566-568, s. 1179-1184
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Tidskriftsartikel (refereegranskat)abstract
- Silicon samples were implanted by small mass-selected Ar cluster and Ar+ monomer ions with energies in the range of 1.5-18.0 keV/ion. Atomic force microscopy (AFM) shows simple and complex crater formation on the Si surface at the collision spots. A typical complex crater is surrounded by a low-height (0.5 nm) rim and it encloses a centre-positioned cone-shaped hillock with height of up to 3.5 nm depending on the implantation conditions. The morphology and dimensions of the craters and hillocks are studied as a function of the cluster size and implantation energy. A model explaining the hillock formation with relation to the thermal-transfer effect and local target melting at the collision spot is proposed.
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| 2. |
- Popok, Vladimir, 1966, et al.
(författare)
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Nanohillock formation by impact of small low-energy clusters with surfaces
- 2003
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Ingår i: Nuclear Instruments and Methods in Physics Research B. ; 207:2, s. 145-153
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Tidskriftsartikel (refereegranskat)abstract
- Results on nanoscale structuring of different substrates (silicon, pyrolytic graphite, indium-tin-oxide) using clusters from 20 to 100 atoms in size formed from gaseous precursors (O2, N2, Ar) at relatively low impact energy up to 15 keV are presented. Images of the substrate surfaces after cluster collisions obtained using atomic force microscopy (AFM) show the formation of hillocks from a few to 15 nm height with a basal diameter from 50 to 300 nm depending on implantation conditions. The shape and size of the structures are found to be a function of the cluster size and species, implantation energy, impact angle and the type of substrate. A model explaining the hillock formation is discussed.
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| 3. |
- Popok, Vladimir, 1966, et al.
(författare)
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Surface nanostructuring by implantation of cluster ions
- 2004
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X. ; 76:2-3, s. 265-272
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Tidskriftsartikel (refereegranskat)abstract
- A brief state-of-the-art review in the field of cluster ion implantation is presented. Ionised cluster beams are considered as a controllable and versatile tool for modification and processing of surfaces and near-surface layers on an atomistic scale as an alternative to ion implantation and ion assisted deposition. The main effects occurring under cluster-surface collisions as well as advantages in the application of cluster ion beams are reviewed. The problem of surface erosion under impact of energetic cluster ions is emphasised in the paper. A model explaining crater and hillock formation on target surfaces with relation to the thermal-transfer effect and local target melting at the collision spot is discussed.
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| 4. |
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| 5. |
- Prasalovich, Sergei, 1976, et al.
(författare)
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Experimental studies of complex crater formation under cluster implantation of solids
- 2005
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 36, s. 79-88
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Tidskriftsartikel (refereegranskat)abstract
- The results of a systematic study of surface defect formation after energetic Arn+ (n = 12, 22, 32, 54) and Xen+ (n = 4, 16) cluster ion implantation into silicon and sapphire are presented. Implantation energies vary from 3 to 18 keV/ion. Two cases of comparative studies are carried out: the same cluster species are implanted into two different substrates, i.e. Arn+ cluster ions into silicon and sapphire and two different cluster species Arn+ and Xen+ are implanted into the same kind of substrate (silicon). Atomic force, scanning electron and transmission electron microscopies (AFM, SEM and TEM) are used to study the implanted samples. The analysis reveals the formation of two types of surface erosion defects: simple and complex (with centrally positioned hillock) craters. It is found that the ratio of simple to complex crater formation as well as the hillock dimensions depend strongly on the cluster species, size and impact energy as well as on the type of substrate material. Qualitative models describing the two comparative cases of cluster implantation, the case of different cluster species and the case of different substrate materials, are proposed.
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| 6. |
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| 7. |
- Prasalovich, Sergei, 1976, et al.
(författare)
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Surface entropy of rare-gas clusters
- 2005
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Ingår i: J. Chem. Phys.. - : AIP Publishing. - 0021-9606. ; 123
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Tidskriftsartikel (refereegranskat)abstract
- Abundances of Ar and Xe clusters produced in a supersonic expansion source are inverted to find relative dissociation energies. The values around the shell and subshell closings at N=55, 71, and 147 differ from theoretical values derived from ground-state energies of Lennard-Jones clusters. A significant part of the difference can be accounted for by the conformational entropies of surface atoms and vacancies.
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