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BETA
Andersson, Jon Martin
Alternative names
Publications (10 of 13) Show all publications
Wallin, E., Andersson, J. M., Lattemann, M. & Helmersson, U. (2008). Influence of residual water on magnetron sputter deposited crystalline Al2O3 thin films. Thin Solid Films, 516(12), 3877-3883
Open this publication in new window or tab >>Influence of residual water on magnetron sputter deposited crystalline Al2O3 thin films
2008 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 516, no 12, p. 3877-3883Article in journal (Refereed) Published
Abstract [en]

The effects of residual water on the phase formation, composition, and microstructure evolution of magnetron sputter deposited crystalline alumina thin films have been investigated. To mimic different vacuum conditions, depositions have been carried out with varying partial pressures of H2O. Films have been grown both with and without chromia nucleation layers. It is shown that films deposited onto chromia nucleation layers at relatively low temperatures (500 °C) consists of crystalline alpha-alumina if deposited at a low enough total pressure under ultra high vacuum (UHV) conditions. However, as water was introduced a gradual increase of the gamma phase content in the film with increasing film thickness was observed. At the same time, the microstructure changed drastically from a dense columnar structure to a structure with small, equiaxed grains. Based on mass spectrometry measurements and previous ab initio calculations, we suggest that either bombardment of energetic negative (or later neutralized) species being accelerated over the target sheath voltage, adsorbed hydrogen on growth surfaces, or a combination of these effects, is responsible for the change in structure. For films containing the metastable gamma phase under UHV conditions, no influence of residual water on the phase content was observed. The amounts of hydrogen incorporated into the films, as determined by elastic recoil detection analysis, were shown to be low. Overall, the results demonstrate that residual water present during film growth drastically affects film properties, also in cases where the hydrogen incorporation is found to be low.

Place, publisher, year, edition, pages
ScienceDirect, 2008
Keywords
Aluminum oxide, Phase formation, Sputtering, Water
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-11476 (URN)10.1016/j.tsf.2007.07.135 (DOI)
Note
Original publication: E. Wallin, J.M. Andersson, M. Lattemann, and U. Helmersson, Influence of residual water on magnetron sputter deposited crystalline Al2O3 thin films, 2008, Thin Solid Films, (516), 12, 3877-3883. http://dx.doi.org/10.1016/j.tsf.2007.07.135. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2017-12-13Bibliographically approved
Wallin, E., Andersson, J., Münger, P., Chirita, V. & Helmersson, U. (2007). Ab initio studies of adsorption and diffusion processes on alpha-Al2O3 (0001) surfaces. In: AVS 54th International Symposium,2007.
Open this publication in new window or tab >>Ab initio studies of adsorption and diffusion processes on alpha-Al2O3 (0001) surfaces
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2007 (English)In: AVS 54th International Symposium,2007, 2007Conference paper, Published paper (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-40633 (URN)53683 (Local ID)53683 (Archive number)53683 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2013-10-30
Wallin, E., Andersson, J., Münger, P., Chirita, V. & Helmersson, U. (2007). Ab initio studies of adsorption and diffusion processes on alpha-Al2O3 (0001) surfaces. In: International Symposium on Reactive Sputter Deposition,2007.
Open this publication in new window or tab >>Ab initio studies of adsorption and diffusion processes on alpha-Al2O3 (0001) surfaces
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2007 (English)In: International Symposium on Reactive Sputter Deposition,2007, 2007Conference paper, Published paper (Other academic)
Abstract [en]

As one of the technologically most important ceramic materials, alumina (Al2O3) thin film growth has been studied extensively in the past. However, the mechanisms behind the formation of different phases and microstructures are still poorly understood, especially for physically vapor deposited films. An increased atomic scale understanding of alumina surface processes would thus be an important step towards a more complete understanding and control of the deposition process. In the present work, density functional theory based methods were used to study the adsorption of Al, O, AlO, and O2 on different terminations of alpha-alumina (0001) surfaces. The results show the existence of several metastable adsorption sites on the O-terminated surface and provide a possible explanation for the well-known difficulties in growing -Ñ-alumina at lower temperatures. Moreover, we demonstrate that Al adsorption in bulk positions is unstable, or considerably weaker, for completely hydrogenated surfaces, indicating that hydrogen stemming from residues in vacuum systems, might hinder the growth of crystalline alpha-alumina. Furthermore, nudged elastic band investigations of dynamic energy barriers for different surface diffusion processes show that Al diffusion, on the Al-terminated (0001) surface, requires only ~0.7 eV. This value is considerably lower than what is generally expected for the low temperature synthesis of alpha-alumina phase. These results add significantly to understanding the effects of several important factors on alumina growth, and their implication, on optimizing deposition processes for the synthesis of alumina films with desired properties, will be discussed.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-40632 (URN)53682 (Local ID)53682 (Archive number)53682 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2013-10-30
Alami, J., Eklund, P., Andersson, J. M., Lattemann, M., Wallin, E., Böhlmark, J., . . . Helmersson, U. (2007). Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering. Thin Solid Films, 515(7-8), 3434-3438
Open this publication in new window or tab >>Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering
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2007 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 7-8, p. 3434-3438Article in journal (Refereed) Published
Abstract [en]

Ta thin films were grown on Si substrates at different inclination angles with respect to the sputter source using high power impulse magnetron sputtering (HIPIMS), an ionized physical vapor deposition technique. The ionization allowed for better control of the energy and directionality of the sputtered species, and consequently for improved properties of the deposited films. Depositions were made on Si substrates with the native oxide intact. The structure of the as deposited films was investigated using X-ray diffraction, while a four-point probe setup was used to measure the resistivity. A substrate bias process-window for growth of bcc-Ta was observed. However, the process-window position changed with changing inclination angles of the substrate. The formation of this low-resistivity bcc-phase could be understood in light of the high ion flux from the HIPIMS discharge.

Place, publisher, year, edition, pages
Elsevier, 2007
Keywords
HPPMS, Ionized PVD, IPVD, Pulsed sputtering
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-10442 (URN)10.1016/j.tsf.2006.10.013 (DOI)
Note
Original publication: J. Alamia, P. Eklunda, J.M. Anderssona, M. Lattemanna, E. Wallina, J. Bohlmarka, P. Perssona, and U. Helmersson, Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering, 2007, Thin Solid Films, (515), 7-8, 3434-3438. http://dx.doi.org/10.1016/j.tsf.2006.10.013. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2007-12-14 Created: 2007-12-14 Last updated: 2017-12-14Bibliographically approved
Wallin, E., Andersson, J. M., Münger, E. P., Chirita, V. & Helmersson, U. (2006). Ab initio studies of Al, O, and O2 adsorption on α-Al2O3 (0001) surfaces. Physical Review B. Condensed Matter and Materials Physics, 74(12), 125409-1-125409-9
Open this publication in new window or tab >>Ab initio studies of Al, O, and O2 adsorption on α-Al2O3 (0001) surfaces
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2006 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 74, no 12, p. 125409-1-125409-9Article in journal (Refereed) Published
Abstract [en]

The interactions of Al, O, and O2 with different α- Al2O3 (0001) surfaces have been studied using ab initio density functional theory methods. All three surface terminations obtainable by cleaving the bulk structure [single Al-layer (AlO), double Al-layer (AlAl), and O terminations] have been considered, as well as a completely hydrogenated O-terminated surface. Adsorbed Al shows strong ioniclike interaction with the AlO - and O-terminated surfaces, and several metastable adsorption sites are identified on the O-terminated surface. On the completely hydrogenated surface, however, Al adsorption in the bulk position is found to be unstable or very weak for the studied configurations of surface H atoms. Atomic O is found to interact strongly with the AlAl -terminated surface, where also O2 dissociative adsorption without any appreciable barrier is observed. In contrast, O adsorption on the AlO -terminated surface is metastable relative to molecular O2. On the O-terminated surface, we find the creation of O surface vacancies to be plausible, especially upon exposure to atomic O at elevated temperatures. The results are mainly discussed in the context of alumina thin film growth and provide insight into phenomena related to, e.g., preferred adsorption sites and effects of hydrogen on the growth.

Place, publisher, year, edition, pages
College Park, MD, United States: American Physical Society, 2006
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-10427 (URN)10.1103/PhysRevB.74.125409 (DOI)000240872500080 ()
Note

Original publication: E. Wallin, J.M. Andersson, E.P. Münger, V. Chirita & U. Helmersson, Ab initio studies of Al, O, and O2 adsorption on α- Al2 O3 (0001) surfaces, 2006, Physical Review B, (74), 125409. http://dx.doi.org/10.1103/PhysRevB.74.125409. Copyright: The America Physical Society, http://prb.aps.org/

Available from: 2007-12-12 Created: 2007-12-12 Last updated: 2018-07-03Bibliographically approved
Andersson, J. M., Wallin, E., Münger, P. & Helmersson, U. (2006). Energy distributions of positive and negative ions during magnetron sputtering of an Al target in Ar/O2 mixtures. Journal of Applied Physics, 100(3), Art. No. 033305 AUG 1 2006
Open this publication in new window or tab >>Energy distributions of positive and negative ions during magnetron sputtering of an Al target in Ar/O2 mixtures
2006 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 100, no 3, p. Art. No. 033305 AUG 1 2006-Article in journal (Refereed) Published
Abstract [en]

The ion flux obtained during reactive magnetron sputtering of an Al target in Ar/O2 gas mixtures was studied by energy-resolved mass spectrometry, as a function of the total and O2 partial pressures. The positive ions of film-forming species exhibited bimodal energy distributions, both for direct current and radio frequency discharges, with the higher energy ions most likely originating from sputtered neutrals. For the negative oxygen ions a high-energy peak was observed, corresponding to ions formed at the target surface and accelerated towards the substrate over the sheath potential. As the total pressure was increased the high-energy peaks diminished due to gas-phase scattering. Based on these results, the role of energetic bombardment for the phase constituent of alumina thin films are discussed.

Place, publisher, year, edition, pages
College Park, MD, United States: American Institute of Physics (AIP), 2006
Keywords
aluminium, sputter deposition, diffusion, mass spectra, high-frequency discharges, plasma materials processing
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-10472 (URN)10.1063/1.2219163 (DOI)000239764100014 ()
Note

Original publication: Jon M. Andersson, E. Wallin, E. P. Münger & U. Helmersson, Energy distributions of positive and negative ions during magnetron sputtering of an Al target in Ar/O2 mixtures, 2006, Journal of Applied Physics, (100), 033305. http://dx.doi.org/10.1063/1.2219163. Copyright: American Institute of Physics, http://jap.aip.org/jap/top.jsp

Available from: 2007-12-19 Created: 2007-12-19 Last updated: 2017-12-14
Andersson, J. M., Wallin, E., Münger, E. P. & Helmersson, U. (2006). Molecular content of the deposition flux during reactive Ar/O2 magnetron sputtering of Al. Applied Physics Letters, 88(05), Art. No. 054101 JAN 30 2006-
Open this publication in new window or tab >>Molecular content of the deposition flux during reactive Ar/O2 magnetron sputtering of Al
2006 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 88, no 05, p. Art. No. 054101 JAN 30 2006-Article in journal (Refereed) Published
Abstract [en]

The deposition flux obtained during reactive radio frequency magnetron sputtering of an Al target in Ar/O2 gas mixtures was studied by mass spectrometry. The results show significant amounts of molecular AlO+ (up to 10% of the Al+ flux) in the ionic flux incident onto the substrate. In the presence of ~10–4 Pa H2O additional OH+ and AlOH+ were detected, amounting to up to about 100% and 30% of the Al+ flux, respectively. Since the ions represent a small fraction of the total deposition flux, an estimation of the neutral content was also made. These calculations show that, due to the higher ionization probability of Al, the amount of neutral AlO in the deposition flux is of the order of, or even higher than, the amount of Al. These findings might be of great aid when explaining the alumina thin film growth process.

Place, publisher, year, edition, pages
Institutionen för fysik, kemi och biologi, 2006
Keywords
alumina, dielectric thin films, sputter deposition, mass spectra
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-10452 (URN)10.1063/1.2170404 (DOI)
Note
Original publication: Andersson, J.M., Wallin, E., Münger, E.P. & Helmersson, U., Molecular content of the deposition flux during reactive Ar/O2 magnetron sputtering of Al, 2006, Applied Physics Letters, (88), 054101. http://dx.doi.org/10.1063/1.2170404. Copyright: American Institute of Physics, http://apl.aip.org/apl/top.jspAvailable from: 2007-12-17 Created: 2007-12-17 Last updated: 2017-12-14
Andersson, J. M., Wallin, E., Helmersson, U., Kreissig, U. & Münger, E. P. (2006). Phase control of Al2O3 thin films grown at low temperatures. Thin Solid Films, 513(1-2), 57-59
Open this publication in new window or tab >>Phase control of Al2O3 thin films grown at low temperatures
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2006 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 513, no 1-2, p. 57-59Article in journal (Refereed) Published
Abstract [en]

Low-temperature growth (500 °C) of α-Al2O3 thin films by reactive magnetron sputtering was achieved for the first time. The films were grown onto Cr2O3 nucleation layers and the effects of the total and O2 partial pressures were investigated. At 0.33 Pa total pressure and ≥ 16 mPa O2 partial pressure α-Al2O3 films formed, while at lower O2 pressure or higher total pressure (0.67 Pa), only γ phase was detected in the films (which were all stoichiometric). Based on these results we suggest that α phase formation was promoted by a high energetic bombardment of the growth surface. This implies that the phase content of Al2O3 films can be controlled by controlling the energy of the depositing species. The effect of residual H2O (10− 4 Pa) on the films was also studied, showing no change in phase content and no incorporated H (< 0.1%). Overall, these results are of fundamental importance in the further development of low-temperature Al2O3 growth processes.

Place, publisher, year, edition, pages
Elsevier, 2006
Keywords
Aluminum oxide, Chromium oxide, Sputtering, Ion bombardment, X-ray diffraction
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-14318 (URN)10.1016/j.tsf.2006.01.016 (DOI)
Note
Original publication: Andersson, J.M., Wallin, E., Helmersson, U., Kreissig, U. and Münger, E.P., Phase control of Al2O3 thin films grown at low temperatures, 2006, Thin Solid Films, (513), 1-2, 57-59. http://dx.doi.org/10.1016/j.tsf.2006.01.016. Copyright: Elsevier B.V., http://www.elsevier.com/ Available from: 2007-03-02 Created: 2007-03-02 Last updated: 2017-12-13Bibliographically approved
Trinh, D. H., Högberg, H., Andersson, J. M., Collin, M., Reineck, I., Helmersson, U. & Hultman, L. (2006). Radio frequency dual magnetron sputtering deposition and characterization of nanocomposite Al2O3-ZrO2 thin films. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, 24(2), 309-316
Open this publication in new window or tab >>Radio frequency dual magnetron sputtering deposition and characterization of nanocomposite Al2O3-ZrO2 thin films
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2006 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 24, no 2, p. 309-316Article in journal (Refereed) Published
Abstract [en]

Radio frequency magnetron sputtering from oxide targets has been used to synthesize crystalline alumina–zirconia nanocomposites at a relatively low temperature of 450  °C. Films of different compositions have been deposited ranging from pure zirconia to pure alumina, the compositions being measured with Rutherford backscattering and elastic recoil detection analysis. X-ray diffraction studies show the presence of the monoclinic zirconia phase in pure zirconia films. Addition of alumina into the film results in the growth of the cubic zirconia phase and amorphous alumina. No crystalline alumina was detected in either the composite or the pure alumina film. The microstructure of the films as studied by high resolution electron microscopy and scanning transmission electron microscopy shows a columnar growth mode in both the pure zirconia and nanocomposite films, but reveals differences in the intracolumnar structure. For the nanocomposite small equiaxed grains, ~5  nm in size, are found at the base of the columns at the interface with the substrate. An amorphous tissue of alumina was present between the small crystallites in the case of the nanocomposite.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-14051 (URN)10.1116/1.2171709 (DOI)
Available from: 2006-10-06 Created: 2006-10-06 Last updated: 2017-12-13Bibliographically approved
Andersson, J. M., Wallin, E., Chirita, V., Münger, E. P. & Helmersson, U. (2005). Ab initio calculations on the effects of additives on alumina phase stability. Physical review. B, Condensed matter and materials physics, 71(014101), 014101-
Open this publication in new window or tab >>Ab initio calculations on the effects of additives on alumina phase stability
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2005 (English)In: Physical review. B, Condensed matter and materials physics, ISSN 1098-0121, Vol. 71, no 014101, p. 014101-Article in journal (Refereed) Published
Abstract [en]

The effects of substitutional additives on the properties and phase stability of - and -alumina (Al2O3), are investigated by density functional theory total energy calculations. The dopants explored are 5 at. % of Cr, Mo, Co, and As substituting for Al, respectively, N and S substituting for O, in the and lattices. Overall, the results show that it is possible to shift, and even reverse, the relative stability between - and -alumina by substitutional additives. The alumina bulk moduli are, in general, only slightly affected by the dopants but density of states profiles reveal additional peaks in the alumina band gaps. We also show that phase separations into pure oxides are energetically favored over doped alumina formation, and we present results on a number of previously unstudied binary oxides.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13582 (URN)10.1103/PhysRevB.71.014101 (DOI)
Available from: 2005-12-13 Created: 2005-12-13 Last updated: 2013-10-30
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