1. Pulsed plasmas open up many newfascinating ideas for materials design!
The effect of a positive pulse following ahigh-power impulse magnetron sputtering (HiPIMS) pulse are studied usingenergy- and time-resolved mass spectrometry. This includes exploring theinfluence of a 200 μs long positive voltage pulse (Urev = 10-150 V) following atypical HiPIMS pulse on the ion- energy distribution function (IEDF) of thevarious ions. We find that, a portion of the Ti+ flux is affected by gainingenergy which corresponds to the acceleration over the full potential Urev. TheAr+ IEDF on the other hand illustrates that a large fraction of theAr+accelerated, gain energy only to a portion of Urev. The Ti+ IEDFs areconsistent with the assumption that practically all the Ti+ that becomeaccelerated during the reverse pulse come from a region adjacent to the target,in which the potential is uniformly increased with the applied potential Urev,while much of the Ar+ come from a region further away from the target thatcontains a boundary with a drop in potential from Urev to a lower potential consistentwith the plasma potential achieved without the application of Urev. Thedeposition rate is only slightly affected and decreases with Urev to ~90% atUrev= 150 V. Both the Ti+ IEDF and the small deposition rate change indicatethat the potential increase in the region close to the target is uniform andessentially free of electric fields, with the consequence that the motion ofthe ions inside it are not much influenced by the application of Urev. In thissituation, Ti+ will flow towards the outer boundary of the target-adjacentregion, due to their momentum achieved during the HiPIMS discharge pulse,independent whether the positive pulse is applied or not. The metal ions thatcross the boundary in the direction towards the substrate, and do this duringthe positive pulse, all gain an energy corresponding to the full positiveapplied potential Urev.
2. Wires, trusses and pillars produced byassembly of plasma generated nanoparticles.
Nanoparticles generated or supplied to aplasma attains a negative potential due to the nature of the plasma. This openup interesting possibilities in synthesis and assembly of the nanoparticlescreating structures in the nano- and micro-range. In this work, we use hollowcathode sputtering powered with high-power pulse to ensure close to fullionized of the source material. This promotes rapid growth of the nanoparticlesto desired sizes and the negative charge makes it possibility to guidenanoparticles for assembly and collection on desired positions. This is demonstratedby attracting nanoparticles to substrate positions with a positive potentialand focusing nanoparticles through a matrix of electrostatic lenses to assemblethe nanoparticles into pillars. For ferromagnetic nanoparticles, we alsodemonstrate generation of nanowires as well as nanowires cross-linked intotrusses. Since the iron nanoparticles are generated under relatively purecondition they assemble into wires without oxides in the interfaces. Nanowiresand trusses assembled on conducting substrates can potentially be used as lowcost large area electrodes.
Ulf Helmersson, professor in Thin FilmPhysics (IFM)
Dr. Ulf Helmersson, head of thePlasma & Coatings Physics division at Linköping University (LiU), hasfocused his research on the complex relationship among thin film growthkinetics, microstructural evolution, and physical properties. He has madesignificant contributions in all areas. Ulf started as an electronmicroscopist using the tools to investigate materials physics (i.e.nanoscience) rather than using the microscope as an end in itself. Earlyin his career he worked on the growth of hard transition metal nitride thinfilms by magnetron sputtering and, in particular, the role of low energy ionirradiation during deposition. He grew the first man-made artificial"super-hard" material — single crystal TiN/VN superlattices — withhardness comparable to diamond. The materials choice was prescient sincehe later showed the extreme enhancement in hardness over both of theconstituents, a factor of greater than 2.5 times which is amazing for this property;crystal growth dynamics are also important since optimizations require aninterfacial roughness of the order of a few Ångstroms or less. Suchcontrol was unheard of in the mid-1980s (even MBE growth of GaAs/GaAlAs was notsuperior). Recognizing that any application of this new science wouldhave to involve polycrystalline films (as wear resistant layers on steel tools,crankshafts, etc.), he spent much of his thesis work and early post-graduateresearch understanding the growth of these more complex materials where localcoherency and interfacial control is much more difficult and enhanced surfacediffusion via momentum transfer from low-energy ion bombardment must besubstituted for high growth temperatures which, especially for steelsubstrates, are not allowed. His ground-breaking work on super-hardmultilayers spawned a global industry and his results on the atomisticunderstanding of ion/surface interactions during the dynamic process of crystalgrowth is the basis of much of what we know in this important field today.
As a professor at LiU, Ulf continued his hard-coating work, but alsostarted a new effort in perovskite-structure high temperature superconductorand ferroelectric oxides. In this case he contributed significantly usinghis atomistic understanding, in combination with high-resolution electron microscopyand physical property measurements, to understand the role of O-negative ion bombardment during oxide film growth by magnetronsputtering. His understanding, together with strategies to eithermitigate the effects (when deleterious, i.e. for materials with low bulk atomdisplacement thresholds) or to utilize them for property enhancement, is wellknown in the oxide community.
Over the last several years, Ulf has truly pioneered the development ofHigh Power Impulse Magnetron Sputtering (HiPIMS),the most significant development in physical vapor deposition over the lastdecade. He co-authored the first paper in that field and, in cooperationwith plasma scientists in Stockholm and Iceland and many other scientists,several extremely important and highly cited papers concerning the science andfunctionality of HiPIMS.
Ulf is an important contributor and invitedspeaker to many conferences. He has regularly attended the InternationalSymposium of the AVS (former American Vacuum Society), the InternationalMetallurgical Coatings and Thin Films conference in San Diego, The Society ofVacuum Coaters, the International Vacuum Congress, and the Plasma and SurfaceEngineering conference in Garmisch-Partenkirchen. He also teachesshort courses through CEI in Europe and the Thin Film physics course atLinköping University.
Ulf has been a mentor for about 20 young scientists that are currentlymaking careers in industry or in academia. Several have become professorsand many are key scientists at major companies (see list below). A recentsuccess story is Daniel Lundin, graduated with a PhD in May 2010, who has wonfirst prize within the “Mentor4Research” program (an entrepreneurial programfor young scientists) as well as being selected as number 65 among 101"Supertalents" by the business journal “Veckans Affärer”. Hehas now, in cooperation with Ulf, founded the company Ionautics AB. Another recent graduate, Erik Wallin, became the first non-American student toreceive a top-level student award (in this case the Russell and Sigurd VarianAward) from the AVS (former American Vacuum Society) in 2008.
Date of birth:April 11, 1955
Home address: Vinkelvägen 59, SE-590 45Brokind, Sweden
Office address: IFM, Linköping University,SE-581 83 Linköping, Sweden
Mobile phone: +46-13-281685
· Master of Science in Physics(civilingenjörsexamen, teknisk fysik), Linköping University, Sept. 1981
· Ph.D. in materials Physics, LinköpingUniversity, Dec. 1986 (supervisor: Jan-Eric Sundgren)
· Docent in Thin Film Physics, LinköpingUniversity 1992.
· University of Illinois (several periods beforeand after PhD. In total 9 month).
· Visiting Scientist at National Institute ofAdvanced Industrial Science and Technology, Nagoya, Japan (2 month).
· Head of division: Plasma & Coatings Physics2004 -
· Professor, Thin Film Physics 2000 –
· Lecturer or Associate Professor (Högskolelektor)1998-1999 (Lin. Univ.)
· Acting Professor (T.f. Professor) 1997 -1998 (Linköping Univ.)
· Lecturer or Associate Professor (Högskolelektor)1992 - 1996 (Lin. Univ.)
· Assistant professor 1987 - 1992 (LinköpingUniv.)
· Teaching and research assistant Oct. 1981 - 1987(Linköping Univ.)
Commissionof trust (2005-)
· Swedishrepresentative at The European Joint Committee on Plasma and Ion SurfaceEngineering (EJC/PISE) since 2002.
· Vicechairman of the Asian-European International Conference on Plasma SurfaceEngineering (AEPSE 2013), Jeju, Republic of Korea, 2013.
· Facultyopponent at Ph.D. defenses: Uppsala University, 2012.
· Chairmanof the International Conference on Plasma Surface Engineering (PSE 2012),Garmisch-Partenkirchen 2012.
· Externalmember of PhD-committee at École Polytechnique Montreal, Canada, 2011.
· Chairmanof the Reactive Sputter Deposition Symposium (RSD 2011) in Linköping.
· Chairmanof PhD-defense, Orleans, France, 2010.
· Memberof the international program committee of the 11th European Vacuum Conference,EVC-11, Salamanca, 2010
· Memberof Editor Board of the International Conference on Plasma Surface Engineering,Busan, Korea 2009.
· Memberof the Executive Committee of the ASED of AVS, 2008. www.avs.org.
· Memberof the international organizing committee for the Symposium on Plasma Chemistry(ISPC 19), Bochum July 26-31, 2009.
· Member of the IUVSTA Surface Engineering (SED)Executive Committee 2007-2010.
· Memberof Editor Board and the Local Organizing Committee of the 17thInternational Vacuum Congress (IVC-17), Stockholm, July 2-6, 2006.
· Memberof VR committee (beredningsgrupp) 2006 and 2010.
· Memberof Editor Board and the International Scientific Committee for theInternational Conference on Plasma Surface Engineering, Garmisch-Partenkirchen,bi-annual 2002-2014.
· Facultyopponent at Ph.D. defenses: Dublin City University, 2005
· Treasuryof the Swedish Vacuum Society, 2005 – ongoing.
· Memberof the International Scientific and Technical Committee at the 5thAsian-European Conference on Plasma Surface Engineering, 2005, China.
· Memberof the committee at Ph.D. defense (several occasions)
· Reviewsarticles for a number of high level international journals (Applied PhysicsLetter, Journal of Applied Physics, Journal of Physics D, Journal of Vacuum Scienceand Technology, Surface Science and Technology, Thin Solid Films, Vacuum,European Physics Letters, etc.)
Invited talks given (or will be given) at internationalconferences and workshops (2007 and later)
· Designed Nanoparticle Synthesis by hollow cathodesputtering for surface treatments, SVC Techcon, April 25-30, 2015, Santa Clara,USA.
· High Power Impulse Magnetron Sputtering - Physics and Applications, ISPlasma 2015,March 26-31, 2015, Nagoya, Japan. Plenary presentation
· Opportunities using HiPIMS, The 14th International Conference on Plasma Surface Engineering,Sept. 14-19, 2014, Garmisch-Partenkirchen, Germany, Tutorial presentation
· Nanoparticle synthesis using pulsed highdensity plasma, 4th InternationalSymposium on Plasma Nanoscience, Aug. 25-29, 2013, Asilomar, CA, USA.
· Ionized physical vapor deposition: Technologyand applications, 31th InternationalConference of Phenomena in Ionized Gases, July 14-19, 2013, Granada, Spain. GeneralLecture.
· HiPIMS Basics, Wilhelmund Else Heraeus Seminar Physics of Ionized and Ion-Assisted PVD: Principlesand Current Trends, June 25-29, 2013, Dresden, Germany
· The use of highly ionized pulsed plasmas forthe synthesis of advanced thin films and nanoparticles, 68th IUVSTA workshop, “Multifunctional Surface Engineeringfor Advanced Energy Applications", December 9-13, 2012. CityUniversity of Hong Kong.
· Opportunities using HiPIMS, The 13th International Conference on Plasma Surface Engineering,Sept. 10-14, 2012, Garmisch-Partenkirchen, Germany, Tutorial presentation
· HiPIMS - the future of thin film deposition, The 11th International Workshop on Plasma-Based IonImplantation & Deposition, Sept. 8-12, 2011, Harbin, China. Plenarytalk
· Fundamentals of high power impulse magnetronsputtering, Reactive Sputter Deposition 2010, December 9 – 10, Ghent, Belgium. Plenarytalk
· Oxide, nitride, and carbide thin films byHiPIMS, Institute of Physics, London, June 16,2010.
· High power impulse magnetron sputtering – thesputtering technique for tomorrow? 5th MikkeliInternational Industrial Coating Seminar, Mikkeli, Finland, March 17-19, 2010
· High Power Impulse Magnetron Sputtering – thesputtering technique for tomorrow? 16thInternational Summer School on Vacuum, Electron and Ion Technologies, Sept 28 –Oct 2, 2009, Sunny Beach, Bulgaria.
· High Power Impulse Magnetron Sputtering – thesputtering technique for tomorrow! The International Conference on PlasmaSurface Engineering (PSE 2009), Sept. 20 – 25, 2009, Haewoondae-gu, Busan,South Korea. Plenary talk
· High Power Impulse Magnetron Sputtering;Plasma Conditions, Reactive Sputtering, and Film Growth, The 10th International Symposium on Sputtering and PlasmaProcesses, July 8 - 10, 2009, Kanazawa, Japan.
· HiPIMS for deposition of hard wear resistantcoatings, EMRS Spring Meting 2009, May 18 - 22,2009, Strasbourg, France.
· Reactive sputtering with HiPIMS, IUVSTA Workshop on HiPIMS, Nov. 12-15, 2008, Mons, Belgium.
· Ionized-PVD with HiPIMS – IndustrialPotentials and Scientific Challenges, TheInternational Conference on Plasma Surface Engineering (PSE 2008), September15-19, 2008, Garmisch-Partenkirchen, Germany. Plenary talk
· The high power impulse magnetron sputteringprocess; a review of present status, The 5thSymposium on Functional Coatings and Surface Engineering, June 1 -4, 2008,Montreal, Canada.
· Ionized-PVD with HIPIMS - Industrial Potentialsand Scientific Challenges, 35th InternationalConference on Metallurgical Coatings and Thin Films, Apr 28 - May 2, 2008, SanDiego, CA, USA.
· The use of high power impulse magnetron sputteringfor improved thin films and thin film processes, 9thInternational Workshop on Plasma-Based Ion Implantation & Deposition, Sept2-6, 2007, Leipzig, Germany.
· Ionized deposition using high power impulsemagnetron sputtering, Plasmas, the annual one daymeeting on “Surfaces and Thin Films”, Institute of Physics, June 20, 2007,London, UK.
· The use of high power impulse magnetronsputtering for improved thin film depositions, 16thInternational Colloquium on Plasma Processes, June 4-8, 2007, Toulouse, France.
Other Invited talks (2007-)
· Highly ionized carbon plasmas for the growthof diamond-like carbon thin films with magnetron sputtering, Oct. 10, 2012, Nippon ITF, Ltd., Kyoto, Japan.
· HiPIMS, Oct. 9,2012, Sumitomo Electric Industries, Ltd., Osaka, Japan.
· High power impulse magnetron sputtering, Sept. 6, 2012, Saint-Goabin Recherche, Paris, France.
· High power impulse magnetron sputtering –physical background and potential for synthesis of new and better thin filmmaterials, Oct. 3, 2011, Lobachevsky StateUniversity of Nizhny Novgorod, Russia.
· High Power Impulse Magnetron Sputtering(HIPIMS) for Improved Thin Films and Thin Film Processes, Sept. 5, 2007 Max Planck Institute of Microstructure Physics, Halle,Germany.
Invitations that had to be declined or transferred togroup members (2007-)
· International Conference: Power Electronics forPlasma Engineering (PE2), May 20-22, 2014, Warsaw/Zielonka, Poland.
· International Conferences on Modern Materials& Technologies (CIMTEC) 2010, June 6-18, 2010, Montecatini Terme, Italy.
· 4-th Symposium on Vacuum based Science and Technologyin conjunction with 8-th Annual Meeting of German Vacuum Society (DVG), September21-23, 2009, Koszalin- Koobrzeg, Poland.
· The 29th International Conference on Phenomenain Ionized Gases, July 13 - 18, 2009, Cancun, Mexico.
· Asia-Pacific Conference on Plasma Science andTechnology, Oct. 8-11, 2008, Huangshan City, China.
· Symposium on Vacuum Based Science and Technology2007, September 5-7, 2007, Greifswald, Germany
· The entrepreneurial researcher of the year (2013) at Linköping University awarded by the Innovation Office inLinköping.
· Fellow in the AVS Technology Society (formerAmerican Vacuum Society) 2008. “This is a prestigious membership level towhich members are elected; therefore the membership percentage cannot exceed0.5% in any calendar year”.
· R.F. Bunshah Award for thebest Technical Paper at the International Conference on Metallurgical Coatingsand Thin Films, 2002, San Diego, USA.
· See: http://www.researcherid.com/rid/B-6060-2008including citation data.
· 167 articles published inpeer-reviewed high level scientific journals and books as well as manyconference contributions.
· Citations: about 5300 (32per article) and a h-index, April 2014, of 40 (according to ISI).
· Citations: about 7000 and ah-index, April 2014, of 46 (according to Google scholar).
· Invited review article: “The high power impulsemagnetron sputtering discharge” J. Vac. Sci. Technol. A, 2012.
· Invited critical reviewarticle: "The Physics of Highly Ionized Physical Vapor DepositionProcesses" Thin Solid Films, 2006.
Research Grants: (given in SEK or Euro, Nov 2014: 1 Euro = 9.2SEK)
· 2015-2017 Knut and Alice Wallenberg Foundation(KAW): SEK 23,004,000 – main applicant.
· 2015-2018 Swedish Research Council (VR): SEK 3,200,000– main applicant.
· 2012-2014 Swedish Research Council (VR): SEK 2,850,000– main applicant.
· 2013-2014 Knut and Alice Wallenberg Foundation(KAW): SEK 15,336,000 – main applicant.
· 2013-2018 LiU professor contract: SEK 11,000,000
· 2011-2013 EU NoScratch: EUR 238,200 - mainapplicant from LiU.
· 2011-2013 Industrial funding (Japan): SEK1,133,000.
· 2012-2013 Industrial funding (France, Finland):EUR 110,000.
· 2012-2016 Linnaeus grant Swedish ResearchCouncil (VR): SEK 28,800,000 - co-applicant.
· 2010-2014 AFM: SEK 110,000,000 - co-applicant
· Patent submitted March 2013.
· Founder of TiÅ AB – a nanoparticlecompany (2012)
· Patents (WO2012138279) on highly ionized carbonplasmas (2011)
· Founder of Ionautis ABin cooperation with Daniel Lundin and Johan Ahlström (2010)
· Patent (SE535381) onnanoparticle manufacturing (2010)
· Founder of a researcherowned holding and conculting company PlasmAdvance AB (2008)
· Patent (WO2008148673), ownerAB Sandvik (2007)
Teaching andteaching administration.
· Responsible for the Applied Physics profile onMaterials- and nano-physics at the Master level at Linköping University(2000-2009).
· ThinFilmPhysics. Undergraduate/graduate course given for Y-students, InternationalMaster students, and PhD-students.
· Plasma Physics for the Material Scientist. Ph.D.-course.
· Supervision of Ph.D.-students. Presentposition:
Gunnar Larsson,Lic 1990 Unknown
TorbjörnSelinder, PhD 1992 DiamondInnovations, OH, USA
Marie E.Johansson, Lic 1995 SolFocus,CA, USA
NiclasEdvardsson, PhD 1998 AppliedNordic Sensor, Sweden
Xin Wang, PhD1998 AcreoAB, Sweden
Sissel N.Jacobsen, PhD 1998 SensoNorAS, Norway
Karol Macák, PhD1999 Kratos,Inc., UK
Denis Music, PhD2003 AachenUniversity, Germany
Veronika M.Kugler, PhD 2003 CarlZeiss SMT Ltd, UK
Jones Alami, PhD2005 SulzerMetaplas GmbH, Germany
Jon Andersson, PhD2005 SecoTools AB, Sweden
Johan Böhlmark, PhD2006 SandvikTooling, Sweden
Erik Wallin, PhD2008 SolibroAB, Sweden
Daniel Lundin, PhD2010 IonauticsAB, Sweden
MattiasSamuelsson, PhD 2012 ImpactCoatings AB, Sweden
Montri Aiempanakit,PhD 2013 SilpakornUniversity, Thailand
Asim Aijaz, PhD2014 LinköpingUniversity
Daniel Magnfält,PhD 2014 LinköpingUniversity
RickardGunnarsson, new 2013
Martin Mickan, new2013
· Post-docs in the group:
L.D.Madsen,1994-1995 Director at NSF, USA
Sveinn Olafsson,1997-1998 Professor at University of Iceland
JochenSchneider, 1998-1999 Professor at Aachen University
Dalibor Buc,1999 Lecturerat Slovak Univ. of Technology
Zhongchun Wang,1999-2001 Senior scientist at Soladigm Inc. CA, USA
Jon TomasGudmundsson, 2001 Professorat Shanghai Jiao Tong University
Elisabeth Åbom,2002-2004 Product Development Manager, SAPA, Finspång
MartinaLattemann, 2004-2007 Senior R&DEngineer, Sandvik Coromant
DanielSöderström, 2008-2010 Assistantprofessor Linköping University
KostasSarakinos, 2010-2011 Associate professor Linköping University
Iris Pilch,2010-2014 Assistantprofessor Linköping University
Michelle M.Villamayor, 2015-