The Experts below are selected from a list of 235140 Experts worldwide ranked by ideXlab platform
Tomas Kubart - One of the best experts on this subject based on the ideXlab platform.
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evolution of sputtering Target Surface composition in reactive high power impulse magnetron sputtering
Journal of Applied Physics, 2017Co-Authors: Tomas Kubart, Asim AijazAbstract:The interaction between pulsed plasmas and Surfaces undergoing chemical changes complicates physics of reactive High Power Impulse Magnetron Sputtering (HiPIMS). In this study, we determine the dynamics of formation and removal of a compound on a titanium Surface from the evolution of discharge characteristics in an argon atmosphere with nitrogen and oxygen. We show that the time response of a reactive process is dominated by Surface processes. The thickness of the compound layer is several nm and its removal by sputtering requires ion fluence in the order of 1016 cm−2, much larger than the ion fluence in a single HiPIMS pulse. Formation of the nitride or oxide layer is significantly slower in HiPIMS than in dc sputtering under identical conditions. Further, we explain very high discharge currents in HiPIMS by the formation of a truly stoichiometric compound during the discharge off-time. The compound has a very high secondary electron emission coefficient and leads to a large increase in the discharge current upon Target poisoning.The interaction between pulsed plasmas and Surfaces undergoing chemical changes complicates physics of reactive High Power Impulse Magnetron Sputtering (HiPIMS). In this study, we determine the dynamics of formation and removal of a compound on a titanium Surface from the evolution of discharge characteristics in an argon atmosphere with nitrogen and oxygen. We show that the time response of a reactive process is dominated by Surface processes. The thickness of the compound layer is several nm and its removal by sputtering requires ion fluence in the order of 1016 cm−2, much larger than the ion fluence in a single HiPIMS pulse. Formation of the nitride or oxide layer is significantly slower in HiPIMS than in dc sputtering under identical conditions. Further, we explain very high discharge currents in HiPIMS by the formation of a truly stoichiometric compound during the discharge off-time. The compound has a very high secondary electron emission coefficient and leads to a large increase in the discharge cu...
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modelling of sputtering yield amplification in serial reactive magnetron co sputtering
Surface & Coatings Technology, 2012Co-Authors: Tomas Kubart, Andreas Pflug, Matthias Wuttig, Tomas Nyberg, Michael Siemers, M. Austgen, Rudiger Schmidt, Sören BergAbstract:Serial magnetron co-sputtering can be used to increase the deposition rate in reactive deposition of thin films. The increase in deposition rate is achieved by sputtering yield amplification through doping the sputtering Target by a heavy element. The dopant is introduced by means of sputtering from an auxiliary Target onto a rotating primary magnetron. During sputtering of the primary Target, the dopant is implanted into the Target Surface. Here we present a model describing the serial co-sputtering technique. The model is based on the binary collision approximation and takes into account the dynamical sputtering and mixing at the Target Surface. As an example, W and Bi doping in reactive sputter deposition of Al2O3 is analyzed. W is shown to be very efficient dopant which can increase the deposition rate for oxide up to 100% with 1.6 at.% of W in the resulting coating. Doping by Bi is not very effective due to the low Surface binding energy of Bi. The simulations show that sputtering yield amplification can be realized in the serial co-sputtering setup with rotating magnetrons.
Diederik Depla - One of the best experts on this subject based on the ideXlab platform.
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the influence of Target Surface morphology on the deposition flux during direct current magnetron sputtering
Thin Solid Films, 2013Co-Authors: Francis Boydens, Wouter Leroy, Rosita Persoons, Diederik DeplaAbstract:Abstract The effect of the Target Surface morphology on the sputter deposition flux and the energy flux is investigated by comparing solid Targets to pressed powder Targets. A significant, material dependent difference of the effective sputter yield between both Target types is noticed. This difference is explained by combining two effects: a local increase of the elemental sputter yield and the redeposition of sputtered atoms onto the Target. Both effects strongly depend on the Target Surface morphology. The experimental trends are reproduced by Monte Carlo simulations. This allows a description of the angular distribution of the sputtered atoms which is an important parameter to define the particle flux and the energy distribution of the atoms arriving on the substrate. Using the previously developed particle trajectory code simtra , the latter is demonstrated for the studied materials (Al, Ag, Cu, and Ti).
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understanding the discharge voltage behavior during reactive sputtering of oxides
Journal of Applied Physics, 2007Co-Authors: Diederik Depla, J Haemers, S Heirwegh, Stijn Mahieu, R. De GryseAbstract:The discharge voltage was measured for 15 different metallic Target materials at constant current before and after plasma oxidation in order to understand its behavior during reactive magnetron sputtering. Plasma oxidation of the Target Surface was achieved by sputtering the Target in pure oxygen. The discharge voltage measured in pure argon is characteristic for each kind of metallic Target and is related to the ion induced secondary electron emission (ISEE) coefficient of the Target material. Based on this relation a value for the ISEE coefficient of the oxidized Target Surface can be calculated. Two distinct groups can be discerned: for one group the ISEE coefficient of the oxidized Target Surface is larger than the ISEE coefficient of the metal, while the opposite behavior is noticed for the second group. This difference seems to find its origin in the reduction behavior of the oxides under ion bombardment, since the ISEE coefficient of the oxide can be related to the simulated degree of reduction of ...
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Modeling of the Target Surface modification by reactive ion implantation during magnetron sputtering
Journal of Vacuum Science & Technology A: Vacuum Surfaces and Films, 2004Co-Authors: Diederik Depla, R. De Gryse, Z. Y. Chen, Annemie Bogaerts, V. Ignatova, Renaat GijbelsAbstract:The erosion rate of an aluminum Target bombarded with Ar+ and O2+ ions was simulated using TRIDYN. An abrupt change of the erosion rate is noticed at a critical mole fraction of O2+ ions. This Target behavior can also be described by a simple analytical model showing that the abrupt change finds its origin in an avalanche induced by reaction ion implantation. Indeed, by the reduction of the average sputter yield by compound formation, more reactive ions become implanted into the Target as the number of implanted ions depends inversely on the average sputter yield. As such, an avalanche situation can develop which finally results in a completely oxidized Target. It is also shown that the critical mole fraction depends linearly on the sputter yield of the Target material and that Target poisoning induced by ion implantation can result in a hysteresis behavior for the Target condition.
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Target Surface condition during reactive glow discharge sputtering of copper
Plasma Sources Science and Technology, 2002Co-Authors: Diederik Depla, J Haemers, R. De GryseAbstract:During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the Target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the Target Surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the Target Surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded.
Asim Aijaz - One of the best experts on this subject based on the ideXlab platform.
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evolution of sputtering Target Surface composition in reactive high power impulse magnetron sputtering
Journal of Applied Physics, 2017Co-Authors: Tomas Kubart, Asim AijazAbstract:The interaction between pulsed plasmas and Surfaces undergoing chemical changes complicates physics of reactive High Power Impulse Magnetron Sputtering (HiPIMS). In this study, we determine the dynamics of formation and removal of a compound on a titanium Surface from the evolution of discharge characteristics in an argon atmosphere with nitrogen and oxygen. We show that the time response of a reactive process is dominated by Surface processes. The thickness of the compound layer is several nm and its removal by sputtering requires ion fluence in the order of 1016 cm−2, much larger than the ion fluence in a single HiPIMS pulse. Formation of the nitride or oxide layer is significantly slower in HiPIMS than in dc sputtering under identical conditions. Further, we explain very high discharge currents in HiPIMS by the formation of a truly stoichiometric compound during the discharge off-time. The compound has a very high secondary electron emission coefficient and leads to a large increase in the discharge current upon Target poisoning.The interaction between pulsed plasmas and Surfaces undergoing chemical changes complicates physics of reactive High Power Impulse Magnetron Sputtering (HiPIMS). In this study, we determine the dynamics of formation and removal of a compound on a titanium Surface from the evolution of discharge characteristics in an argon atmosphere with nitrogen and oxygen. We show that the time response of a reactive process is dominated by Surface processes. The thickness of the compound layer is several nm and its removal by sputtering requires ion fluence in the order of 1016 cm−2, much larger than the ion fluence in a single HiPIMS pulse. Formation of the nitride or oxide layer is significantly slower in HiPIMS than in dc sputtering under identical conditions. Further, we explain very high discharge currents in HiPIMS by the formation of a truly stoichiometric compound during the discharge off-time. The compound has a very high secondary electron emission coefficient and leads to a large increase in the discharge cu...
R. De Gryse - One of the best experts on this subject based on the ideXlab platform.
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understanding the discharge voltage behavior during reactive sputtering of oxides
Journal of Applied Physics, 2007Co-Authors: Diederik Depla, J Haemers, S Heirwegh, Stijn Mahieu, R. De GryseAbstract:The discharge voltage was measured for 15 different metallic Target materials at constant current before and after plasma oxidation in order to understand its behavior during reactive magnetron sputtering. Plasma oxidation of the Target Surface was achieved by sputtering the Target in pure oxygen. The discharge voltage measured in pure argon is characteristic for each kind of metallic Target and is related to the ion induced secondary electron emission (ISEE) coefficient of the Target material. Based on this relation a value for the ISEE coefficient of the oxidized Target Surface can be calculated. Two distinct groups can be discerned: for one group the ISEE coefficient of the oxidized Target Surface is larger than the ISEE coefficient of the metal, while the opposite behavior is noticed for the second group. This difference seems to find its origin in the reduction behavior of the oxides under ion bombardment, since the ISEE coefficient of the oxide can be related to the simulated degree of reduction of ...
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Modeling of the Target Surface modification by reactive ion implantation during magnetron sputtering
Journal of Vacuum Science & Technology A: Vacuum Surfaces and Films, 2004Co-Authors: Diederik Depla, R. De Gryse, Z. Y. Chen, Annemie Bogaerts, V. Ignatova, Renaat GijbelsAbstract:The erosion rate of an aluminum Target bombarded with Ar+ and O2+ ions was simulated using TRIDYN. An abrupt change of the erosion rate is noticed at a critical mole fraction of O2+ ions. This Target behavior can also be described by a simple analytical model showing that the abrupt change finds its origin in an avalanche induced by reaction ion implantation. Indeed, by the reduction of the average sputter yield by compound formation, more reactive ions become implanted into the Target as the number of implanted ions depends inversely on the average sputter yield. As such, an avalanche situation can develop which finally results in a completely oxidized Target. It is also shown that the critical mole fraction depends linearly on the sputter yield of the Target material and that Target poisoning induced by ion implantation can result in a hysteresis behavior for the Target condition.
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Target Surface condition during reactive glow discharge sputtering of copper
Plasma Sources Science and Technology, 2002Co-Authors: Diederik Depla, J Haemers, R. De GryseAbstract:During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the Target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the Target Surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the Target Surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded.
Zhiyi Wei - One of the best experts on this subject based on the ideXlab platform.
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effective fast electron acceleration along the Target Surface
Optics Express, 2008Co-Authors: Xiaohui Yuan, Zhongxin Zheng, Wenxi Liang, Yuanjie Zhang, Feng Liu, Jens Bernhardt, Sunlong Wang, Z Wang, Weijun Ling, Zhiyi WeiAbstract:The dependence of angular distributions of fast electrons generated in the interaction of p-polarized femtosecond laser pulses with foil Targets on laser intensities is investigated. A novel fast electron beam along the front Target Surface is observed for high laser intensity. It is found that the electron acceleration along the Target Surface is more efficient than those in other directions.
