Mechanisms of target poisoning during magnetron sputtering as investigated by realtime in situ analysis and collisional. Film thickness less than 10 nm initial growth stage. The atomic weights of the ions and the target atoms should be close. During reactive magnetron sputtering from a metallic target, a reactive gas is added to the discharge to deposit compound material 2. This phenomenon is influenced by a multitude of factors such as sputtering target properties and deposition process parameters, conditions and quality in general. Black nodules consist mainly of indiumsuboxide in 2o. The right pressure for a sustainable plasma 10 mtorr the right cathode voltage so that the ions have the right energy for sputtering e ion 100 ev and v cath 25 kv the right angle for high sputter.
In this study, the influence of target properties and sputtering parameters on nodule formation in sputtering targets of tungsten with 10 and 15 wt % titanium was investigated. This phenomenon is influenced by a multitude of factors such as sputtering target. Characterization of indiumtin oxide sputtering targets showing various densities of nodule formation article in thin solid films 5031. Among these methods, the magnetron sputtering is widely used since the method is superior in its controllability and high deposition rate. Magnetron sputtering at uio at minalab uio semicore triaxis with 3 cathodes 1 dc and 2 rf allows sputtering of more than one material at once uniformity measurement variyng the angle. Magnetron sputtering technology basic sputtering process there are many different ways to deposit materials such as metals, ceramics, and plastics onto a surface substrate and to form a thin film. Eight ito target materials for dc magnetron sputtering, showing different densities of nodule formation, were subjected to analyses of lattice parameter, relative density, electrical properties, optical absorption spectra in 0. Mixed target processing requires special attention to prevent the formation of. Nodule formation on magnetron sputtering targets vacuum. The target grain structure has been identified as one parameter determining their formation, and sprayed targets behave different from cast targets in this respect. Characterization of indiumtin oxide sputtering targets. The latter technology implemented as dc magnetron sputtering prevails today in the industry. Sputter target erosion and its effects on long duration dc. Nodules when sputtering ito nodules originate due to redeposition of sputtered species onto the target.
Magnetron sputtering requires an ito sputtering target. The improved target showed less nodule formation and fewer arcing compared with conventional target. Advanced indium tin oxide ceramic sputtering targets rotary and. Since sputtering is a purely physical process, adding chemistry to, for example, deposit a compound layer must be done ad hoc through the addition of a reactive gas to the plasma, i. Abstractabstractindium tin oxide ito ceramic sputtering targets used for the. Request pdf characterization of indiumtin oxide sputtering targets showing various densities of nodule formation eight sndoped in2o3 ito target materials for directcurrent dc magnetron. The mag keeper design is the latest addition to our torus family of sputtering magnetron solutions. Torus mag keeper uhv compatible circular magnetron.
The formation of nodules on the target surface during the sputtering process over time is associated. Among these is a process called sputtering that has. Mixedmaterial sputtering targets are also produced by cerac for use in printer head coatings, magnetic data recording layers, thin film resistors, wearresistant coatings, transparentconducting coatings, and other optical and electrooptical applications. Sputter target erosion and its effects on long duration dc magnetron sputter coating by michael elliott schoff master of science in engineering sciences mechanical engineering university of california, san diego, 2009 professor mark tillack, chair plasma discharge sputter. Effects of adding hydrocarbon gas to a highpower impulse. German, university of iowa abstract a ferromagnetic shim was placed between the target and the magnets of a planar magnetron sputtering target assembly to shunt the magnetic field. There is generally more material available to sputter on a rotary target, which increases runtimes. These nodule problems can cause undesired downtime due to the need for frequent cleaning of target surfaces. Rotatable magnetron sputtering in r2r web coating of optical. To learn more, explore dc magnetron sputtering, rf magnetron sputtering, and pulsed dc sputtering links below. Principle of the magnetron sputtering process 10 magnetron sputtering deposition techniques are widely applied both in industrial processes and in advanced material development or treatment 11. A parabolic relation showed a saturated nodule size with increased sputtering. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density.
Film thickness distribution in magnetron sputtering s swarm, edwards high vacuum international, manor royal, crawley, w. Unfor tunately, black growths, or nodules, commonly form in target. The use of high frequency in ac dual magnetron sputtering can reduce arc rate and nodule growth. Causes and their control by mf power supplies the growth of nodules on the target surface can become a serious problem in the reactive. Magnetron sputtering is a plasma based thin film deposition process where atoms are ejected from a target by energetic ions which deposit on a substrate. The growth of nodules on the target surface can become a serious problem in the reactive sputtering of oxide films. Power solution trends to failureproof data centers monday, february 03, 2020 data centers are energyintensive hubs, thanks to the exponential increase and explosive growth in big data, digital content, ecommerce, social media networks, the internet of things, mobility and cloud computing. Rotatable magnetron sputtering in r2r web coating of.
As an alternative to reactive sputtering from metallic targets, the use of. The effect of tin oxide dispersion condition on the nodule formation in the ito sputtering target was investigated. The ability to individually control each magnetron increases target erosion uniformity, while fixedfrequency. Diffusive racetrack oxidation in a ti sputter target by. The grs will typically use x3 more of the available target material compared to a planar magnetron giving a much longer between changeover. When the carbon film is sputtered for extended period in a production sputtering machine, nodular growth occurs over the sputtering surface of the carbon target. Request pdf nodule formation on sputtering targets. Effect of target composition and sputtering deposition.
For planar targets the target utilization is typically around 25%. However, a downside of using a rotatable magnetron is the lack of a dark space shield to confine the plasma close to the target and collect the plasma electrons as they leave the plasma trap. The aja international uhv sputtering system uses five shuttered magnetron guns containing two inch diameter targets to sputter deposit single thin films or stacked film layers on 1 4 diameter wafers, glass slides and small samples with optional substrate heating and rotation for enhanced film properties and improved film uniformity. Magnetron sputtering is available in a variety of source configurations and compatible with many of angstroms process control capabilities and advanced fixturing options. The magnetron design utilizes both monolithic and bonded target. The benefits of the developed ito rotary targets for industrial nanosized film processing e.
Effect of tin oxide dispersion on nodule formation in ito. Nodule formation on indiumoxide tinoxide sputtering targets. A plasma is created by ionizing a sputtering gas generally a chemically inert, heavy gas like argon. However, a downside of using a rotatable magnetron is the lack of a dark space shield to confine the plasma close to the target. The magnetron design utilizes both monolithic and bonded target configurations up to 0. Thin film growth through sputtering technique and its applications. However, the addition of the reactive gas not only results in the formation of compound material on the substrate but also on the target surface where its formation is balanced by the sputtering. Advanced indium tin oxide ceramic sputtering targets. It is already proved that a ceramic tco target needs to have high density and low resistivity in order to prevent abnormal arcing and nodule formation during film deposition. Rotary magnetron rotary cathode sputtering technology is broadly used in display manufacturing, both for rigid and flexible display applications.
Sputter deposition is a physical vapor deposition pvd method of thin film deposition by sputtering. Nodule growth on sputtering targets is caused by redeposition near the arc spot during arcing. Chemical evolution of target surfaces during rf magnetron. Often, magnetron sputtering processes are used for this purpose. Arnell centre for advanced materials and surface engineering, university of salford, salford m5 4wt, uk received 20 september 1999 abstract magnetron sputtering. Advanced indium tin oxide ceramic sputtering targets rotary and planar for transparent conductive nanosized films. The tin oxide dispersion condition was improved by using finer raw powder and by. The tin oxide dispersion condition was improved by using finer raw powder and by modifying mixing process.
Nodule formation growth on sputtering targets is a complex phenomenon that occurs on the target surfaces during certain sputter deposition processes. Indeed, at this high current density the ratedetermining step in the reaction is not the supply of oxygen atoms to the target, as it is the case during ion beam experiments. We manufacture sputtering targets in a wide range of materials, sizes, forms and configurations. Mar 19, 20 thus, specific embodiments and applications of the design and use of dc magnetron sputtering systems have been disclosed. Particle contamination formation and detection in magnetron. The use of high frequency in ac dual magnetron sputtering can.
Particle contamination formation in magnetron sputtering. Magnetron sputtering is a plasma vapor deposition pvd process in which a plasma is created and positively charged ions from the plasma are accelerated by an electrical field superimposed on the negatively charged electrode or target. Dc magnetron cathodes there was the additional opportunity to sputter up to three targets in the row without interrupting the vacuum. Dc magnetron cathodes there was the additional opportunity to sputter up to three targets. Particle contamination formation in magnetron sputtering processes. Sputter removal of these features is inhibited by the dependence of sputter.
There, film redeposition induces filament or nodule growth. High dynamic deposition rates of 50 nmmmin tio 2 up to 100 nmmmin nb 2 o 5 ensure high performance, yield and productivity of such films. This motion also reduces ito target nodule formation, which is a problem for most planar magnetron sputtering situations. There is much more to designing a worldclass magnetron than simply strapping some magnets into a watercooled cavity and hoping for the best. This paper reports experimental results for nearsurface ti sputter target oxidation in a magnetron racetrack during reactive high power impulse magnetron sputtering hipims at. Particle contamination formation in magnetron sputtering processes gary s. It has been observed in the past that in certain cases, when sputtering metal or ceramic materials, nodules are formed on the surface of sputter. Reactive gas feeding technique in deposition of titanium nitride film by magnetron sputtering witthawat wongpisan, kanin ruthairung, autcharaporn srion, suphakan kijamnajsuk and panadda. The target grain structure has been identified as one parameter determining their formation, and sprayed targets behave different from cast targets. Major cause of noduleformation is particulates from the sputtering system, less important are particulate inclusions in the target material. Films deposited by this method show good uniformity over wide area on large sized substrates 1418. Substantial cost reduction of the sputtering process can be achieved by using rotatable targets, since sputtering from rotatable targets promises an increase of throughput as well as target utilization. Sputtering target for conventional flat panel sputtering process is produced completely separated from the backing plate that supports the sputtering target. Diamondlike carbon dlc films were prepared via reactive highpower impulse magnetron sputtering hipims using a mixture of argon and a small amount of c 2 h 4 or ch 4 gas.
Such nodules are a source of process instability and of coating pinholes. The amount and life of the nodules as a function of target. Pdf advanced indium tin oxide ceramic sputtering targets. Nodule formation on magnetron sputtering targets vacuum coating.
Aside from sputtering the second important process is the emission of secondary electrons from the target surface. The deposition conditions are shown in detail in table 1. Rotatable targets of transparent conductive oxides. Quantitative measurement of nodule formation in wti. Rotatable magnetron sputtering in r2r web coating of optical layer stacks outline rotatable magnetron sputtering ac sputtering of dielectric films sio 2 sputtering impedance control tio 2, nb 2o 5 sputtering ceramic dc sputtering aspects of ito sputtering sputter roll coater for polymer films process flexibility. A carbon film for protecting a magnetic disk is sputtered by a dc magnetron sputtering method, with the addition of superimposed ac power on the dc power applied to the carbon target. Magnetron sputtering deposition magnetron sputtered thin. No nodule formation on the target surface and significantly reduced flaking are key factors for more perfect film growth. However, very few studies have reported the chemical evolution of target surfaces under an electromagnetic field during rf magnetron sputtering. Preventing plasma bombardment of the ito layer and in. Sputter target erosion and its effects on long duration dc magnetron sputter coating by michael elliott schoff master of science in engineering sciences mechanical engineering university of california, san diego, 2009 professor mark tillack, chair plasma discharge sputter coaters have been used to create uniform thin layers.
This involves ejecting material from a target that is a source onto a substrate such as a silicon wafer. Indiumtinoxide ito films and sm or ybdoped ito films were deposited by dc magnetron sputtering using sintered ceramic ito targets containing 3. Studying target erosion in planar sputtering magnetrons using. In this region, film redeposition is followed by filament or nodule growth and enhanced trapping which increases filament growth. A voltage is applied between them so that the target is the cathode and the substrate is attached to the anode. Nodules are a preferred spots for arc ignition, which can enhance their growth. Cleaning of target periodically, nodule formation may occur. Magnetron sputtering sputtering is only one result of ion bombardment sputtering of a target atom is just one of the possible results of ion bombardment of a surface. Arnell centre for advanced materials and surface engineering, university of salford, salford m5 4wt, uk received 20 september 1999 abstract magnetron sputtering has become the process of choice for the deposition of a wide range of industrially important. This eliminates the need for construction of expensive compound targets or the use of highly volatile gases. Modelling of the target voltage behaviour in reactive. So in sputtering, the target material and the substrate is placed in a vacuum chamber. The amount and life of the nodules as a function of target life was determined.
Since rotary sputtering decreases nodule formation, targets can have longer continuous runtimes. Sussex, uk of crucial importance to the thin film process engineer is an understanding of the parameters which affect the film. Quantitative measurement of nodule formation in wti sputtering. Initial growth and texture formation during reactive. The formation of nodules on the target surface during the sputtering process over time is associated with the fact that indiumoxide exists in three allotropic phases. Magnetron sputtering overview angstrom engineering. Thin film growth through sputtering technique and its.
Particle contamination generated during thin film processing can be detected using laser light scattering, a powerful diagnostic technique which provides realtime, in situ imaging of particles 0. Rotary target utilization is usually 80%, as opposed to 30% for planar targets. Tftlcd technology makes use of tco materials predominantly ito to provide the transparent electrode on the front side of the lcd pixel. Us5507930a method of sputtering a carbon protective film. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. Nodule formation on ito sputtering targets was investigated by stop action insitu video observation, 3dsims, and epma. Reactive dc magnetron sputter deposition from planar ceramic targets is the. Sputtering targets our highpurity, lowspit targets can resolve your concerns for uniformity, reproducibility and homogeneity. In this region, film redeposition is followed by filament or nodule. Weissb materials research corporation, 200 route 303, north congers, new york 10920 federico sequedac and carrie huangd.
Us5507930a method of sputtering a carbon protective film on. Film thickness distribution in magnetron sputtering. It is thought that the formation of nodules on sputtering targets can be influenced by a number of factors including. A simple low cost method for increased performance of planar magnetron sputtering targets j. Reactive gas feeding technique in deposition of titanium. Diffusive racetrack oxidation in a ti sputter target by reactive high power impulse magnetron. This causes an undesired downtime reducing production rate and so unquestionably formation of nodules on the target surface is highly undesirable. Rotatable magnetron sputtering in r2r web coating of optical layer stacks holger proehl, martin dimer, michael hentschel, falk otto, johannes struempfel. Magnetron sputtering deposition magnetron sputtered thin films. A nodule growth mechanism and strategies to minimize nodule formation are. Apr 11, 2020 nodule formation growth on sputtering targets is a complex phenomenon that occurs on the target surfaces during certain sputter deposition processes.
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