Chapter 16 from 50 Years of Vacuum Coating Technology A Brief Modern History and the Growth of the Society of Vacuum Coaters, edited by Donald M. Mattox and Vivienne Harwood Mattox, of Cathodic Arc Coating Society of Vacuum Coaters, 2007 André Anders Lawrence Berkeley National Laboratory, University of California, Berkeley, California

Introduction Cathodic Arc Deposition Emerges as an Industrial Coatings based on the condensation of cathodic arc plasmas are widely Process used for a range of applications including hard and wear resistant The history of broad application of cathodic arc deposition is closely coatings on tools and automotive parts and corrosion resistant and related to work done in the 1960s by of a group of researchers at the decorative coatings on building supplies such as faucets and handles. National Science Center, Kharkov Institute of Physics and Technology The origin of the technology can be traced back to the 18th century. (NSC KIPT) [11]. Kharkov is a sizable city in Ukraine, which was part Many observations were closely related to the development of electrical of the Soviet Union at that time. Researchers at the Plasma Physics power sources and early electrical engineering. Major advancements Division studied means of obtaining high vacuum using sorption prop- on cathodic arc physics were made after the electron was discovered erties of condensates made by vacuum arcs. In 1964, L.P. Sablev and (J.J. Thomson 1897) and the structure of the atom was roughly under- coworkers succeeded in burning a steady-state vacuum arc on titanium, stood (E. Rutherford 1911). The early history of arc discharges and first and a Soviet Patent was issued in 1966 for a vacuum arc sorption pump arc-based coatings is described in other publications [1-3]. The actual [12]. This pump research was expanded by A.A. Romanov and A.A. industrial use of cathodic arc technology evolved in the 1970s in the Andreev to coating applications, including the synthesis of diamond-like Soviet Union and 1980s in the Western hemisphere. In this contribution, carbon using graphite as the arc cathode material. Soviet patents were the modern history is briefly reviewed, including the development of filed [13-15], but otherwise the work was kept secret and only published industrial arc coaters for hard and decorative coatings, the need for the in part, years later [16]. Apart from titanium and graphite, molybdenum implementation of macroparticle filtering, and the use of arc plasmas for was used in reactive mode to produce molybdenum nitride coatings the fabrication of multilayers, composite coatings, and nanostructures. with microhardness of 32-36 GPa. Although (or because!) these results where pioneering and of great practical importance, the work was not Arc Research and Development After World War II published until years later [17, 18]. Significant improvements of wear By the middle of the 20th century, arcs, both of the thermionic and performance of diesel engine piston rings and cutting tools were dem- cathodic modes, were widely used for special illumination and in mer- onstrated, as explained by Aksenov in his account of Soviet-area arc cury rectifiers, respectively. No such application was seen for coatings coatings history [11]. Understandably, these results caused great interest applications, after the early attempts by Edison were less than successful. in the new technology by tool and machine manufacturers in the Soviet Yet, the mystery of cathode processes stimulated much research before Union. A decision to construct a pilot commercial facility was reached. and after WWII, especially on the questions of the very high ion veloc- Based on outline drawings from the NSC KIPT group, technical design- ity [4] and current density [5]. ers of the Malyshev Plant, Kharkov Branch, detailed the design plans From the many contributions, one should be highlighted here. Igor and specifications under supervision by A.A. Ehtingant. Detailed draw- Greogevitch Kesaev worked in the late 1950s on “cold-cathode arcs” ings and specifications as well as the manufactured cathodic arc sources at the Gas Discharge Apparatus Laboratory in Moscow, Soviet Union. were delivered to the KIPT group. In 1973, the KIPT group started col- Although he focused on mercury arcs due to their industrial relevance laborating with the Moscow Machine Tool Institute and the All-Union as high-current rectifiers, his research included other cathode materials Research Institute for Tools. Additionally, in joint work with the Tomilin as well. One of his many contributions was the confirmation of a spot Diamond Tool Plant, metallization of natural and synthetic diamond sub-structure, which he called cells. He confirmed the notion that the was demonstrated. The KIPT group grew by a number of researchers cathodic arc spot is a location were current density is unevenly distrib- who should later become well-known for their work on filtered cathodic uted with peaks in spot cells reaching about 1011 A/m2. He stressed that arcs: Vladimir M. Khoroshikh, V.E. Strel’nitskij, Ivan I. Aksenov, and the apparent increase of measured current density values over the years Vitaly A. Belous. is directly related to the improvement of experimental technology rather The Soviet Union did not have a market economy but was centrally than a physics phenomenon. He suspected that future improvements state-controlled. Therefore, in order to bring the technology to its full may uncover even higher peak values in current density, with important potential, high-level government support was needed. In 1974, the USSR implication for the theoretical modeling of spot operation and electron State Committee of Science and Technology issued a decree ordering emission mechanism. His interpretations, later further developed in a nation-wide commercialization of the technology under the leadership Russian-only published book [6], became paradigms for a whole genera- of KIPT, i.e. the Kharkov institute where the first steps were made and tion of Soviet physicists and engineers dealing with cathodic arcs. This where most expertise was concentrated. This decree covered the devel- is of importance because cathodic arc deposition technology was origi- opment and commercialization of arc technology for the deposition of nally developed in the Soviet Union in the 1960s and 1970s. wear resistant coatings on tools and machine components, metalliza- The 1960s and 1970s were characterized by a number of improve- tion of diamond, and the synthesis of superhard materials. The decree ments to vacuum technology and the experimental techniques applied had wide-ranging consequences for the development of arc deposition to cathodic vacuum arc research. Milestone papers describing cathodic technology in the Soviet Union and, and with the transfer of technology arc plasmas as energetic with multiple charge states were published to the United States in 1979, affected the coatings technology in many by Plyutto and co-wokers [7], Davis and Miller [8], and Lunev and countries. coworkers [9]. While most work dealt with continuous (DC) arcs, one Still in 1974, a couple of pilot arc systems, dubbed “Bulat-2,” were can also find research dedicated to pulsed arcs [10]. set up by KIPT at a Kharkov Plant. They represented the first industrial arc coating machines, typically used for the deposition of titanium

46 2009 Summer Bulletin nitride. With these machines, knowledge of arc deposition processing • a first book dedicated to vacuum arcs was published outside the went from an R&D lab to industry. In the fall of 1974, KIPT was re- Soviet Union by James Lafferty, in 1980 [40]. organized; Valentin G. Padalka became the head of the laboratory, • first US patents, describing the principal construction of com- and a large material science group under V.V. Kunchenko was estab- mercial-grade (random motion) cathodic arc sources, were granted lished. The greater group, and funded by the Soviet Decree, expanded in 1971 to the American Alvin Snaper [41] and in 1974 to Leonid pioneering research in tool coating [19, 20], magnetic spot steering Sablev and coworkers from Kharkov, Ukraine (USSR) [42]. [21-24], interaction of streaming metal plasma with background gas Attempts were made to bringing the latest Soviet technology of mag- [17, 25], transport of plasma streams [24], and synthesis of superhard netically steered arc sources to the West. In December of 1979, despite materials including tetrahedral amorphous carbon [16, 26-33]. much Cold War secrecy and restrictions, the Bulat-3 arc technology for While these physical measurements and materials development the deposition of titanium nitride on tools was licensed to the American activities were ongoing, the next generation of cathodic arc sources, company “Noble Field,” which a little later was renamed to Multi-Arc Bulat-3, was designed (Figure 1). The first 20 units were manufactured Vacuum Systems. Through the initial work by Multi-Arc, cathodic arc by plants in Kharkov in 1977 and 1978. Mass production of these deposition became well-known outside the Soviet Union. sources started in 1979 not only in Kharkov but also in other plants in Tallinn (Estonian Soviet Republic) and Kiev (Ukraine), and later also Large Scale Industrial Use in the 1980s and 1990s in Saratov and Novosibirsk. By the late 1980s, a total of about 4000 Even with the first commercial arc sources operating in the US, the eye cathodic arc coating systems (Bulat-3 and its successor models) were was of course on the vast experience hidden behind the Iron Curtain. produced and in operation in many manufacturing plants throughout At the 1983 SVC conference, H.R. Smith, Jr., of Industrial Vacuum the Soviet Union. Engineering talked about “Current Vacuum Coating Processes in the Soviet Union” [43]. Clark Bergman of Multi-Arc Systems Inc. presented the company’s first contribution in 1985 entitled “Arc Plasma Physical Vapor Deposition” [44], which indeed was a useful summary of arc physics and practical steps for coating, including the use of high nega- tive bias for metal ion etching, as later used and patented in the arc bond sputtering (ABS) process (see below). A handful of companies, such as Multi-Arc, Vac-Tec Systems, and Hauzer, made deposition by arc evaporation, as it is sometimes called, their core technology for hard and decorative coatings. In the 1980s, not much was reported at technical meetings like the SVC Conferences continued on page 48

Figure 1. Cathodic arc source of the Bulat type, Soviet Union in the mid 1970s (photo taken by the author in 2003, Tomsk, Russia). In the United States and elsewhere, the role of vacuum-based coating technology was recognized and gained rapidly in popularity (though, here we mostly refer to evaporation and sputter deposition, rather than arc coating). The Society of Vacuum Coaters (SVC) was founded in 1957, and in 1960 the International Symposia on Discharges and Electrical Insulation (ISDEIV) started, a biannual series of sym- posia dealing with vacuum arcs and arc-based coatings (among the larger topics of electrical insulation, breakdown, and vacuum-based switching). In 1965, Kikuchi and coworkers of the Tokyo Institute of Technology pointed out that vacuum arc deposition might be especially advantageous for the “refractory and hard superconducting materials” [34]. Their electron diffraction studies of films deposited at room temperature showed that the films were “amorphous or composed of very small crystallites.” At the 1978 Technical Conference of the SVC, I. Kuznetsov from the U.S. Vacuum Technology Delegation gave an over- view on “Electron Beam Evaporation Processes in the Soviet Union” [35]. The development of arc sources outside the Soviet Union was “in the air,” as evidenced by • arc spot steering by magnetic fields was patented in 1961 by Harold Wroe in England [36, 37] (although the spot’s retrograde motion was observed much earlier, e.g. by M. Minorsky in 1928 [38], who was not mentioned by Wroe). • fundamental research on vacuum arc erosion was done by C.W. Kimblin at Westinghouse Research Laboratories in Pittsburgh, Pennsylvania, and by J.E. Daalder at the Eindhoven University of Technology in Eindhoven, The Netherlands [39].

2009 Summer Bulletin 47 History of Cathodic Arc Coating In the 1950s, the Soviet Union and the United States developed continued from page 47 sizeable research programs for thermo-nuclear fusion of the hydrogen isotopes deuterium and tritium [54]. One concept was the Tokamak (exception [45]), perhaps to protect the few proprietary recipes devel- fusion reactor, a toroidal (doughnut-shaped) plasma machine. By the oped by these companies. Though, first reviews on arcs and coatings 1960s, plasma physicists made detailed investigations of transport and appeared in the scientific literature [46, 47]. stability of hydrogen plasma and its heavy-element contaminants in Users critically looked at the economical advantages and the perfor- toroidal magnetic confinement. The motion of pulsed plasma jets, or mance, and macroparticles clearly diminished the value of arc coatings. “plasmoids,” was studied theoretically and experimentally. For this pur- For example, Gary Vergason, well familiar with evaporation, sputtering, pose, quarter and half-torus devices were built. By injecting plasmoids and (unfiltered) cathodic arc coatings, concluded that “of the three in curved filters, one attempted to separate the light hydrogen isotopes deposition techniques, sputtering offers the widest range of coatings from the much heavier contaminations. Figure 2 from V.S. Voitsenya with a high degree of process control and production repeatability.” et al.’s 1967 publication [55], shows a quarter torus used for the inves- [48]. The presence of macroparticles is one of the greatest drawbacks tigation of plasmoid transport and filter properties. One can easily of the large-scale cathodic arc technology until today. Yet, cathodic arc recognize the similarity with what became the 90°-degree duct filter deposition was established for mass production using both batch and used a decade later (Figure 3). The work of Ivan Aksenov and coworkers in-line coaters, though the former are clearly in the majority in coating [56, 57] in Ukraine lead to the now classic 90° filtered arc system. This 6 plants. It is common that large numbers of parts (> 10 annually) are group deserves recognition for the pioneering work done in the field of coated in one plant [49] using rapid cell cycling technology, which cathodic arc filtering, including the classic 90°-degree filter and also for includes systems for automated cleaning and preheating. The coatings a number of other filter geometries [58]. The filtered arc source became are usually multifunctional (corrosion resistant, decorative, etc.) and the core technology for the arc coating system “Bulat-4” (Figure 4). the parts are mainly supplied to the automotive and buildings industry After publishing their approach in the late 1970s and 1980s [56, 59], it (e.g. car headlights, faucets). took about a decade before several groups in the world copied and fur- Cathodic arc coatings are among the preferred coatings technologies ther developed the concept. For example, Schemmel and coworkers at because they are economical and they allow a greater variety of colors, Vac-Tech in Boulder, CO, reported in 1989 that filtered arc is promising a very important factor for consumers. In the 1990s, further improve- for the high rate deposition of high-quality aluminum oxide [60]. Phil ments to the products were made by combining traditional, thick Martin and coworkers reported at the 1993 SVC Conference on proper- electroplated coatings with thinner but denser and harder coatings. It ties of their filtered arc-deposited films [61], which included carbides, was reported that decorative coating by arc PVD on top of electroplated nitrides, and oxides of optical quality [62, 63]. In the United States, coatings improves the corrosion resistance and enhances the palette Commonwealth Scientific Corporation commercialized an arc system of colors [50]. Interestingly, the reverse order, a plated film on top of a with a 45º knee-filter, as reported by Dave Baldwin at the 1995 SVC hard arc PVD coating can also be used, in the case of gold plated TiN Conference [64]. for high-end decorative products such as watch wristbands and frames for eyeglasses [51]. Another interesting use of cathodic arc plasmas is its use for mate- rial removal by metal ion etching, rather than film deposition. In the arc-bond-sputtering (ABS) technology, introduced in the early 1990s, argon sputter cleaning was replaced by sputtering using ions from the cathodic arc plasma. The to-be-sputtered parts are highly negatively biased in the cleaning process before being coated. The metal ion etch improved the adhesion of coating on parts such as cutting tools [52].

Macroparticle Filtering: Enabling Precision Coating for High Tech Applications To eliminate, or at least reduce, the defects and roughness caused be macroparticles, magnetic macroparticle filters were considered very Figure 2. Quarter torus used for the investigation of plasmoids transport and early but they were not broadly introduced to any production due to filter properties (1: coaxial plasma source, 2: solenoid coil producing curved significant plasma losses, leading to lower deposition rates, hence lost magnetic field, 3: duct chamber, 4: RF antenna, 5: Thomson mass spectro- economical benefits. Clearly, the application of filters needed to be lim- graph; from a 1967 publication by Voitsenya et al. [55]). ited to high-end application were the quality of the coating, the value added, is of utmost importance. The occasional presence of macroparticles and uncertainty in Magnetic guiding of plasma from the cathode to the substrate has film uniformity and thickness are issues not acceptable in high-tech been suggested much earlier than is generally known. For example, in applications such as metallization of semiconductors and deposition a patent filed in 1937, the Germans Wilhelm Burkhardt and Rudolf of protective layers on magnetic storage media and devices. Therefore Reinecke claimed a method of coating articles where charged particles further improvements were sought, leading to novel geometries such as of vaporized material (i.e. ions of the cathodic arc plasma) are “concen- the off-plane double bend (OBDB) filter by Shi Xu, Beng Kang Tay and trated in the form of a beam proceeding from the fused material towards co-workers at the Nanyang Technological University, Singapore [65, the surface to be coated by a magnetic field produced above the fused 66], the S-filter [67] and Twist filter [68] investigated at Berkeley Lab material…and extending towards the surface to be coated.” [53] in California, Ryabchikov’s Venetian Blind filter [69, 70] in Siberia, and Apart from such early experiments, one may state that the invention the modular filter developed by Peter Siemroth and co-workers [71] in of macroparticle filtering was a spin-off from thermo-nuclear fusion Germany. More information on these filter concepts and geometries can research and not a targeted result of cathodic arc development. be found in reviews [72-74].

48 2009 Summer Bulletin Figure 5. Modular filtered arc system, developed by the IWS, Fraunhofer Figure 3. Classic 90° duct filter for the removal of macroparticles from the Society, for metallization of semiconductors (Germany, 2000, photo courtesy of cathodic arc plasma (adapted from [57]). the Fraunhofer Society). Of importance are the development of advanced filters, the utiliza- tion of the filtered, fully ionized arc plasma by substrate bias techniques, and the expansion of the technology from hard and decorative coatings into the fields of ultrathin films, nanostructures, and bio-medial coat- ings. Advances in computerized control equipment with fast feedback loops become enabling for precision coatings. Of special interest is the deposition of tetrahedral amorphous carbon (ta-C), the most diamond-like material within the family of diamond- like carbon (DLC) materials. Filtered arc enabled the deposition of continuous, extremely thin films, down to the nm range, suitable for the protection of magnetic storage disks and read-write heads [77, 78]. Another example of unusual precision coatings is the filtered arc metal- lization of semiconductor integrated circuits [71, 79]. continued on page 50

Figure 4. Filtered arc system “Bulat-4”, Soviet Union, late 1970s (photo cour- tesy of Dmitry Karpov).

Improvements of coating quality and reproducibility, enabling high- tech applications In the last years of the 20th century, a number of modern develop- ments expanded the use of cathodic arc technology towards several high-tech applications, as is evident by the development of macropar- ticle filters. Additional work focuses on improvement of the arc trigger mechanisms and tighter control of the arc spot location. The goal is to utilize the highly ionized arc plasma not just for commodities but for high end applications by bringing the cathodic arc systems to preci- sion levels long known to other coatings techniques (Figure 5). By combining control and reproducibility with the inherent advantages of cathodic arc technology, such as high deposition rates associated with copious amounts of plasma produced, high degree ionization and the presence of ions with hyperthermal velocities (corresponding the ener- gies of many 10s of eV), a unique brand of coating tools is emerging. The high compressive stress exhibited by cathodic arc films can be modified in controlled ways by advanced biasing techniques [75]. Inserting film-forming ions at high energy (1 keV or higher) can locally anneal the material and reduce stress while largely maintaining many other film properties, which is now well established by experiment as well as by molecular dynamics simulation [76].

2009 Summer Bulletin 49 History of Cathodic Arc Coating continued from page 49 Advances in Diagnostics and Modeling of Arc Plasma Processes Arc spots presented (and still do) a challenge to investigators due to short duration and very small scale of micro-explosions and related plasma gradients. Fast, high-resolution diagnostics has brought greatly improved insight. Until the 1990s, fast oscilloscopes provided evidence for short events [80], and electron microscopy of the erosion traces brought best evidence of small scales [5, 81]. Fast image-converter cam- eras became available and enabled observation of spot dynamics [82, 83] and spot structures, sometimes called fragments, and elemen- Figure 6. Very large deposition chamber for cathodic arc coatings; one can tary processes associated with the apparent spot motion [84, 85]. see a row of six arc sources of the Bulat-3 type, Russia, 1990s (photo cour- Another route to high-resolution diagnostics is via short-pulsed illumi- tesy of Dmitry Karpov). nation, e.g. from sub-nanosecond lasers. By tuning the laser wavelength, the time-dependent density distribution of selected species was deter- mined, e.g. density of free electrons, or ions and atoms in the ground state or in specific exited states, by either laser absorption [86, 87] or interferometry [88]. The conceptual understanding of cathode spot processes is still developing and closely associated with advances in plasma diagnostics and modeling. Based on experimental evidence, Mesyats [89, 90] intro- duced his “ecton” concept, which essentially postulates that the arc spot processes can be interpreted as a sequence of elementary microexplo- sions, each having a quantum-like minimum action. This approach allowed Mesyats and co-workers to model basic features of the erosion process and plasma parameters. Noteworthy is also the concept that spot processes superimpose in random fashion, and the concept of elementary steps need to be supple- mented with a statistical component, ultimately leading to self-similarity and a rather wide range of temporal and spatial fluctuations [91], which can be best interpreted by a fractal model of cathode processes [92]. The transport of plasma in the absence and presence of a magnetic field was investigated by deposition probes [93], a technique that has been made much more powerful by using now-available low-cost scan- ners and imaging software [94]. Plasma transport models developed included the computationally effective (but not self-consistent) drift model by Shi and co-workers [95] and the hydrodynamic model by Alterkop and co-workers [96, 97].

Cathodic Arcs for Large-Area Coatings Figure 7. Electrically switched arc for large area batch deposition; the sam- ples are placed on a rotating holder in the center of the system, while arc For almost all deposition processes, the question of scaling to large spots travel back and forth along long cathodes (adapted from [98]). areas needs to be addressed to reach the economy of scale. The cathodic arc process is challenging to scale because the source of plasma is the cathode spot, i.e., inherently a small area, even at higher current and Multilayers and Nanostructures of Multicomponent when using large cathodes. Plasma expansion is naturally used but large Materials Systems area coatings require the spot location to move over large cathode areas. In recent years, the science and technology of nanostructures has also Alternatively, a number of “point” sources can be used, like in the large reached the field of arc coatings. In the sense of multilayers of nm-thick system shown in Figure 6. film deposition, this was actually practiced for some years. However, Several practical solutions have been found, among them is high-resolution characterization, such as transmission electron micros- Vergason’s concept of switched arcs [98, 99] where the spot travels copy (TEM), has only recently reached the atomic scale. Examples are rapidly in a controlled fashion on cathodes of arbitrarily large size, the multicomponent coatings fabricated by arc (and sputtering) tech- usually exceeding 1 m length (Figure 7). Alternatively, spot motion can niques, such as (TiCr)N [105], Ti1-xAlxN [106, 107], TiCxN1-x [108], be magnetically steered on very elongated cathodes (Figure 8), and by and nanolaminates thereof [109]. These structures have unique proper- managing the magnetic field strength with computer-controlled distri- ties because stress issues can be addressed and spinodal decomposition bution, large area coatings are possible [100, 101]. Linear filter concepts [107] can form embedded nanocrystals. High toughness materials, have been put forward to accommodate large, essentially linear cathodes and material systems that are self-lubricating at high temperature have [102, 103]. Using an S-filter of elongated, rectangular cross section been developed, as needed for high speed cutting tools [110, 111]. New (Figure 9), films of optical quality on medium size glass panes have multicomponent materials are being explored, sometimes by combining been obtained [104]. cathodic arc coatings with sputtering (like the CrN/NbN system [112])

50 2009 Summer Bulletin 4. R. Tanberg, “On the cathode of an arc drawn in vacuum,” Phys. Rev., vol. 35, pp. 1080- 1089, 1930. 5. P.E. Secker and I. A. George, “Preliminary measurements of arc cathode current density,” J. Phys. D: Appl. Phys., vol. 2, pp. 918-920, 1969. 6. I.G. Kesaev, Cathode Processes of an Electric Arc (in Russian). Moscow: Nauka, 1968. 7. A.A. Plyutto, V.N. Ryzhkov, and A.T. Kapin, “High speed plasma streams in vacuum arcs,” Sov. Phys. JETP, vol. 20, pp. 328-337, 1965. 8. W.D. Davis and H.C. Miller, “Analysis of the electrode products emitted by dc arcs in a vacuum ambient,” J. Appl. Phys., vol. 40, pp. 2212-2221, 1969. 9. V.M. Lunev, V.G. Padalka, and V.M. Khoroshikh, “Plasma properties of a metal vacuum arc. II,” Sov. Phys. Tech. Phys., vol. 22, pp. 858-861, 1977. 10. A. Gilmour and D.L. Lockwood, “Pulsed metallic-plasma generator,” Proc. IEEE, vol. 60, pp. 977-992, 1972. 11. I.I. Aksenov and A.A. Andreev, “Vacuum arc coating technologies at NSC KIPT,” Problems Atomic Sci. Technol., Series: Plasma Physics, vol. 3, p. 242, 1999. 12. L.P. Sablev, V.V. Usov, A.A. Romanov, J.I. Dolotov, V.M. Lunev, V.N. Lutsenko, N.P. Atamansky, and A.S. Kushnir, Patent: USSR N235523, 1966. 13. A.A. Romanov and A.A. Andreev, Patent: USSR N367755, 1970. 14. A.A. Romanov, A.A. Andreev, and V.N. Kozlov, Patent: USSR N284883, 1969. 15. A.A. Romanov and A.A. Andreev, Patent: USSR N359977, 1970. 16. V.M. Lunev and V.P. Samoilov, “(in Russian),” Sintetis Almazy (Diamond Synthesis), no.4, Figure 8. Batch coater with door open: one can see the elongated cathode pp. 28, 1977. (target) of “racetrack” shape, such coater can be used for magnetron sput- 17. I.I. Aksenov, V.G. Bren’, V.G. Padalka, and V.M. Khoroshikh, “Chemical reactions in the tering and cathodic arc deposition (photo courtesy of Hauzer Techno Coating). condensation of metal-plasma streams,” Sov. Phys -Tech. Phys., vol. 23, pp. 651-653, 1978. 18. A.A. Andreev, L.V. Bulatova, G.N. Kartmasov, T.V. Kostritsa, V.M. Lunev, and A.A. Romanov, Fizika i Khimiya Obrabotki Materialov, vol. 2, pp. 169, 1979. 19. L.G. Odintsov, A.A. Romanov, A.A. Andreev, A.A. Ehtingant, V.M. Gorelik, A.S. Vereshchaka, and O.V. Pylinin, Patent: USSR N607659, 1976. 20. A.A. Andreev, A.A. Romanov, A.A. Ehtingant, and A.S. Vereshchaka, Patent: USSR N819217, 1976. 21. L.P. Sablev, Y.I. Dolotov, R.I. Stupak, and V.A. Osipov, “Electric-arc vaporizer of metals with magnetic confinement of cathode spot,” Instrum. Exp. Tech., vol. 19, pp. 1211- 1213, 1976. 22. I.I. Aksenov and A.A. Andreev, “Motion of the cathode spot of a vacuum arc in an inhomogeneous magnetic field,“ Sov. Tech. Phys. Lett., vol. 3, pp. 525, 1977. 23. L.P. Sablev, “Electric-arc vaporizer of metals with magnetic confinement of cathode spot,” Instrum. Exp. Tech., vol. 22, pp. 1174, 1979. 24. I.I. Aksenov, V.G. Padalka, and V.M. Khoroshykh, “Investigation of a flow of plasma generated by a stationary erosion electric arc accelerator with magnetic confinement of the cathode spot,” Sov. J. Plasma Phys., vol. 5, pp. 341, 1979. 25. V.M. Lunev, V.G. Padalka, and V.M. Khoroshikh, “Plasma properties of a metal vacuum arc. I,” Sov. Phys. Tech. Phys., vol. 22, pp. 855-858, 1977. 26. V.M. Lunev, V.P. Samoilov, V.P. Zubar’, V.G. Digtenko, and M.D. Kokoshko, (in Russian), Sintetis Almazy (Diamond Synthesis), vol. 4, pp. 26, 1978. 27. N.N. Matyushenko, V.E. Strel’nitskii, and A A. Romanov, (in Russian), Doklady Akad. Nauk UkrSSR, Ser. A, vol. 5, pp. 459, 1976. Figure 9. Deposition system for transparent oxide coatings on glass using a 28. V.E. Strel’nitskii, N.N. Matyushenko, A.A. Romanov, and V.T. Tolok, (in Russian), Doklady two linear filtered arc sources (Tel Aviv, Israel, about 2003. (photo courtesy of Akad. Nauk UkrSSR, Ser. A, vol. 8, pp. 760, 1977. Ray Boxman). 29. V.E. Strel’nitskii, V.G. Padalka, and S.I. Vakula, “Properties of the diamond-like carbon film produced by the condensation of a plasma stream with an RF potential,” Sov. or with plasma-enhanced chemical vapor deposition (e.g. the Zr-Si-N Phys.-Techn. Phys., vol. 23, pp. 222-224, 1978. system [113]). Many papers and even books were published recently to 30. I.I. Aksenov, A.A. Andreev, V.G. Bren’, S.I. Vakula, I.V. Gavrilko, E.E. Kudryavtseva, “Vacuum coatings obtained by condensation of plasma flows in vacuum (The method of describe or review these developments, see, for example, [114-120]. condensation with ionic bombardment)” (in Russian), Ukr. Fiz. Zh. (Russ. Ed.) vol. 24, pp.515-525, 1979. Acknowledgements 31. S.I. Vakula, V.G. Padalka, V.E. Strel’nitskii, and A.I. Cheoskin, Sverkhtverdye Materialii (Superhard Materials), no.1, p. 18, 1980. The contributions of many colleagues is gratefully acknowledged, 32. S.I. Vakula, V.G. Padalka, V.E. Strel’nitskii, and A.I. Usoskin, “Optical properties of including, but not limited to, Ray Boxman, Vladimir Gorokhovsky, diamond-like carbon films,” Sov. Techn. Phys. Lett., vol. 5, pp. 573-574, 1979. Dmitry Karpov, Don Mattox, Efim Oks, Thomas Schülke, Peter 33. I.I. Aksenov, S.I. Vakula, V.V. Kunchenko, N.N. Matyushenko, I.L. Ostapenko, V.G. Padalka, Siemroth, and Gera Yushkov. This work was supported by the Assistant and V.E. Strel’nitskii, Sverkhtverdye Materialii (Superhard Materials), no.3, p. 12, 1980. 34. M. Kikuchi, S. Nagakura, H. Ohmura, and S. Oketani, “Structures of the metal films Secretary for Energy Efficiency and Renewable Energy, Office of produced by vacuum-arc evaporation method,” Jap. J. Appl. Phys., vol. 4, p. 940, 1965. Building Technology, of the U.S. Department of Energy under Contract 35. I. Kuznetsov, “Electron beam evaporation processes in the Soviet Union,” 21st Annual No. DE-AC02-05CH11231. Technical Conference Proceedings of the Society of Vacuum Coaters, pp. 87-89, 1978. 36. 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52 2009 Summer Bulletin 104. R.L. Boxman, V. Zhitomirsky, S. Goldsmith, T. David, and V. Dikhtyar, “Deposition of grown by filtered cathodic arc deposition,” Appl. Phys. Lett., vol. 82, pp. 1634-1636, th SnO2 coatings using a rectangular filtered vacuum arc source,” 46 Annual Technical 2003. Conference Proceedings of the Society of Vacuum Coaters, pp. 234-239, 2003. 118. H. Huang, C.H. Woo, H.L. Wei, and X.X. Zhang, “Kinetics-limited surface structures at 105. J. Vetter, “Vacuum arc coatings for tools - potential and application,” Surf. Coat. the nanoscale,” Appl. Phys. Lett., vol. 82, pp. 1272-1274, 2003. Technol., vol. 77, pp. 719-724, 1995. 119. Z. Werner, J. Stanisawski, J. Piekoszewski, E.A. Levashov, and W. Szymczyk, “New types 106. A. Hörling, L. Hultman, M. Odén, J. Sjolén, and L. Karlsson, “Thermal stability of arc of multi-component hard coatings deposited by arc PVD on steel pre-treated by evaporated high aluminum-content Ti1-xAlxN thin films,” J. Vac. Sci. Technol. A, vol. 20, pulsed plasma beam,” Vacuum, vol. 70, pp. 263-267, 2003. pp. 1815-1823, 2002. 120. P.H. Mayrhofer, C. Mitterer, L. Hultman, and H. Clemens, “Microstructural design of 107. P.H. Mayrhofer, A. Hörling, L. Karlsson, J. Sjolen, T. Larsson, C. Mitterer, and L. Hultman, hard coatings,” Progress in Materials Science, vol. 51, pp. 1032-1114, 2006. “Self-organized nanostructures in the Ti-Al-N system,” Appl. Phys. Lett., vol. 83, pp. 2049-2051, 2003. 108. L. Karlsson, L. Hultman, M.P. Johansson, J.E. Sundgren, and H. Ljungcrantz, “Growth, microstructure, and mechanical properties of arc evaporated TiCxN1-x (0 <= x <= 1) For further information, contact André Anders, films,” Surf. Coat. Technol., vol. 126, pp. 1-14, 2000. Lawrence Berkeley National Laboratory at 109. Y.N. Kok, P. E. Hovsepian, Q. Luo, D.B. Lewis, J.G. Wen, and I. Petrov, “Influence of [email protected]. the bias voltage on the structure and the tribological performance of nanoscale multilayer C/Cr PVD coatings,” Thin Solid Films, vol. 475, pp. 219-226, 2005. André Anders is a Senior Scientist and the Leader 110. A. Hörling, L. Hultman, M. Odén, J. Sjölén, and L. Karlsson, “Mechanical properties and of the Plasma Applications Group at Lawrence machining performance of Ti1-xAlxN-coated cutting tools,” Surf. Coat. Technol., vol. 191, pp. 384-392, 2005. Berkeley National Laboratory, Berkeley, CA. For about 20 years he worked on plasma and materi- 111. P.E. Hovsepian, D.B. Lewis, Q. Luo, W.-D. Munz, P.H. Mayrhofer, C. Mitterer, Z. Zhou, and W.M. Rainforth, “TiAlN based nanoscale multilayer coatings designed to adapt their als issues and has become best known for his tribological properties at elevated temperatures,” Thin Solid Films, vol. 485, pp. 160- work on cathodic arc plasmas. He is the author 168, 2005. of A Formulary for Plasma Physics (1990) and 112. D.B. Lewis, D. Reitz, C. Wüstefeld, R. Ohser-Wiedemann, H. Oettel, A.P. Ehiasarian, and editor of the Handbook of Plasma Immersion P.E. Hovsepian, “Chromium nitride/niobium nitride nano-scale multilayer coatings Ion Implantation and Deposition (2000). His lat- deposited at low temperature by the combined cathodic arc/unbalanced magnetron André Anders technique,” Thin Solid Films, vol. 503, pp. 133-142, 2006. est book, Cathodic Arcs: From Fractal Spots to Energetic Condensation, was published by Springer, 113. A. Winkelmann, J.M. Cairney, M.J. Hoffman, P.J. Martin, and A. Bendavid, “Zr-Si-N films fabricated using hybrid cathodic arc and chemical vapour deposition: Structure vs. NY, in 2008. He is the author or co-author of about 250 papers in peer-reviewed jour- properties,” Surf. Coat. Technol., vol. 200, pp. 4213-4219, 2006. nals. He is a member of the Editorial Board of Applied Physics Letters, the Journal 114. A. Anders (Ed.), Handbook of Plasma Immersion Ion Implantation and Deposition. of Applied Physics, and the Elsevier journal of Surface and Coatings Technology. New York: John Wiley & Sons, 2000. Anders was elected Fellow of the American Physical Society (APS, 2008), Fellow of 115. S.-Y. Chun and A. Chayahara, “Pulsed vacuum are deposition of multilayers in the the Institute of Physics (IOP, 2002), and Fellow Institute of Electrical and Electronic nanometer range,” Surf. Coat. Technol., vol. 132, pp. 217-221, 2000. Engineers (IEEE, 2000). 116. P. Chen, S.P. Wong, M.F. Chiah, H. Wang, W.Y. Cheung, N. Ke, and Z.S. Xiao, “Magnetic properties of (Pr0.17Co0.83)(69)C-31 nanocomposite films prepared by pulsed filtered vacuum arc deposition,” Appl. Phys. Lett., vol. 81, pp. 4799-4801, 2002. 117. E. Byon, T.H. Oates, and A. Anders, “Coalescence of nanometer silver islands on oxides

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