Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/24—Vacuum evaporation
  • C23C14/32—Vacuum evaporation by explosion; by evaporation and subsequent ionisation of the vapours, e.g. ion-plating
  • C23C14/325—Electric arc evaporation
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/24—Vacuum evaporation
  • C23C14/32—Vacuum evaporation by explosion; by evaporation and subsequent ionisation of the vapours, e.g. ion-plating
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/32—Gas-filled discharge tubes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/32—Gas-filled discharge tubes
  • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/32—Gas-filled discharge tubes
  • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
  • H01J37/3411—Constructional aspects of the reactor
  • H01J37/3414—Targets
  • H01J37/3426—Material

Definitions

• the present invention relates to a method for coating workpieces by means of cathodic spark evaporation and electrically conductive ceramic targets.
• the invention relates to a source for a coating installation for carrying out the above-mentioned method.
• the invention particularly relates to a coating system for carrying out the above-mentioned method.
• droplet vaporizing plays a key role in the sputtering of metallic tagrgets: rapid local heating of the metallic target material causes macroscopic spatters resulting from molten target material to be thrown from the target, which then precipitates onto the surfaces to be coated as a droplet.
• Such droplets can extremely negatively affect coating properties, such as wear resistance or surface roughness. Therefore, much effort is made to substantially avoid such droplets.
• CONFIRMATION COPY is to filter out the droplets before they can settle on the substrate.
• a measure is complex and usually has a negative impact on the coating rate. Since the droplet formation is greater, the slower the arc moves on the metallic target surface, there is also the possibility to reduce the droplet problem by forcing the arc on the target surface, for example by means of horizontally radially oriented magnetic field lines in a rapid movement.
• the published patent application WO200016373 discloses a configuration of a coating source in which magnetic means are provided behind the metallic target which leads to such a desired magnetic field distribution outside the central region of the target. Since there are vertical components of the magnetic field in the central region of the target, which would virtually capture the arc, the cover prevents the arc from getting there. For example, boron nitride and / or titanium nitride are indicated as the cover. As described therein, these materials have a lower secondary electron emission rate and a lower surface energy than the metallic target material.
• the droplet problem is essentially not given.
• the melting of the target material by the high melting point is much more complex than in such metallic compounds. Evaporation is more likely to be a sublimation process.
• Most of the pieces knocked out of the ceramic target surface by the arc are so large that they do not reach the workpieces to be coated due to gravity, but deposit themselves at the bottom of the coating chamber.
• the layer formed on the workpieces still comprises measurable so-called droplets. However, these are so sparse that no further measures against them are necessary.
• ceramic targets are essentially not used industrially in spark evaporation.
• An exception to this is tungsten carbide, whose thermal shock resistance in comparison to other ceramic materials in particular such as titanium nitride (TiN), titanium diboride (TiB 2 ), ZrB2, NbB2 tungsten boride (WB) or tungsten nitride (W2N) is lower.
• TiN titanium nitride
• TiB 2 titanium diboride
• ZrB2 ZrB2 tungsten boride
• WB tungsten nitride
• W2N tungsten nitride
• the invention is therefore based on the object, even those layer materials of ceramic targets can evaporate economically by means of electric arc, for which this has not been possible in any case on an industrial scale.
• TiN, TiB 2 , WB and / or W 2 N targets for vaporization by means of an arc, without early target breakage occurring.
• the inventors therefore investigated how the thermal shock transmitted to the target by the are can be efficiently trapped.
• sputtering technology which is a PVD coating method alternative to spark evaporation, to bond the sputtering target material with so-called cooling plates in order to enable efficient heat removal.
• Such cooling plates have a high thermal conductivity and are attached to the sputtering target material as widely as possible and with good thermal bridges.
• these cooling plates have a similar coefficient of expansion as the target material used for sputtering. Due to the high target power during sputtering, due to the comparatively high discharge voltage, a high thermal input occurs on the sputtering target, albeit distributed uniformly over the entire target.
• thermal stresses which can occur during spark evaporation and which can lead to thermal shock are localized and characterized by high temperature gradients, which leads to a mechanical overstressing of the ceramic target.
• thermal shock resistance due to the uniform temperature distribution m target is not relevant during sputtering.
• the inventors have found that, surprisingly, some measures that result in a reduction of the droplet problem associated with the sputtering of metallic targets, in connection with the ceramic targets, reliably and without damaging the ceramic and cold plate target Sparking can be applied. According to the invention, therefore, the spark evaporation is carried out in such a way that is evaporated by a ceramic target, on the back of a cooling plate is bonded by arc, characterized in that the arc is forced to rapid movement on the target surface.
• An arc source according to the invention for coating installations for arc evaporation therefore comprises at least one ceramic target, on whose rear side with good thermal contact, preferably bonded, a cooling plate is provided, characterized in that means are provided in the installation of which the cathode spot of the arc is forced to move, which reduce the local heating and thereby the formation of microcracks and prevent even in the case of the formation of small microcracks at this point increased residence probability of the cathode spot.
• Fig. 1 shows a source according to the invention with inventive target plate in a schematic side view.
• FIG. 2 shows an embodiment of an inventive component of the arc source.
• FIG. 3 shows a further embodiment of an inventive component of the arc source.
• Fig. 1 an inventive arc evaporator source is shown, as it is used in an arc evaporation chamber for coating substrates. It usually includes an ignition device 20 - as shown purely schematically - to ignite the arc. Furthermore, an electrical high-current I H , low-voltage U L DC voltage source 23 is connected between the target plate 1 and an anode 21, again shown purely schematically.
• the arc source according to the invention comprises the electrically conductive ceramic target plate 1 with surface 2 to be vaporized.
• a cooling plate 10 is provided with the target plate 1 in a thermally effective manner ,
• the cooling plate 10 is made of a material having high thermal conductivity.
• the cooling plate is able to distribute the local energy input occurring through the cathode spot onto the target surface 2 rapidly and efficiently over the entire target cross section.
• the risk of destruction of the target plate 1 due to thermal shock is thus already somewhat mitigated by this precaution.
• the cooling plate is additionally electrically conductive, the electrical contact can take place the target plate 1 to the voltage source 23 via the cooling plate 10 may be realized.
• molybdenum may be considered as a cold plate material, but other materials known in sputtering technology may be used.
• the thermal bonding is made by bonding the cooling plate to the target plate.
• the stain therefore remains at this point, which means that the thermal shock assumes orders of magnitude which even the cooling plate can no longer absorb.
• the arc source according to the invention therefore also comprises means which force the cathode spot or, if appropriate, the cathode spots of the arc to move over the target and optionally away from microcracks.
• these means comprise behind the cooling plate arranged inner permanent magnet 1 1 and an outer ring magnet 13 which is oriented opposite to the inner permanent magnet 1 1 opposite pole. Due to the inner permanent magnet 11 and the outer ring magnet 13, there are magnetic field lines extending from north to south or from south to north over the surface 2 to be vaporized.
• a cover 3 is arranged in a central region on the surface 2 of the electrically conductive ceramic target plate 1, wherein the cover 3 is such that no additional supply of electrons is ensured in this region, which could feed the arc at the cathode spot.
• at least the surface of the cover 3 is made of non-conductive material, such as Al 2 0 3 or boron nitride. It is conceivable but also to make the cover 3 of conductive material, however, to isolate them from the voltage source 23 or bring at least in worse electrical contact with the voltage source 23. Thus, with such an arrangement of the electron supply is prevented or at least greatly inhibited.
• the cathode spot of the arc will preferably migrate where sufficient electron replenishment is provided, thus avoiding the central region 6 in which vertical components of the magnetic field predominate.
• FIG. 2 schematically shows a target plate 1 with a bonded cooling plate 10.
• the target plate has a central bore and the cooling plate 10 has an internal thread, so that a shield 3 according to the invention is screwed to the combination of target plate 1 and cooling plate 10 by means of a likewise shown screw 15 can.
• FIG. 3 shows a further embodiment according to the invention of a target plate 1 with bonded cooling plate 10 and shielding 3.
• the shield 3 is embedded in a large-area hole of the target plate 1.
• there is a small transition of the shield 3 over the target plate 1 so as to prevent the cathode spot from approaching an edge of the target plate 1 and being caught there.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Analytical Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physical Vapour Deposition (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=44121711

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (2)

Citations (6)

Family Cites Families (21)

• 2011
  • 2011-04-13 WO PCT/EP2011/001856 patent/WO2011137967A1/de not_active Ceased
  • 2011-04-13 KR KR1020127031710A patent/KR101814228B1/ko not_active Expired - Fee Related
  • 2011-04-13 JP JP2013508382A patent/JP5721813B2/ja not_active Expired - Fee Related
  • 2011-04-13 CA CA2798210A patent/CA2798210C/en not_active Expired - Fee Related
  • 2011-04-13 EP EP11716177.8A patent/EP2566999B1/de not_active Not-in-force
  • 2011-04-13 CN CN2011800222872A patent/CN102859027A/zh active Pending
  • 2011-04-13 US US13/695,839 patent/US20130220800A1/en not_active Abandoned
  • 2011-04-13 CN CN201610725648.4A patent/CN106435488A/zh active Pending

Patent Citations (7)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events