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
  • C23C14/34—Sputtering
  • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
  • C23C14/354—Introduction of auxiliary energy into the plasma
• • 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
  • C23C14/225—Oblique incidence of vaporised material on substrate
• • 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
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/08—Oxides
  • C23C14/083—Oxides of refractory metals or yttrium
• • 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
  • C23C14/34—Sputtering
  • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
• • 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
  • C23C14/34—Sputtering
  • C23C14/46—Sputtering by ion beam produced by an external ion source
• • 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
  • H01J37/32431—Constructional details of the reactor
  • H01J37/3266—Magnetic control means
• • 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
  • H01J37/3402—Gas-filled discharge tubes operating with cathodic sputtering using supplementary magnetic fields
  • H01J37/3405—Magnetron sputtering

Definitions

• This invention relates to deposition methods of bi-axially textured coatings where the bi-axial texturing is induced by bombardment during deposition by energetic particles under a specifically controlled angle.
• a bi-axially textured coating is a coating in which two crystallographic directions are parallel in adjacent grains. It is a known fact that a flux of energetic particles directed, during deposition, under an angle less than 90 with respect to the substrate surface can induce bi-axial texturing in a coating. It is also known that, depending on the crystal structure of the material to be deposited, there will be an optimal angle of incidence for the energetic particles which will result in the highest degree of bi-axial texturing, L.S. Yu, J.M. Harper, J.J. Cuomo and D.A. Smith, J. Vac. Sci. Technol. A 4(3), p. 443, 1986, R.P. Reade, P. Berdahl, R.E. Russo, S.M.
• the present invention provides a method for deposition of bi-axially textured coatings onto a substrate using one or more magnetron sputtering devices as a source of both the particles to be deposited and a directed flux of energetic particles inducing the bi-axial texturing.
• the present invention also includes use of an unbalanced magnetron including a sputter gas and a target for sputtering target material onto a substrate, to generate an ion beam by ambipolar diffusion, said ion beam consisting essentially of ions of the sputter gas.
• the present invention also provides a method for deposition of bi-axially textured coatings onto a substrate utilising one or more magnetron sputtering devices generating both a flux of material to be deposited and a flux of energetic particles with a controllable direction and thereby controllable angle of incidence on the substrate.
• the present invention also includes a magnetron sputter source generating a beam of energetic particles together with material to be deposited directed towards a substrate under an angle controlled in such a way that a bi-axially textured coating is deposited on the substrate.
• Fig. 1 is a schematic representation of a planar magnetron sputtering source in accordance with one embodiment of the present invention.
• Fig. 2 is a schematic representation of a rotating cathode magnetron sputtering source in accordance with one embodiment of the present invention.
• Figs. 3a and b are schematic representations of the magnetic field lines of a planar and a rotating magnetron sputtering source in accordance with the present invention.
• Figs. 4a - d are schematic representations of electrostatic deflection shields which may be used with any of the embodiments of the present invention.
• Figs. 5 and 6 are schematic representations of multiple planar and rotating cathode sputtering sources in accordance with an embodiment of the present invention.
• Fig. 7 is a schematic representation of a planar magnetron sputtering source in accordance with another embodiment of the present invention.
• the method for the deposition of bi-axially textured coatings according to the present invention may be used for coating stationary substrates, rotating substrates, batches of substrates and in continuous coating processes.
• the magnetron sputter device or devices used may be any suitable sputtering magnetron, e.g. magnetrons with planar circular targets or planar rectangular targets, or rotatable devices.
• a target material 3 is located in a vacuum chamber (not shown) with a magnet assembly 2 on one side thereof and a substrate 6 to be sputter coated located on the other side thereof.
• the atmosphere of the vacuum chamber may include sputtering gases such as argon and may also include reactive gases such as oxygen or nitrogen when reactive sputtering is to be carried out.
• Substrate 6 may be a stationary plate or a moving strip of material.
• the target material 3 may be cooled, e.g. by a water circuit (not shown) which is not accessible from the vacuum chamber.
• the negative pole of an electrical supply (not shown) is connected to the target 3.
• the combination of the crossed electric and magnetic fields above the target 3 generate a plasma 4 above the target 3.
• the plasma 4 is generally in areas of high magnetic field generated by poles 8, 9 of the magnet assembly 2.
• the magnet assembly 2 may include a central magnet array 9 which has one pole directed towards the target 3 (either north or south) and outer magnet arrays 8 which have the other pole (south or north) directed towards the target 3. If the target 3 is circular, the magnet arrays 8 and 9 may also be circular.
• the poles 8, 9 may be located on a soft magnetic material keeper 7, e.g. soft iron.
• Fig. 2 is a schematic representation of a rotating cathode sputtering magnetron 1 in accordance with the present invention.
• a generally cylindrical target 3 is provided in a vacuum chamber (not shown) with sputtering gas or gasses as previously described.
• a magnet assembly 2 is provided within the target 3 and a means for generating relative motion between the target 3 and magnet assembly 2 is also provided. Usually the target 3 is rotated and the magnet assembly 2 is held 6 still.
• An electric supply (not shown) holds the target 3 at a negative potential.
• the poles 8, 9 of the magnet assembly 2 are located close to the inner surface of target 3 and generate magnet fields above the target 3. These magnet fields with the crossed electric field generate a plasma 4 usually in the form of a "race-track" above the surface of the target 3.
• a substrate 6 is located.
• Substrate 6 may be a stationary plate or a moving strip of material.
• the magnetron sputter device 1 and the substrate 6 may be configured as schematically represented in Figs. 1 or 2, with a flux 5 of energetic particles, coming from the magnetron sputter device 1, directed toward the substrate 6 under a specific angle ⁇ that will give the maximum degree of bi-axial texturing.
• the angle ⁇ depends on the material to be deposited. For a cubic material in the coating, for instance, ⁇ will be approximately equal to 54.74°.
• the flux 5 of energetic particles is substantially only generated by the sputtering device 1 which provides not only this flux 5 but also sputters the coating onto the substrate 6 which is to be textured.
• the flux 5 may be substantially free of any ions from the target material.
• the flux 5 may consist substantially of ionised gas atoms or molecules, e.g. from the sputter gas.
• the directed flux 5 of energetic particles from a magnetron sputter device is obtained in accordance with the present invention by using an unbalanced magnet configuration 2 that causes secondary electrons emitted at the target 3 and electrons generated in the plasma 4 to move along the magnetic field lines toward the substrate 6, resulting, through ambipolar diffusion, in a directed flux 5 of energetic ions toward the substrate 6.
• a balanced magnetron most of the field lines leaving one pole of the magnet assembly are collected on the opposite pole of the magnet assembly.
• an unbalanced magnetron some of the magnetic filed lines from one pole are not collected on the other pole.
• Unbalancing may be achieved in a variety of ways, e.g. by using magnets of different strengths, by using magnets of different sizes, by weakening part of the magnet assembly by placing magnets of opposed polarity close to one of the poles of the assembly, by locating a competing 7 electromagnet close to one of the poles.
• the magnet assembly 2 of the magnetron sputter device 1 either planar (Fig. 3a) or rotating cathode (Fig. 3b), in accordance with the present invention is configured in such a way that a substantial number of magnetic field lines 11 emanating from the outer magnet array 8 in the magnet assembly 2, cross the substrate surface. This can be achieved by considerably stronger outer magnets 8 compared with inner magnets 9.
• the result of unbalancing the magnetron 1 in this way is to produce a three dimensional volume 12 which is defined by the field lines 11 of the outer magnets 8 which do not collect on the inner magnets 9.
• Some electrons from the plasma 4 follow the field lines 11 thereby also "dragging" with them a flow of high energy positive ions, typically ions of the surrounding gasses. Such a flow may be called an ambipolar flow.
• the flux 5 is directed towards the substrate 6 within and around the volume 12 and can texturise the coating which is being sputtered onto the substrate 6 by normal sputtering action. Hence, in accordance with the present invention the flux 5 has a definable direction.
• the energy of the electrons following the field lines 11 towards the substrate is preferably not such as to cause significant ionisation.
• the electrons in the flux 5 do not initiate nor support a significant plasma at, or close to the surface of the substrate 6.
• a significant plasma is meant a plasma which may disturb the directionality of the high energy ions in the flux 5 which induce the surface texturing of the coating. It is this directionality and its relationship to the crystal structure of the deposited coating which allows texturing of this coating.
• the ion beam 5 generated in accordance with the present invention should impinge on the substrate 6 at a defined angle.
• the electron energy in the flux 5 should preferably be greater than 30 eV, more preferably greater than 50 eV and most preferably between 50 and 70 eV. If a disturbing plasma develops at the substrate surface, its effects may be reduced by changing the degree of unbalance of the magnetron 1 so that the energy of the particles, particularly the electrons in the flux 5 is reduced. 8
• the directed flux 5 of energetic particles from an unbalanced magnetron sputter device 1 can be enhanced by using electrostatic deflection shields 13 that increase the number of electrons reaching the substrate 6 by moving along the magnetic field lines 11.
• the deflection shields 13 are preferably held at a negative potential in order to repel electrons.
• the deflections shields 13 should preferably not extend too deeply into the region 12 otherwise they may start to trap positive ions in the flux 5.
• Some examples of such deflection shield configurations are schematically shown in Fig. 4 in cross-section for a planar magnetic configuration.
• straight shields 13 may be used which are oriented perpendicular to the target 3.
• the shields 13 may be in the form of a cylinder.
• the shields 13 are "V" shaped in cross-section or inclined inwards towards the substrate, respectively.
• Such shields 13 may assist in channelling any electrons with a wide trajectory towards the substrate 6.
• the shields may be inclined outwardly as shown schematically in Fig. 4d, thus concentrating the electron flow close to the target 3.
• the deflection shields 13 shown in Figs. 4a to d can also be used with rotatable magnetron devices.
• any inhomogeneity of the coating deposition on the substrate 6 in the configurations schematically shown in Fig. 1 and in Fig. 2 may be overcome by using multiple unbalanced magnetron sputter devices 1 within the same vacuum chamber.
• the flux 5 of energetic particles from each of these devices is preferably directed so that it reaches the substrate 6 at the same angle ⁇ to the substrate 6 in order to avoid competing texturing processes.
• An embodiment of the present invention with two unbalanced magnetron devices 1 is shown schematically in Fig. 5 for a planar magnetron and in Fig. 6 for a rotating cathode magnetron.
• the configuration will be determined by the crystal structure of the material of the growing coating on the substrate 6 and the desired bi-axially textured structure.
• four devices e.g. for a 9 cubic material where bi-axially texturing with the (100) axis perpendicular to the substrate normal and another crystallographic axis (e.g. (111) or (110)) parallel in adjacent grains, two unbalanced magnetron devices may be added to the above configuration of Fig. 5 or 6, with the plane formed by the normals to the surfaces of the target 3 and the substrate 6 being perpendicular to the corresponding plane of the two original devices.
• the optimal angle of incidence with respect to the substrate surface normal for energetic particles is equal to the inverse tangent of the square root of 2, which approximately equals 54.74°, in order to obtain bi-axial texturing with the crystallographic (100) plane of all the grains in the coating perpendicular to the substrate surface and another crystallographic direction (e.g. (I l l)) parallel in adjacent grains in the coating.
• FIG. 7 A further embodiment of the present invention is shown schematically in Fig. 7, in which an additional magnet 10 is positioned behind the substrate 6 in order to influence the flux of energetic particles 5 directed towards the substrate 6.
• an additional magnet 10 is positioned behind the substrate 6 in order to influence the flux of energetic particles 5 directed towards the substrate 6.
• field lines emanating at the outer magnet array 8 behind the target 3 will arrive at the magnet 10 behind the substrate 6 and the magnetic field will be more focussed. This will result in a focussing of the plasma flux and a better control of the direction of the plasma flux.
• the addition of a magnet 10 behind the substrate 6 in this configuration will result in an increase of the magnetic field at the substrate 6. This increase in magnetic field will result in an increased gyrating speed of the electrons and because of conservation of energy in a decreased speed parallel to the field lines.
• the magnet 10 may be a controllable electromagnet. 10

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• 1999
  • 1999-03-30 CA CA002326202A patent/CA2326202C/en not_active Expired - Fee Related
  • 1999-03-30 KR KR1020007010530A patent/KR20010042128A/ko not_active Application Discontinuation
  • 1999-03-30 AU AU34188/99A patent/AU746645C/en not_active Ceased
  • 1999-03-30 RU RU2000127113/02A patent/RU2224050C2/ru not_active IP Right Cessation
  • 1999-03-30 JP JP2000541356A patent/JP2002509988A/ja not_active Withdrawn
  • 1999-03-30 WO PCT/EP1999/002168 patent/WO1999050471A1/en not_active Application Discontinuation
  • 1999-03-30 CN CN99804648A patent/CN1295628A/zh active Pending
  • 1999-03-30 EP EP99915721A patent/EP1070154A1/de not_active Withdrawn

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