WO2014142737A1

WO2014142737A1 - Arrangement and method for high power pulsed magnetron sputtering

Info

Publication number: WO2014142737A1
Application number: PCT/SE2014/050292
Authority: WO
Inventors: Ulf Helmersson
Original assignee: Ulf Helmersson
Priority date: 2013-03-13
Filing date: 2014-03-11
Publication date: 2014-09-18

Abstract

Disclosed is an arrangement (1a, 1b) for high power pulsed magnetron sputtering for deposition of a thin film onto a substrate (2) surface. The arrangement (1a, 1b) is provided with a guide (11a, 11 b) provided between the target (3a, 3b) and the substrate (2), providing a magnetic field which guides the plasma towards the substrate (2) surface, wherein all surface normals of an active surface portion of said target (3a, 3b) are directed such that negative ions travelling along such surface normals are prevented from reaching said substrate (2). The arrangement is further provided with means for preventing a substantial portion of negative ions from reaching the substrate (2) surface. Thereby, detrimental effects on the growing film on the substrate (2) surface from negative ions produced in the high power pulsed magnetron sputtering process are reduced. Disclosed is also a method of depositing a thin film onto a substrate (2) surface through high power pulsed magnetron sputtering such that detrimental effects on the growing film from negative ions produced in the method are reduced.

Description

ARRAN pEMENI ΑΝΡ_^ ΕΤΉΟΡ H PQ ER PULSED

MAGNETRON SPUTTERING

Technical Field

The present disclosure relates to an arrangement for high power pulsed magnetron sputtering for deposition of a thin film onto a substrate surface and to a method of depositing a thin film onto a substrate surface through high power pulsed magnetron sputtering.

Technical Background

High power pulsed magnetron sputtering (HPPMS) of which high power impulse magnetron sputtering (HiPIMS) is the most well-known, is a physical vapor deposition technology which has gained substantial interest in recent years for applying functional thin films to various substrates. In HiPIMS the power is applied to the target in pulses of low duty cycle (<10%) and frequency (<10 kHz) leading to pulse target power densities of several kW/cm². This mode of operation results in generation of ultra-dense plasmas with unique properties, such as a high degree of ionization of the sputtered atoms. These features make possible the deposition of coatings on complex- shaped substrates, which coatings are dense, smooth, hard, wear resistant, demonstrate good conductivity and adhesion to the underlying substrate.

HPPMS, just like conventional dc magnetron sputtering, may be used both with planar magnetrons and rotating cylindrical magnetrons.

In Leroy et al. (W. P. Leroy, S. Konstantinidis, S. Mahieu, R. Snyders, D. Depla, J. Phys. D: Appl. Phys. 44 (2011 ) 115201 ) a rotating cylindrical magnetron is operated in HiPIMS mode and dc mode. A comparison of the energy flux towards the substrate and the energy per arriving adparticle for the different modes is made in metallic and oxide regime as a function of angle around the cylindrical target. It was shown that angular emission and transport of particles had similar angular profiles for the dc and HiPIMS modes. Leroy briefly discusses that high-energy negative oxygen ions produced in the process may have detrimental effects on the growth behavior of the thin film.

Mahieu et al. (S. Mahieu, W.P. Leroy, K. van Aeken, D. Depla, J. Appl. Phys. 106 (2009) 093302) teaches that in dc magnetron reactive sputtering processes there is an unwanted high-energy negative ion bombardment of the growing film resulting in degradation of the film quality both for planar and cylindrical targets. Mahieu et al. shows that negative ions formed on the target surface from the reactive gases used in the process are accelerated away from the target surface impinging upon the growing film, resulting in a degradation of the film quality.

Summary

It is an object of the present disclosure to present an arrangement for depositing a thin film onto a substrate surface with high power pulsed magnetron sputtering. A specific object is to present such an arrangement wherein detrimental effects on the growing film from negative ions produced in the high power pulsed magnetron sputtering process are reduced. Further objects are to present a method for depositing a thin film onto a substrate surface with high power pulsed magnetron sputtering such that detrimental effects on the growing film from negative ions produced in the method are reduced.

The invention is defined by the appended independent claims.

Embodiments are set forth in the dependent claims, in the attached drawings and in the following description.

According to a first aspect, there is provided an arrangement for high power pulsed magnetron sputtering for deposition of a thin film onto a substrate surface, comprising: a substrate onto which surface deposition is to be made, a target which constitutes a cathode or is electrically connected to a cathode and is formed at least in part from a material(s) to be included in the thin film, a pulsed power supply for applying voltage pulses between an anode and the cathode to make discharges between the anode and cathode, producing a plasma, and a first magnet assembly for providing a first magnetic field in a magnetron configuration at a surface of the target trapping electrons in a first magnetic field, resulting in a confinement of the plasma close to the target surface. The arrangement is further provided with a guide provided between the target and the substrate, providing a second magnetic field which guides the plasma towards the substrate surface, wherein all surface normals of an active surface portion of the target are directed such that negative ions travelling along such surface normals are prevented from reaching the substrate surface.

An active surface portion is here defined as a portion of the target surface where the momentary target erosion takes place during the sputtering process, i.e. a target erosion area. Preferably, the target erosion area is the area from which 80 - 90%, 90 - 95% or 95 - 99% of the sputtered material is produced.

Mahieu et al. has shown that in dc magnetron reactive sputtering processes there is an unwanted high-energy negative ion bombardment of the growing film on the substrate surface resulting in degradation of the film quality both for planar and cylindrical targets. The same problem applies also to HPPMS processes. The negative ions (Ο^', N^" , HS^", CH₃ ^". F^", CI^", Br^", I^" etc.) formed from reactive gases (0₂, N₂, H₂S, CH₄, F, CI, Br, I etc.) used in the process, or more seldom originating from the target itself, are accelerated to the target surface impinging upon the growing film. The impact energy of the negative ions is sufficiently great to displace atoms in the growing film, resulting in a degradation of the film quality. The negative ions may be considered being a part of the plasma, but are due to their high energy not easily guided by the applied second magnetic field. Due both to the sign of their charge and their lower energy the positive ions of the plasma, including material sputtered from the target, are guidable due to interactions with the electrons of the plasma and, hence, travels with the plasma in a main direction of plasma propagation towards the substrate surface.

Since all surface normals of an active surface portion of the target are directed such that negative ions travelling along such surface normals are prevented from reaching the substrate surface, films deposited on the substrate surface with such an arrangement are superior in quality to films where negative ions have been allowed to reach the substrate surface.

The portion of negative ions prevented from reaching the substrate surface may in one embodiment be 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100% of all negative ions present in the arrangement.

In the arrangement for high power pulsed magnetron sputtering, a degree of ionization of material sputtered from the target may be at least 20%, at least 40% or at least 60%.

The invention is applicable to HPPMS range and in particular to the HiPI S range.

Hence, a momentary peak power density, P_peak , at the active surface portion of the target may be about 0.05-100 kW/cm², or about 0.1 -50 kW/cm², or about 0.5-20 kW/cm², or about 1-20 kW/cm², or about 2-20 kW/cm², or about 5-20 kW/cm², or about 5-10 kW/cm².

The peak power density, , is here to be understood as the peak momentary electric power i - u divided by the area of the active surface portion of the target surface as defined above.

A duty cycle, F_D __g,_c(e , of the pulsed power supply may be related to the peak power density at the target in such a way that the product, I - U - F_D ^ , of them, provides a time averaged power in the active surface portion, which may be about 0.01-500 kW/cm², or about 0.01-100 kW/cm², or about 0.5-500 kW/cm², or about 0.5-100 kW/cm², or about 1-500 kW/cm², or about 1-100 kW/cm².

The arrangement and the method (described below) may be operated at a momentary peak power density as described above and/or at a time averaged power as described above.

It is noted that the time averaged power in the active surface portion at which damage to the target is incurred normally provides an upper limit to the duty cycle at each given peak power density. Hence, at any given peak power density, the duty cycle range is normally limited upwardly by the power limit (which provides an upper limit) and downwardly by a value which is about 1/10 - 1/20 of the power limit.

The arrangement may further comprise a shield for preventing negative ions from reaching the substrate surface. The shield may comprise an apertured constriction.

An aperture area of the apertured constriction may be substantially circular, elliptical, or elongate. An elongate aperture area may for example be a slit.

The aperture area of the constriction may be adjustable.

The shield may be formed by, or integrated with, the guide. By integrated is here meant that the guide and the shield may be made of the same part or as two parts permanently connected to each other.

At least one of the surface normals of an active surface portion may be directed towards the shield.

The guide may be arranged to guide the plasma, but not negative ions or uncharged atoms, past the shield

In one embodiment, the guide may be arranged along a shortest distance between the substrate and the target.

In another embodiment, the guide may be arranged offset a shortest distance between the substrate and the target.

The guide may comprise at least one solenoid. Such a solenoid may be connected to a DC power supply to generate a controlled second magnetic field. In one example two or more solenoids may be connected in series.

The power to the solenoid may be connected to a pulsed power supply giving a magnetic field that is synchronized with the pulsed power on the cathode. In one embodiment the cathode current can also drive the solenoid.

The guide may be arranged to alter the main direction of plasma propagation.

The target may be selected from a group comprising a substantially cylindrical target, a semicylindrical target, a partial cylindrical target, polygonal targets, arc-formed targets, rectangular or substantially flat targets. In the case with a substantially cylindrical target, a semicylindrical target or a partial cylindrical target, the target surface to be sputtered may be the convex outside surface of the target.

In one embodiment the surface from which atoms are sputtered may be a continuous surface.

In another embodiment, the surface from which atoms are sputtered may be a faceted surface.

The target may be a rotating substantially cylindrical target.

The target may be formed at least in part of a substance selected from a group consisting of Al, Ti, Cr, Cu, Zr, Zn, Ag, Sn, Ta, Pt, In, Ga, Ce, Y or any combination of two or more thereof. The substance or substances are to be included in the thin film found on the substrate surface.

According to a second aspect there is provided a method of depositing a thin film onto a substrate surface through high power pulsed magnetron sputtering, the method comprising the steps of:

- providing a substrate onto which surface deposition is to be made;

- providing a target which constitutes a cathode or is connected to a cathode and is formed at least in part from a material(s) to be included in the thin film;

- applying voltage pulses by an electrical power supply connected between the cathode and an anode to make discharges between the anode and cathode producing a plasma;

- providing a first magnetic field in a magnetron configuration at a surface of the target, trapping the electrons in the first magnetic field, confining the plasma close to the target surface;

- sputtering atoms from the target by means of the plasma, causing ionization of at least part of the sputtered target atoms;

- providing a second magnetic field between the substrate and the target;

- guiding the plasma towards the substrate surface; and

- preventing negative ions travelling along a surface normal of an active surface portion of the target from reaching the substrate surface. The step of preventing negative ions from reaching the substrate surface may comprise shielding of the negative ions.

The step of guiding the plasma towards the substrate surface may comprise altering the main direction of plasma propagation.

Brief description of the drawings

Fig. 1 shows a schematic cross-sectional view of an arrangement for high power pulsed magnetron sputtering with a substantially cylindrical target for deposition of a thin film onto a substrate surface.

Fig. 2 shows a schematic cross-sectional view of an arrangement for high power pulsed magnetron sputtering with a substantially flat target for deposition of a thin film onto a substrate surface.

Detailed description

Cross- sectional views of two different arrangements 1 a, 1 b for high power pulsed magnetron sputtering for deposition of a thin film onto a substrate 2 surface are schematically shown in Fig. 1 and Fig. 2. The substrate 2 may be all kind of substrates, such as metallic, ceramic, plastics and glass substrates. The substrate may be a stationary substrate or a substrate which is movable beneath the sputtering target, e.g. in a reel-to-reel arrangement.

The target 3a, 3b used may be formed at least in part from AS, Ti, Cr, Cu, Zr, Zn, Ag, Sn, Ta, Pt, In, Ga, Ce, Y or combinations of two or more thereof. These materials are to be included in the thin film which is to be deposited on the substrate 2 surface. The target 3a in Fig. 1 constitutes a cathode, which may be partially surrounded by a ground shield 4. In another embodiment the target may be electrically connected to a cathode.

In the arrangement shown in Fig. 1 , the target is a substantially cylindrical target 3a. Targets with other shapes are, however, possible, such as a semicylindrical target, a partial cylindrical target, polygonal targets, arc- formed targets, rectangular or substantially flat targets 3b (shown in Fig. 2). The targets of the arrangements 1a, 1 b shown in Fig 1 and Fig 2 may be extended in a direction perpendicular to their surface normals. The surface of the target 3a, 3b from which surface atoms are sputtered are in Fig. 1 and Fig. 2 continuous areas. In another embodiment the surface of the target may be faceted.

In the arrangement 1b shown in Fig. 2 the substantially flat target 3b and the substrate 2 are arranged off-set each other and the target 3b surface has no surface normal pointing towards the substrate 2. The substrate 2 is laterally spaced from the target 3b. The surface normal at the target 3b closest to the substrate 2 may be laterally spaced from the surface normal of the substrate 2 closest to the target 3b.

In the arrangement in Fig. 2, a first magnet assembly 5b is mounted at a small distance from the rear side of the target 3b surface for providing a first magnetic field in a magnetron configuration at the surface of the target 3b. Magnetic north poles, N, are here arranged at the periphery of the target 3b and magnetic south poles, S, at the center of the target 3b. The magnetic field lines thus pass from the periphery of the target 3b to the center thereof. It is also possible to position the south poles, S, at the periphery and the north poles, N, in the centre, creating field lines from the center to the periphery of the target 3b. In other embodiments of the arrangement in Fig. 2, the exact positioning of the magnets in the magnet assembly 5b may different.

As shown in Fig. 1 , a first magnet assembly 5a comprising magnetic north- and south poles, N, S, is mounted inside the substantially cylindrical target 3a. In other embodiments of the arrangement in Fig. 1 , the exact positioning of the magnets in the magnet assembly 5a may be different.

Due to the convex outer surface of the substantially cylindrical target

3a shown in the arrangement 1 a in Fig. 1 , most surface normals of the target 3a are not directed towards the substrate 2 surface.

In one embodiment, the substantially cylindrical target 3a in the arrangement in Fig. 1 is a rotating cylindrical target. The rotating cylindrical target may rotate around a stationary magnet assembly. A rotatable cylindrical target has the advantage compared to stationary configurations, that there due to the rotation is a more uniform target erosion during the sputtering, resulting in a more effective target utilization.

The rotating substantially cylindrical target may rotate around the stationary magnet assembly with a speed of 1-50 rpm.

The arrangement 1a, 1 b for high power pulsed magnetron sputtering in

Fig. 1 or Fig. 2 may be located in a substantially enclosed and evacuable chamber 6 (Fig. 1 ). A sputtering gas may be introduced into the chamber through a gas inlet 7. The sputtering gas may be a mixture of an inert gas with a reactive gas (0₂₎ N₂, H₂S, CH₄, F, CI, Br, I, etc). Typical mixtures are argon and nitrogen or argon and oxygen, which are known as such.

An electric pulsed power supply 8 is connected to an anode, e.g. the evacuable chamber 6 or the ground shield 4, with its positive end and with its negative terminal connected to the target 3a, 3b, which in Fig. 1 constitutes the cathode. The power supply 8 generates high voltage pulses between the anode and cathode 3a, 3b resulting in electric discharges, producing a plasma. The high voltage pulses are e.g. substantially square shaped pulses, and often voltage pulses superimposed on DC voltage. Other alternatives are, however, also possible.

High power pulsed magnetron sputtering processes are well-known as such and are for example described in a review article by Gudmundsson et al. (J.T. Gudmundsson, N. Brenning, D. Lundin, U. Helmersson, High power impulse magnetron sputtering discharge, J. Vac. Sci. Technol. A 30(3), May/June 2012.)

A degree of ionization of material sputtered from the target 3a, 3b in the arrangements 1 a, 1 b shown in Fig 1 or Fig. 2 may be at least 20%, at least 40% or at least 60%.

An active surface portion of the target is here a portion of the target surface where the momentary target erosion takes place during the sputtering process, i.e. a target erosion area. Preferably, the target erosion area is the area from which 80 - 90%, 90 - 95% or 95 - 99% of the sputtered material is produced. A momentary peak power density, P_peak , at the active surface portion of the target may be about 0.05-100 kW/cm², or about 0.1 -50 kW/cm², or about 0.5-20 kW/cm², or about 1-20 kW/cm², or about 2-20 kW/cm², or about 5-20 kW/cm², or about 5-10 kW/cm².The peak power density, P_peak , is here to be understood as the peak momentary electric power / ·(/ divided by the area of the active surface portion of the target surface as defined above.

A duty cycle, v, ₉,_c/e ,of the pulsed power supply may be related to the peak power density at the target in such a way that the product, / · U · F_D ,_e , of them, provides a time averaged power in the active surface portion, which may be about 0.01 -500 kW/cm², 0.01-100 kW/cm², or about 0.5-500 kW/cm², or about 0.5-100 kW/cm², or about 1-500 kW/cm², or about 1 -100 kW/cm².

The preferred process parameters above defines high power impulse magnetron sputtering (HiPIMS), a high power pulsed magnetron sputtering process which is well-known as such and for example is described in said review article by Gudmundsson et ai.

The arrangements 1 , 1 b may be operated at a momentary peak power density as described above and/or at a time averaged power as described above.

Mahieu et al. has shown that in DC magnetron reactive sputtering processes there is an unwanted high-energy negative ion bombardment of the growing film on the substrate surface resulting in degradation of the film quality both for planar and cylindrical targets. The same problem applies also to HPPMS processes. The negative ions (O^", N^" , HS^", CH₃ ^". F^", CI^", Br^", I^" etc.) formed from reactive gases (0₂, N₂, H₂S, CH₄, F, CI, Br, I etc.) used in the process, or more seldom originating from the target itself, are accelerated to the target surface impinging upon the growing film. The impact energy of the negative ions is sufficiently great to displace atoms in the growing film and implant the negative ions into the film surface, resulting in a degradation of the film quality.

Main spreading directions of negative ions, X^", from the surface of substantially cylindrical targets 3a and substantially flat targets 3b are roughly indicated by dashed arrows in Fig. 1 and Fig. 2.

Due to the convex outer surface of the target in Fig. 1 all surface normals of an active surface portion are directed such that negative ions travelling along such surface normals are prevented from reaching the substrate 2 surface.

Since the target 3b and the substrate 2 in Fig. 2 are arranged off-set to each other, few negative ions will reach the substrate 2 surface. The exact spreading patterns of negative ions in both arrangements 1 a, 1 b shown in the figures are further determined by the arrangement of the magnetic south - and north poles, N, S, in the first magnet assembly 5a, 5b.

For further preventing detrimental negative ions, X^", from reaching the substrate 2 surface the arrangements 1 a, 1 b shown in Fig. 1 and Fig. 2 are provided with a shield 9a, 9b between the target 3a, 3b and the substrate 2 surface to be coated, shielding the negative ions, allowing a restricted flow between the target 3a, 3b and the substrate 2. The shield may be grounded, a floating ground (electrically isolated from earth) or a shield having an applied voltage.

By utilizing the main spreading directions of negative ions, X^", from the target surfaces 3a, 3b together with shields (9a, 9b) 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100% of all negative ions present in the arrangements 1 a, 1 b may be prevented from reaching the substrate 2 surface.

The shield 9a, 9b in Fig. 1 and Fig. 2 comprises an apertured constriction. An aperture area 10a, 10b of the apertured constriction may be substantially circular, elliptical, or elongate, and is preferably adapted to the shape of the target 3a, 3b and the negative ion distribution pattern therefrom. In one embodiment the aperture area may be adjustable. The arrangements 1 a, 1 b in Fig. 1 and Fig. 2 are further provided with a guide 11a, 1 1 b between the substrate 2 and the target surface 3a, 3b arranged to confine and guide the plasma, but not negative ions or uncharged atoms past the shield 9a, 9b. The guide 11 a, 11 b provides a second magnetic field. The negative ions may be considered a part of the plasma, but are due to their large mass, compared to the mass of the electrons of the plasma, not easily guided by the applied second magnetic field. The positive ions of the plasma, Me⁺, including material sputtered from the target 3b, are guidable due to electronic interactions and, hence, travels with the plasma in the main direction of plasma propagation towards the substrate 2 surface.

The guide 11a, 1 1 b is here comprised of a solenoid, which is connected to a DC power supply (not shown) to generate a controlled second magnetic field. More than one solenoid may be connected in series in other embodiments. The shield 9a, 9b in Fig, 1 and Fig. 2 is integrated with the guide 1 1a, 1 1 b and is made of the same part, i.e. the solenoid constitutes both the shield 9a, 9b and the guide 11a, 1 1 b and constitutes a surface for catching ions.

In other embodiments the shield 9a, 9b and the guide 11 a, 1 1 b may be separate parts. In yet an embodiment the shield 9a, 9b and guide 1 1a, 11 b may be two parts permanently connected.

In Fig. 2, the guide 11 b is arranged to alter the main direction of plasma propagation, which direction is indicated in the figure. The plasma has to be deflected in order to pass the shield 9b and reach the substrate 2 surface. The directions of the negative ions, X^", are not altered in the same way and continue in there determined directions which do not coincide with the main direction of plasma propagation.

As can be seen in Fig. 1 , also here the main direction of plasma propagation and the main spreading directions of negative ions, X^", do not coincide. Here the shape of the target 3a surface having active surface portions from which material is sputtered determines the directions of the negative ions, X^", from the target 3a, 3b surface. In Fig. 1 the guide 11a is arranged along a shortest distance between the substrate 2 and the target 3a.

In other embodiments, the guide 11 a, 11b may be arranged offset a shortest distance between the substrate 2 and the target 3a, 3b.

As can be seen in both Fig. 1 and Fig. 2 there is at least a portion of a distance between the target 3a, 3b and the substrate 2 where a main direction of plasma propagation is non-parallel to a surface normal of a surface portion of the target 3a, 3b. This results in that a substantial proportion of the negative ions may be separated from the rest of the plasma and, hence, are prevented from reaching the substrate 2 surface. Thereby, the quality of such a deposited film on the substrate 2 surface is superior to a film where negative ions have been allowed to reach the substrate 2 surface.

The said at least a portion of a distance between the target 3a, 3b and the substrate 2 may be 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100% of a total distance between the target 3a, 3b and the substrate 2.

An angular deviation between the main direction of plasma propagation and the surface normal of a surface portion of the target 3a, 3b may be 5°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90° or 100°.

Claims

1. An arrangement (1a, 1 b) for high power pulsed magnetron sputtering for deposition of a thin film onto a substrate (2) surface, comprising:

- a substrate (2) onto which surface deposition is to be made;

- a target (3a, 3b) which constitutes a cathode or is electrically connected to a cathode and is formed at least in part from a material(s) to be included in said thin film;

- a pulsed power supply (8) for applying voltage pulses between an anode and said cathode to make discharges between said anode and cathode, producing a plasma;

- a first magnet assembly (5a, 5b) for providing a first magnetic field in a magnetron configuration at a surface of said target (3a, 3b) trapping electrons in a first magnetic field, resulting in a confinement of said plasma close to said target surface; and

- a guide (11 a, 11 b) provided between said target (3a, 3b) and said substrate (2), providing a second magnetic field which guides said plasma towards said substrate (2) surface, wherein all surface normals of an active surface portion of said target (3a, 3b) are directed such that negative ions travelling along such surface normals are prevented from reaching said substrate (2) surface.

2. An arrangement (1a, 1 b) according to any of the preceding claims, wherein a portion of negative ions prevented from reaching said substrate (2) surface is 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100% of all negative ions present in said arrangement (1 a, 1 b).

3. An arrangement (1a, 1 b) according to any of the preceding claims, wherein a degree of ionization of material sputtered from said target (3a, 3b) is at least 20%, at least 40% or at least 60%.

4. An arrangement (1a, 1 b) according to any of the preceding claims, wherein a momentary peak power density at the active surface portion of said target (3a, 3b) is about 0.05-100 kW/cm², or about 0.1-50 kW/cm², or about 0.5-20 kW/cm², or about 1-20 kW/cm², or about 2-20 kW/cm², or about 5-20 kW/cm², or about 5-10 kW/cm².

5. An arrangement (1a, 1 b) according to claim 4, wherein a duty cycle of said pulsed power supply (8) is related to said peak power density at said target (3a, 3b) in such a way that a product of them, provides a time averaged power in said active surface portion, which is about 0.01-500 kW/cm², or about 0.01-100 kW/cm², or about 0.5-500 kW/cm², or about 0.5- 100 kW/cm², or about 1-500 kW/cm², or about 1-100 kW/cm².

6. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said arrangement comprises a shield (9a, 9b) for preventing negative ions from reaching said substrate (2) surface.

7. An arrangement (1a, 1 b) according to claim 6, wherein said shield (9a, 9b) comprises an apertured constriction.

8. An arrangement (1a, 1 b) according claim 7, wherein an aperture area (10a, 10b) of said apertured constriction is substantially circular, elliptical, or elongate. 9. An arrangement (1a, 1 b) according to any of claims 6-8, wherein said shield (9a, 9b) is formed by, or integrated with, said guide (11 a, 1 1 b).

10. An arrangement (1a, 1 b) according to any one of claims 6-9, wherein at least one of said surface normals is directed towards said shield (9a, 9b).

1 1. An arrangement (1a, 1 b) according to any one of claims 6-10, wherein said guide (1 1a, 1 1 b) is arranged to guide said plasma, but not negative ions or uncharged atoms past said shield (9a, 9b). 12. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said guide (1 1a, 1 1 b) is arranged along a shortest distance between said substrate (2) and said target (3a, 3b). 3. An arrangement (1a, 1 b) according to claim 1-12, wherein said guide (1 1a, 11 b) is arranged offset a shortest distance between said substrate (2) and said target (3a, 3b).

14. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said guide (1 1a, 11 b) comprises at least one solenoid.

15. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said guide (11a, 1 1 b) is arranged to alter the main direction of plasma propagation. 16. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said target (3a, 3b) is selected from a group comprising a substantially cylindrical target, a semicylindrical target, a partial cylindrical target, polygonal targets, arc-formed targets, rectangular or substantially flat targets.

17. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said target (3a, 3b) surface from which atoms are sputtered is a continuous surface.

18. An arrangement (1a, 1 b) according to claim 1-16, wherein said target (3a, 3b) surface from which atoms are sputtered is a faceted surface.

19. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said target (3a) is a rotating substantially cylindrical target.

20. An arrangement (1a, 1 b) according to any of the preceding claims, wherein said target (3a, 3b) is being formed at least in part of a substance selected from a group consisting of Al, Ti, Cr, Cu, Zr, Zn, Ag, Sn, Ta, Pt, In, Ga, Ce, Y or any combination of two or more thereof.

21. A method of depositing a thin film onto a substrate (2) surface through high power pulsed magnetron sputtering, the method comprising the steps of:

- providing a substrate (2) onto which surface deposition is to be made;

- providing a target (3a, 3b) which constitutes a cathode or is electrically connected to a cathode and is formed at least in part from a material(s) to be included in said thin film;

- applying voltage pulses by an electrical power supply (8) connected between said cathode and an anode to make discharges between said anode and cathode producing a plasma;

- providing a first magnetic field in a magnetron configuration at a surface of said target (3a, 3b), trapping said electrons in said first magnetic field, confining said plasma close to said target (3a, 3b) surface;

- sputtering atoms from said target (3a, 3b) by means of said plasma, causing ionization of at least part of said sputtered target atoms;

- providing a second magnetic field between said substrate (2) and said target (3a, 3b);

- guiding said plasma towards said substrate (2) surface; and

- preventing negative ions travelling along a surface normal of an active surface portion of said target (3a, 3b) from reaching said substrate (2) surface.

22. A method according to claim 21 , wherein said step of preventing negative ions from reaching said substrate (2) surface comprises shielding of said negative ions.

23. A method according to claim 21 or 22, wherein said step of guiding said plasma towards said substrate (2) surface comprises altering a main direction of plasma propagation.