Sputter System for Uniform Sputtering
20170029940 ยท 2017-02-02
Inventors
- Ivan VAN DE PUTTE (Waregem, BE)
- Niek DEWILDE (Kruishoutem, BE)
- Guy GOBIN (Oostende, BE)
- Wilmert De Bosscher (Drongen, BE)
Cpc classification
H01J37/3461
ELECTRICITY
C23C14/35
CHEMISTRY; METALLURGY
H01J37/347
ELECTRICITY
International classification
C23C14/54
CHEMISTRY; METALLURGY
C23C14/35
CHEMISTRY; METALLURGY
Abstract
A sputter system for applying a coating on a substrate is described. The sputter system comprises at least two cylindrical sputter units for the joint sputtering of a single coating. Each sputter unit comprising an elongated magnet configuration and at least one elongated magnet configuration comprising a plurality of magnet structures and magnet structure control systems along the length direction of the elongated magnet configuration. At least one magnet structure is adjustable in position and/or shape by a magnet structure control system, while a sputter target is mounted on the sputter unit.
Claims
1-22. (canceled)
23. A sputter system for applying a coating on a substrate, the sputter system comprising: a substrate holder, upon which a substrate can be positioned, in such a way that the substrate is substantially stationary during the application of the coating; at least two cylindrical sputter units for the joint sputtering of a coating, each sputter unit comprising an elongated sputter magnet configuration; wherein at least one elongated magnet configuration comprises a plurality of magnet structures and magnet structure control systems along the length direction of the elongated magnet configuration, wherein at least one magnet structure is adjustable in position and/or shape by a magnet structure control system, while a sputter target is mounted on the sputter unit, in order to influence the homogeneity of the sputtered coating on the substrate.
24. A sputter system according to claim 23, wherein at least part of the elongated magnet configurations comprises a plurality of magnet structures and magnet structure control systems along the length direction of the elongated magnet configurations, whereby a part of the magnet structure is remotely adjustable in position and/or shape by a magnet structure control system.
25. A sputter system according to claim 23, wherein the cylindrical sputter units are oriented substantially parallel with respect to each other.
26. A sputter system according to claim 23, wherein the magnetic axis of the elongated magnet configuration of at least one of the sputter units is configured parallel to the substrate, when the substrate is positioned in the substrate holder.
27. A sputter system according to claim 23, wherein the influence of an individual adjustment in position and/or shape of a magnet structure of an elongated magnet configuration is only detectable in the magnetic field vector over a fraction of the length of the elongated magnet configuration.
28. A sputter system according to claim 23, wherein one or more magnet structure control systems is/are configured to adjust the position of the corresponding magnet structures.
29. A sputter system according to claim 28, wherein the one or more magnet structure control systems is/are configured to adjust the position of the corresponding magnet structures by rotating the corresponding magnet structures around a rotation axis parallel to the longitudinal axis of the elongated magnet configuration.
30. A sputter system according to claim 28, wherein the one or more magnet structure control systems is/are configured to adjust the position of the magnet structures by shifting the magnet structures.
31. A sputter system according to claim 23, wherein one or more magnet structure control systems is/are configured to adjust the shape of the corresponding magnet structures.
32. A sputter system according to claim 31, wherein the one or more magnet structure control systems is/are configured to adjust the shape of the corresponding magnet structures by shifting only part of the corresponding magnet structures and/or wherein the one or more magnet structure control systems are configured to adjust the shape of the corresponding magnet structures by rotating a part of the corresponding magnet structure around a rotation axis parallel to the longitudinal axis of the elongated magnet configuration.
33. A sputter system according to claim 31, wherein the one or more magnet structure control systems is/are configured to adjust the shape of the magnet structures by differently rotating individual parts of the corresponding magnet structure around a rotation axis parallel to the longitudinal axis of the elongated magnet configuration.
34. A sputter system according to claim 23, wherein the cylindrical sputter units comprise a cylindrical sputter target, the cylindrical sputter target being provided with a cylindrical cavity extending in the longitudinal direction of the cylinder axis, inside which cavity the elongated magnet configuration can be positioned.
35. A sputter system according to claim 23, wherein one or more magnet structure control systems comprise a motor and an embedded control electronics.
36. A sputter system according to claim 35, wherein the one or more magnet structure control systems further comprise an actuator for converting the movement of the motor in a translation movement and/or a rotational movement of the corresponding magnet structure.
37. A sputter system according to claim 23, wherein the sputter system comprises a controller for controlling magnet structure control systems in the plurality of elongated magnet configurations, the controller being adapted for, when controlling elements from one magnet configuration, to also take into account the control of elements from one or more of the other magnet configurations.
38. A sputter system according to claim 23, wherein each elongated magnet configuration comprises a control unit for controlling the plurality of magnet structure control systems for controlling the plurality of magnet structures and/or wherein at least one magnet structure is controllable in position and/or shape by a magnet structure control system so as to influence the homogeneity of the sputtered coating in at least two different dimensions of the coating.
39. A sputter system according to claim 23, wherein the sputter system further comprises a monitoring system for monitoring a characteristic of a sputtered coating at a plurality of positions in different directions over the coating.
40. A sputter system according to claim 39, wherein the monitoring system is connected with a controller in a feedback loop, such that the controller can adjust the control as a function of the measured value of the specific parameter.
41. A method for sputtering a coating on a substrate, the system comprising, adjusting a plurality of magnet structures of at least one elongated magnet configuration of a cylindrical sputter unit in a system comprising at least two cylindrical sputter units, by adjusting the position and/or the shape of at least one magnet structure, while a sputter target is mounted on the sputter unit, in order to influence the homogeneity of the sputtered coating.
42. A method according to claim 41, wherein the method furthermore comprises monitoring the homogeneity of a parameter of the coating at a plurality of positions over the sputtered coating, and adjusting the plurality of magnet structures as a function of the measured parameter of the coating.
Description
SHORT DESCRIPTION OF THE DRAWINGS
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[0062] The drawings are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes.
[0063] Any reference signs in the claims shall not be construed as limiting the scope. In the different drawings, the same reference signs refer to the same or analogous elements.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0064] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings included and described herein are schematic and are not limiting the scope of the invention. It is also noted that in the drawings, the size of some elements may be exaggerated and, therefore, not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.
[0065] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.
[0066] Moreover, the terms top, bottom, above, front and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.
[0067] It is to be noticed that the term comprising, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof Thus, the scope of the expression a device comprising A and B should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.
[0068] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases in one embodiment or in an embodiment in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.
[0069] Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
[0070] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.
[0071] In the description provided herein, numerous specific details are set forth. However, it is to be understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, procedures and techniques have not been described in detail, so as not to obscure the present invention.
[0072] In a first aspect, the present invention relates to a sputter system for applying a coating on a substrate. The sputter system thereby typically comprises a substrate holder, whereto, e.g. upon which a substrate can be positioned, so that the substrate is substantially stationary during the application of the coating. Where in the present invention reference is made to substantially stationary substrate, what is meant is that the average position of the substrate remains constant during the sputter process. Small position variations of the substrate, for example as an additional action to obtain a more uniform deposition of the coating, also fall within the definition that the substrate is substantially stationary. Movement of the substrate as is typically used in a continuous in-line deposition system does not fall within the definition of a substantially stationary substrate, because in this case the substrate will not be at the same position relative to the sputter source at two different moments in time. The same applies for movement of the substrate wherein there is an overall movement of the substrate overt time. .sup.2The sputter system according to embodiments of the present invention furthermore comprises at least two cylindrical sputter units. In a preferred embodiment the sputter system comprises a set of parallel cylindrical sputter units, closely positioned next to each other. Each sputter unit thereby comprises an elongated magnet configuration. The axes in the length direction of the elongated magnet configurations may all be located at an equal distance from the substrate, or may, in other embodiments, have a different distance to the substrate. Even the axis of a single elongated magnet configuration need not have a constant distance relative to the substrate, in other words, the elongated magnet configuration may be tilted with respect to the plane defined by the substrate.
[0073] At least one elongated magnet configuration comprises a plurality of magnet structures and magnet structure control systems along the length direction of the elongated magnet configuration. In embodiments of the present invention at least one magnet structure is adjustable in position and/or shape by a magnet structure control system, while a sputter target is mounted on the sputter unit. In a preferred embodiment, magnet structures of multiple elongated magnet configurations are adjustable in position and/or shape. In some embodiments, magnet structures are remotely adjustable in position and/or shape. In some embodiments this is even possible while water cooling for the sputter unit is connected, or even while the cooling system is operational and cooling liquid is circulating, or even while the sputter target is being electrically powered, or even during sputtering with the sputter unit. Controlling the position and/or shape of at least one magnet structure may result in influencing and improving the homogeneity of the sputtered coating over the substrate. The magnet structure control system may be operable remotely, from a distance. It is an advantage of embodiments of the present invention that it allows to adjust the position of the magnet configurations during sputtering and/or when the sputtering is for example temporarily interrupted but the sputter system 100 is still under vacuum.
[0074] It is a particular advantage of embodiments of the present invention that variations in the coating in one or two dimensions over the surface of the substrate can be reduced or avoided.
[0075] In embodiments of the present invention typically sputter targets will be positioned between the magnet configurations and the substrate. The sputter targets used in systems according to the present invention are typically cylindrical sputter targets. It is an advantage of embodiments of the present invention that it is not necessary to remove the sputter targets prior to adjustment of the magnet configurations.
[0076] In embodiments of the present invention, some or all of the magnet structures in one or more elongated magnet configurations may be individually controlled. The magnet structure control systems may be configured in such a way that they can control individual magnet structures or a group of magnet structures.
[0077] Where in the present invention reference is made to controlling a magnet structure, or more specifically to controlling the position and/or shape thereof, this can mean selecting a shape or position, or can mean effectively configuring the magnet structure so that the latter obtains a specific shape or position. Adjusting the shape or position of a magnet structure comprises adjusting the distance to the sputter target and/or adjusting the orientation of the magnet structure. Adjusting the orientation allows to change the direction of the magnetic field vectors. Adjusting the distance to the sputter target surface allows to change the magnetic field strength. Each of these adjustments allows to change the material flux vector locally and in a controlled manner.
[0078] By way of illustration, embodiments of the present invention not being limited thereto, standard and optional features of some embodiments of the sputter system 100 are illustrated, referring to
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[0080] In some embodiments of the present invention, movement of the servo motor 151 is converted by a conversion system 154 into a translation movement or a rotational movement or a combination of both. Such a conversion system 154 may be a gear box. The magnet structure control system 150 may alsounder some circumstances, e.g. when a good fixed setting is foundbe frozen to guarantee a certain position of the magnet configuration 140. In some embodiments, an anti-rotation block 1101 is provided for this purpose.
[0081] In the embodiment of the present invention shown in
[0082] In this way, each of the magnet structure control systems 150 can be controlled via the central control unit 170. By providing the necessary interface (e.g. user interface), in this way the user has control over the sputter process. An example of a central control unit 170 which is connected to multiple control units 160 is schematically represented in
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[0084] In embodiments of the present invention the adjustment of the position or shape of a magnet structure 140 is only perceptible or sensible in the magnetic field over a fraction of the length of the elongated magnet configuration in the sputter unit 125. This fraction may for example be smaller than 50% of the length of the elongated magnet configuration. The fraction over which an adjustment can be sensed is typically related to the number of magnet structures 140 present per elongated magnet configuration. The larger the number of magnet structures 140, the smaller the distance of sensibility may be. As a consequence, by using a larger number of magnet structures, the magnetic field can be adjusted with a finer resolution. It is then an advantage of embodiments of the present invention that both the magnitude and the direction or orientation of the magnetic field vectors can be locally adjusted.
[0085] In particular embodiments of the present invention the magnet structure control system 150 may be configured to rotate the magnet structure 140 around a rotation-axis 310 parallel to the axis of the elongated magnet structure. The angular range over which can be rotated is at least between 60 and +60, or preferably at least between 30 and +30. In embodiments of the present invention, the rotation has an accuracy of 1, or better than 1. A possible embodiment hereof, is schematically illustrated in
[0086] Optionally the magnet structures 140 of the sputter system 100 can be divided in several sub-configurations 410. These sub-configurations may then be moved individually. The sub-configurations can be moved relatively to each other in such a way, e.g. to such an extent, that they do not hinder each other's movement. A possible division in sub-configurations is illustrated in
[0087] More specifically, in an embodiment of the present invention, the magnet configuration 140 is divided in a first sub-configuration 410a and a second sub-configuration 410b. The first sub-configuration 410a can thereby rotate around a first rotation-axis 310a parallel to the magnet compartment-axis, and the second sub-configuration 410b can rotate around a second rotation-axis 310b parallel to the magnet compartment-axis. An example of such an embodiment of the present invention is shown in
[0088] In yet another embodiment of the present invention the first rotation axis 310a and the second rotation axis 310b coincide. Examples thereof are illustrated in
[0089] In embodiments of the present invention the magnet structure 140 can be shifted by the magnet structure control system 150. By shifting the magnet structure away from the sputter target surface, the material flux vector of the target material can be reduced at the location of the magnet structure 140. In case the plurality of magnet structures within a same magnet compartment can be moved independently from one another, this allows to adjust the material flux vector in the length direction of the elongated magnet configuration in the sputter unit 125. Consequently, it is an advantage of embodiments of the present invention that the material flux vector cannot only be adjusted between the different sputter units, but also in the length direction of the sputter units. Furthermore, the magnet structure 140 is in certain embodiments of the present invention divided in sub-configurations which can be shifted independently from one another. An example hereof is illustrated in
[0090] In embodiments of the present invention, the magnet configuration 140 can be shifted as a whole.
[0091] In embodiments of the present invention the magnet structure 140 or a sub-configuration thereof can be adjusted over a distance of 10 mm with an accuracy of 0.1 mm, or even better.
[0092] In sputter systems 100 according to embodiments of the present invention, it is possible to apply target material. To this end, a sputter target holder 120 is present in the sputter system 100. This sputter target holder 120 makes it possible to mount a sputter target 121 between a magnet compartment 125 and a substrate 111. The latter may be positioned on a substrate holder 110. In embodiments of the present invention there is one sputter target holder 120 per sputter unit 125. Each sputter target holder 120 thereby allows to mount a cylindrical sputter target 121 to the corresponding sputter unit 125. Moreover, in particular embodiments of the present invention it is possible to rotate the sputter targets 121 by means of the sputter target holders 120. An example of a sputter target holder 120 for a cylindrical sputter target 121 is illustrated in
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[0094] In preferred embodiments of the present invention, the mechanical connections, the communication interconnections and the power interconnections are automatically established when mounting the magnet compartment.
[0095] In preferred embodiments of the present invention furthermore a cooling system is present for cooling the sputter targets 121 and the magnet structures 140. Other components which are typically comprised in a sputter unit and are known to the skilled person may also be incorporated in the system.
[0096] In a second aspect, the present invention relates to a method 1200 for sputtering a coating on a substrate 111. The method allows to obtain a better homogeneity of a parameter of the deposited coating. Such parameter may be the thickness, but may also be another physical parameter such as for example the resistivity or another electrical parameter, an optical parameter, etc.
[0097] The method 1200 of sputtering a coating on a substrate typically comprises arranging a substrate opposite the sputter target material, whereafter the sputter process is started. In order to obtain an even coating on the substrate, the position and/or shape of the magnet structures 140 may be adjusted during the sputter process.
[0098] Optionally it is also possible to adjust the position and/or shape of the magnet structures 140, between the time of sputtering a coating on the first substrate and the time of sputtering of a coating on the second substrate, but after inspection of the first substrate. The adjustment of the magnet structures 140 may also be performed during the sputtering of the coating on the second substrate, after inspection of the coating on the first substrate. The inspection of the substrate and the suitable adjustment of the magnet structures 140 may be performed manually or in an automatised manner, via algorithms and logical processors.
[0099] The method 1200 makes use 1210 of a sputter system, wherein individually controllable magnet structures 140 (e.g. remotely controllable) are present.
[0100] Thereafter a substrate can be provided 1220 and the sputter process can be started. The method typically comprises adjusting 1240 of the position of the magnet structures while the sputter targets are mounted on the sputter units. This may be on a non-operational sputter system, or on an operational sputter system, i.e. during sputtering. Preferably the adjustment can take place while the system is under vacuum, so that the vacuum need not be broken for performing the adjustment. The adjustment can preferably also take place while the water cooling is connected. In some embodiments the controlling can also take place while the sputter target is being powered, or during sputtering. By modifying the position and/or the shape of one or more magnet structures, both the amplitude as well as the orientation of the material flux vector can be adapted. As the positions and shape of the magnet structures can be changed independently from one another, the magnetic field vectors can be adjusted locally. The magnetic field vectors have a direct effect on the local material flux vectors of the target material on the substrate, so that these can also be adjusted locally. By locally adjusting the material flux vector, a homogeneous coating can be obtained on the substrate. This may comprise a homogeneity in thickness, but may also comprise a homogeneity in another parameter such as resistivity or another electrical parameter, an optical parameter, etc.
[0101] In a subsequent step the substrate is removed 1250, whereafter optionally sputtering can be resumed on a next substrate, or whereafter the sputter process may be stopped 1260.
[0102] Further optional steps may comprise or be associated with the inspection 1270 of the coating on a substrate for improving subsequent sputter processes. Based on the results of previously deposited coatings, the adjustment step 1240 may be updated, e.g. fine-tuned. This can be achieved manually or in an automated manner. Also the initial positions of the magnet configurations can be adjusted 1290 prior to providing the next substrate 1290, and starting the next sputter process 1230.
[0103] The various aspects can be easily combined with each other, and the combinations thus also correspond to embodiments of the present invention.