KR102337787B1 - Methods for coating a substrate and coater - Google Patents

Abstract

A method is provided for coating a substrate (100) using at least one cathode assembly (10) having three or more rotatable targets (20), wherein the three or more rotatable targets (20) are each , including a magnet assembly 25 positioned therein. The method includes a plurality of different angular positions with respect to a plane 22 extending perpendicularly from the substrate 100 to an axis 21 of each of the three or more rotatable targets 20 . rotating the magnet assemblies (25); and the power provided to the three or more rotatable targets 20 , the residence time of the magnet assemblies 25 , and continuously varying according to a function stored in a database or memory. varying at least one of the angular rates of

Description

METHODS FOR COATING A SUBSTRATE AND COATER

[0001] The present application relates to a method and a coater for coating a substrate, and specifically, to a method for sputtering a layer on a substrate with high uniformity and a coater for performing the method.

[0002] Forming a layer on a substrate with high uniformity (ie, uniform thickness and electrical properties over an extended surface) is a major concern in many technical fields. For example, in the field of thin film transistors (TFTs), thickness uniformity and uniformity of electrical properties can be major concerns in reliably manufacturing display channel regions. Moreover, typically, a uniform layer allows for manufacturing reproducibility.

[0003] One method for forming a layer on a substrate is sputtering, which has been developed as a very beneficial method in various manufacturing fields, such as the fabrication of TFTs. During sputtering, atoms are expelled from the target material by bombardment of the target material by energetic particles (eg, energized ions of an inert or reactive gas). The expelled atoms may be deposited on the substrate, thereby forming a layer of sputtered material.

However, forming a layer by sputtering can have high uniformity specifications, eg, due to the geometry of the substrate and/or target. In particular, uniform layers of sputtered material and ion bombardment over vast substrates can be difficult to achieve due to the irregular spatial distribution of sputtered material and ion bombardment. Providing multiple targets across the substrate can improve layer uniformity.

[0005] In view of the above, new methods and coaters for coating a substrate that overcome at least some of the problems in the art would be beneficial.

[0006] In view of the above, a method and coater for coating a substrate are provided. Additional aspects, advantages, and features of the disclosure are apparent from the claims, the detailed description, and the accompanying drawings.

According to an aspect, there is provided a method for coating a substrate using at least one cathode assembly having three or more rotatable targets, each of the three or more rotatable targets comprising: a positioned magnet assembly. The method includes rotating magnet assemblies in a plurality of different angular positions with respect to a plane extending perpendicularly to an axis of each of the three or more rotatable targets from a substrate; and varying at least one of a power provided to the three or more rotatable targets, a residence time of the magnet assemblies, and a continuously varying angular velocity of the magnet assemblies according to a function stored in a database or memory. include

According to a further aspect, a coater for performing a method for coating a substrate is provided.

Additional aspects, details, advantages, and features are apparent from the dependent claims, the detailed description, and the accompanying drawings.

Embodiments also relate to apparatus for performing the disclosed methods, and include apparatus parts for performing each described method aspect. These method aspects may be performed by hardware components, by a computer programmed by suitable software, by any combination of the two, or in any other manner. Furthermore, embodiments according to the present disclosure also relate to methods for operating the described apparatus. Methods for operating an apparatus described include method aspects for performing functions of the apparatus.

[0011] A more specific description of the disclosure briefly summarized above may be made with reference to embodiments, in such a way that the above-listed features of the disclosure may be understood in detail. The accompanying drawings relate to embodiments of the present disclosure and are described below.
1 shows a schematic cross-sectional view of a coater, illustrating a method for coating a substrate, in accordance with embodiments described herein;
2 shows a schematic cross-sectional view of a coater, illustrating a method for coating a substrate, in accordance with embodiments described herein;
3A and 3B show schematic cross-sectional views of a coater, illustrating a method for coating a substrate, in accordance with embodiments described herein;
4 shows a schematic cross-sectional view of a coater, illustrating a method for coating a substrate, in accordance with embodiments described herein;
5 illustrates a change in power as a function, according to embodiments described herein.
6 illustrates the continuous change of angular velocity as a function of the present invention, according to embodiments described herein.
7 illustrates a further change in power as a function, in accordance with embodiments described herein.
8 illustrates a further change in power as a function, and a change in dwell time as a function, in accordance with embodiments described herein, according to embodiments described herein.
9 shows a schematic cross-sectional view of three or more rotatable targets positioned for coating a substrate, in accordance with embodiments described herein.
10A and 10B show a comparison of the thickness of a film deposited by a conventional process to that of a film deposited by the processes described herein.
11A and 11B show a comparison of electrical properties of films deposited by conventional processes with those of films deposited by the processes described herein.

Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. Within the following description of the drawings, like reference numbers refer to like components. Typically, only differences to individual embodiments are described. Each example is provided as a description of the disclosure and is not intended as a limitation of the disclosure. Additionally, features illustrated or described as part of one embodiment may be used with or on other embodiments to create a still further embodiment. It is intended that this description cover such modifications and variations.

[0013] Sputtering may be undertaken as diode sputtering or magnetron sputtering. Magnetron sputtering is particularly advantageous in that deposition rates are high. Typically, a magnet is positioned within a rotatable target. Typically, a rotatable target as used herein is a rotatable curved target. By arranging a magnet or magnets behind the target, i.e. arranging the magnet or magnets inside the target in the case of a rotatable target, in order to trap free electrons in a generated magnetic field that is created just below the target surface, these electrons generate a magnetic field. Forced to move inside, no escape is possible. This typically improves the probability of ionizing gas molecules by several powers of 10. This in turn significantly increases the deposition rate.

[0014] The term “magnet assembly” as used herein is a unit capable of generating a magnetic field. Typically, the magnet assembly includes a permanent magnet. Specifically, the magnet assembly may be composed of a permanent magnet. Typically, this permanent magnet is arranged within the rotatable target such that free electrons are trapped in a magnetic field created below the rotatable target surface. In some embodiments, the magnet assembly includes a magnet yoke. According to an aspect, the magnet assembly may be movable within the rotatable tube. By moving the magnet assembly, more specifically by rotating the magnet assembly along the axis of the rotatable tube as a center of rotation, the material being sputtered can be directed in different directions.

[0015] The substrate may be moved continuously during coating (“dynamic coating”), or the substrate to be coated may be stationary during coating (“static coating”). According to embodiments described herein, methods provide a static deposition process. Typically, particularly in the case of large area substrate processing, such as processing of vertically oriented large area substrates, a distinction can be made between static deposition and dynamic deposition. Dynamic sputtering, i.e., an in-line process in which a substrate moves continuously or quasi-continuously near a deposition source, allows the process to stabilize before the substrates move into the deposition region, which then becomes constant as the substrates pass the deposition source. Due to the fact that it can be maintained, it will be easier. However, dynamic deposition can have other drawbacks, such as particle generation. This is particularly applicable for TFT backplane deposition. According to embodiments described herein, static sputtering may be provided, for example, for TFT processing, wherein the plasma may be stabilized prior to deposition onto a pristine substrate. It should be noted that the term static deposition process, which is different as compared to dynamic deposition processes, does not exclude any movement of the substrate, as will be appreciated by one of ordinary skill in the art. The static deposition process may include, for example, a static substrate position during deposition, a vibrating substrate position during deposition, a substantially constant average substrate position during deposition, a dithering substrate position during deposition, a wobbling substrate position during deposition. , a deposition process in which one chamber is provided with cathodes, i.e. the chamber is provided with a predetermined set of cathodes, during the deposition of a layer, the deposition chamber is provided with adjacent chambers, for example by closing valve units separating the chamber from an adjacent chamber. a substrate position with a sealed atmosphere with respect to, or a combination thereof. Accordingly, a static deposition process may be understood as a deposition process having a static position, a deposition process having a substantially static position, or a deposition process having a partially static position of a substrate. Thus, a static deposition process as described herein can be clearly distinguished from a dynamic deposition process, with the substrate position relative to the static deposition process not being shifted at all during deposition.

[0016] The term "vertical orientation" or "vertical orientation" may be understood to distinguish it from "horizontal orientation" or "horizontal orientation". That is, “vertical orientation” or “vertical orientation” may refer to, for example, a substantially vertical orientation of the carrier and substrate, wherein the exact vertical direction or number from the vertical orientation, such as at most +/-10° or even at most A deviation of +/−15° can still be considered a “substantially vertical orientation” or a “substantially vertical orientation”. The vertical direction may be substantially parallel to gravity.

[0017] According to embodiments described herein, which may be combined with other embodiments described herein, substantially perpendicular is +/-20° from the vertical direction or thereof, particularly when indicating substrate orientation. It can be understood that a deviation of less than, such as +/-10° or less, is permitted. This deviation may be provided because, for example, a substrate support having a slight deviation from vertical orientation may result in a more stable substrate position. However, substrate orientation during deposition of organic material may be considered substantially vertical, which may be considered different from horizontal substrate orientation.

[0018] The term "substantially perpendicular" may relate, for example, to a substantially perpendicular orientation of an axis of rotation and a support surface or substrate surface, wherein the number from the exact vertical orientation, such as up to +/-10 Deviations of ° or even up to +/-15° may still be considered “substantially vertical”.

Examples described herein may be utilized, for example, for lithium battery fabrication or deposition onto large area substrates for electrochromic windows. For example, a plurality of thin film batteries may be formed on a large area substrate using a cooling device to process a layer comprising a material having a low melting temperature. According to some examples, the large area substrate is ^{GEN 4.5 corresponding to about 0.67 m 2} substrates (0.73 x 0.92 m), GEN 5 corresponding to about 1.4 m ² substrates (1.1 m x 1.3 m), about 4.29 m ² GEN 7.5 corresponding to substrates (1.95 mx 2.2 m), GEN 8 corresponding to approximately 5.3 m ² substrates (2.16 mx 2.46 m), or even corresponding to approximately 9.0 m ² substrates (2.88 mx 3.13 m) It may be GEN 10. Even larger generations and corresponding substrate areas such as GEN 11, GEN 12, etc. can be implemented similarly.

[0020] The term “substrate” as used herein shall specifically encompass inflexible substrates, such as glass plates. The present disclosure is not limited thereto, and the term “substrate” may also encompass flexible substrates such as webs or foils.

[0021] Sputtering may be used in the production of displays. More specifically, sputtering may be used for metallization, such as the creation of electrodes or buses. Sputtering is also used for the creation of thin film transistors (TFTs). Sputtering can also be used to create an indium tin oxide (ITO) layer.

[0022] Sputtering can also be used in the production of thin film solar cells. A thin film solar cell includes a back contact, an absorbing layer, and a transparent and conductive oxide layer (TCO). Typically, the back contact and TCO layers are produced by sputtering, while the absorber layer is typically produced in a chemical vapor deposition process.

[0023] In the context of this application, the terms “coating”, “deposition”, and “sputtering” are used synonymously.

[0024] According to embodiments described herein, a method for coating a substrate is provided. The method may be performed by a coater. The coater includes at least one cathode assembly having three or more rotatable targets. Each of the three or more rotatable targets, specifically the three or more rotatable targets, includes a magnet assembly positioned therein. Typically, the magnet assemblies are provided at a plurality of different angles with respect to a plane extending perpendicularly to the axis of each of the three or more rotatable targets from the substrate, particularly during deposition of material onto the substrate. rotated to positions. Specifically, for each of the plurality of different angular positions, the magnet assemblies are angled with respect to a plane extending perpendicularly from the substrate to the axis of each of the three or more rotatable targets. Typically, the three or more rotatable targets may each be a cylindrical sputter cathode rotatable about an axis of rotation.

[0025] According to an aspect of the present disclosure, as a function, at least one of a power provided to three or more rotatable targets, a residence time of the magnet assemblies, and an angular velocity of the magnet assemblies, which is continuously varied, as a function. is changed That is, three or more rotatable targets are provided with non-constant power, and/or different dwell times are used, and/or a continuously varying angular velocity of the magnet assemblies is used. Typically, the sputter power, residence time, and/or angular rate is varied with the magnet assembly position. In particular, the sputter power generally directly corresponds to the power applied to the rotatable target. Except for values close to 0 V, the relationship between the applied voltage and the sputter power is linear in the first approximation. Accordingly, a description of a change in power provided to three or more rotatable targets 20 may be understood as a change in voltage provided to three or more rotatable targets 20 , The reverse is also true. Specifically, in practice, the sputter power may be varied, which may result in a change in the power applied to the three or more rotatable targets. Typically, the voltage may be varied in the range of -200 V to -800 V, specifically in the range of -300 V to -550 V. In addition, it is also possible to vary the current provided to three or more rotatable targets. Accordingly, an explanation of the change in power provided to the three or more rotatable targets 20 is a change in the voltage provided to the three or more rotatable targets 20 , and/or three or as a change in the current provided to more rotatable targets 20 , and vice versa.

[0026] According to embodiments described herein, varying the residence time of the magnet assemblies at each angular position is performed according to a discrete function, and/or angular velocity of the magnet assemblies at each angular position Transformation is performed according to a continuous function.

[0027] According to embodiments described herein, at least one of a change in power provided to the three or more rotatable targets, a change in residence time of the magnet assemblies, and a successive change in the angular velocity of the magnet assemblies A function for one is read from the database or memory. A change in at least one of the power provided to the three or more rotatable targets, the residence time of the magnet assemblies, and the angular velocity of the magnet assemblies, which is continuously varying or varied, is then performed as a function. Specifically, the function may be predetermined, eg, for a particular process, and may be read from a database or memory before that particular process is performed. For example, different functions for different thicknesses of the layer to be sputtered may be stored.

That is, the function is stored in the memory, and a change is performed according to the function. Typically, the function may be a function dependent on each position, ie, the function may contain different values for each different positions. According to embodiments, the amount of material sputtered on the substrate at each position may be determined by a function. That is, by including values dependent on each position, it may be possible to sputter a layer with high uniformity onto the substrate when practicing the embodiments. Typically, the function may be predetermined based on a number of trails.

[0029] Typically, the power provided to the three or more rotatable targets and one of the continuously varying angular velocity of the magnet assemblies and the residence time of the magnet assemblies are varied as a function. Specifically, the residence time of the magnet assemblies may be varied according to a discontinuous function and/or the angular velocity of the magnet assemblies may be varied according to a continuous function. that is, the power provided to the three or more rotatable targets and the residence time of the magnet assemblies vary as a function, or continuously varied with the power provided to the three or more rotatable targets; The angular velocity of the magnet assemblies varies as a function.

[0030] In the context of the present application, a continuous change in angular velocity can be distinguished from a discontinuous change in angular velocity, such as a step change in angular velocity, i.e., from zero to a specific value and vice versa. have.

[0031] When practicing the embodiments, the formation of layers with high quality onto a substrate may be enabled. In particular, the thickness of the deposited layer on the substrate can be highly uniform across the entire substrate. In addition, high homogeneity of the layer (eg, with respect to properties such as structure, resistivity, and/or layer stress of the grown crystal) may be enabled. For example, embodiments may actually be advantageous for forming metallization layers in the production of TFTs (eg, for the manufacture of TFT-LCD displays), where the signal delay depends on the thickness of the layer, and thus , since thickness non-uniformity may cause pixels to be energized at slightly different points in time. Moreover, embodiments may indeed be advantageous for forming layers that are subsequently etched, since uniformity of the layer thickness allows to achieve the same results at different positions of the formed layer.

[0032] In the context of the present application, the three or more rotatable targets may each be a cylindrical sputter cathode rotatable about an axis of rotation.

According to embodiments, the coating system comprises a vacuum chamber, in which the sputtering process is performed. As used herein, the term “vacuum” refers to ^{a pressure less than 10 -2} mbar (such as, ^{but not limited to, approximately 10 -2} mbar, which may be the case where processing gas is flowing within the vacuum chamber). , or more specifically a pressure of less than ^{10 -3 mbar (such as, but not limited to, approximately 10 -5} mbar, which may be the case where no processing gas is flowing within the vacuum chamber). refers to The coating system may form a process module forming part of the manufacturing system. For example, the coating system may include, but is not limited to, a system for manufacturing a TFT, or more specifically a system for manufacturing a TFT-LCD, such as, but not limited to, the AKT-PiVot PVD System (Applied Materials, Santa Clara, CA). can be implemented in

1 schematically illustrates a substrate 100 being positioned on a substrate holder 110 . A rotatable target 20 of the cathode assembly 10 may be positioned over the substrate 100 . A negative potential may be applied to the rotatable target 20 . A magnet assembly 25 is schematically shown positioned within a rotatable target 20 . In many embodiments, an anode (not shown in FIG. 1 ) to which a positive potential may be applied may be positioned near the rotatable target 20 . Such an anode may have the shape of a bar, typically the axis of the bar being arranged parallel to the axis of the angular tube. In other embodiments, a separate bias voltage may be applied to the substrate. “Positioning the magnet assembly” as used herein may be understood as operating the coater with the magnet assembly positioned in a particular constant position. In FIG. 1 , only one rotatable target 20 of three or more rotatable targets 20 is shown. However, for two or more of the three or more rotatable targets 20 the same principles can be applied.

[0035] A typical permanent magnet as used in the embodiments described herein has a pair of first magnets having a first magnetic pole, and second magnets having a second magnetic pole. These poles each refer to the surface of the magnet assembly. Typically, the surfaces face the rotatable target from the inside.

[0036] According to embodiments described herein, a magnet assembly has a first magnetic pole in a direction of a first plasma racetrack, and a second magnetic pole in a direction of a second plasma racetrack. The first magnetic pole may be the magnetic south pole, and the second magnetic pole may be the magnetic north pole. In other embodiments, the first magnetic pole may be the magnetic north pole and the second magnetic pole may be the magnetic south pole. The second pair of magnets engages second magnetic poles (eg, south poles or north poles) in the direction of the first plasma racetrack and first magnetic poles (eg, north poles or south poles) in the direction of the second plasma racetrack. can have

[0037] Accordingly, three magnets, each of which may be configured as one or more sub-magnets, may form two magnetrons, one magnetron forming a first plasma racetrack, and one magnetron forming a first plasma racetrack; A second plasma racetrack is formed. The first plasma racetrack and the second plasma racetrack may each have a major direction in which material is ejected from the target upon bombardment of ions in the plasma. Accordingly, the magnet assembly 25 may include a major direction of material ejection, which may be an overlap of the major directions of the first plasma racetrack and the second plasma racetrack.

In FIG. 1 , an enlarged view of a magnet assembly 25 is shown illustrating an example situation as described herein. As shown, the south poles are positioned in the middle, while the north poles surround the south poles.

The surface of the substrate may define a plane arranged horizontally in the figures shown. In the context of the present application, the angle of the magnet assemblies is defined with respect to a plane extending perpendicularly from the substrate 100 to the axis of the rotatable target 20 . In embodiments described herein, this plane may also be perpendicular to the substrate holder. In the context of this application, this plane may be referred to as a “substrate-target interconnection plane”. 1 , 3A and 3B , this plane is exemplarily shown as a dotted line arranged vertically with reference numeral 22 .

The embodiments shown in the figures illustrate an arrangement of a rotatable target 20 on a horizontally arranged substrate 100 , for which the definition of a substrate-target interconnection plane is exemplified Although generally described, other orientations are also possible. Specifically, the orientation of the substrate may also be vertical as described herein. In particular, considering the large area coating, when the substrate is vertically oriented, transportation and handling of the substrate can be simplified and facilitated. In other embodiments, it is even possible to arrange the substrate in any orientation between a horizontal orientation and a vertical orientation.

[0041] According to embodiments described herein, the magnet assemblies 25 may be rotated to a plurality of different angular positions, wherein in the plurality of different angular positions, the magnet assemblies 25 are planar ( 22 ), the plane 22 extending perpendicularly from the substrate 100 to the axis 21 of each of the three or more rotatable targets. The angle of each position may be equal to or greater than -60°, specifically equal to or greater than -40°, typically greater than or equal to -15°, , and/or less than or equal to 60°, specifically equal to or less than 40°, and typically less than or equal to 15°.

[0042] Further, the magnet assemblies 25 may have a starting angle or a reference angle, wherein the magnet assemblies 25 rotate from the starting angle or reference angle to a first angular position of a plurality of different angular positions. do. The starting angle may be non-zero with respect to the plane 22 , such as +/-5° to +/-15°, the plane 22 being three or more from the substrate 100 . of the rotatable targets 20 of each extend perpendicularly to the axis 21 . Additionally, the ranges specified herein for each position may be for a starting angle. That is, each position can be measured with respect to a starting angle, which can be zero or non-zero with respect to a plane 22 , which plane 22 can move three or more rotatable targets from the substrate 100 ( 20) extending vertically to each axis 21 .

Typically, the rotatable targets 20 have the shape of a cylinder. To specify the angular position of elements, such as a magnet assembly, within a cylinder, cylindrical coordinates may be used. Looking specifically at each position, within the present disclosure, an angle is used for an indication of the position. Within the present disclosure, the zero angular position should be defined as the position in the rotatable target that is closest to the substrate. Thus, typically, the zero angular position lies within the direct substrate target connection plane 22 .

As shown in FIG. 2 , the magnet assemblies 25 may be positioned at an angular position with an angle α within the rotatable targets 20 . More specifically, the magnet assemblies 25 may be positioned at a plurality of angular positions having an angle α within the rotatable targets 20 . That is, the magnet assemblies 25 can be rotated into a plurality of different angular positions, in which the magnet assemblies have an angle α with respect to the plane 22 , the plane 22 . ) extends vertically from the substrate 100 in the axis 21 of each of the three or more rotatable targets 20 .

3A and 3B show a first angular position (see FIG. 3A ) having a negative angle (−α) and a second angular position having a positive angle (α) among a plurality of different angular positions ( 3B) exemplarily illustrates a situation in which the magnet assembly 25 is rotated. Reference number 23 illustrates the direction of material ejection from the magnet assembly 25 .

For example, the magnet assemblies 25 may be rotated into a plurality of angular positions at an angular velocity having an absolute value greater than zero. Specifically, the magnet assemblies can be rotated from one limit of a range for angle α, such as an upper limit, to another limit, such as a lower limit, of range for angle α, and vice versa. At the limits of the range, a turning of the angular velocity may occur, ie the angular velocity may change sign.

Alternatively, the magnet assemblies 25 may be rotated in a stepwise manner from one angular position to another angular position. That is, the magnet assemblies 25 may be rotated to one angular position in which the magnet assemblies 25 may remain stationary for a predetermined dwell time, and thereafter, the same or another predetermined dwell time. The magnet assemblies 25 may be rotated to other angular positions while remaining stationary. Such stepwise movement may be repeated to rotate the magnet assemblies 25 to a plurality of different angular positions, such as four or more different angular positions.

[0048] Additionally, the angle α may also indicate a major direction of material emission. That is, specifically, the material will be sputtered onto the substrate in the direction of angle α. By changing the angular position of the magnet assembly, the major direction of emission can be varied across the substrate 100 .

[0049] In practicing embodiments, the uniformity of the layer formed is dependent on the power applied for the respective angular positions, how long the magnet assemblies stay in the individual positions, and/or at what angular velocity the magnet assemblies move. Depending on whether it is rotated, it can be improved. Specifically, sputtering may be performed while the magnet assemblies are held in each position for a dwell time.

[0050] In particular, by varying the power provided to the three or more rotatable targets, by varying the residence time of the magnet assemblies, and/or by continuously varying the angular velocity of the magnet assemblies as a function of sputtering The homogeneity, in particular the uniformity, of the layer to be formed can be improved. Accordingly, the homogeneity can be improved by sputtering with varying time and/or power. In the case of varying residence times, it is additionally possible to switch off the sputtering electric field at the time of movement (ie each position is being changed), which can further increase the uniformity.

4 exemplarily illustrates a cathode assembly as used in embodiments described herein in greater detail. It should be understood that the elements shown in FIG. 4 may also be applied to other embodiments described herein, particularly those described with respect to FIGS. 1 , 2 , 3A, and 3B . As shown in FIG. 4 , a rotatable target 20 may be placed on a backing tube, and the target material to be sputtered may be applied to the backing tube. A cooling material tube 40 may be provided on the interior of the rotatable target 20 to reduce the high temperature of the target resulting from the sputtering process. Typically, water may be used as the cooling material. When practicing the embodiments, most of the energy put into the sputtering process - typically on the order of a few kilowatts - is transferred to heat in the target, which can be cooled as described herein. . As shown in the schematic diagram of FIG. 4 , the magnet assembly may be positioned within the backing tube and the cooling material tube, such that the magnet assembly may move to different angular positions within the backing tube and the cooling material tube. According to other embodiments, the entire inner portion of the target tube is filled with a cooling material, such as water.

[0052] The magnet assembly may be mounted on an axis of the target tube. A pivotal movement as described herein may be generated by an actuator that provides a rotational force, such as an electric motor. In typical embodiments, two shafts: a first shaft with a rotatable target tube mounted thereon, and a second shaft mounted on the cathode assembly. The first shaft is rotated during operation of the cathode assembly. Typically, the movable magnet assembly is mounted to the second shaft. The second shaft can move independently of the first shaft, typically in a manner that allows for movement of the magnet assembly as described herein.

[0053] Within the present disclosure, the drawings illustrate schematic cross-sectional views of coaters with substrates shown by way of example. Typically, the cathode assemblies 10 include a rotatable target 20 that may have the shape of a cylinder. In other words, the rotatable target 20, when viewed in the drawings, extends into and out of the paper. The same is also true for the magnet assemblies 25 , which are only schematically shown as cross-sectional elements. The magnet assemblies may extend along the entire length of the cylinder. For technical reasons, it is typical for magnet assemblies to extend at least 100% of the length of the cylinder, more typically at least 105% of the length of the cylinder.

5 illustrates the change in power provided to three or more rotatable targets 20 as a function of FIG. Specifically, the function may provide different values for the power for each different positions. In the graph illustrated in FIG. 5 , the vertical axis is the power (U) provided to the three or more rotatable targets 20 and the horizontal axis is the angle (α).

As the distance from the magnet assembly 25 to the substrate 100 increases, the ion bombardment of the material emitted onto the substrate 100 decreases. The distance between the magnet assembly 25 or the rotatable target 20 and the substrate 100 along a plane extending perpendicularly from the substrate 100 to the axis 21 of the rotatable target 20 may be constant. However, the distance the material ejected from the rotatable target 20 travels to reach the substrate 100 increases as the values or absolute values of angle α increase. Thus, less material is deposited for relatively low angles α than for relatively high angles α.

Additionally, as the values or absolute values of angle α are increased, the angle of incidence at which the material to be deposited reaches the substrate 100 increases, which reduces the energy of the ion bombardment. This effect locally affects the structural, morphological, and electrical or optical properties of the grown film by controlling the local ion bombardment energy and intensity.

According to embodiments, the power provided to the three or more rotatable targets 20 is varied to compensate for reduced material deposition at angular positions with high angles α. . Specifically, the power provided to the three or more rotatable targets 20 is higher the higher the angle α of each position, and vice versa. When practicing the embodiments, the uniformity of the layer to be deposited can be increased, specifically, when the sputtering power is changed over the time the magnet is moved.

As shown in FIG. 5 , the function for varying the power provided to the three or more rotatable targets 20 may be a symmetric function. Additionally, the function for varying the power provided to the three or more rotatable targets 20 may be an asymmetric function. For example, the function for varying the power provided to the three or more rotatable targets 20 may be a polynomial function, a trigonometric function, and/or combinations thereof. For example, the power may be varied in the range of -2 kW to 20 kW, specifically in the range of 5 kW to 10 kW.

[0059] Additionally, the magnet assemblies 25 may be constantly rotated between a left maximum angle and a right maximum angle (“wobbling”). However, as shown in FIG. 6 , in addition to changing the power, the angular speed of the magnet assemblies 25 may be continuously varied to increase the uniformity of the layer to be deposited. Additionally, in the case of continuously changing the angular speed of the magnet assemblies 25 instead of changing the electric power, in practice, similar results for uniformity can be obtained.

[0060] Given the relationship described herein between the value of angle α and material deposited at each position with angle α, the relatively larger absolute values of angle α than It can be beneficial to continuously vary the angular velocity of the magnet assembly in such a way that for smaller absolute values the angular velocity is higher. That is, the magnet assembly 25 rotates faster for relatively smaller absolute values of angle α than for relatively larger absolute values of angle α. Thus, a higher deposition rate at each position with a relatively smaller absolute value of angle α decreases the effective residence time or time at which material is deposited at each of these positions, thereby resulting in a relatively larger value of angle α. Compensation can be achieved by comparing each position with a high absolute value.

The function for continuously varying the angular velocity of the magnet assemblies 25 may be a symmetric function. Additionally, the function for continuously varying the angular velocity of the magnet assemblies 25 may be an asymmetric function. For example, the function for continuously varying the angular velocity of the magnet assemblies 25 may be a polynomial function, a trigonometric function, and/or combinations thereof.

[0062] A function for varying the power provided to the three or more rotatable targets 20 is an upwardly opened function, ie, more on the vertical axis for larger absolute values on the horizontal axis. While it can be a function with large values, the function for continuously varying the angular velocity of the magnet assemblies 25 is a downward-opening function, i.e. a function with smaller values on the vertical axis relative to the greater absolute values on the horizontal axis. can For example, the angular velocity may be continuously varied in the range of 0.5 °/s to 500 °/s, specifically, in the range of 2 °/s to 200 °/s.

7 shows a further example of a function for varying the power provided to three or more rotatable targets 20 . Specifically, FIG. 7 shows an asymmetric function for varying the power provided to three or more rotatable targets 20 .

Additionally, FIG. 7 shows two different ways of varying the power provided to three or more rotatable targets 20 . The solid line represents a continuous function for varying the power provided to the three or more rotatable targets 20 , while individual points in the graph are directed to the three or more rotatable targets 20 . Represents a discrete function for varying the power provided. The continuous function may be used for wobbling magnet assemblies, ie, continuously rotating the magnet assemblies 25 at a constant angular velocity or at a continuously varying angular velocity. The discontinuous function may be used for the case of the magnet assemblies 25 being rotated stepwise, ie the magnet assemblies 25 being rotated stepwise from one angular position to another angular position.

[0065] As used herein, the term “continuous change” or “continuously varied” angular velocity of an angular velocity is a step-change, as is the case for step-rotated magnet assemblies 25 . It will be distinguished in particular from the angular velocity at which it becomes Specifically, in the case of stepwise rotation, generally, the angular velocity is zero while the magnet assemblies 25 are staying in each position, and a predetermined value when the magnet assemblies are moved from one angular position to the next angular position. jump to Such a movement can be understood in particular as a discontinuous movement. Accordingly, the residence time of the magnet assemblies may be varied according to a discontinuous function, and/or the angular velocity of the magnet assemblies may be varied according to a continuous function.

According to embodiments, the discrete function includes more than four steps. In particular, the more steps the discontinuous function has, the more it approximates the continuous function. Thus, to implement a function in a coater for performing the methods described herein, it may be beneficial to use a discrete function while increasing the number of steps to approximate the continuous function.

8 shows a further example of a function for varying the power provided to three or more rotatable targets 20 , and an example of a function for varying the residence time of magnet assemblies.

[0068] As outlined herein, the magnet assemblies 25 dwell for a specified dwell time in each stage of the stepwise rotation of the magnet assemblies 25. By varying the residence time for the stepwise rotation of the magnet assemblies 25, an effect similar to that which can be achieved by continuously varying the angular velocity for the continuously rotating magnet assemblies 25 can be achieved. . Specifically, the residence time may be lower for relatively smaller absolute values of angle α than for relatively larger absolute values of angle α. That is, the magnet assembly 25 dwells for a shorter amount of time for relatively smaller absolute values of angle α than for relatively larger absolute values of angle α. Thus, a higher deposition rate at each position with a relatively smaller absolute value of angle α decreases the residence time at which material is deposited at each of these positions, thereby resulting in a relatively higher absolute value of angle α. can be compensated by comparing it with each position having . Accordingly, the function for changing the residence time of the magnet assemblies 25 may be an upwardly open function. For example, the residence time may be varied in the range of 0.5 s to 30 s, specifically in the range of 2 s to 10 s.

[0069] In accordance with embodiments described herein, the power provided to three or more rotatable targets 20 and the angular velocity of the magnet assemblies 25 and the continuously varied magnet assemblies One of the residence times in (25) can be varied as a function. That is, the power provided to the three or more rotatable targets 20 may, in the case of a stepwise rotation, vary with the residence time of the magnet assemblies 25 , the wobbling magnet assemblies ( 25), it can be changed with a continuous change in the angular velocity of the magnet assemblies 25 . FIG. 8 illustrates a combination of a change in dwell time and a change in power provided to three or more rotatable targets 20 . Accordingly, a function may depend on multiple variables, and/or may be multi-dimensional, and/or may include one or more sub-functions.

[0070] By combining a change in power with a change in time (dwell time or angular velocity), the uniformity of the layer to be deposited can be further increased. Additionally, the power provided to the rotatable targets 20 may be technically limited to an upper and/or lower range of power that may be provided to the rotatable targets 20 . For example, it may be contemplated for the cathode assembly 10 to use a certain value for the power provided to the rotatable targets 20 that are not technically specified. Thus, for the power provided to the rotatable targets 20 , a value within the specified range may be used, and deviations from the value considered may be compensated for by varying the dwell time or angular velocity. Specifically, if the power provided to the rotatable targets 20, which is greater than a specified range, is to be used for a particular angular position, the deviation will result in a greater dwell time for that particular angular position, or that particular angular position. can be compensated by a smaller angular velocity for , and vice versa. When practicing embodiments, high throughput can be achieved which reduces overall processing time and costs.

According to embodiments, a processing chamber is provided. Specifically, the processing chamber may be a vacuum processing chamber. The processing chamber may include at least one cathode assembly as described herein. Additionally, the processing chamber may be configured to perform a method for coating a substrate, as described herein. Typically, the processing chamber may be configured to coat one substrate at a time. Multiple substrates may be coated one after the other.

According to embodiments, at least three rotatable targets may be arranged in a one-dimensional array of regularly arranged rotatable targets. Typically, the number of rotatable targets is between 3 and 20, more typically between 8 and 16.

According to embodiments, the rotatable targets 20 may be equidistant from each other. Typically, the length of the rotatable targets 20 may be slightly longer than the length of the substrate to be coated. Additionally or alternatively, the area spanned by the rotatable targets 20 may be slightly wider than the width of the substrate. Typically, “a little” includes the range of 100% to 110%. Providing a slightly larger coating length/width helps to avoid boundary effects. Generally, the cathode assemblies are positioned equidistant from the substrate.

According to embodiments, three or more rotatable targets 20 may be arranged along the shape of an arc. The shape of the arc may be such that the rotatable targets 20 are positioned closer to the substrate 100 than the outer rotatable targets 20 . Such a situation is schematically illustrated in FIG. 9 . Alternatively, it is also possible that the shape of the arc defining the positions of the rotatable targets 20 causes the outer rotatable targets 20 to be positioned closer to the substrate 100 than the inner rotatable targets 20 . do. The scattering behavior depends on the material to be sputtered. Thus, depending on the application, ie the material to be sputtered, providing the rotatable targets 20 in an arc shape can actually further increase the homogeneity. The orientation of the arc may depend on the application.

In addition or alternatively, three or more rotatable targets 20 are rotatable outward from inward rotatable targets 20 such that the distance between two adjacent rotatable targets 20 is It can be arranged in such a way that it changes to the targets 20 . For example, the distance between adjacent outer rotatable targets 20 may be greater than the distance between adjacent inner rotatable targets 20 . Alternatively, the distance between adjacent outer rotatable targets 20 may be less than the distance between adjacent inner rotatable targets 20 . By providing the outer rotatable targets 20 with a distance less than the distance between adjacent inner rotatable targets 20 , the outermost rotatable targets 20 are moved closer to the inner portion of the substrate. According to embodiments, less material can be wasted.

Additionally, FIG. 9 shows exemplary anode bars positioned between cathode assemblies that may be used in some of the embodiments described herein.

[0077] According to embodiments, a function of at least one of a change in power provided to the three or more rotatable targets, a change in residence time of the magnet assemblies, and a continuous change in angular velocity of the magnet assemblies may be the same for all rotatable targets. Alternatively, different functions may be used for different rotatable targets.

For example, for the outer or outermost targets 20 , a different function than the function for other rotatable targets 20 may be used. In general, the outermost rotatable targets 20 are material on an area of the substrate 100 where the deposited layer is an overlap of material from the rotatable targets 20 less than in the inner area of the substrate 100 . To compensate for this variation in asymmetric deposition, an asymmetric function can be used for the outer or outermost targets 20 . Thus, the function is that for regions where the deposited layer is an overlap of material from less rotatable targets 20 than in the inner region of substrate 100 , higher values for power, higher values for residence time values, and/or lower values for each speed.

In the context of the present application, an “outer” rotatable target may be understood as a rotatable target arranged close to the edge of the substrate, whereas an “inner” rotatable target is arranged close to the inner regions of the substrate. It can be understood as a rotatable target. Specifically, when referring to an “outer” rotatable target and an “inner” rotatable target, the “outer” rotatable target may be closer to the edge of the substrate than the “inner” rotatable target. Furthermore, an “outermost” rotatable target can be understood as a rotatable target arranged closer to the edge of the substrate than neighboring rotatable targets.

10A and 10B show a comparison of the thickness of a film deposited by a conventional process to that of a film deposited by the processes described herein. Deposition is accomplished using rotatable targets arranged at positions of solid lines spaced apart from the substrate.

10A schematically shows two film profiles measured after deposition using a conventional process and after deposition using the processes described herein. The y-axis expresses metrical units for the thickness of the film, while the x-axis expresses metrical units for the length of the substrate. As can be seen from FIG. 10A , the thickness of the film deposited in the region between the rotatable targets 20 by the processes described herein is less than is the case for the conventional process in the region immediately below the rotatable targets. has a smaller deviation from the thickness of

[0082] FIG. 10B shows a statistical analysis of the variation in the thickness of a film deposited by a conventional process and the variation in the thickness of a film deposited by the processes described herein. As can be seen from FIG. 10B, the variation in thickness is higher for the conventional process shown on the left than for the process described herein shown on the right. When practicing the embodiments, the uniformity of the layer thickness can be increased.

11A and 11B show a comparison of the electrical properties of a film deposited by a conventional process to that of a film deposited using the processes described herein. Deposition is accomplished using rotatable targets arranged at positions of solid lines spaced apart from the substrate.

11A schematically shows three film profiles measured after deposition using two different conventional processes and after deposition using the processes described herein. The y-axis expresses units of measure for the electrical properties of the film, while the x-axis expresses units of measure for the length of the substrate. As can be seen from FIG. 11A , the illustrated electrical properties of films deposited by the processes described herein are more consistent than that for conventional processes, specifically more uniform overall.

[0085] FIG. 11B shows a statistical analysis of variations in electrical properties of films deposited by two conventional processes and variations in electrical properties of films deposited by the processes described herein. As can be seen from FIG. 11B , the illustrated variation of electrical characteristics is higher for the conventional processes shown on the left and middle than for the process described herein shown on the right. When practicing the embodiments, the uniformity of the electrical properties of the deposited layer may be increased.

[0086] In the following, embodiments that result in particularly high uniformity are described.

According to an aspect, there is provided a method for coating a substrate using at least one cathode assembly having three or more rotatable targets, each of the three or more rotatable targets comprising: a positioned magnet assembly. The method includes rotating the magnet assemblies into a plurality of different angular positions with respect to a plane extending perpendicularly to an axis of each of the three or more rotatable targets from a substrate; and varying at least one of a power provided to the three or more rotatable targets, a residence time of the magnet assemblies, and a continuously varying angular velocity of the magnet assemblies according to a function stored in a database or memory. include

According to embodiments, there is provided a method for coating a substrate using at least one cathode assembly having three or more rotatable targets, each of the three or more rotatable targets comprising: and a magnet assembly positioned therein. The method includes rotating the magnet assemblies to a plurality of different angular positions, in the plurality of different angular positions, the magnet assemblies are perpendicular from the substrate to an axis of each of the three or more rotatable targets. has a certain angle with respect to the plane extending to ―; reading from the memory a function for at least one of a change in power provided to the three or more rotatable targets, a change in residence time of the magnet assemblies, and a successive change in angular velocity of the magnet assemblies; and varying, as a function, at least one of a power provided to the three or more rotatable targets, a residence time of the magnet assemblies, and a continuously varying angular velocity of the magnet assemblies.

According to embodiments, there is provided a method for coating a substrate using at least one cathode assembly having three or more rotatable targets, each of the three or more rotatable targets comprising: and a magnet assembly positioned therein. The method includes rotating the magnet assemblies to more than four different angular positions, wherein in the more than four different angular positions, the magnet assemblies are ejected from the substrate to each rotatable target of the three or more rotatable targets. at an angle to a plane extending perpendicularly to the axis of ―; reading a function of the change in residence time of the magnet assemblies for more than four different angular positions; and varying, as a function, the residence time of the magnet assemblies for more than four different angular positions.

According to embodiments, there is provided a method for coating a substrate using at least one cathode assembly having three or more rotatable targets, each of the three or more rotatable targets comprising: and a magnet assembly positioned therein. The method includes rotating magnet assemblies in more than four different angular positions with respect to a plane extending perpendicularly to an axis of each of the three or more rotatable targets from a substrate; and varying the residence time of the magnet assemblies for more than four different angular positions according to a function stored in the database.

[0091] Typically, the residence time is different for each different position.

[0092] According to embodiments, a coater for performing the methods described herein is provided. The coater may include a memory from which functions may be read. Specifically, the memory may include a look-up table, and the function is stored in the look-up table.

[0093] A method and coater as disclosed herein may be used to deposit material on substrates. More specifically, the method and coater enable a high uniformity of the deposited layer and thus can be used in the production of displays, such as flat panel displays, such as TFTs. Given the improved uniformity, as an additional effect of the improved uniformity, overall material consumption can be reduced, which is particularly desirable when using expensive materials. For example, the proposed method and coater can be used for deposition of an indium tin oxide (ITO) layer in the production of flat panel displays.

According to certain embodiments, a conductive layer fabrication process and/or system is provided, the fabrication process and/or system may be for fabrication of an electrode or bus (especially in a TFT), the fabrication process and/or the system includes a method for coating a substrate and/or a system for coating a substrate, respectively, according to embodiments herein. For example, such a conductive layer may be, but is not limited to, a metal layer or a transparent conductive layer, such as, but not limited to, an indium tin oxide (ITO) layer. For example, the methods described herein can be used to form an active layer in a TFT, such as an active layer made of or comprising IGZO (indium gallium zinc oxide).

For example, at least some embodiments of the present disclosure can yield high uniformity or resistivity of an aluminum layer or IGZO layer formed on a glass substrate. For example, thickness variations of 0% to 2% or even 0.5% to ±1.5% over a substrate area of 406 mm x 355 mm can be achieved. In addition, variations in electrical properties of 2% to 8% or even 5% to 7% over a substrate area of 406 mm x 355 mm can be achieved.

[0096] Within this disclosure, at least some drawings illustrate schematic cross-sectional views of coating systems and substrates. At least some of the illustrated targets are shaped as cylinders. In these figures, when looking at the figures, it should be noted that the target extends into and out of the paper. The same is also true for magnet assemblies shown only schematically as cross-sectional elements. The magnet assemblies may extend along the entire length of the cylinder defined by the cylindrical target. For technical reasons, it is typical for magnet assemblies to extend at least 100% of the length of the cylinder, more typically at least 105% of the length of the cylinder.

[0097] While the foregoing relates to embodiments of the present disclosure, other and additional embodiments of the disclosure may be devised without departing from the basic scope of the disclosure, the scope of the disclosure being determined by the claims.

Claims (15)

A method for coating a substrate (100) using at least one cathode assembly (10) having three or more rotatable targets (20), the method comprising:
each of the three or more rotatable targets includes a magnet assembly (25) positioned therein;
The method is
a plurality of different angular positions with respect to a plane 22 extending perpendicularly from the substrate 100 to the axis 21 of each of the three or more rotatable targets 20 . rotating the magnet assemblies (25) with ); and
The magnet assemblies ( 25) varying at least one of the respective velocities of
The higher the power provided to the three or more rotatable targets 20, the greater the absolute value of the angle α of each position;
the effective residence time for relatively smaller absolute values of the angle α is shorter than the effective residence time for relatively larger absolute values of the angle α, and
The function is to compensate for variations in asymmetric deposition as material overlaps from fewer rotatable targets in an outer region of the substrate 100 than in an inner region of the substrate 100 , the three or more comprising an asymmetry function for use with respect to an outer one of the rotatable targets 20 of
A method for coating a substrate. According to claim 1,
The power provided to the three or more rotatable targets 20 , and the continuously varying angular velocity of the magnet assemblies 25 and the residence time of the magnet assemblies 25 are one of the which changes according to the function,
A method for coating a substrate. According to claim 1,
a change in power provided to the three or more rotatable targets 20 from the database or the memory, a change in residence time of the magnet assemblies 25 , and further comprising reading a function for at least one of the successive changes in each velocity;
A method for coating a substrate. According to claim 1,
wherein the function comprises at least one selected from the group consisting of a polynomial function and a trigonometric function,
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
the function determines the amount of material sputtered onto the substrate ( 100 ) at the plurality of different angular positions;
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
The function is to sputter a uniform layer on the substrate (100).
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
The database includes a look-up table,
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
wherein the function is a function dependent on each position,
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
wherein the function is a function dependent on each rotatable target (20) of the three or more rotatable targets (20);
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
wherein the magnet assembly (25) is rotated into the plurality of different angular positions at an angular velocity greater than zero;
A method for coating a substrate. 5. The method according to any one of claims 1 to 4,
The function comprises a discontinuous function for varying the dwell time, wherein the three or more rotatable targets 20 are rotated into the plurality of different angular positions in a stepwise manner according to the discontinuous function. ,
A method for coating a substrate. A method for coating a substrate (100) using at least one cathode assembly (10) having three or more rotatable targets (20), the method comprising:
each of the three or more rotatable targets includes a magnet assembly (25) positioned therein;
The method is
More than four different angular positions with respect to a plane 22 extending perpendicularly from the substrate 100 to the axis 21 of each of the three or more rotatable targets 20 . rotating the magnet assemblies (25) with a furnace; and
varying the residence time of the magnet assemblies (25) for the more than four different angular positions according to a function stored in a database or memory;
including,
the residence time for relatively smaller absolute values of the angle α of each position is shorter than the residence time for relatively larger absolute values of the angle α, and
The function is to compensate for variations in asymmetric deposition as material overlaps from fewer rotatable targets in an outer region of the substrate 100 than in an inner region of the substrate 100 , the three or more comprising an asymmetry function for use with respect to an outer one of the rotatable targets 20 of
A method for coating a substrate. For coating a substrate using the method according to any one of claims 1 to 4 and 12,
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