CN112301318A

CN112301318A - Sputtering apparatus and sputtering method using the same

Info

Publication number: CN112301318A
Application number: CN202010138214.0A
Authority: CN
Inventors: 李宽龙; 南相睦; 金显佑; 边宰号
Original assignee: Samsung Display Co Ltd
Current assignee: Samsung Display Co Ltd
Priority date: 2019-08-01
Filing date: 2020-03-03
Publication date: 2021-02-02
Also published as: KR20210016189A

Abstract

An embodiment of the present disclosure discloses a sputtering apparatus, including: a chamber in which a sputtering target and a target are installed, respectively; and a magnet portion that forms a magnetic field in the object and moves back and forth along a first direction, the magnet portion including one or more unit magnets including a center magnet extending along a second direction perpendicular to the first direction and a peripheral magnet surrounding the center magnet at a predetermined interval, the center magnet having a width at an end along the second direction that is narrower than a center portion of a body of the center magnet.

Description

Sputtering apparatus and sputtering method using the same

Technical Field

The present disclosure relates to a sputtering apparatus for performing an evaporation operation using a magnetic field and a sputtering method using the same.

Background

For example, a thin film transistor or the like suitable for a display device is manufactured by a vapor deposition process using a magnetic field such as magnetron sputtering. That is, a thin film having a desired pattern is formed on a substrate of a display device, which is a material to be vapor-deposited, by sputtering a prepared target for vapor deposition using a magnetic field.

Disclosure of Invention

However, in the sputtering process, the evaporation target may not be consumed uniformly as a whole, but a specific portion may be consumed concentratedly. This phenomenon occurs mainly because the plasma energy generated during sputtering is concentrated at a specific portion. In this case, due to excessive consumption of the specific portion, only the target object that is still sufficiently left may be replaced at an early stage, and there is a possibility that productivity is greatly adversely affected.

Embodiments of the present disclosure provide a sputtering apparatus and a sputtering method using the same, which are improved to prevent excessive consumption of a specific portion of a target object, thereby realizing a stable evaporation process.

The disclosed embodiment provides a sputtering apparatus, including: a chamber in which a sputtering target and a target are installed, respectively; and a magnet portion that forms a magnetic field in the object and moves back and forth along a first direction, the magnet portion including one or more unit magnets including a center magnet extending along a second direction perpendicular to the first direction and a peripheral magnet surrounding the center magnet at a predetermined interval, the center magnet having a width at an end along the second direction that is narrower than a center portion of a body of the center magnet.

The central portion of the body of the central magnet may have a constant width, and the width of the end portion may be gradually narrowed toward the outside along the second direction.

The width of the inner space of the peripheral magnet surrounding the central magnet may be narrower at an end portion in the second direction than at a central portion of the body of the central magnet.

The inner space of the peripheral magnet may have a constant width at a central portion of the body of the central magnet, and the width of the inner space may be gradually narrowed toward the outside along the second direction at the end portion.

The width of the inner space of the peripheral magnet may be gradually narrowed by forming a step at the end portion.

The width of the inner space of the peripheral magnet may be inclined and continuously narrowed at the end portion.

The position where the width of the central magnet starts to narrow may coincide with the position where the width of the inner space of the peripheral magnet starts to narrow along the second direction.

The position where the width of the central magnet starts to narrow may not coincide with the position where the width of the inner space of the peripheral magnet starts to narrow along the second direction.

The plurality of unit magnets may be arranged along the first direction, and when a width of the peripheral magnet of each unit magnet is defined as t1, an interval between end portions of adjacent peripheral magnets is defined as d1, a moving distance of each unit magnet in the first direction is defined as SL, and an interval between center portions of bodies of adjacent center magnets is defined as W, a relationship of W1 +3 · t1< SL may be satisfied.

In the vapor deposition operation, plasma may be formed between the target and the peripheral magnet in a shape corresponding to the gap between the central magnet and the peripheral magnet.

Other aspects, features, and advantages in addition to those described above will be apparent from the following drawings, claims, and detailed description of the disclosure.

Drawings

Fig. 1 is a front view schematically showing the structure of a sputtering apparatus according to an embodiment of the present disclosure.

Fig. 2 is a plan view showing an overlapping arrangement relationship among the magnet portion, the target, the substrate, and the mask in the sputtering apparatus shown in fig. 1.

Fig. 3A is a plan view showing a magnet portion in the sputtering apparatus shown in fig. 1.

Fig. 3B is a plan view showing the comparative example of fig. 3A.

Fig. 4A is a perspective view illustrating a case where plasma is formed by the magnet portion of fig. 3A.

Fig. 4B is a perspective view showing a case where plasma is formed by the magnet portion of fig. 3B.

Fig. 5 is a plan view showing specification conditions of the magnet portion shown in fig. 3A.

Fig. 6A to 6D are plan views showing deformable examples of the magnet portion shown in fig. 3A.

Fig. 7 is a cross-sectional view illustrating an organic light-emitting display device as an example of an object that can be deposited by the sputtering device shown in fig. 1.

Detailed Description

While the disclosure is susceptible to various modifications and alternative embodiments, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. The effects, features and methods for achieving them of the present disclosure will be apparent with reference to the embodiments described later in detail together with the accompanying drawings. However, the present disclosure is not limited to the following embodiments, and may be implemented in various forms.

In the following embodiments, the terms first, second, and the like are not used for limitation, but are used for the purpose of distinguishing one constituent element from another constituent element.

In the following embodiments, expressions in the singular number include expressions in the plural number without making a contrary definition.

In the following embodiments, the terms including or having mean that there are features or constituent elements described in the specification, and the addition possibility of one or more other features or constituent elements is not excluded in advance.

For convenience of description, the sizes of constituent elements in the drawings may be enlarged or reduced. For example, the size and thickness of each structure shown in the drawings are arbitrarily illustrated for convenience of description, and the present disclosure is not necessarily limited to the illustrated one.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings, and the same reference numerals are given to the same or corresponding components when the embodiments are described with reference to the drawings.

As shown in the figure, the sputtering apparatus of the present embodiment may include a chamber 200, a magnet portion 100, and the like, and the target 20 for vapor deposition and the substrate 10 as the target are arranged in the chamber 200 so as to face each other, and the magnet portion 100 forms a magnetic field in the target 20.

During sputtering, as shown in fig. 1, discharge is caused by supplying argon gas into the chamber 200 while using the target 20 as a cathode and the substrate 10 as an anode. At this time, plasma is formed while generating argon ions from the argon gas, the argon ions of the plasma collide with the target 20 to scatter fine particles of the target 20, and the scattered fine particles pass through the pattern holes 31 of the mask 30 to be deposited on the substrate 10 and form a thin film. The magnet portion 100 forms a magnetic field to increase the sputtering rate due to collision of argon ions.

Here, the magnet unit 100 includes a plurality of unit magnets 110, and each unit magnet 110 includes a center magnet 111 having an S-pole and a peripheral magnet 112 surrounding an N-pole of the center magnet 111. The magnet unit 100 moves back and forth along the X-axis direction (hereinafter, also referred to as a first direction) in fig. 1, and applies a uniform magnetic field to the entire target 20.

Fig. 2 is a plan view showing an arrangement relationship of the magnet portion 100, the target 20, the substrate 10, and the mask 30 in fig. 1.

As is apparent from fig. 2, since both the substrate 10 and the target 20 are configured to have a larger area than the pattern holes 31 of the mask 30, it can be seen that the edge portions located outside the pattern holes 31 are not effectively used in the actual vapor deposition operation.

However, even so, if excessive consumption occurs at the edge portion of the object 20, the entire object 20 needs to be replaced. This is because, if vapor deposition is continued even when excessive consumption occurs and the edge portion is almost consumed, the device on the rear side of the target 20 may be directly damaged by heat, plasma, fine particles, or the like.

However, in the actual vapor deposition operation, excessive wear occurs almost all at the edge of the target 20. That is, the plasma formed by the unit magnets 110 of the magnet portion 100 is formed in a shape that promotes the consumption of the edge portion of the target 20.

Therefore, in the present embodiment, in order to solve such a problem, as shown in fig. 3A, a magnet portion 100 in which the structure of the unit magnet 110 is improved is provided.

As shown in the drawing, a plurality of unit magnets 110 are arranged in the magnet portion 100, and the unit magnets 110 have the same configuration.

When one of the unit magnets 110 is viewed, the unit magnet 110 includes a center magnet 111 having an S-pole extending in the Y direction (hereinafter, also referred to as a second direction) in the figure and a peripheral magnet 112 surrounding an N-pole of the center magnet 111, and a gap is provided between the center magnet 111 and the peripheral magnet 112.

The central portion of the main body of the center magnet 111 has the same width, but the width of the both side end portions 111a becomes narrower toward the outside.

The peripheral magnet 112 also has an inner space 110a surrounding the central magnet 111 having the same width at a position corresponding to the central portion of the body of the central magnet 111, but the width of the inner space 110a formed by the both side end portions 112a is narrowed toward the outside.

That is, the central magnet 111 and the peripheral magnet 112 extend in the Y direction perpendicular to the X direction in which the magnet portion 100 reciprocates, and are configured to have a narrower width than the central portion at both

side end portions

111a and 112 a.

This is a measure for preventing the excessive wear of the edge portion of the object 20 as described above, and for the purpose of explaining this effect, a comparative example in which both side end portions 111a ', 112 a' are also configured to have the same width as the central portion as shown in fig. 3B will be described. That is, in the magnet portion 100 ' of the comparative example shown in fig. 3B, both the center magnet 111 ' and the peripheral magnet 112 ' extend in the Y direction up to both end portions without changing the width.

Such a difference in the structure of the magnet portion 100 of the present embodiment in fig. 3A and the magnet portion 100' of the comparative example in fig. 3B induces a difference in the shape of plasma generated during vapor deposition. That is, since the plasma formed between the target 20 and the substrate 10 is formed in a shape corresponding to the shape of the gap between the central magnets 111, 111 'and the peripheral magnets 112, 112', if the shapes of the central magnets 111, 111 'and the peripheral magnets 112, 112' are changed as described above, the shape of the plasma is also changed.

Fig. 4A shows a plasma 40 formed between the target 20 and the substrate 10 by the structure of the magnet portion 100 of the present embodiment of fig. 3A, and fig. 4B shows a plasma 40 'formed between the target 20 and the substrate 10 by the structure of the magnet portion 100' of the comparative example of fig. 3B.

Here, it is understood that the plasma is formed in a shape corresponding to the shape of the gap between the central magnets 111, 111 ' and the peripheral magnets 112, 112 ', and thus the shapes of the a and a ' portions as the end portions are formed differently. That is, in fig. 4A as the present example, the end portion a of the plasma 40 is formed in a sharp shape, whereas in fig. 4B as the comparative example, the end portion a 'of the plasma 40' is formed in a shape elongated in the X direction. Such a difference determines whether or not excessive consumption of the end portion of the target 20 in the Y direction occurs.

That is, in the configuration of fig. 4A, since the end portion a of the plasma 40 has a sharp shape, there is no portion that is located in the plasma 40 region at all times when the unit magnet 110 moves back and forth in the X direction. In fig. 4A, the end portion a of the plasma 40 is extremely similar to a straight line shape that is straightened in the Y direction, and the portion of the target 20 that overlaps with the straight line changes constantly when the straight line is reciprocated in the X direction. Thus, a phenomenon that a certain specific part is intensively consumed does not occur.

However, in the comparative example in which the distal end a 'of the plasma 40' is elongated in the X direction as in fig. 4B, when the unit magnet 110 'reciprocates in the X direction, the portion of the target 20 corresponding to the distal end a' of the plasma 40 'is exposed to the plasma 40' for a significantly longer time than other portions. In the extreme, when the unit magnet 110 ' is reciprocated by a distance shorter than the length of the end portion a ' in the X direction, exposed portions may also occur under the influence of the plasma 40 ' during the entire evaporation operation. If so, the consumption of the portion exposed to the plasma 40' for a longer time may be relatively severe, and therefore, even if the target 20 is sufficiently remained in other portions, the entire target 20 should be replaced in order to prevent damage to other devices due to the excessively consumed portion.

In contrast, in the present embodiment of fig. 4A, since the central magnet 111 and the peripheral magnet 112 of the unit magnet 110 are configured such that the end portion a of the plasma 40 has a sharp shape as described above, the portion exposed to the plasma 40 changes constantly when the unit magnet 110 moves back and forth in the X direction, and thus, a phenomenon in which a certain specific portion is intensively consumed does not occur. Further, due to the difference in the structures of the end portions of the unit magnets 110 and 110 ', the magnetic field strength is also different, and when the magnetic field strength is actually measured, it can be confirmed that the magnetic field strength at the end portion of the unit magnet 110 shown in fig. 3A and 4A is reduced from the magnetic field strength at the end portion of the unit magnet 110' of the comparative example shown in fig. 3B and 4B.

Therefore, if the magnet portion 100 having the structure shown in fig. 3A and 4A is used, it is possible to prevent a phenomenon in which a specific portion of the target 20 is excessively consumed, and it is possible to smoothly eliminate problems such as early replacement of the target 20, which is disadvantageous in terms of productivity.

On the other hand, as described above, there is a problem in that a portion of the target 20 exposed to the plasma 40 for a relatively long time exists, but conversely, it is difficult to have a portion of the target 20 not exposed to the plasma 40 at all. In this case, an unconsumed portion that does not contribute to evaporation is generated in the target 20, and this unconsumed portion may act as another contamination source. For example, a phenomenon called redeposition (redeposition) may occur in which fine particles scattered from the target 20 by the plasma 40 adhere to the unconsumed portions, and a vicious circle may be performed in which the redeposition portions also serve as a contamination source that hinders precise vapor deposition. Particularly in the present embodiment, both side end portions of the unit magnet 110 are formed in a shape of narrowing the width, and therefore, the interval between the adjacent unit magnets 110 becomes relatively farther at both side end portions than the center portion. Thus, if the reciprocating distance is set in consideration of only the center portion of the unit magnet 110, a region not exposed to the plasma 40 may be formed at both side end portions.

Fig. 5 shows conditions for preventing the occurrence of unworn spots at both side ends of the target 20, and when the width of the peripheral magnet 112 of each unit magnet 110 is defined as t1, the interval between the end portions of the adjacent peripheral magnets 112 is defined as d1, the moving distance of each unit magnet 110 in the X direction (first direction) is defined as SL, and the interval between the center portions of the bodies of the adjacent center magnets 111 is defined as W, the relationship of W ═ d1+3 · t1< SL may be satisfied.

Even if the width of both side ends of the unit magnet 110 is made narrow, an unconsumed portion of the target 20 not exposed to the plasma 40 is not generated.

Before describing the sputtering process by the sputtering apparatus as described above, the structure of the display apparatus 300 will be briefly described as an example of an object that can be deposited with a thin film by the sputtering apparatus with reference to fig. 7.

As shown in fig. 7, the display device 300 includes a thin film transistor 310 and an organic light emitting element 320.

First, the organic light emitting element 320 is driven by the thin film transistor 310 to emit light, thereby forming an image, and the organic light emitting element 320 includes a pixel electrode 321 and a counter electrode 323 facing each other, and a light emitting layer 322 disposed between the pixel electrode 321 and the counter electrode 323.

A constant voltage is constantly applied to the counter electrode 323, and a voltage is selectively applied to the pixel electrode 321 connected to the thin film transistor 310 through the thin film transistor 310. Therefore, according to selective voltage application of the thin film transistor 310, if an appropriate voltage is formed between the two electrodes (the pixel electrode 321 and the counter electrode 323), the light-emitting layer 322 between the pixel electrode 321 and the counter electrode 323 constitutes an image while emitting light.

The thin film transistor 310 is configured such that an active layer 316, a gate electrode 317, a source electrode 318, a drain electrode 319, and the like are sequentially stacked over a substrate 330. Therefore, if an electric signal is applied to the gate electrode 317, current can be conducted from the source electrode 318 to the drain electrode 319 through the active layer 316, and thus, a voltage is applied to the pixel electrode 321 connected to the drain electrode 319, thereby inducing light emission of the light-emitting layer 322 as described above.

Reference numeral 311 denotes a buffer layer interposed between the substrate 330 and the active layer 316, reference numeral 312 denotes a gate insulating layer, reference numeral 313 denotes an interlayer insulating film, reference numeral 314 denotes a passivation film, and reference numeral 315 denotes a pixel defining film, respectively.

For reference, a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Transport Layer (ETL), an Electron Injection Layer (EIL), and the like may be further stacked adjacent to the light emitting Layer 322 in the organic light emitting element 320. Also, the respective pixels of the light emitting layer 322 are separately formed such that pixels emitting red, green, and blue light are condensed to form one unit pixel. Alternatively, the light-emitting layer 322 may be formed in common across the entire pixel region regardless of the position of the pixel. In this case, the light-emitting layer 322 may be formed by vertically stacking or mixing layers containing light-emitting substances that emit red, green, and blue light, for example. Of course, if white light can be emitted, other colors can be combined. The color filter may further include a color changing layer or a color filter for converting the emitted white light into a predetermined color. A thin film encapsulation layer (not shown) in which an organic film and an inorganic film are alternately stacked may be formed on the counter electrode 323.

In such a structure, the sputtering apparatus can be used when forming various conductive layers of the thin film transistor 310. For example, when a gate electrode 317 made of Mo, a source electrode 318 and a drain electrode 319 made of Ti/Al/Ti, an active layer 316 made of TiN or IZO, or the like is formed, if the sputtering apparatus having the magnet portion 100 is used, the deposition operation can be smoothly performed without frequently replacing the target 20. In this case, the substrate 330 of the display device 300 may be considered to correspond to the substrate 10 installed in the chamber 200 of fig. 1.

The sputtering apparatus can be used as follows.

First, as shown in fig. 1, a substrate 10 as an object to be subjected to evaporation and a target 20 as an evaporation source are respectively installed in a chamber 200.

The magnet unit 100 is located outside the chamber 200 and close to the target 20, and moves back and forth in preparation for starting vapor deposition.

In this state, argon gas is injected into the chamber 200, and sputtering is performed while forming plasma 40 by applying a voltage to the target 20 and the substrate 10.

The magnet unit 100 reciprocates in the X direction of fig. 1 so that a uniform magnetic field acts on the target 20.

At this time, as shown in fig. 4A, since the plasma 40 is formed in a sharp shape at both side ends of the target 20 in the Y direction, excessive consumption does not occur at a certain specific portion, thereby eliminating problems such as early replacement of the target 20, and if the specification conditions as shown in fig. 5 are satisfied, an unconsumed portion of the target 20 is not generated. This stabilizes the deposition operation and improves the productivity.

In addition, the end portions of the unit magnets 110 of the magnet portion 100 can be deformed into various shapes. That is, the width of the center magnet 111 and the width of the inner space 110a of the peripheral magnet 112 are substantially the same as the shape in which the center portion becomes narrower at both side end portions, but may be deformed into more shapes.

First, fig. 6A shows the above-described configuration as it is, and the end 111a of the center magnet 111 has a shape in which the width is continuously narrowed, and the end 112a of the peripheral magnet 112 has a shape in which the inner space 110a is continuously narrowed while being inclined.

However, as shown in fig. 6B, the center magnets 111 have the same shape, and the end portions 112a of the peripheral magnets 112 may be deformed into a stepped shape that is gradually narrowed.

Further, although fig. 6A and 6B illustrate a configuration in which the position where the central magnet 111 starts to narrow and the position where the internal space 110a of the peripheral magnet 112 starts to narrow are substantially coincident with each other, as shown in fig. 6C and 6D, the position where the central magnet 111 starts to narrow and the position where the internal space 110a of the peripheral magnet 112 starts to narrow may not be coincident with each other. That is, similar effects can be expected even if the center magnet 111 and the peripheral magnet 112 do not have to be narrowed from the same position.

Therefore, with the sputtering apparatus having such a configuration, it is possible to prevent excessive consumption of a specific portion of the target for vapor deposition, and to eliminate problems such as early replacement of the target, and therefore, it is possible to stabilize the vapor deposition operation and improve productivity.

As described above, the present disclosure has been described with reference to one embodiment shown in the drawings, but this is merely an example, and it should be understood by those skilled in the art that various modifications and embodiment modifications may be made therefrom. Therefore, the true technical scope of the present disclosure should be defined according to the technical idea of the claims.

Claims

1. A sputtering apparatus, wherein the sputtering apparatus comprises:

a chamber in which a sputtering target and a target are installed, respectively; and

a magnet portion that forms a magnetic field in the target and moves back and forth in a first direction,

the magnet unit includes one or more unit magnets including a center magnet extending in a second direction perpendicular to the first direction and a peripheral magnet surrounding the center magnet at a predetermined interval,

the width of the end portion of the center magnet in the second direction is narrower than the center portion of the body of the center magnet.

2. The sputtering apparatus according to claim 1,

the central portion of the body of the central magnet has a constant width, and the width of the end portion gradually decreases toward the outside along the second direction.

3. The sputtering apparatus according to claim 1,

the width of the inner space of the peripheral magnet surrounding the center magnet is narrower at an end portion in the second direction than at a center portion of the body of the center magnet.

4. The sputtering apparatus according to claim 3,

the inner space of the peripheral magnet has a constant width in the center portion of the body of the center magnet, and the width of the inner space gradually decreases toward the outside in the second direction in the end portion.

5. The sputtering apparatus according to claim 4,

the width of the inner space of the peripheral magnet is gradually narrowed by forming a step at the end portion.

6. The sputtering apparatus according to claim 4,

the width of the inner space of the peripheral magnet is inclined and continuously narrowed at the end portion.

7. The sputtering apparatus according to claim 3,

the position where the width of the center magnet starts to narrow coincides with the position where the width of the inner space of the peripheral magnet starts to narrow along the second direction.

8. The sputtering apparatus according to claim 3,

the position where the width of the central magnet starts to narrow and the position where the width of the inner space of the peripheral magnet starts to narrow do not coincide along the second direction.

9. The sputtering apparatus according to claim 1,

a plurality of the unit magnets are arranged along the first direction,

when the width of the peripheral magnets of each of the unit magnets is defined as t1, the interval between the tip end portions of the adjacent peripheral magnets is defined as d1, the moving distance in the first direction of each of the unit magnets is defined as SL, and the interval between the center portions of the bodies of the adjacent center magnets is defined as W,

satisfy the relation of W ═ d1+3 · t1< SL.

10. The sputtering apparatus according to claim 1,

during the vapor deposition operation, plasma having a shape corresponding to the gap between the central magnet and the peripheral magnet is formed between the target and the target.