SUBSTRATE POLISHING APPARATUS

Description

CROSS-REFERENCE TO RELATED APPLICATION

This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2024-0108555, filed on Aug. 13, 2024, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The inventive concept relates to a substrate polishing apparatus, and more specifically, relates to a substrate polishing apparatus that improves a dispersion of a substrate by using magnetic force.

Various processes may be performed to fabricate a semiconductor device. For example, the semiconductor device may be fabricated through a photolithography process, an etching process, and a deposition process performed on a substrate. It may be required that a surface of the substrate be planarized prior to each process. A polishing process may be executed on the substrate. The polishing process may be fulfilled in a variety of ways. For example, a chemical mechanical polishing (CMP) process may be used to planarize the substrate.

SUMMARY

In some embodiments, a substrate polishing apparatus that uses magnetic force is provided.

In some embodiments, a substrate polishing apparatus that improves a dispersion of a substrate is provided.

The problem to be solved by the inventive concept is not limited to the problems mentioned above, and other problems not mentioned may be clearly understood by those skilled in the art from the description below.

A substrate polishing apparatus according to some embodiments of the inventive concept may include a platen, a polishing pad on the platen, a polishing head on the polishing pad, the polishing head including a polishing head body and a first magnetic structure on a side surface of the polishing head body, and a second magnetic structure adjacent to the first magnetic structure, wherein the second magnetic structure overlaps at least a portion of the first magnetic structure in a plan view.

A substrate polishing apparatus according to some embodiments of the inventive concept may include a platen configured to rotate a polishing pad, a polishing head on the polishing pad, the polishing head including a first magnetic structure, a second magnetic structure in the platen, and a power supply device electrically connected to the second magnetic structure, wherein the first magnetic structure and the second magnetic structure are configured to form a magnetic force between the first magnetic structure and the second magnetic structure.

A substrate polishing apparatus according to some embodiments of the inventive concept may include a platen configured to support and rotate a polishing pad, a polishing head on the polishing pad, the polishing head including a polishing head body and a first magnetic structure surrounding a side surface of the polishing head body, a second magnetic structure in the platen, a slurry supply device supplying slurry onto the polishing pad, a conditioning device spaced apart from the polishing head on the platen, and a power supply device electrically connected to the second magnetic structure, wherein the second magnetic structure overlaps at least a portion of the first magnetic structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the following brief description taken in conjunction with the accompanying drawings. The accompanying drawings represent non-limiting, example embodiments as described herein.

FIG. 1 is a perspective view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

FIG. 2 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

FIG. 3 is a cross-sectional view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept, taken along line A-A′ of FIG. 2.

FIG. 4 to FIG. 6 are enlarged views illustrating region ‘P1’ of FIG. 3.

FIG. 7 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

FIG. 8 is a cross-sectional view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept, taken along line B-B′ of FIG. 7.

FIG. 9 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

FIG. 10 is a cross-sectional view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept, taken along line A-A′ of FIG. 9.

FIG. 11 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

FIG. 12 is a cross-sectional view illustrating another substrate polishing apparatus according to some embodiments of the inventive concept, taken along line A-A′ of FIG. 11.

FIG. 13 is an enlarged view illustrating region ‘P2’ of FIG. 12.

FIG. 14 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

DETAILED DESCRIPTION

Hereinafter, embodiments of the inventive concept will be described with reference to the attached drawings. Throughout the specification, the same reference numerals may refer to the same components.

The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the disclosure are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure.

To clearly describe the present disclosure, description of some conventional elements or parts are omitted, and like numerals refer to like or similar components throughout the specification.

Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the present disclosure is not limited to the illustrated sizes and thicknesses. In the drawings, the thicknesses of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, for better understanding and ease of description, the thicknesses of some layers and areas are exaggerated.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Likewise, when components are “immediately” adjacent to one another, no intervening components may be present. Further, in the specification, the word “on” or “above” may include on or below the object portion, and does not necessarily mean positioned on the upper side of the object portion based on a gravitational direction.

The terms “first,” “second,” etc., may be used herein merely to distinguish one component, layer, direction, etc. from another. In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. The term “and/or” includes any and all combinations of one or more of the associated listed items. The term “connected” may be used herein to refer to a physical and/or electrical connection.

Further, throughout the specification, the phrase “in a plan view” means when an object portion is viewed from above, and the phrase “in a cross-sectional view” means when a cross-section taken by vertically cutting an object portion is viewed from the side.

FIG. 1 is a perspective view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept. FIG. 2 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept. FIG. 3 is a cross-sectional view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept, taken along line A-A′ of FIG. 2.

Referring to FIGS. 1, 2, and 3, a substrate polishing apparatus 1 may be provided. The substrate polishing apparatus 1 according to embodiments of the inventive concept may be a chemical mechanical polishing (CMP) device that polishes one surface of a substrate WF. The term substrate WF used in this specification may mean a silicon (Si) wafer, but is not limited thereto. The substrate polishing apparatus 1 may include a polishing unit 10, a polishing head 20, a slurry supply device 30, and a conditioning device 40. The substrate polishing apparatus 1 according to embodiments of the inventive concept may further include a first magnetic structure MS1 and a second magnetic structure MS2.

The polishing unit 10 may include a polishing pad 11 and a platen 13. The polishing pad 11 and the platen 13 may be coupled to each other. In addition, the polishing pad 11 and the platen 13 may be separated from each other. For example, the polishing pad 11 may be separated from the platen 13 after a certain period of time and replaced with a new polishing pad 11, but is not limited thereto.

The polishing pad 11 of the polishing unit 10 may be positioned on the platen 13. For example, a lower surface of the polishing pad 11 may be in contact with an upper surface of the platen 13. The polishing pad 11 may have a disk shape having an upper surface parallel to a first direction D1 and a second direction D2. A center of rotation of the polishing pad 11 may be located on the same line as a center of rotation of the platen 13. The polishing pad 11 may rotate together with the platen 13. For example, the polishing pad 11 may rotate about a first axis X1 parallel to a third direction D3. A substrate WF may be located on the polishing pad 11 (as can be seen in FIG. 3). An upper surface of the polishing pad 11 and one surface of the substrate WF may be in contact with each other. As the polishing pad 11 rotates, the polishing pad 11 may polish the substrate WF. The polishing pad 11 may be divided into a plurality of regions, but is not limited thereto. For example, the polishing pad 11 may include a polymer material such as polyurethane.

In the present specification, the first direction D1 and the second direction D2 may intersect with each other. The third direction D3 may also intersect with the first direction D1 and the second direction D2. For example, the first direction D1, the second direction D2, and the third direction D3 may be orthogonal to each other. In the present specification, the first direction D1 and the second direction D2 may be referred to as horizontal directions, and the third direction D3 may be referred to as a vertical direction.

The platen 13 of the polishing unit 10 may be positioned below the polishing pad 11. The platen 13 may support the polishing pad 11 below the polishing pad 11. The platen 13 may rotate about the first axis X1 parallel to the third direction D3. The platen 13 may be coupled with the polishing pad 11 to rotate the polishing pad 11. For example, the platen 13 may be rotated by a driving unit including a motor. When the polishing pad 11 has a disk shape, the platen 13 may also have a disk shape. For example, a diameter of the platen 13 may be about 700 mm to about 900 mm. That is, the polishing unit 10 may have a rotation speed about the first axis X1, which is one rotation axis.

The polishing head 20 may be positioned on the polishing pad 11 of the polishing unit 10 and may support and/or rotate the substrate WF. When viewed in a plan view, at least a portion of the polishing head 20 may be positioned between an inner magnet IMO and an outer magnet OMO of the second magnetic structure MS2 described later. In some embodiments, the polishing head 20 overlaps one or both of the inner magnet IMO and the outer magnet OMO. For example, the polishing head 20 may place the substrate WF on the polishing pad 11 such that one side of the substrate WF faces the polishing pad 11. In other words, the substrate WF may be pinned between the polishing head 20 and the polishing unit 10. The polishing head 20 may rotate independently of the polishing unit 10. For example, the polishing head 20 may rotate about a second axis X2 parallel to the third direction D3. A relative rotation speed of the polishing head 20 with respect to the polishing unit 10 may be variously changed with time. A relative position of the polishing head 20 with respect to the polishing unit 10 may be variously changed with time. For example, the polishing head 20 may move horizontally on the polishing pad 11. According to some embodiments of the inventive concept, the polishing head 20 may include a head support member 21, a polishing head body 23, a retainer ring 25, and a first magnetic structure MS1.

The head support member 21 of the polishing head 20 may be combined with the polishing head body 23. As a result, the head support member 21 may place the substrate WF combined with the polishing head body 23 at a certain position on the polishing pad 11. The head support member 21 may include a driving unit, and the driving unit may rotate the polishing head body 23.

The polishing head body 23 of the polishing head 20 may be located below the head support member 21. The polishing head body 23 may support the substrate WF. For example, the polishing head body 23 may support the substrate WF on a lower surface thereof using vacuum pressure. The polishing head body 23 may include a porous structure exposed on the lower surface thereof, but is not limited thereto.

The first magnetic structure MS1 may be located on the side surface of the polishing head body 23. When viewed in a plan view, the first magnetic structure MS1 may surround or be on a side of the polishing head body 23. For example, the first magnetic structure MS1 may have a shape of a ring around the second axis X2 of the polishing head 20. The first magnetic structure MS1 may include a magnetic material. According to some embodiments of the inventive concept, the first magnetic structure MS1 may be a permanent magnet.

The retainer ring 25 of the polishing head 20 may be located below the polishing head body 23. The retainer ring 25 may be coupled to the polishing head body 23. For example, the retainer ring 25 may be coupled to a lower surface of the polishing head body 23. The retainer ring 25 may surround or be on a side of the substrate WF. Therefore, the substrate WF may be positioned inside the retainer ring 25 on the lower surface of the polishing head body 23.

The second magnetic structure MS2 may be provided inside the platen 13 of the polishing unit 10. The second magnetic structure MS2 may include an inner magnet IMO and an outer magnet OMO. The inner magnet IMO and the outer magnet OMO may be positioned at the same level inside the platen 13. The outer magnet OMO may be positioned on the outer side of the inner magnet IMO. The inner magnet IMO and the outer magnet OMO may be spaced apart from each other. For example, the inner magnet IMO may be positioned in a center region of the platen 13, and the outer magnet OMO may be positioned in an edge region of the platen 13. In other words, the outer magnet OMO may be positioned closer to the edge of the platen 13 in the first and second directions D1, D2 relative to the inner magnet IMO. Each of the inner magnet IMO and the outer magnet OMO may include a magnetic material. According to some embodiments of the inventive concept, each of the inner magnet IMO and the outer magnet OMO may be an electromagnet.

According to some embodiments of the inventive concept, each of the inner magnet IMO and the outer magnet OMO may be a rotating body. For example, each of the inner magnet IMO and the outer magnet OMO may have a ring shape around the first axis X1 of the polishing unit 10. A diameter of the outer magnet OMO may be larger than a diameter of the inner magnet IMO. When viewed in a plan view, the inner magnet IMO may partially overlap the first magnetic structure MS1 of the polishing head 20. When viewed in a plan view, the outer magnet OMO may partially overlap the first magnetic structure MS1 of the polishing head 20. For example, a portion of the first magnetic structure MS1 that overlaps the inner magnet IMO and another portion of the first magnetic structure MS1 that overlaps the outer magnet OMO may face each other. That is, when viewed in a plan view, the second magnetic structure MS2 may overlap at least a portion of the first magnetic structure MS1.

In some embodiments, when viewed in plan view, the first magnetic structure MS1, the outer magnet OMO, and the inner magnet IMO may all be rings and may be positioned such that the first magnetic structure MS1 and inner magnet IMO are both within the bounds of the outer magnet OMO. In such a configuration, the inner magnet IMO and outer magnet OMO may both be centered around the first axis X1. Furthermore, a point on the edge of the first magnetic structure MS1 may overlap with a part of the outer magnet OMO and a different point of the edge of the first magnetic structure MS1 may overlap with a part of the inner magnet IMO.

A power supply device 50 connected to the second magnetic structure MS2 may be further provided. The power supply device 50 may be located outside the polishing unit 10. The power supply device 50 may be electrically connected to the second magnetic structure MS2 to supply current to the second magnetic structure MS2. More specifically, the power supply device 50 may supply current to each of the inner magnet IMO and the outer magnet OMO of the second magnetic structure MS2. As a result, each of the inner magnet IMO and the outer magnet OMO may form a magnetic field.

The slurry supply device 30 may be spaced apart from the polishing pad 11 in a vertical direction. When viewed in a plan view, the slurry supply device 30 may be positioned between the conditioning device 40 and the polishing head 20. For example, the slurry supply device 30 may be positioned between a rear end of the conditioning device 40 and a front end of the polishing head 20 with respect to a rotational direction of the polishing unit 10. The slurry supply device 30 may supply slurry onto the polishing pad 11. For example, the slurry supply device 30 may supply slurry to an upper surface of the polishing pad 11 so that the polishing process for the substrate WF may proceed smoothly.

The conditioning device 40 may be positioned on the polishing pad 11 of the polishing unit 10. When viewed in a plan view, the conditioning device 40 may be arranged to be spaced apart from the polishing head 20 and the slurry supply device 30. According to some embodiments of the inventive concept, the conditioning device 40 may include a conditioning body 41 and a conditioning pad 43. The conditioning body 41 and the conditioning pad 43 may be coupled to each other, or may be separated from each other.

The conditioning body 41 of the conditioning device 40 may include a driving unit. The conditioning body 41 may be rotated by a driving unit including a motor. For example, the conditioning body 41 may rotate about a third axis X3 parallel to the third direction D3. The conditioning body 41 may rotate independently of the polishing unit 10. A relative rotation speed of the conditioning body 41 with respect to the polishing unit 10 may be variously changed over time. A relative position of the conditioning body 41 with respect to the polishing unit 10 may be variously changed over time. For example, the conditioning body 41 may move horizontally on the polishing pad 11.

The conditioning pad 43 of the conditioning device 40 may be positioned below the conditioning body 41. As the conditioning pad 43 is coupled with the conditioning body 41, the conditioning pad 43 may rotate together with the conditioning body 41. The conditioning pad 43 may optionally come into contact with the polishing pad 11. While the polishing pad 11 rotates, the conditioning pad 43 may come into contact with the polishing pad 11. As a result, the conditioning pad 43 may polish a portion of the polishing pad 11. A condition of the upper surface of the polishing pad 11 may be changed by the conditioning pad 43. That is, the conditioning pad 43 may polish the polishing pad 11 and maintain the upper surface of the polishing pad 11 in a constant state. For example, the conditioning pad 43 may be comprised of diamond.

FIGS. 4 to 6 are enlarged views of region ‘P1’ of FIG. 3.

Hereinafter, for the convenience of explanation, portions that are substantially the same as those described with reference to FIGS. 1 to 3 will be omitted and only differences will be described.

Referring to FIG. 4, the polishing head 20 may be positioned to be in contact with the upper surface of the polishing pad 11 of the polishing unit 10. More specifically, the lower surface of the retainer ring 25 of the polishing head 20 may be in contact with the upper surface of the polishing pad 11. In addition, one surface of the substrate WF located on the inner side of the retainer ring 25 may also be in contact with the upper surface of the polishing pad 11.

The first magnetic structure MS1 may be positioned on a side surface 23S of the polishing head body 23 and may be in contact with the side surface 23S of the polishing head body 23. The second magnetic structure MS2 may be positioned below an upper surface 13U of the platen 13. As a result, the second magnetic structure MS2 may be spaced apart from the polishing pad 11 in the third direction D3. That is, the second magnetic structure MS2 may not be in contact with the polishing pad 11, but is not limited thereto. The inner magnet IMO of the second magnetic structure MS2 may be positioned to vertically overlap a portion of the first magnetic structure MS1 in the platen 13. The outer magnet OMO of the second magnetic structure MS2 may be positioned to vertically overlap another portion of the first magnetic structure MS1 in the platen 13. That is, each of the inner magnet IMO and the outer magnet OMO of the second magnetic structure MS2 may vertically overlap the first magnetic structure MS1.

According to some embodiments of the inventive concept, the first magnetic structure MS1 may be a permanent magnet, and the second magnetic structure MS2 may be an electromagnet. However, the inventive concept is not limited thereto. For example, the first magnetic structure MS1 may be an electromagnet, and the second magnetic structure MS2 may be a permanent magnet. Alternatively, both the first magnetic structure MS1 and the second magnetic structure MS2 may be permanent magnets or electromagnets.

The second magnetic structure MS2 may be supplied with current by the power supply device 50 of FIG. 3 to form a magnetic field. As a result, a first magnetic force MF1 may be formed between a portion of the first magnetic structure MS1 and an inner magnetic IMO that are vertically overlapped. A second magnetic force MF2 may be formed between another portion of the first magnetic structure MS1 and the outer magnetic OMO that are vertically overlapped. The first magnetic force MF1 and the second magnetic force MF2 may have substantially the same magnitude. That is, a uniform magnetic force may be formed between the first magnetic structure MS1 and the second magnetic structure MS2. The first and second magnetic forces MF1 and MF2 between the first magnetic structure MS1 and the second magnetic structure MS2 may apply a uniform pressure to both ends of the polishing head 20.

Referring to FIG. 5, each of the inner magnet IMO and the outer magnet OMO of the second magnetic structure MS2 may be provided in the plural. For example, the inner magnet IMO may include first to third inner magnets IMOa, IMOb, and IMOc, and the outer magnet OMO may include first to third outer magnets OMOa, OMOb, and OMOc. The first to third inner magnets IMOa, IMOb, and IMOc may be spaced apart from each other in a horizontal direction. The first to third outer magnets OMOa, OMOb, and OMOc may be spaced apart from each other in a horizontal direction. The first to third inner magnets IMOa, IMOb, and IMOc and the first to third outer magnets OMOa, OMOb, and OMOc may be electrically connected to the power supply device 50 of FIG. 3 and may be individually supplied with current.

Among the first to third inner magnets IMOa, IMOb, and IMOc, the second inner magnet IMOb may be vertically overlapped with a portion of the first magnetic structure MS1. The first and third inner magnets IMOa and IMOc may be positioned offset from a portion of the first magnetic structure MS1. That is, the first and third inner magnets IMOa and IMOc may not vertically overlap a portion of the first magnetic structure MS1. Likewise, the second outer magnet OMOb among the first to third outer magnets OMOa, OMOb, and OMOc may be vertically overlapped with another portion of the first magnetic structure MS1. As the first and third outer magnets OMOa and OMOc are positioned offset from another portion of the first magnetic structure MS1, the first and third outer magnets OMOa and OMOc may not be vertically overlapped with another portion of the first magnetic structure MS1.

The power supply device 50 of FIG. 3 may supply current to at least one of the first to third inner magnets IMOa, IMOb, and IMOc and at least one of the first to third outer magnets OMOa, OMOb, and OMOc. As a result, a first magnetic force MF1 may be formed between the first to third inner magnets IMOa, IMOb, and IMOc and a portion of the first magnetic structure MS1, and a second magnetic force MF2 may be formed between the first to third outer magnets OMOa, OMOb, and OMOc and another portion of the first magnetic structure MS1. When current is supplied to the second inner magnet IMOb and the second outer magnet OMOb, each of the first magnetic force MF1 and the second magnetic force MF2 may be parallel to the third direction D3. When current is supplied to the first inner magnet IMOa and the first outer magnet OMOa or the third inner magnet IMOc and the third outer magnet OMOc, each of the first magnetic force MF1 and the second magnetic force MF2 may be tilted in the third direction D3. In other words, the vectors of each of the first magnetic force MF1 and the second magnetic force MF2 may not be parallel with the third direction D3. A direction of the first and second magnetic forces MF1 and MF2 may be adjusted, a pressure applied to both ends of the polishing head 20 may be adjusted precisely.

Referring to FIG. 6, the first magnetic structure MS1 may include a first magnet MO1a and the second magnet MO1b. The first magnet MO1a may be located on the side surface 23S of the polishing head body 23. For example, the first magnet MO1a may be substantially identical to the first magnetic structure MS1 described with reference to FIGS. 4 and 5. The second magnet MO1b of the first magnetic structure MS1 may be positioned on the first magnet MO1a. The second magnet MO1b may be in contact with the first magnet MO1a. For example, the first magnet MO1a and the second magnet MO1b may be configured as a single object. The second magnet MO1b may extend from the first magnet MO1a to an upper surface 23U of the polishing head body 23. The first magnet MO1a and the second magnet MO1b may have an ‘L’-shape.

That is, as the first magnetic structure MS1 extends from the side surface 23S of the polishing head body 23 to the upper surface 23U of the polishing head body 23, a magnetic force between the first magnetic structure MS1 and the second magnetic structure MS2 may be formed even inside the polishing head body 23. As a result, a range of pressure applied to both ends of the polishing head 20 may be widened.

Referring again to FIGS. 5 and 6, in other words, the first and second magnetic forces MF1 and MF2 between the first magnetic structure MS1 and the second magnetic structure MS2 may be formed at both ends of the polishing head 20. The first and second magnetic forces MF1 and MF2 between the first magnetic structure MS1 and the second magnetic structure MS2 may apply a uniform pressure to both ends of the polishing head 20. For example, an attractive or repulsive force may be applied to both ends of the polishing head 20 in the third direction D3. As a result, a gap between the retainer ring 25 and the polishing pad 11 may be reduced or increased. Accordingly, an edge polishing rate of the substrate WF may be increased or decreased. For example, the edge polishing rate of the substrate WF may be controlled to be substantially the same as the center polishing rate of the substrate WF. As a result, a dispersion of the substrate WF may be improved.

FIG. 7 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept. FIG. 8 is a cross-sectional view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept, taken along line B-B′ of FIG. 7.

Referring to FIGS. 7 and 8, the second magnetic structure MS2 may include a plurality of straight magnets SMO. Each of the plurality of straight magnets SMO may have a shape extending in one direction. When viewed in a plan view, each of the plurality of straight magnets SMO may have a shape of a line or a bar. A length of each of the plurality of straight magnets SMO extending in one direction may be smaller than a radius of the polishing unit 10. For example, the length of each of the plurality of straight magnets SMO may be substantially equal to the diameter of the polishing head 20.

The plurality of straight magnets SMO may be arranged two-dimensionally. For example, the plurality of straight magnets SMO may be arranged in a circumferential direction of the polishing unit 10. A spacing between the plurality of straight magnets SMO may increase from the central region of the polishing unit 10 toward the edge region of the polishing unit 10. When viewed in a plan view, the straight magnets SMO may be arranged radially with respect to a rotation axis (the first axis X1 of FIG. 1) of the polishing unit 10.

A plurality of straight magnets SMO of the second magnetic structure MS2 may be positioned in the platen 13 of the polishing unit 10. The plurality of straight magnets SMO may be positioned at the same level in the platen 13. The plurality of straight magnets SMO may be electrically connected to the power supply device 50 and may individually receive current from the power supply device 50. Each of the plurality of straight magnets SMO may form a magnetic field by the supplied current. According to some embodiments of the inventive concept, the power supply device 50 may be configured to individually turn on/off the current supplied to the plurality of straight magnets SMO. As a result, a magnetic field of each of the plurality of straight magnets SMO may be formed and then extinguished.

The polishing head 20 may include a front region FR and a rear region RR. The front region FR and the rear region RR of the polishing head 20 may be defined based on the rotational direction of the polishing unit 10. For example, the front region FR of the polishing head 20 may be adjacent to the slurry supply device 30. The rear region RR of the polishing head 20 may be distant from the slurry supply device 30. When viewed in a plan view, each of the front region FR and the rear region RR may have a semicircular shape.

When viewed in a plan view, some of the plurality of straight magnets SMO that overlap the front region FR of the polishing head 20 may be first straight magnets SMO1. When viewed in a plan view, some of the plurality of straight magnets SMO that overlap the rear region RR of the polishing head 20 may be second straight magnets SMO2. In other words, the second magnetic structure MS2 may include straight magnets SMO that do not vertically overlap the polishing head 20, first straight magnets SMO1 that vertically overlap the front region FR of the polishing head 20, and second straight magnets SMO2 that vertically overlap the rear region RR of the polishing head 20. When viewed in a plan view, the first straight magnets SMO1 may overlap a portion of the first magnetic structure MS1, and the second straight magnets SMO2 may overlap another portion of the first magnetic structure MS1. That is, the second magnetic structure MS2 may planarly overlap at least a portion of the first magnetic structure MS1.

As the polishing unit 10 rotates, friction may occur between the retainer ring 25 of the polishing head 20 and the polishing pad 11 of the polishing unit 10. The friction between the retainer ring 25 and the polishing pad 11 may be greater in the front region FR than in the rear region RR of the polishing head 20. As a result, the polishing head 20 may tilt to one side, causing the rear region RR of the polishing head 20 to be spaced apart from the polishing pad 11 more than the front region FR thereof.

According to some embodiments of the inventive concept, the first and second straight magnets SMO1 and SMO2 supplied with current from the power supply device 50 may form a magnetic field. In contrast, as current is not supplied to straight magnets SMO other than the first and second straight magnets SMO1 and SMO2, a magnetic field may not be formed. As a result, a magnetic force may be formed between the first magnetic structure MS1 and the first and second straight magnets SMO1 and SMO2. The magnetic force between the first magnetic structure MS1 and the first and second straight magnets SMO1 and SMO2 may prevent or reduce the polishing head 20 from being spaced apart from the polishing pad 11. Accordingly, the polishing head 20 may be prevented or reduced from being tilted to one side due to friction, thereby improving a dispersion of the substrate WF.

According to some embodiments of the inventive concept, as the polishing unit 10 rotates, the first and second straight magnets SMO1 and SMO2 may be sequentially changed. For example, depending on the rotational direction of the polishing unit 10, the first and second straight magnets SMO1 and SMO2 may be changed into a plurality of adjacent straight magnets SMO. However, relative positions of the first and second straight magnets SMO1 and SMO2 and the polishing head 20 may be constant. That is, as the first and second straight magnets SMO1 and SMO2 are sequentially changed depending on the rotation direction of the polishing unit 10, the current supplied to the plurality of straight magnets SMO may be sequentially turned on/off.

FIG. 9 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept. FIG. 10 is a cross-sectional view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept, taken along line A-A′ of FIG. 9.

Referring to FIG. 9 and FIG. 10, the second magnetic structure MS2 may include an inner magnet IMO, an outer magnet OMO, and a plurality of straight magnets SMO. When viewed in a plan view, each of the inner magnet IMO and the outer magnet OMO may have a ring shape. The outer magnet OMO may be located on the outer side of the inner magnet IMO. The inner magnet IMO and the outer magnet OMO may be spaced apart from each other. The inner magnet IMO and the outer magnet OMO may be located at the same level in the platen 13. That is, the inner magnet IMO and the outer magnet OMO may be substantially the same as those described with reference to FIGS. 1 to 3.

A plurality of straight magnets SMO may be located between the inner magnet IMO and the outer magnet OMO. When viewed in a plan view, each of the plurality of straight magnets SMO may have a shape of a bar extending in one direction. The plurality of straight magnets SMO may be spaced apart from the inner magnet IMO and the outer magnet OMO. In addition, the plurality of straight magnets SMO may be spaced apart from each other. The plurality of straight magnets SMO may be positioned at the same level as the inner magnet IMO and the outer magnet OMO in the platen 13. The plurality of straight magnets SMO may be arranged in the circumferential direction of the polishing unit 10. When viewed in a plan view, the plurality of straight magnets SMO may be arranged radially. That is, the plurality of straight magnets SMO may be substantially the same as those described with reference to FIGS. 7 and 8.

The inner magnet IMO, the outer magnet OMO, and the plurality of straight magnets SMO may be electrically connected to a power supply device 50. The power supply device 50 may individually supply current to the inner magnet IMO, the outer magnet OMO, and the plurality of straight magnets SMO. Each of the inner magnet IMO, the outer magnet OMO, and the plurality of straight magnets SMO may receive current and form a magnetic field. In addition, since the inner magnet IMO, the outer magnet OMO, and the plurality of straight magnets SMO are spaced apart from each other, interference of the magnetic fields between each other may be reduced or minimized.

When viewed in a plan view, the first magnetic structure MS1 of the polishing head 20 may overlap some of the inner magnet IMO, the outer magnet OMO, and the plurality of straight magnets SMO of the second magnetic structure MS2. A magnetic force may be formed between the first magnetic structure MS1 and the second magnetic structure MS2. Therefore, an edge polishing rate of the substrate WF may be controlled while preventing the polishing head 20 from tilting to one side. Accordingly, a distribution of the substrate WF may be improved.

FIG. 11 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept. FIG. 12 is a cross-sectional view illustrating another substrate polishing apparatus according to some embodiments of the inventive concept, taken along line A-A′ of FIG. 11. FIG. 13 is an enlarged view illustrating region ‘P2’ of FIG. 12. FIG. 14 is a plan view illustrating a substrate polishing apparatus according to some embodiments of the inventive concept.

Referring to FIGS. 11, 12, and 13, a substrate polishing apparatus 1 may further include a spindle structure SPS. The spindle structure SPS may be positioned on the polishing head 20. For example, the spindle structure SPS may be coupled to a head support member 21 of the polishing head 20. The spindle structure SPS may be positioned at a higher level than the polishing head 20.

More specifically, the spindle structure SPS may include a spindle SP and a spindle arm SPA. The spindle SP may be coupled with the head support member 21. The spindle arm SPA may have a form that extends in the first direction D1. The spindle arm SPA may be coupled with the spindle SP while penetrating the spindle SP. A second magnetic structure MS2 may be coupled to both ends of the spindle arm SPA. For example, even when the polishing head 20 rotates, the spindle structure SPS may not rotate due to the spindle SP.

The second magnetic structure MS2 may be connected to the spindle structure SPS. As the spindle structure SPS is positioned on the polishing head 20, the second magnetic structure MS2 may be positioned on the first magnetic structure MS1. The second magnetic structure MS2 may be electrically connected to a power supply device 50 to receive current. Therefore, the second magnetic structure MS2 may form a magnetic field. For example, the second magnetic structure MS2 may have a ring shape around the second axis X2 of the polishing head 20 that is the same as the first magnetic structure MS1. In addition, the second magnetic structure MS2 may have substantially the same diameter as the first magnetic structure MS1. Therefore, the second magnetic structure MS2 may overlap at least a portion of the first magnetic structure MS1.

According to some embodiments of the inventive concept, a magnetic force may be formed between the first magnetic structure MS1 and the second magnetic structure MS2. The magnetic force between the first magnetic structure MS1 and the second magnetic structure MS2 may apply pressure to the edge portion of the polishing head 20. Therefore, a gap between the lower surface of the retainer ring 25 and the polishing pad 11 may be constant in all directions. In addition, an edge polishing rate of the substrate WF may be increased or decreased. Therefore, a dispersion of the substrate WF may be improved.

Referring to FIG. 14, the second magnetic structure MS2 may be composed of two blocks. Each of the two blocks of the second magnetic structure MS2 may be coupled to each end of the spindle structure SPS. That is, the two blocks may be arranged to face each other. For example, one of the two blocks may be located in the front region FR of the polishing head 20. The other of the two blocks may be located in the rear region RR of the polishing head 20. When viewed in a plan view, the two blocks of the second magnetic structure MS2 may overlap a portion of the first magnetic structure MS1.

According to some embodiments of the inventive concept, a magnetic force may be formed between the second magnetic structure MS2 and the first magnetic structure MS1. The magnetic force between the second magnetic structure MS2 and the first magnetic structure MS1 may prevent the rear region RR of the polishing head 20 from being spaced apart from the polishing pad 11. Therefore, a distribution of the substrate WF may be improved.

However, the inventive concept is not limited thereto. The number of blocks constituting the second magnetic structure MS2 may be more than two. For example, the second magnetic structure MS2 may be composed of six or more blocks. In this case, a plurality of spindle arms SPA constituting the spindle structure SPS may be provided. In addition, the plurality of blocks may be arranged at a constant interval in the circumferential direction of the polishing head 20.

The substrate polishing apparatus according to embodiments of the inventive concept may include the first magnetic structure and the second magnetic structure that are vertically overlapped with each other. The magnetic forces between the first magnetic structure and the second magnetic structure may apply the uniform pressure to both ends of the polishing head. As a result, the gap between the retainer ring and the polishing pad may be reduced or increased. In addition, the polishing head may be prevented or reduced from being separated from the polishing pad. Accordingly, the dispersion of the substrate may be improved.

While embodiments are described above, a person skilled in the art may understand that many modifications and variations are made without departing from the spirit and scope of the inventive concept defined in the following claims. Accordingly, the example embodiments of the inventive concept should be considered in all respects as illustrative and not restrictive, with the spirit and scope of the inventive concept being indicated by the appended claims.