KR101329028B1 - Polishing head of chemical mechanical polishing assembly - Google Patents

Abstract

The polishing head of the chemical mechanical polishing apparatus according to the present invention includes a rotary shaft coupling member, a retainer guide coupled to a lower circumference of the rotary shaft coupling member, a retainer coupled to an inner diameter and a lower portion of the retainer guide, and a lower circumference of the retainer. A retainer ring coupled to the portion, a supporter coupled to the inner diameter of the retainer, a pressure plate disposed under the supporter, an expansion member fixing plate disposed under the pressure plate, and a lower portion of the expansion member fixing plate An expansion member, an expansion member fixing ring for fixing the expansion member to the expansion member fixing plate, and a pressure equalization ring coupled to the inner diameter of the retainer ring and the lower periphery of the expansion member.

Description

Polishing head of chemical mechanical polishing device {POLISHING HEAD OF CHEMICAL MECHANICAL POLISHING ASSEMBLY}

The present invention relates to an apparatus for use in manufacturing a wafer of a semiconductor, and more particularly, to a polishing head of a chemical mechanical polishing apparatus for chemically and mechanically polishing a surface of a semiconductor wafer.

In recent years, a chemical mechanical polishing (CMP) apparatus for simultaneously chemically polishing a wafer to planarize a polishing surface (process surface) has been widely used. The chemical mechanical polishing apparatus which is commonly used is uniformly applied to the front surface of the wafer to be polished by contact with the polishing pad or fixed by vacuum adsorption of the wafer at the bottom during the chemical mechanical polishing process, as described in Korean Patent Application No. 2001-001055. And a polishing head for transmitting pressure.

The polishing head uniformly transmits the pressure formed by the expansion of the chamber-forming expansion member and the chamber-forming expansion member to contact the wafer with the polishing pad through expansion using pneumatic pressure, and is formed by the contraction of the chamber-forming expansion member. The backing member which adsorb | sucks a wafer using a vacuum suction force and the surface tension which it has is included, and the retaining ring which surrounds the outer periphery of a wafer so that a wafer may not leave during a grinding | polishing process.

Since the retaining ring is applied to the polishing pad with a pressure higher than the pressure applied to the wafer to prevent the wafer from leaving, the rebounding of the polishing pad occurs, causing uneven stress at the edge of the wafer. . On the other hand, the chamber-forming expansion member and the backing member expanded by the application of pneumatic pressure causes deformation at the wafer edge due to the coupling relationship with the retaining ring, so that abnormal polishing occurs at the edge of the wafer during polishing. The problem arises that the polishing profile of the wafer is not uniform.

In order to solve such a problem, the "head assembly for a wafer polishing apparatus" disclosed in the prior-art patent publication 2010-0081695 of the prior art was proposed.

The head assembly for the wafer polishing apparatus includes the expansion member 20 and the back film 30 attached to the rubber chuck 3 by an adhesive means such as a double-sided adhesive to be attached to the bottom of the expansion member 20. The outer retainer ring 40 attached to the lower edge of the rim 30 and the inner retainer ring 50 provided on the back film 30 along the inner circumference of the outer retainer ring 40 are provided. ) To solve the problem of uneven polishing profile of the wafer by reducing uneven stress at the edge of the wafer and preventing deformation at the wafer edge of the expansion member 20 and the back film 30 due to air pressure. Doing.

However, the head assembly for the wafer polishing device should not only have a plurality of retainer rings 40 and 50, but also be provided with a back film 30, and due to continuous use, the expansion member 20, the back film ( 30), when one of the outer retainer ring 40 or the inner retainer ring 50 is broken or broken, part of the structural characteristics are all attached to the rubber chuck 30 as an assembly part by an adhesive means or the like. There is a problem that replacement and repair are impossible and must be exchanged as a whole.

KR 2010-0081695 A

Therefore, the problem to be solved by the present invention is to solve the above problems by reducing the non-uniform stress induced phenomenon of the wafer edge portion by retaining during the polishing process of the wafer and to prevent the deformation phenomenon at the wafer edge portion of the expansion member to polish the wafer It is to provide a polishing head of a chemical mechanical polishing apparatus capable of ensuring profile uniformity.

In addition, another problem to be solved by the present invention is to solve the above problems of the removal of the backing film as well as the chemical mechanical polishing apparatus that can be easily disassembled and replaced separately when the retaining or expansion member is broken or broken It is to provide a polishing head.

The polishing head of the chemical mechanical polishing apparatus according to the embodiment of the present invention for solving the above problems is a rotary shaft coupling member, a retainer guide coupled to the lower circumference of the rotary shaft coupling member, the inner diameter and the lower portion of the retainer guide Retainer coupled to the retainer ring is coupled to the lower circumference of the retainer, the supporter coupled to the inner diameter of the retainer, the pressure plate is disposed in the lower portion of the supporter, the expansion member fixing plate disposed in the lower portion of the pressure plate, An expansion member disposed below the expansion member fixing plate, an expansion member fixing ring for fixing the expansion member to the expansion member fixing plate, and an inner diameter of the retainer ring and a pressure equalization ring coupled to the lower circumference of the expansion member. It includes.

A first elastic member fixing ring coupled to at least a portion of the retainer, and one side is fixedly coupled between the supporter and the rotary shaft coupling member, and the other side is fixedly coupled between the retainer guide and the rotary shaft coupling member. The central part further includes a first elastic member coupled to and fixed between the retainer and the first elastic member fixing ring, wherein the first chamber is in an inner space closed by the rotation shaft coupling member and the first elastic member. Can be formed.

The second elastic member first fixing ring coupled to the upper peripheral portion of the pressure plate, the second elastic member second fixing ring coupled to the side peripheral portion of the pressure plate, and one side of the pressure plate and the second elastic member The first fixing ring is fixedly coupled between the other side, the other side further comprises a second elastic member is fixedly coupled between the supporter and the second elastic member of the second fixing ring, the rotary shaft coupling member, the supporter, the pressure plate And a second chamber in an inner space closed by the second elastic member.

A third elastic member fixing ring coupled to an upper portion of the expansion member fixing ring, and

One side is fixedly coupled between the expansion member fixing ring and the third elastic member fixing ring, the other side further comprises a third elastic member is fixedly coupled between the retainer and the retainer ring, the pressure plate, the expansion The third chamber may be formed in the inner space closed by the member and the third elastic member.

The rotating shaft coupling member may include at least one first hole communicating with the outside through a first air passage connected with the first chamber, and at least one communicating with the outside through a second air passage connected with the third chamber. Each of the second holes may be formed.

It may further include an air flow path tube connecting the second air flow path and the third chamber.

The pressure plate has a penetrating pressure plate air flow path, the expansion member holding plate is formed with a fixed plate air flow passage penetrated to communicate with the pressure plate air flow path, the air flow path tube is the second air flow path and the pressure plate air flow path It is desirable to interconnect them.

The pressure homogenization ring is made of polyether ether ketone, polymethylmethacrylate, polyethylene, polyphenylene sulfide, polytetrafluoroethylene and polyvinylidene fluoride. It may be made of at least one material of polyvinylidene fluoride.

The edge pressure equalization ring may have an inner diameter of 0.1 to 0.5% larger than the outer diameter of the wafer, and an outer diameter of 5 to 25% larger than the outer diameter of the wafer.

The thickness of the pressure equalization ring is preferably within an error range of ± 10% from the thickness of the wafer.

As described above, according to the polishing head of the chemical mechanical polishing apparatus according to the present invention, by adopting a pressure equalization ring at the wafer edge portion in the inner circumference of the retaining ring, the phenomenon of causing uneven stress in the wafer edge portion due to the retaining ring during the polishing process of the wafer is eliminated. There is an advantageous effect of reducing and preventing deformation at the wafer edge of the expansion member to ensure uniformity of the polishing profile of the wafer.

In addition, according to the polishing head of the chemical mechanical polishing apparatus according to the present invention, by employing a pressure equalization ring on the inner circumference of the retainer ring and increasing the vacuum suction force of the wafer, not only the removal of the backing film requiring frequent replacement, but also the retainer ring Alternatively, there is an advantageous effect that disassembly and individual replacement can be easily performed when the expansion member is broken or broken.

1 is a perspective view of a general chemical mechanical polishing apparatus including a polishing head,
2 and 3 are respectively a perspective view from above and below of a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention;
4 and 5 are exploded perspective views of the polishing head shown in Figs. 2 and 3, respectively;
6 is a perspective view of a pressure equalization ring which is a main portion of a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention;
Sectional drawing which cut | disconnected the polishing head of FIG. 7 along the VII-VII line,
8 to 12 are cross-sectional views of a polishing head for explaining a process of polishing a wafer by using a polishing head of a chemical mechanical polishing apparatus according to one embodiment of the present invention, respectively.
8 is a cross-sectional view illustrating a process of attaching a wafer to a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention;
9 and 10 are cross-sectional views illustrating a process in which a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention, in which a wafer is attached, approaches a polishing pad and is polished, respectively;
11 is a cross-sectional view showing a process in which a polishing head of a chemical mechanical polishing apparatus adsorbs a wafer after polishing is completed, and
12 is a cross-sectional view illustrating a process of removing a polished wafer from a polishing head of a chemical mechanical polishing apparatus.

Specific details for carrying out the invention are included in the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various other forms, and it should be understood that the present embodiment is intended to be illustrative only and is not intended to be exhaustive or to limit the invention to the precise form disclosed, To fully disclose the scope of the invention to a person skilled in the art, and the invention is only defined by the scope of the claims.

Like reference numerals refer to like elements throughout. Embodiments described herein will be described with reference to perspective and cross-sectional views, which are ideal schematic diagrams of the invention.

Hereinafter, a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, before describing a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention, a general chemical mechanical polishing apparatus using a polishing head or a general polishing head according to an embodiment of the present invention will be described with reference to FIG. 1. Briefly explain.

1 is a perspective view of a general chemical mechanical polishing apparatus including a polishing head.

As shown in FIG. 1, a general chemical mechanical polishing apparatus 1 includes a polishing station 110 and a polishing head assembly 120.

The polishing station 110 includes a slurry supply member 111, a polishing pad conditioning member 112, and a rotary table 113 having a polishing pad 114 attached thereto.

The slurry supply member 111 is a conventional reaction reagent (e.g., deionized water for oxidizing polishing), friction particles (e.g., silicon dioxide for polishing oxide) and a chemical reaction catalyst (e.g., potassium hydroxide for polishing oxide) during polishing of the wafer. Supplying a slurry configured to include a surface of the polishing pad 114.

 The polishing pad conditioning member 112 continuously grinds or scrapes the top surface of the polishing pad 114 to maintain a constant roughness of the polishing pad 114 that decreases with the polishing process.

The rotary table 113 is connected to a rotating means (not shown) and rotates at about 50 to 80 revolutions per minute by the rotating means in the polishing process. Of course, the rotating means can also rotate the rotary table 113 at lower or higher revolutions per minute. The polishing pad 114 may be composed of a known material having a rough polishing surface.

The polishing head assembly 120 includes a drive motor 121, a first rotation shaft 122, a reducer 123, a second rotation shaft 124, and a polishing head 200.

The drive motor 121 rotates at 200 to 2000 revolutions per minute by an external energy supply means (not shown). The first rotary shaft 122 connected to the drive motor 121 transmits the rotational force generated by the drive motor 121 to the reducer 123.

The reducer 123 slows down the rotational speed per minute of the drive motor 121 transmitted through the first rotational shaft 122 to 40 to 200 rotational speeds, which are rotational speeds necessary for polishing the wafer. The second rotary shaft 124 connected to the reducer 123 transmits the rotational force decelerated by the reducer 123 to the polishing head 200.

The polishing head 200 corresponds to the polishing pad 114 to hold the wafer in the polishing process and provide uniform downward pressure on the backside of the wafer. To this end, at least two air supply flow paths (not shown) may be connected to the polishing head 200 to form a vacuum for adsorbing the wafer or to provide air pressure to polish the wafer. Of course, these air supply flow paths may be connected to pumps (not shown) which are generally used as vacuum and air pressure forming members, which will be described later.

The present invention relates to a polishing head (200) having an improved function than the prior art, hereinafter, in detail with reference to the accompanying drawings for the polishing head and its operating method of the chemical mechanical polishing apparatus according to an embodiment of the present invention. Explain.

First, the polishing head of the chemical mechanical polishing apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 7.

2 and 3 are perspective views of the polishing head of the chemical mechanical polishing apparatus according to an embodiment of the present invention, respectively, from top and bottom, and FIGS. 4 and 5 are exploded perspective views of the polishing head shown in FIGS. 2 and 3, respectively. 6 is a perspective view of a pressure equalization ring which is a main part of a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention, and a cross-sectional view of the polishing head of FIG. 7 taken along the line VII-VII.

Polishing head 200 according to an embodiment of the present invention is a rotating shaft coupling member 210, the first to third elastic members (220, 223, 225), the first to third elastic member fixing rings (230, 233, 234, 235, retainer 240, retainer guide 243, retainer ring 245, supporter 250, pressure plate 260, air flow path tube 270, expansion member 280, expansion member fixing plate 281 ), Expansion member fixing ring (285) and pressure equalization ring (290).

The rotation shaft coupling member 210 transmits the rotational force transmitted through the second rotation shaft 124 to the supporter 250 as shown in FIGS. 1 and 7, and a part of the coupling portion 215 opened for this purpose is external to the supporter 250. The upper central portion is coupled to the second rotation shaft 124 by a coupling pin 219 to be closed in communication with the pump (not shown), which is a vacuum and air pressure forming member provided in the through hole (not shown).

The rotating shaft coupling member 210 has at least one first hole 211 and a second hole 213 communicating with a pump (not shown), which is a vacuum and air pressure forming member, which are provided on an outer surface thereof. At least one first air passage 212 communicating with the first hole 211 and a space portion forming a first chamber C1 communicating with the first air passage 212 are formed in the second hole ( At least one second air passage 214 communicating with 213 is formed through.

Retainer guide 243 is coupled to the lower periphery of the rotating shaft coupling member 210, guides the vertical movement of the retainer 240 to be described later, the slurry or polishing liquid is introduced into the first chamber (C1) during the polishing process To prevent ingress.

The retainer 240 is coupled to the inner diameter and the lower circumference of the retainer guide 243, and transmits the pressure transmitted through the first elastic member 220 to the retainer ring 245.

The retainer ring 245 is coupled to the lower circumference of the retainer 240, and is lowered by the pressure transmitted through the retainer 240 to support the side circumference of the wafer 10 (see FIG. 9), so that the wafer is in the polishing process. The 10 is prevented from being separated from the polishing head 200. The retaining ring 245 may be formed of glass epoxy, polyetheretherketone, or the like.

The supporter 250 is coupled to the lower portion of the rotating shaft coupling member 210 and the inner diameter of the retainer 240 and has at least one air communicating therewith with the second air passage 214 and the pressure plate air passage 262 to be described later. A space portion for accommodating the flow path tube 270 and forming the second chamber C2 is formed.

The pressure plate 260 is disposed below the center of the supporter 250, and a first pressure plate air flow passage 262 is formed in the vertical direction so as to communicate with the pressure plate hole 261 formed on the upper surface. The pressure plate 260 is pushed down when air is supplied from the second rotating shaft 124 to the second chamber C2 through a through hole (not shown) of the rotating shaft coupling member 210, and the expansion member fixing plate 281 to be described later. Push it down. This reduces the space of the third chamber (C3) to be described later, so that the polishing head 200 is easily vacuum-adsorbed to the expansion member 280 again the polishing process 10 is completed.

The air passage tube 270 is connected at one end to the end of the second air passage 214, and the other side thereof is connected to the pressure plate air passage 262 through the pressure plate hole 261 to be described later with the second air passage 214. The third chamber C3 is interconnected.

The expansion member fixing plate 281 is disposed below the pressure plate 260 and is coupled to the expansion member fixing ring 285 to fix the expansion member 280 surrounding the expansion member fixing plate 281. The expansion member fixing plate 281 receives the air pressure generated by the air entering the third chamber C3 through the air passage tube 270 during the polishing process of the wafer 10, and the fixing plate hole 283 and the fixing plate air passage 284. Evenly indirectly through the expansion member 280 through the expansion member 280 to the entire back surface of the wafer 10, when the air escapes through the air flow tube 270 to the third chamber 341 is a vacuum member 280 is used to indirectly chuck the wafer 10. On the other hand, the lower surface of the expansion member fixing plate 281 is formed with a recess 282 connected to the fixed plate air flow path 284 in a state where the third chamber C3 has an increased cross-sectional area so as to easily form a vacuum and air pressure. .

The expansion member 280 surrounds the expansion member fixing plate 281 at the bottom of the expansion member fixing plate 281 and is located inside the retainer ring 245 and the pressure equalization ring 290 and communicates with the air flow tube 270. It is a film | membrane which forms the 3rd chamber 341 mentioned later. The expansion member 280 is made of a rubber (rubber) material, but usually provides an elastic force and can be replaced with other materials known to be flexible.

The expansion member fixing ring 285 is coupled to the upper edge of the expansion member fixing plate 281 in a state accommodating the edge of the expansion member 280 to fix the expansion member 280 and the expansion member fixing plate 281 of the expansion member fixing plate 281. It serves as a guide when moving up and down.

The pressure equalization ring 290 is coupled to the inner diameter of the retainer ring 245 and the lower circumference of the expansion member 280 so that the retainer ring 245 pushes the polishing pad 114 higher than the wafer 10 during the polishing process. To prevent deformation of the polishing pad 114 from occurring near the edge of the wafer 10, thereby affecting the deformation of the polishing pad 114 on the wafer 10 located inside the pressure equalization ring 290. Don't let it go. On the other hand, the non-uniform pressure applied to the edge portion of the wafer 10 caused by the coupling relationship between the expansion member 280 and the retainer ring 245 expanded by the pneumatic application is given only by the pressure equalization ring 290. Since the wafer 10 positioned inside the pressure equalization ring 290 receives only a uniform pressure from the expansion member 280, it is possible to secure a uniform polishing profile of the wafer 10. The pressure equalization ring 290 may be provided with a double-sided tape on the mating surface for the convenience of coupling with the expansion member 280, but the corresponding concave-convex portion for coupling with the expansion member 280 is provided to each other through this coupling. You may.

The pressure homogenization ring 290 is made of polyether ether ketone, polymethylmethacrylate, polyethylene, polyphenylene sulfide, polytetrafluoroethylene and polyvinyl. It may be made of at least any one material of polyvinylidene fluoride. The pressure equalization ring 290 is preferably provided with an inner diameter of 0.1 to 0.5% larger than the outer diameter of the wafer 10 to facilitate accommodating the wafer 10 as well as to increase the fixing force for the separation prevention. It is desirable to provide 5 to 25% larger than the outer diameter of 10) to efficiently reduce the polishing pad deformation occurring near the edge portion while ensuring the required size of the wafer 10 as much as possible. In addition, it is preferable that the thickness of the pressure equalization ring 290 is within ± 10% of an error range with the thickness of the wafer 10 so that the step of the wafer 10 does not occur during polishing.

The first elastic member fixing ring 230 is coupled to at least a portion of the upper portion of the retainer 240 with the first elastic member 220 interposed therebetween to fix the first elastic member 220.

 The first elastic member 220 is fixedly coupled between the supporter 250 and the rotating shaft coupling member 210 on the inner side, and the outer side of the first elastic member 220 is fixedly coupled between the retainer guide 243 and the rotating shaft coupling member 210. The coupling is fixed between the retainer 240 and the first elastic member fixing ring 230. As shown in FIG. 7, the first elastic member 220 forms the first chamber C1 in the closed inner space together with the rotation shaft coupling member 210.

Since the first elastic member 220 is made of a thin elastic membrane, the first elastic member 220 is expanded by the air pressure supplied from the outside to the first chamber C1 of the rotating shaft coupling member 210 to push down the retainer 240, and vice versa. When a vacuum is applied, it contracts and lifts the retainer 240. To this end, the first elastic member 220 is usually made of a rubber material, but provides a resilient force and can be replaced with another flexible material.

The second elastic member first fixing ring 233 is coupled to the upper circumference of the pressure plate 260 with an inner portion of the second elastic member 223 interposed therebetween, and the second elastic member second fixing ring 234. Is coupled to the lower portion of the supporter 250 with the outer portion of the second elastic member 223 interposed therebetween to fix the second elastic member 223.

The second elastic member 223 is also made of the same material as the first elastic member 221, the inner side is fixedly coupled between the pressure plate 260 and the second elastic member first fixing ring 233, the outside is the supporter It is fixedly coupled between the 250 and the second elastic ring second fixing ring 234. As shown in FIG. 7, the second elastic member 223 forms the second chamber C2 in the inner space closed together with the rotation shaft coupling member 210, the supporter 250, and the pressure plate 260.

The second elastic member 223 expands by the air pressure supplied to the second chamber C2 through a through hole (not shown) of the rotating shaft coupling member 210 from the outside to push down the pressure plate 260 downwards, and conversely When a vacuum is applied, it contracts and lifts the pressure plate 260.

The third elastic member fixing ring 235 is coupled to the upper portion of the expansion member fixing ring 281 with the third elastic member 225 therebetween to fix the third elastic member 225.

The third elastic member 225 is also provided with the same material as the first elastic member 221, the inner side is fixed to the expansion member fixing ring 285 between the third elastic member fixing ring 235, the outer side It is fixedly coupled between the retainer 240 and the retainer ring 245. As shown in FIG. 7, the third elastic member 225 does not leak air pressure supplied through the second hole 213 of the rotating shaft coupling member 210 from the outside to the outside through the expansion member 280. The third chamber C3 is formed together with the pressure plate 260 and the expansion member 280 to apply pressure to the 10.

Looking at the assembly method of each component of the polishing head 200 of the chemical mechanical polishing apparatus according to an embodiment of the present invention described above, first, the pressure plate 260 and the second elastic member 223, the second elastic member first Fix it with a fixing ring (233). After the supporter 250 and the retainer 240 are coupled to each other, the outer side of the second elastic member 223 previously coupled to the second elastic member second fixing ring 234 is coupled to the lower portion of the supporter 250. do.

Then, the retainer guide 243 is positioned on the outer upper portion of the retainer 240, the first elastic member 230 is placed on the retainer 260, and the retainer 260 is fixed to the first elastic member fixing ring 230. And the first elastic member 220 is fixedly coupled. Then, the rotary shaft coupling member 210 is placed thereon and coupled to each other by a known coupling member 264 such as a screw.

In addition, after the expansion member 280 is wrapped around the lower surface of the expansion member fixing plate 281, the expansion member fixing ring 285 is placed on the upper surface of the expansion member fixing plate 281 and is mutually coupled by a known coupling member such as a screw. . Then, the third elastic member 225 is placed on the upper surface of the expansion member fixing ring 285 and fixed with the third elastic member fixing ring 235, and then the expansion member fixing plate 281 is attached to the lower surface of the pressure plate 260. Side by side, the assembly of the polishing head 200 is completed by mutual coupling with a known coupling member.

Hereinafter, a polishing process of a wafer using the polishing head 200 of the chemical mechanical polishing apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 8 to 12.

8 to 12 are cross-sectional views of a polishing head for explaining a process of polishing a wafer using a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention, respectively, and FIG. 8 is an embodiment of the present invention. 9 and 10 are cross-sectional views illustrating a process of attaching a wafer to a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention, in which a polishing head of a chemical mechanical polishing apparatus according to an embodiment of the present invention is attached to a polishing pad. 11 is a cross-sectional view showing a process and a polishing process, FIG. 11 is a cross-sectional view showing a process in which the polishing head of the chemical mechanical polishing apparatus adsorbs a wafer after polishing is completed, and FIG. 12 is a chemical mechanical polishing apparatus. Is a cross-sectional view showing a process of removing a polished wafer from a polishing head of the present invention.

In general, the polishing process of the wafer 10 is divided into a wafer attaching step of attaching the wafer 10 to the expansion member 280 of the polishing head 200, and the attached wafer 10 is illustrated in FIG. 1. A polishing step of polishing using the illustrated polishing station 110 and the polishing head assembly 120, a wafer adsorption step of vacuum-suctioning the wafer 10 to the expansion member 280 of the polishing head 200 after polishing is completed; And a wafer removal step of removing the wafer 10 from the polishing head 200.

Each step will be described in more detail with reference to Table 1 below.

The first chamber The second chamber Third chamber Wafer Attach Step vacuum vacuum vacuum Polishing Step Pressure vacuum Pressure Wafer adsorption step Pressure Pressure vacuum Wafer Removal Steps vacuum vacuum Pressure

First, as shown in FIG. 8, in the wafer attaching step, the polishing head 200 is spaced apart from the polishing pad 114. A vacuum is formed in the first chamber C1, and a vacuum is also formed in the second chamber C2 through the through hole (not shown), and the second air flow path 214, the air flow path tube 270, and the pressure plate air flow path are formed. A vacuum is also formed in the third chamber C3 through the 262 and the fixed plate air flow path 284. In this state, the wafer 10 to be polished is manually attached to the expansion member 280 by a machine or an operator.

In this case, the reason why the vacuum is formed not only in the third chamber C3 but also in the first chamber C1 and the second chamber C2 is to increase the vacuum suction force so that the attachment of the wafer 10 becomes easier. If the vacuum adsorption of the wafer 10 is possible only by the vacuum state formed in the chamber C3, the first chamber C1 and the second chamber C2 do not form a vacuum and are equal to the external pressure of the polishing head 200. It may be kept as.

After the attachment of the wafer 1 is completed, the polishing head 200 is lowered until the wafer 10 contacts the polishing pad 114.

Next, as shown in FIG. 9, in the polishing step, the second chamber C2 applies air pressure to the sieve first chamber C1 and the third chamber C3 maintaining the vacuum state.

The first elastic member 220, the retainer 240, and the retainer ring 245 are respectively moved downward by the air pressure applied in the first chamber C1. In addition, the expansion member 280 is expanded by the air pressure applied in the third chamber C3. Accordingly, as shown in FIG. 10, the slurry is supplied through the slurry supply member 111 while the wafer 10 and the retaining ring 245 are in contact with the polishing pad 114, and the polishing head 200 and the rotation are rotated. As the table 113 rotates in opposite directions, a polishing process for polishing the entire surface of the wafer 10 to be polished is performed.

At this time, as shown in FIG. 10, the deformation of the polishing pad 114 occurring near the edge of the wafer 10 due to the pressure applied to the retainer ring 245 is placed between the retainer ring 245 and the wafer 10. The posted pressure equalization ring 290 is reduced by pressing the polishing pad 144 to ensure uniformity of the wafer 10 polishing profile.

When the polishing process step is completed, as shown in FIG. 11, the polishing head 200 vacuum-adsorbs the wafer 10 to the expansion member 280 and then moves upwards to separate the polishing pad 114. . To this end, the first chamber C2 is maintained in a pressurized state, but the second chamber C2 is changed to a pressurized state, and the third chamber C3 is changed in a vacuum state.

As the third chamber C3 is in a vacuum state, the expansion member 280 contracts, and the expansion member 280 vacuum-adsorbs the wafer 10. At this time, since the pressure plate 260 is moved downward by the air pressure applied in the second chamber C2, the volume of the third chamber C3 is reduced, so that vacuum formation is facilitated. Even if the conventional backing member that requires replacement is omitted, the advantageous effect of easily vacuum-adsorbing the wafer 10 to the expansion member can be obtained.

Next, as shown in FIG. 12, in the wafer removing step, the first chamber C1 and the second chamber C2 are changed to a vacuum state, and the third chamber C3 is changed to a pressurized state.

Accordingly, the expansion member 280 expands downward so that the side circumference of the wafer 10 comes out of the retaining ring 245 and moves downwards to easily remove the wafer 10 from the polishing head 200. have.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of right.

1: chemical mechanical polishing apparatus 10: wafer
110: polishing station 111: slurry supply member
112: polishing pad conditioning member 114: polishing pad
120: polishing head assembly 121: drive motor
122: first rotating shaft 123: reducer
124: second axis of rotation 200: polishing head
210: rotating shaft coupling member 211: first hole
212: first air passage 213: second hole
214: second air flow path 215: coupling portion
219: coupling pins 220, 223, 225: elastic member
230, 233, 234, 235: elastic member retaining ring
240: retainer 243: retainer guide
245: retaining ring 250: supporter
260: pressure plate 261: pressure plate hole
262: pressure plate air flow path 270: air flow path tube
280: expansion member 281: expansion member fixing plate
282: depression 283: fixing plate hole
284: fixed plate air flow path 285: expansion member fixing ring
290: pressure equalization ring

Claims (10)

Rotating shaft coupling member,
Retainer guide is coupled to the lower periphery of the rotating shaft coupling member,
A retainer coupled to the inner diameter and a lower portion of the retainer guide;
A retainer ring coupled to the lower periphery of the retainer,
A supporter coupled to the inner diameter of the retainer,
A pressure plate disposed under the supporter;
Expansion member fixing plate disposed in the lower portion of the pressure plate,
An expansion member disposed below the expansion member fixing plate;
An expansion member fixing ring for fixing the expansion member to the expansion member fixing plate, and
Pressure equalization ring coupled to the inner diameter of the retainer ring and the lower periphery of the expansion member
/ RTI >
A first elastic member fixing ring coupled to at least a portion of the retainer, and
One side is fixedly coupled between the supporter and the rotary shaft coupling member, the other side is fixedly coupled between the retainer guide and the rotary shaft coupling member, the central portion is coupled and fixed between the retainer and the first elastic member fixing ring First elastic member,
More,
A first chamber is formed in the inner space closed by the rotating shaft coupling member and the first elastic member,
A first fixing ring of the second elastic member is coupled to the upper circumference of the pressure plate,
A second fixing member coupled to the side circumference of the pressure plate, and
One side is fixedly coupled between the pressure plate and the second elastic member first fixing ring, the other side is the second elastic member is fixedly coupled between the supporter and the second elastic member second fixing ring.
More,
A second chamber is formed in the inner space closed by the rotating shaft coupling member, the supporter, the pressure plate and the second elastic member,
A third elastic member fixing ring coupled to an upper portion of the expansion member fixing ring, and
One side is fixedly coupled between the expansion member fixing ring and the third elastic member fixing ring, the other side is a third elastic member is fixedly coupled between the retainer and the retainer ring
More,
A third chamber is formed in the inner space closed by the pressure plate, the expansion member and the third elastic member,
The non-uniform pressure applied to the wafer edge portion caused by the coupling relationship between the expansion member and the retainer ring expanded by pneumatic application is given only to the pressure equalization ring so that the wafer located inside the pressure equalization ring Receiving a uniform pressure from the expansion member,
After completion of the polishing process, when the second chamber is in a pressurized state and the third chamber is in a vacuum state, the pressure plate is moved downward by the air pressure applied in the second chamber to easily form a vacuum in the third chamber. The expansion member contracted by shrinking the volume of the third chamber so as to facilitate the vacuum suction of the wafer.
Polishing head of chemical mechanical polishing device. delete delete delete In claim 1,
The rotating shaft coupling member,
At least one first hole communicating with the outside through a first air passage connected to the first chamber, and
At least one second hole communicating with the outside through a second air passage connected to the third chamber;
Each of which is formed
Polishing head of chemical mechanical polishing device. The method of claim 5,
An air passage tube connecting the second air passage and the third chamber
Further comprising
Polishing head of chemical mechanical polishing device. The method of claim 6,
The pressure plate is formed through the pressure plate air flow path,
The expansion member fixing plate is formed with a fixed plate air passage penetrated so as to communicate with the pressure plate air passage,
The air passage tube interconnects the second air passage and the pressure plate air passage.
Polishing head of chemical mechanical polishing device. In claim 1,
The pressure equalization ring
Polyether ether ketone, Polymethylmethacrylate, Polyethylene, Polyphenylene Sulfide, Polytetrafluoroethylene and Polyvinylidene Fluoride Made of at least one of the materials
Polishing head of chemical mechanical polishing device. In claim 1,
The edge pressure equalization ring
The inner diameter is 0.1 to 0.5% larger than the outer diameter of the wafer,
Outer diameter is 5-25% larger than outer diameter of wafer
Polishing head of chemical mechanical polishing device. In claim 1,
The thickness of the pressure equalization ring
The range of error with the thickness of the wafer is within ± 10%
Polishing head of chemical mechanical polishing device.

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