CMP device, and CMP method

Abstract

To provide a CMP device that cn suppress dryness of slurry to be recovered.SOLUTION: A CMP device, which supplies slurry onto an abrasive pad 60, and pushes a work-piece held by a polishing head 7 against the abrasive pad 60 on a platen 6 and polishes the same, comprises: a slurry recover nozzle 1 which is adjacent to a top face of the abrasive pad 60, and of which an opening can face an outer edge of the abrasive pad 60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a CMP apparatus and a CMP method. [Background technology]

[0002] As design rules for semiconductor integrated circuits become smaller, chemical mechanical polishing (CMP) is widely used in the planarization process for interlayer films, etc. Wafers to be polished are polished by CMP, which simultaneously performs chemical processing using components contained in the abrasive (slurry), which is a mixture of abrasives and chemicals, and mechanical processing using abrasive grains (silica, alumina, zirconia, etc.) contained in the slurry.

[0003] The mainstream CMP system uses a polishing pad attached to the top surface of a circular platen, which is then rotated in contact with a carrier (polishing head) holding a wafer while slurry is dropped onto the pad. The slurry is supplied to the polishing pad and, as the polishing process progresses, is pushed outward from the outer edge of the platen (the outer edge of the polishing pad) and discharged. In recent years, in order to be environmentally friendly and reduce production costs, techniques for recovering and reusing slurry after polishing have been studied. For example, techniques for recovering slurry are described in Patent Documents 1 to 3.

[0004] 15 and 16 are schematic diagrams of an example of a conventional CMP apparatus 500. As shown in FIG. 15, the conventional CMP apparatus 500 includes a platen 506, a polishing head 507, and a slurry nozzle 508. The platen 506 has a polishing pad 560 attached to its upper surface and rotates. The wafer W is attached to the polishing head 507 and rotates integrally with the polishing head 507. The polishing pad 560 may be made of a type that uses a foamed resin, a type that uses a non-foamed resin, or a type made of nonwoven fabric.

[0005] Typically, the polishing pad 560 has a diameter two to three times that of the wafer W, and the wafer W is maintained in a state where its center is offset from the polishing pad 560. The rotation axis of the wafer W and the rotation axis of the polishing pad are parallel but not collinear.

[0006] As shown in FIG. 15, in the polishing process, the wafer W is held by a polishing head 507 and pressed against a polishing pad 560 on a platen 506, and a slurry 509 is supplied onto the polishing pad 560 on the platen 506 through a slurry nozzle 508 to polish the wafer.

[0007] The slurry 509 typically uses extremely small abrasive particles (abrasive particles) of silica (SiO2), alumina (Al2O3), or ceria (Ce2O3), typically 20 to 200 nanometers in diameter, suspended in an aqueous liquid. Chemical components may include components that modify the film to be polished, such as acids and alkalis, abrasive dispersants, surfactants, etc.

[0008] The slurry 509 is continuously flowed onto the polishing pad 560 and is pushed out from the outer edge of the platen 506 (the outer edge of the polishing pad 560) as the platen 506 rotates. The pushed-out slurry 509 is collected in a platen pan 505, which is a collection container fixedly provided below the platen 506.

[0009] 15 , in the polishing process of the CMP apparatus 500, slurry 509 that is pushed out from the outer edge of the platen 506 (the outer edge of the polishing pad 560) and scattered hits the wall surface of the platen pan 505, runs down the wall surface of the platen pan 505 due to its own weight, flows to the bottom of the platen pan 505, and accumulates in the platen pan 505. The slurry 509 that has accumulated in the platen pan 505 flows due to its own weight into a drain 510 that serves as a discharge port, and is discharged and collected via the drain 510 and drain piping 511. In a conventional method for recovering the slurry 509 in the polishing process of the CMP apparatus 500, the slurry 509 may remain on the wall surface of the platen pan 505, inside the platen pan 505, inside the drain 510, etc., which may result in a low recovery efficiency of the slurry 509. Furthermore, because the slurry 509 flows down the wall surface and bottom surface of the platen pan 505 into the drain 510, there is a time delay between when the slurry 509 is scattered from the outer edge of the platen 506 and when it is recovered in the drain 510. As described above, because it takes time from when the slurry 509 is scattered from the platen 506 to when it is recovered, there is a possibility that the slurry 509 may dry in the platen pan 505, which may clog the recovery system or deteriorate the quality of the recovered slurry 509.

[0010] As shown in FIG. 16, during the rinse process of the CMP apparatus 500, a cleaning agent 514 is supplied in large quantities onto the platen 506 through a slurry nozzle 508 to remove abrasive particles and chemicals from the wafer W and the polishing pad 560 and various components of the CMP apparatus 500. In the rinsing process, immediately after the discharge of the cleaning agent 514, the mixture of the slurry 509 adhering to the wall surface of the platen pan 505 and the cleaning agent 514 is discharged and collected through the drain 510 and the drain piping 511. This may cause changes in the concentration and components of the slurry 509, which may make it difficult to reuse the slurry 509. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 4534241 [Patent Document 2] Japanese Patent Application Publication No. 10-58314 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-165104 Summary of the Invention [Problem to be solved by the invention]

[0012] As mentioned above, in conventional CMP apparatuses, the time required for recovery can cause the slurry to dry out, resulting in adhesion to the recovery system or clogging, which can reduce recovery efficiency. Also, when recovering slurry in the rinsing step, as mentioned above, the quality of the slurry can be reduced.

[0013] The present disclosure is intended to solve the problems of the above-described conventional techniques, and aims to provide a CMP apparatus and a CMP method that can efficiently recover slurry. [Means for solving the problem]

[0014] The first CMP apparatus of the present disclosure is a CMP apparatus that supplies slurry onto a polishing pad and polishes a workpiece held by a polishing head by pressing it against the polishing pad on a platen, and is equipped with a slurry recovery nozzle that is adjacent to the upper surface of the polishing pad and has an opening that can face the outer edge of the polishing pad.

[0015] In the CMP method, the slurry used for polishing is supplied to a polishing pad on a platen. As polishing progresses, the slurry is pushed out toward the outer periphery of the platen (in the radial direction) and discharged from the outer edge to the outside of the platen (outside the polishing pad). The slurry recovery nozzle of the CMP apparatus is located adjacent to the upper surface of the polishing pad, with its opening facing the outer edge of the polishing pad. This allows for direct and rapid recovery of the slurry that is discharged from the outer edge of the platen in the radial extension direction (drawing a parabola). As a result, drying of the slurry is suppressed, improving recovery efficiency.

[0016] A second CMP apparatus of the present disclosure is the first CMP apparatus, further comprising a pressure control unit that reduces the pressure inside the slurry recovery nozzle.

[0017] The pressure control unit reduces the pressure inside the slurry collection nozzle, allowing the slurry discharged from the platen to be collected with a shorter exposure time to the outside air. As a result, the drying of the slurry is further suppressed, making collection more efficient. The arrangement of the opening of the slurry collection nozzle ensures that the suction direction and the direction in which the slurry is pushed out by the centrifugal force from the rotating platen are nearly aligned, enabling more efficient collection.

[0018] A third CMP apparatus of the present disclosure is the first CMP apparatus, wherein the slurry recovery nozzle has a groove-shaped cross section in which the opening is formed.

[0019] The slurry discharged from the outer edge of the platen may be scattered upward beyond the radial extension due to the rotation of the platen. A slurry collection nozzle with a grooved cross section can efficiently collect this scattered slurry using the upper and lower flanges.

[0020] A fourth CMP apparatus of the present disclosure is the third CMP apparatus, wherein the groove has a tapered shape that widens continuously or discontinuously toward the opening.

[0021] The tapered groove shape can reduce the amount of slurry that remains unrecovered in the slurry recovery nozzle. By reducing the amount of slurry that remains unrecovered, it is also possible to prevent clogging due to dried solids, etc. For example, if a recovery port of a slurry recovery system, which will be described later, is connected to the narrowed portion of the tapered shape, the slurry can be recovered more efficiently.

[0022] A fifth CMP apparatus of the present disclosure is the first CMP apparatus, further comprising a shutoff unit that stops recovery of the slurry from the slurry recovery nozzle.

[0023] A cleaning process called rinsing or cleaning may be performed as a post-processing step after CMP polishing. In rinsing, a cleaning agent (e.g., water and / or an acid / alkali solution) is provided on the platen, and the cleaning agent is discharged from the outer edge of the rotating platen, in the same manner as in polishing. In the CMP apparatus of this embodiment, the slurry collection is stopped when the shut-off unit is activated, which prevents the cleaning agent from mixing with the collected slurry and suppresses deterioration in the quality of the collected slurry.

[0024] A sixth CMP apparatus of the present disclosure is the fifth CMP apparatus, wherein the shut-off unit includes a shutter that closes the opening.

[0025] In the CMP apparatus of this embodiment, the opening is closed with a shutter, thereby liquid-tightly separating the inside and outside of the slurry collection nozzle. This not only prevents the cleaning agent from being mixed into the collected slurry, but also allows processes such as cleaning of the nozzle (and the connected slurry collection system) to be performed in parallel inside the closed slurry collection nozzle, thereby improving the efficiency of the polishing process and the rinsing process (or cleaning process).

[0026] A seventh CMP apparatus of the present disclosure is the fifth CMP apparatus, wherein the shut-off unit includes a position adjustment subunit that adjusts the attitude of the slurry recovery nozzle to change the orientation of the opening and / or adjusts the position of the slurry recovery nozzle relative to the platen.

[0027] In the CMP apparatus of this embodiment, the shut-off unit includes a position adjustment subunit, so that a simple operation (mechanism) such as adjusting the attitude and position of the slurry recovery nozzle can prevent the cleaning agent from getting into the nozzle.

[0028] An eighth CMP apparatus of the present disclosure is a CMP apparatus according to the seventh CMP apparatus, wherein the position adjustment subunit slides the slurry recovery nozzle in the direction of the upper surface so that the opening does not intersect with an extension of the radius of the upper surface.

[0029] In the CMP apparatus of this embodiment, the slurry recovery nozzle is slid upward or downward relative to the upper surface of the platen so that the opening does not intersect with the radius and extension of the upper surface. As described above, contamination of the cleaning agent into the nozzle can be suppressed with a simpler operation (mechanism). In particular, by sliding the slurry recovery nozzle below the platen, the transfer of the wafer to be polished / has been polished can be performed more smoothly. When polishing is completed (i.e., when slurry recovery is completed), the slurry recovery nozzle slides downward on the platen, creating space around the platen, facilitating subsequent transfer and the like.

[0030] A ninth CMP apparatus of the present disclosure is the first CMP apparatus, wherein the slurry recovery nozzle is configured in a circular or partial circular shape along the outer edge of the upper surface.

[0031] The CMP apparatus of this embodiment is configured to have a circular or partially circular shape in plan view, and therefore can more efficiently collect the slurry extruded from the upper surface of the circular platen.

[0032] A tenth CMP apparatus of the present disclosure is the ninth CMP apparatus, wherein the slurry recovery nozzle is connected to two or more independent slurry recovery systems that recover the slurry via recovery ports, and the recovery port of one of the slurry recovery systems is positioned upstream of the recovery port of the other of the slurry recovery systems in the direction of rotation of the platen relative to the polishing head.

[0033] In the CMP apparatus of this embodiment, multiple slurry recovery systems are connected to the slurry recovery nozzle. Each slurry recovery system consists of a recovery port and subsequent piping, valves, containers, etc., and is typically a closed system, which may be depressurized by a pressure control unit.

[0034] In the polishing process, slurry is supplied to a rotating platen, and a wafer W supported by a rotating polishing head is pressed against the platen. In some cases, the slurry supplied to the polishing position moves to the vicinity of the polishing head as the platen rotates, picks up polishing debris, etc., and is then pushed out from the outer edge of the platen and discharged, while in other cases, the slurry is pushed out from the outer edge of the platen as the platen rotates and discharged before reaching the polishing head. In other words, based on the polishing head, slurry containing almost no polishing debris is often discharged from the outer edge upstream of the platen in the direction of rotation, while based on the polishing head, slurry containing polishing debris is often discharged from the outer edge downstream of the platen in the direction of rotation.

[0035] In the CMP apparatus of this embodiment, the slurry recovery system is separated between the upstream and downstream sides of the platen rotation direction, based on the polishing head. This allows slurries with different cleanliness levels to be recovered separately. In particular, the slurry recovered from the upstream side can often be reused as is, allowing for more efficient recovery. In this case, the slurry recovery nozzle may be a single nozzle or a plurality of nozzles corresponding to the respective slurry recovery systems.

[0036] An eleventh CMP apparatus of the present disclosure is the first CMP apparatus, further comprising a second slurry recovery nozzle that opens toward the upper surface and is disposed within the plane of the upper surface in a plan view.

[0037] Unlike the (first) slurry recovery nozzle, the second slurry recovery nozzle is arranged within the plane of the upper surface of the platen in a plan view (in other words, above the platen). While the (first) slurry recovery nozzle recovers slurry that is discharged to the outside of the platen, the second slurry recovery nozzle recovers slurry toward the top of the platen (preferably by reducing the pressure inside and sucking it up). Slurry can be recovered more efficiently from two different directions.

[0038] A twelfth CMP apparatus of the present disclosure is the eleventh CMP apparatus, wherein a second slurry recovery nozzle is disposed downstream of the polishing head in the direction of rotation of the platen.

[0039] In the CMP apparatus of this embodiment, the second slurry recovery nozzle is positioned downstream of the polishing head in the direction of platen rotation, so that the second slurry can more reliably recover the slurry containing a large amount of polishing debris and the like that is discharged downstream of the polishing head. This is particularly effective when polishing wafers by pressing two or more polishing heads onto a single platen, since the second slurry recovery nozzle more reliably recovers the slurry discharged downstream from one polishing head, resulting in only cleaner slurry being supplied to the other polishing head, thereby improving the polishing efficiency and / or polishing quality.

[0040] A thirteenth CMP apparatus of the present disclosure is the first CMP apparatus, further comprising a controller, which controls the shutoff unit to stop the recovery of the slurry from the slurry recovery nozzle when the recovery of the slurry is completed.

[0041] In the CMP apparatus of this embodiment, the shut-off unit stops collecting the slurry once the collection of the slurry is completed, which prevents foreign matter (such as cleaning agents) from being mixed into the collected slurry, making it easier to collect a higher quality slurry.

[0042] A fourteenth CMP apparatus of the present disclosure is the eighth CMP apparatus, further comprising a controller, wherein the slurry recovery nozzle is configured to be capable of ejecting a cleaning agent (water, acid / alkali solution, etc.), and when the recovery of the slurry is completed, the controller causes the shut-off unit to slide the slurry recovery nozzle above the upper surface, causing the cleaning agent to be ejected from the slurry recovery nozzle.

[0043] The CMP apparatus of this embodiment is configured to be able to discharge a cleaning agent from the slurry collection nozzle after collecting the slurry. The cleaning agent is discharged while the slurry collection nozzle is slid upward, which prevents foreign matter from mixing with the slurry and allows for more efficient rinsing and cleaning.

[0044] The first CMP method of the present disclosure is a CMP method in which a slurry is supplied onto a polishing pad and a workpiece held by a polishing head is pressed against the polishing pad on a platen to be polished, and includes recovering the slurry using a slurry recovery nozzle that is adjacent to the upper surface of the polishing pad and has an opening that can face the outer edge of the polishing pad.

[0045] In the CMP method, the slurry used for polishing is supplied to a polishing pad on a platen, and then as polishing progresses, it is pushed out toward the outer periphery of the platen (in the radial direction) and discharged from the outer edge to the outside of the platen. The slurry recovery nozzle used in the CMP method of the above embodiment is provided adjacent to the upper surface of the polishing pad so that its opening can face the outer edge of the polishing pad. This allows the slurry discharged from the platen in the direction of the radial extension (drawing a parabola) to be collected directly and quickly, preventing the slurry from drying out and improving collection efficiency. [Effects of the Invention]

[0046] According to the present disclosure, a CMP apparatus and a CMP method capable of efficiently recovering slurry are provided. [Brief explanation of the drawings]

[0047] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a CMP apparatus according to a first embodiment. [Figure 2] 1 is a perspective view of a CMP apparatus 100 according to a first embodiment. [Figure 3] 3A to 3C are schematic views showing a polishing process of the CMP apparatus of the first embodiment. [Figure 4] FIG. 4 is a schematic view showing a rinsing step of the CMP apparatus of the first embodiment. [Figure 5] 10 is a partially enlarged cross-sectional view schematically showing a polishing step of the CMP apparatus of the first modification. FIG. [Figure 6] 10 is a partially enlarged cross-sectional view schematically showing a rinsing step of the CMP apparatus of Modification 1. FIG. [Figure 7] 10 is a partially enlarged cross-sectional view schematically showing a polishing step of a CMP apparatus according to a second modification. FIG. [Figure 8] FIG. 10 is a perspective view showing a polishing process of the CMP apparatus of the second modification. [Figure 9] 10 is a partially enlarged cross-sectional view schematically showing a rinsing step of the CMP apparatus of Modification 2. FIG. [Figure 10] FIG. 10 is a perspective view showing a rinsing step of the CMP treatment according to the second modification. [Figure 11] 10 is a partially enlarged cross-sectional view schematically showing a polishing step of a CMP apparatus according to a third modification. FIG. [Figure 12] FIG. 11 is a partially enlarged cross-sectional view schematically showing a rinsing step of the CMP apparatus of the third modification. [Figure 13] 10 is a partially enlarged cross-sectional view schematically showing a polishing step of a CMP apparatus according to a fourth modification. FIG. [Figure 14] FIG. 11 is a partially enlarged cross-sectional view schematically showing a rinsing step of the CMP apparatus of Modification 4. [Figure 15] FIG. 2 is an explanatory diagram of the operation of a slurry recovery system. [Figure 16] FIG. 10 is a perspective view showing the configuration of a CMP apparatus according to a second embodiment. [Figure 17] FIG. 10 is a schematic diagram showing the configuration of a CMP apparatus according to a second embodiment. [Figure 18] 1A and 1B are schematic diagrams showing a polishing process of a conventional CMP apparatus. [Figure 19] FIG. 1 is a schematic diagram showing a rinsing process of a conventional CMP apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0048] An embodiment of the CMP apparatus will be described in detail below with reference to the drawings. 1 is a schematic diagram showing the configuration of a CMP apparatus 100 according to the first embodiment, which is partially shown in cross section for ease of explanation. The CMP apparatus 100 performs chemical mechanical polishing (CMP) to polish and planarize the surface of the wafer W. The CMP apparatus 100 includes a slurry recovery nozzle 1, a platen pan 5, a platen 6, a polishing head 7, a slurry nozzle 8, and the like. The CMP apparatus 100, for example, rotates a platen 6 having a polishing pad 60 attached to its upper surface, presses a wafer W held by a polishing head 7 rotating against the polishing pad 60, and abuts the wafer W against the polishing pad 60, and polishes the wafer W while supplying a slurry 9 from a slurry nozzle 8 onto the polishing pad 60 on the platen 6 (hereinafter, this process may be referred to as a polishing process). Note that the platen 6 and the polishing pad 60 may be collectively referred to as the platen 6, and the upper surface of the platen 6 including the polishing pad 60 (i.e., the upper surface of the polishing pad 60) may be referred to as the upper surface of the platen 6. The polishing pad 60 may be, for example, a type using a foamed resin, a type using a non-foamed resin, or a type made of nonwoven fabric. The polishing pad 60 has a diameter, for example, two to three times that of the wafer W. The rotation axis of the wafer W and the rotation axis of the polishing pad 60 (or the platen 6) are, for example, parallel or approximately parallel, and are offset in the radial direction. The slurry 9 uses, for example, ultra-small polishing particles (abrasive particles) of silica (SiO2), alumina (Al2O3), or ceria (Ce2O3) typically 20 to 200 nanometers in diameter suspended in a water-soluble liquid as abrasive grains. Chemical components may include components that modify the film to be polished, such as acids and alkalis, abrasive grain dispersants, surfactants, etc.

[0049] After the polishing step, the CMP apparatus 100 supplies DIW (De-ionized Water) that has undergone a predetermined process as the cleaning agent 14 to remove abrasive particles and chemicals from the wafer W, the polishing pad, and various parts of the apparatus (hereinafter, this may be referred to as the rinsing step). Note that the CMP apparatus 100 may also supply an acid / alkali solution as the cleaning agent 14 to perform the rinsing step. The platen pan 5 is a collection container and is fixed below the platen 6. In plan view, the platen pan 5 is larger than the platen 6 (or the polishing pad 60). The platen pan 5 has an outer wall standing on its outer edge. The platen pan 5 is connected to a drain 10. For example, the drain 10 is connected to the bottom of the platen pan 5. The drain 10 is connected to a drain pipe 11.

[0050] 2 is a perspective view of the CMP apparatus 100 according to the first embodiment. For convenience of explanation, only the necessary components are shown in FIG. The slurry recovery nozzle 1 is provided around the periphery of the upper surface SF of the platen 6. For example, as shown in FIG. 2, the slurry recovery nozzle 1 is formed in a circular ring shape along the outer edge of the upper surface SF of the platen 6. Note that the slurry recovery nozzle 1 may have a configuration other than that shown in FIG. 2, as long as it is capable of recovering the slurry 9 coming out of the platen 6. For example, the slurry recovery nozzle 1 may be made up of a plurality of slurry recovery nozzles 1 arranged at intervals along the outer edge of the upper surface SF of the platen 6 (or polishing pad 60), or may be provided only around a portion of the outer edge of the upper surface SF of the platen 6 (or polishing pad 60).

[0051] Returning to Fig. 1, the cross section of the slurry recovery nozzle 1 is, for example, groove-shaped or U-shaped. The slurry recovery nozzle 1 is composed of a base 1A and a first flange 1B and a second flange 1C extending from both ends of the base 1A. For example, in the cross section of the slurry recovery nozzle 1, the base 1A, the first flange 1B, and the second flange 1C are perpendicular to each other. The cross-sectional shape of the slurry recovery nozzle may be formed into a shape other than the above-mentioned shape. The first flange 1B and the second flange 1C may each have a tapered shape that expands continuously or discontinuously in the direction opposite to the base 1A. The first flange 1B and the second flange 1C may also be curved. For example, they may be shaped to bend downward. Furthermore, a portion of them may be tapered. The slurry recovery nozzle 1 may not have the first flange 1B. The cross-section of the slurry recovery nozzle 1 may be formed into an inverse tapered shape (or a dogleg shape) that widens toward the platen 6 (or polishing pad 60) side. The slurry recovery nozzle 1 has an opening 1-4. That is, the slurry recovery nozzle 1 is open. In the example shown in FIG. 1, the opening 1-4 is formed by being surrounded by the base 1A, the first flange 1B, and the second flange 1C, and faces in the opposite direction from the base 1A. That is, the cross section of the slurry recovery nozzle 1 opens in the opposite direction from the base 1A. For example, the opening 1-4 of the slurry recovery nozzle 1 may face the upper surface SF of the platen 6 or the polishing pad 60 or the outer edge of the upper surface SF. That is, the slurry recovery nozzle 1 opens toward the upper surface SF of the platen 6 or the polishing pad 60 or the outer edge of the upper surface SF. Also, for example, the opening 1-4 may face the center CR of the upper surface SF. In the example shown in FIG. 1, the slurry recovery nozzle 1 is disposed so that the opening 1-4 intersects with an extension line RE of the radius of the upper surface SF of the platen 6 (or the polishing pad 60). Here, "the opening 1-4 intersects with the extension line RE of the radius" means that the extension line RE is configured to pass through the opening 1-4.

[0052] In addition, the opening 1-4 may face in a direction other than that described above, as long as the slurry recovery nozzle 1 is positioned so as to be able to recover the slurry 9 discharged from the platen 6 or polishing pad 60 or the outer edge of the platen 6 or polishing pad 60.

[0053] When the opening 1-4 faces the upper surface SF as shown in FIG. 1, the second flange 1C is disposed below the first flange 1B. In this case, the second flange 1C may have a recessed storage space temporarily below the slurry 9. In addition, in this case, the first flange 1B may be formed so as to cover the upper surface SF. By forming the first flange 1B so as to cover the upper surface SF, scattering of the slurry 9 to the outside can be suppressed, and recovery efficiency can be improved.

[0054] The slurry recovery nozzle 1 is disposed close to or adjacent to the platen 6 or the upper surface SF of the platen 6 (or polishing pad 60). For example, the slurry recovery nozzle 1 is disposed at a position closer to the platen 6 or the upper surface SF of the platen 6 (or polishing pad 60) than the platen pan 5. The slurry recovery nozzle 1 is disposed close to or adjacent to the outer edge, for example, so as not to come into contact with the platen 6 (or polishing pad 60). By disposing the slurry recovery nozzle 1 close to or adjacent to the outer edge, the slurry 9 can be recovered before it dries. Note that the slurry recovery nozzle 1 may be in contact with the platen 6 (or polishing pad 60). The inner diameter of the slurry recovery nozzle 1 surrounding the platen 6 (or polishing pad 60) is slightly larger than the diameter of the platen 6, and for example, the slurry recovery nozzle 1 is spaced 1 to 2 mm from the platen 6 without contacting it. The slurry 9 can then be directly recovered through the slurry recovery nozzle 1. In plan view, the slurry recovery nozzle 1 is smaller than the platen pan 5. For example, in plan view, the slurry recovery nozzle 1 is housed in an area surrounded by the platen pan 5. In other words, the slurry recovery nozzle 1 is located between the outer wall of the platen pan 5 and the outer edge of the platen 6. In other words, the outer edge of the slurry recovery nozzle 1 is located more inward than the outer edge of the platen pan 5. Note that in plan view, the slurry recovery nozzle 1 may be larger than the platen pan 5. If the slurry recovery nozzle 1 is smaller than the platen pan 5 in plan view, the platen pan 5 may be able to receive the slurry 9 and cleaning agent 14 that have scattered on the upper surface of the slurry recovery nozzle 1, for example.

[0055] 18 and 19, the slurry 509 hits the vertical wall of the platen pan 505, which is spaced apart from the outer edge of the platen 506 (or polishing pad 560), and is then collected in the drain 510. During this time, the slurry 509 is exposed to the outside air and is prone to drying. In contrast, the CMP 100 of this embodiment collects the slurry 9 using the slurry collection nozzle 1, which shortens the time the slurry 9 is exposed to the outside air and makes it less likely to dry out.

[0056] One end of the slurry pipe 2 is connected to the slurry recovery nozzle 1 via a recovery port 2A. The other end is connected to a vacuum-drawn recovery tank 15 via a switching valve 3. The slurry pipes 2 are connected via the recovery ports 2A at intervals of 40 to 80 degrees, more preferably at intervals of 60 degrees, around the circumference of the annular slurry recovery nozzle 1. The slurry recovery nozzle 1 is also connected to a cleaning water pipe 4 that prevents clogging of the slurry recovery nozzle 1 with cleaning water and is used for cleaning.

[0057] That is, the slurry recovery nozzle 1 is connected to a slurry recovery system including a recovery port 2A, a slurry pipe 2, a switching valve 3, a recovery tank 15, a valve 33, and a vacuum pump 16. The vacuum pump 16 included in the slurry recovery system reduces the pressure inside the slurry recovery nozzle 1, making the recovery of the slurry more efficient. The pressure inside the slurry recovery nozzle 1 may be reduced by a pressure control unit other than the vacuum pump 16. Examples of such a pressure control unit include an air ejector, a Venturi pump, and a blower. In addition, the components that make up the slurry recovery system include piping, valves, tanks, etc. as in this embodiment, but the configuration is not limited to the above as long as it can collect the slurry recovered from the slurry recovery nozzle 1 and store it as needed.

[0058] 3 is a diagram showing a polishing process of the CMP apparatus 100 of this embodiment. For the sake of convenience, only the necessary components are shown in FIG. A polishing pad 60 is attached to the upper surface of a cylindrical surface platen 6, which rotates. Slurry 9 is supplied onto the upper surface SF of the platen 6 (or polishing pad 60) through a slurry nozzle 8. A wafer W is held by a polishing head 7 and transported onto the platen 6 (or polishing pad 60), where it comes into contact with the polishing pad 60 and is subjected to an appropriate pressing force.

[0059] The slurry 9 pushed out from the outer edge of the platen 6 (the outer edge of the polishing pad 60) is instantly collected by the slurry recovery nozzle 1. The slurry recovery nozzle 1 is depressurized via the slurry piping 2 and the switching valve 3, so it sucks in the slurry 9. In other words, the slurry 9 does not fall under its own weight, but is forcibly sucked in. The slurry recovery system is a closed system, and the slurry 9 is sent to the recovery tank 15 without being exposed to the outside air or drying out.

[0060] 4 is a diagram showing a rinse step of the CMP apparatus 100 of this embodiment. For convenience of explanation, only the necessary components are shown in FIG. The cleaning agent 14 is supplied onto the platen 6 (or polishing pad 60) through the slurry nozzle 8. At this time, the collection of the slurry 9 from the slurry collection nozzle 1 is stopped before the supply of the cleaning agent 14 is started so that the cleaning agent 14 is not collected from the slurry collection nozzle 1 and mixed with the collected slurry 9. For example, the CMP apparatus 100 has a shutoff unit to prevent the cleaning agent 14 from being collected by the slurry collection nozzle 1. The CMP apparatus 100 controls the shutoff unit using a controller (not shown) to prevent the cleaning agent 14 from being collected by the slurry collection nozzle 1. As a result, a higher quality slurry 9 is collected. The CMP apparatus 100 may be configured to suppress the recovery of the cleaning agent 14 by the slurry recovery nozzle 1 using a configuration other than the shut-off unit. 3 and 4 will be described as some modified examples of the CMP 100 of the first embodiment. For the sake of convenience, the shut-off unit around the part A will be described, but the shut-off unit described below may be provided in other parts or the entire slurry collection nozzle 1.

[0061] 5 is a partially enlarged cross-sectional view that schematically shows a polishing process of the CMP apparatus 100 of Modification 1. In FIG. 5, only the components necessary for explanation are shown. 5, in Modification 1, the shut-off unit includes a position adjustment subunit 20 provided on the back surface of the base 1A. As will be described later, the position adjustment subunit 20 has the function of controlling the attitude of the slurry collection nozzle 1, changing the direction of the opening 1-4, and stopping the collection of the slurry. 5, in the polishing process, the slurry 9 is supplied onto the platen 6 (or the polishing pad 60) and is extruded and ejected from the outer edge of the platen 6 (or the polishing pad 60) as the platen 6 rotates. In the drawing, the extruded (discharged or ejected) slurry 9 is represented as slurry 9-1. Typically, the slurry 9-1 is extruded (or ejected) from the outer edge along an extension line RE of the radius or in a parabolic curve outward.

[0062] As shown in Figure 5, during the polishing process, the position adjustment subunit 20 of the shutoff unit positions the slurry recovery nozzle 1 so that the opening 1-4 faces the outer edge of the upper surface SF of the platen 6 or polishing pad 60, or faces the center CR of the upper surface SF. In the example shown in Figure 5, during the polishing process, the base 1A of the slurry recovery nozzle 1 faces the outer edge of the upper surface SF of the platen 6 (or polishing pad 60), the first flange 1B is above the upper surface SF (extension line RE) of the platen 6 (or polishing pad 60), and the second flange 1C is below the upper surface SF (extension line RE) of the platen 6 (or polishing pad 60). 5, in the polishing process, the slurry recovery nozzle 1 is adjacent to the upper surface SF of the platen 6 or the polishing pad 60, so that the slurry 9-1 that splashes out from the outer edge of the upper surface SF of the platen 6 or the polishing pad 60 is immediately collected in the opening 1-4 located on the trajectory. In addition, the first flange 1B also efficiently recovers the slurry 9-1 that splashes upward.

[0063] 6 is a partially enlarged cross-sectional view schematically showing the rinsing step of the CMP apparatus 100 of Modification 1. In FIG. 6, only the components necessary for the explanation are shown. 6, in the rinsing process (or cleaning process), the cleaning agent 14 is supplied onto the platen 6 (or polishing pad 60) and is pushed out from the outer edge of the platen 6 (or polishing pad 60) as the platen 6 rotates. In the figure, the pushed-out (discharged or thrown-out) cleaning agent 14 is represented as cleaning agent 14-1. The cleaning agent 14-1 is pushed out (or thrown-out) from the outer edge along a radial extension line RE or in a parabolic curve outward. 6, in the rinsing step, the position adjustment subunit 20 of the shut-off unit changes the attitude of the slurry recovery nozzle 1 so that the opening 1-4 faces downward. That is, the attitude of the slurry recovery nozzle 1 is adjusted so that an extension line RE of the radius of the upper surface SF of the platen 6 (or polishing pad 60) does not intersect with the opening 1-4 and so that the extension line RE does not penetrate the opening 1-4. In other words, the attitude of the slurry recovery nozzle 1 is changed to face the opening 1-4 downward so that the opening 1-4 does not face the outer edge of the upper surface SF of the platen 6 or polishing pad 60. When the position adjustment subunit 20 adjusts the attitude of the slurry recovery nozzle 1 so that the opening 1-4 faces downward, recovery of the cleaning agent 14-1 by the slurry recovery nozzle 1 is suppressed. In the example shown in Fig. 6, the cleaning agent 14-1 is blocked by the first flange 1B, which further suppresses the possibility of the cleaning agent 14-1 being recovered by the slurry recovery nozzle 1. Note that in Modification 1, it is preferable that the slurry recovery nozzle 1 is provided not around the entire circumference of the platen 6 but around half the circumference or less of a circular ring (partial ring).

[0064] Fig. 7 is a partially enlarged cross-sectional view schematically showing the polishing process of the CMP apparatus 100 of Modification 2, and Fig. 8 is a perspective view showing the polishing process of the CMP apparatus 100 of Modification 2. Figs. 7 and 8 show only the configuration necessary for explanation. As shown in FIG. 7, in the CMP apparatus 100 of the second modification, the shut-off unit includes a position adjustment subunit 21 that can slide the slurry recovery nozzle 1 up and down.

[0065] As shown in Figure 7, during the polishing process, the position adjustment subunit 21 of the shutoff unit positions the slurry recovery nozzle 1 so that the opening 1-4 faces the outer edge of the upper surface SF of the platen 6 or polishing pad 60, or faces the center CR of the upper surface SF. 8, in the polishing process, the slurry recovery nozzle 1 can be arranged around the entire outer edge of the upper surface SF of the platen 6 (or polishing pad 60) so that the openings 1-4 face the outer edge of the upper surface SF of the platen 6 or polishing pad 60, or face the center CR of the upper surface SF. Note that the slurry recovery nozzle 1 may also be arranged in a portion of the outer edge of the upper surface SF of the platen 6 (or polishing pad 60) so that the openings 1-4 face the outer edge of the upper surface SF of the platen 6 or polishing pad 60, or face the center CR of the upper surface SF.

[0066] Fig. 9 is a partially enlarged cross-sectional view schematically showing the rinsing step of the CMP apparatus 100 of Modification 2, and Fig. 10 is a perspective view showing the rinsing step of the CMP apparatus 100 of Modification 2. Figs. 9 and 10 show only the configuration necessary for explanation. 9, in the rinsing step, the position adjustment subunit 21 constituting the shut-off unit slides the slurry recovery nozzle 1 downward so that the opening 1-4 is positioned below the upper surface SF of the platen 6 (or polishing pad 60) (in the direction of the arrow in FIG. 9). That is, the slurry recovery nozzle 1 is positioned so that an extension line RE of the radius of the upper surface SF of the platen 6 (or polishing pad 60) does not intersect with the opening 1-4 and so that the extension line RE of the radius does not penetrate the opening 1-4. That is, the slurry recovery nozzle 1 moves downward while maintaining the orientation of the opening 1-4 so that the opening 1-4 does not face the outer edge of the upper surface SF of the platen 6 or polishing pad 60. 9 and 10, in the rinsing step, the position adjustment subunit 21 can position the slurry collection nozzle 1 so that the first flange 1B is located below the upper surface SF. Note that in the rinsing step, the slurry collection nozzle 1 may be moved so that the first flange 1B is located above the upper surface SF, as long as the amount of collected cleaning agent 14-1 can be reduced compared to the position shown in FIGS. 7 and 8. When the position adjustment subunit 21 slides the slurry recovery nozzle 1 to be positioned below the upper surface SF of the platen 6 or the polishing pad 60, recovery of the cleaning agent 14-1 by the slurry recovery nozzle 1 is suppressed. In the example shown in Figures 9 and 10, the cleaning agent 14-1 is blocked by the first flange 1B, which further suppresses the possibility of the slurry recovery nozzle 1 recovering the cleaning agent 14-1. In the rinsing step of Modification 2, if the slurry recovery nozzle 1 is slid to be positioned below the upper surface SF of the platen 6 or the polishing pad 60, the cleaning agent 14-1 flows over the first flange 1B and can be recovered in the platen pan 5. Therefore, it is preferable that the slurry recovery nozzle 1 is provided along the entire periphery of the platen 6 or the polishing pad 60 and has the first flange 1B.

[0067] 11 is a partially enlarged cross-sectional view that schematically shows a polishing step by the CMP apparatus 100 of Modification 3. In FIG. 11, only the configuration necessary for explanation is shown. As shown in FIG. 11, in the CMP apparatus 100 of the third modification, the shut-off unit includes a shutter 22 that closes the opening 1-4 of the slurry recovery nozzle 1. 11, in the polishing process, the shutter 22 of the shut-off unit of the slurry recovery nozzle 1 moves upward to open the opening 1-4. In this case, the slurry recovery nozzle 1 is positioned so that the opened opening 1-4 faces the outer edge of the upper surface SF of the platen 6 or the polishing pad 60, or faces the center CR of the upper surface SF. 12 is a partially enlarged cross-sectional view schematically showing the rinsing step of the CMP apparatus 100 of Modification 3. In FIG. 12, only the components necessary for explanation are shown. As shown in FIG. 12, after the polishing process or the slurry recovery is completed, the shutter 22 of the shut-off unit of the slurry recovery nozzle 1 moves downward to close the opening 1-4. When the opening 1-4 of the slurry recovery nozzle 1 is closed by the shutter 22, recovery of the cleaning agent 14-1 by the slurry recovery nozzle 1 and contamination of foreign matter are suppressed.

[0068] 13 is a partially enlarged cross-sectional view that schematically shows a polishing step by the CMP apparatus 100 of Modification 4. In FIG. 13, only the components necessary for explanation are shown. As shown in FIG. 13, in the CMP apparatus 100 of the fourth modification, the shut-off unit includes a valve 23 that shuts off the flow of slurry to a slurry recovery system (slurry piping 2) connected to the slurry recovery nozzle 1. As shown in FIG. 13, in the polishing process, the slurry recovery nozzle 1 opens the valve 23 of the shut-off unit. 14 is a partially enlarged cross-sectional view schematically showing the rinsing step of the CMP apparatus 100 of Modification 4. In FIG. 14, only the components necessary for explanation are shown. As shown in FIG. 14, after the polishing process or the slurry recovery is completed, the slurry recovery nozzle 1 closes the valve 23 of the shut-off unit to shut off the flow to the slurry pipe 2. Closing the valve 23 prevents the cleaning agent 14-1 and foreign matter from being mixed into the recovered slurry 9-1. Closing the valve 23 also shuts off the slurry pipe 2 and releases the reduced pressure in the slurry recovery nozzle 1, which may also contribute to stopping the recovery of the slurry 9-1 and the cleaning agent 14-1.

[0069] The above describes Modifications 1 to 4 of the CMP 100 of the first embodiment, but these may be used in combination, and it is particularly preferable to use two or more examples selected from the group consisting of Modifications 2, 3, and 4 in combination.

[0070] The slurry collection nozzle 1 may have a function that contributes to rinsing in addition to collecting the slurry. As one of such functions, the slurry collection nozzle 1 may be configured to be able to discharge air and / or a cleaning agent. There are no particular limitations on the method for discharging air and / or a cleaning agent from the slurry collection nozzle 1, but a method of discharging air and / or a cleaning agent in reverse from a collection port by connecting a branch pipe to the slurry collection system can be used.

[0071] The ejection of air and / or cleaning agent contributes to improving the efficiency of rinsing and cleaning, as well as to cleaning the slurry recovery system, and also has the effect of further suppressing the inclusion of foreign matter in the slurry.

[0072] Next, an example of the operation of the slurry recovery system 50 will be described. FIG. 15 is an explanatory diagram of the operation of the slurry recovery system 50 including the switching valve 3. The flow path for recovering the slurry in the slurry recovery system 50 starts at a recovery port 2A arranged in the slurry recovery nozzle 1 and is composed of a valve 23, a slurry pipe 2, a valve 3-1, and a recovery tank 15. A vacuum pump 16 is connected to the recovery tank 15 via a valve 33 to reduce the pressure in the flow path. During the polishing process, that is, while the slurry 9-1 is being supplied, the vacuum pump 16 reduces the pressure inside the recovery tank 15, and the slurry 9-1 is sucked from the slurry recovery nozzle 1. The slurry 9-1 is collected and stored in the recovery tank 15 via the slurry recovery nozzle 1, the recovery port 2A, the opened valve 23, the slurry pipe 2, and the valve 3-1 opened toward the recovery tank 15.

[0073] Next, cleaning DIW is discharged from valve 3-2 to clean the inside of slurry pipe 2. At this time, valve 23 can be closed and valve 3-1 can be switched to the DRAIN side, which is a pipe for draining water, to clean slurry pipe 2. Also, valve 23 can be opened to discharge cleaning DIW from slurry recovery nozzle 1. When valve 23 is opened, the position of slurry recovery nozzle 1 can be adjusted so that the discharged water can simultaneously rinse the upper surface SF of platen 6. In the above embodiment, DIW is used as the cleaning agent, but instead, a cleaning agent containing an acid or alkali may be used.

[0074] Next, the valve 3-2 is switched to discharge CDA (clean dry air) to dry and remove the cleaning DIW remaining in the slurry pipe 2 and the like.

[0075] Other embodiments will be described below. In the description of the other embodiments, the same parts and configurations as those in the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted. Only parts different from the first embodiment will be described in detail. The CMP apparatus 100 according to the second embodiment differs from the CMP apparatus 100 according to the first embodiment in the configuration of the slurry recovery nozzle. Fig. 16 is a perspective view showing the configuration of a CMP apparatus 100 according to the second embodiment, and Fig. 17 is a schematic view showing the configuration of the CMP apparatus 100 according to the second embodiment. For ease of explanation, Fig. 17 shows a partial cross section. The CMP apparatus 100 includes a slurry recovery nozzle (first slurry recovery nozzle) 1 arranged along the outer edge of the upper surface of the platen 6, and a second slurry recovery nozzle 40 arranged above the upper surface of the platen 6. The first slurry recovery nozzle 1 is formed in a shape that follows part of the outer edge of the upper surface of the platen 6. The first slurry recovery nozzle 1 is formed, for example, in a semicircular ring shape that follows the outer edge of the upper surface of the platen 6. In the example shown in FIG. 16, the slurry recovery nozzle 1 is formed in a semicircular ring shape that covers both the upstream side and the downstream side of the rotation direction of the platen 6 (the direction of the arrow on the upper surface) with respect to the polishing head 7.

[0076] The second slurry recovery nozzle 40 is formed in the shape of an elongated rod. For example, the second slurry recovery nozzle 40 is formed in the shape of a rectangular parallelepiped having a longitudinal direction and a lateral direction. The second slurry recovery nozzle 40 has a groove-like or U-shaped cross section when viewed from the longitudinal direction, and its opening faces the upper surface side of the platen 6. The positions thereof are as follows. The second slurry recovery nozzle 40 is disposed on the platen 6. That is, the second slurry recovery nozzle 40 is disposed within the plane of the upper surface of the platen 6 in a plan view. The second slurry recovery nozzle 40 is disposed in a position immediately downstream of the polishing head 7 in the rotation direction of the platen 6. 16, the second slurry recovery nozzle 40 is disposed across the upper surface SF of the platen 6 from near the downstream end of the semicircular ring of the slurry recovery nozzle 1 in the rotation direction of the platen 6 to near the downstream end of the semicircular ring of the slurry recovery nozzle 1 in the rotation direction of the platen 6. In other words, the second slurry recovery nozzle 40 is adjacent to the downstream end of the semicircular ring of the slurry recovery nozzle 1 in the rotation direction of the platen 6 and is adjacent to the downstream end of the polishing head 7 in the rotation direction.

[0077] The second slurry recovery nozzle 40 is provided with a recovery port 40A, to which a slurry recovery system (not shown) is connected. It is preferable that this slurry recovery system is independent from the slurry recovery system connected to the slurry recovery nozzle 1. Furthermore, the slurry recovery system (closed system) continuing from the recovery port 40A is depressurized, so that the second slurry recovery nozzle 40 can suck the slurry on the platen 6 vertically upward. It is preferable that the second slurry recovery nozzle 40 is disposed in a position close to but not in contact with the polishing pad 60 on the platen 6. It is also possible that the second slurry recovery nozzle 40 is connected to a pipe that supplies cleaning water, such as the cleaning water pipe 4.

[0078] Specifically, the distance between the second slurry recovery nozzle 40 and the platen 6 (or polishing pad 60) is preferably 1 to 2 mm so that the second slurry recovery nozzle 40 does not come into contact with the platen 6 (or polishing pad 60). The position of the second slurry recovery nozzle 40 may be determined depending on the rotation direction of the platen 6 and polishing head 7, and it is preferable to position the second slurry recovery nozzle 40 so that the slurry 9 does not go behind the second slurry recovery nozzle 40.

[0079] Returning to the (first) slurry recovery nozzle 1, recovery ports 2A, 2B, 2C, and 2D are provided at intervals of 40 to 80°, more preferably at intervals of 60°, relative to the slurry recovery nozzle 1, and each is connected to an independent slurry recovery system (closed system). By connecting each independent and depressurized slurry recovery system to multiple recovery ports, the suction force of the slurry recovery nozzle 1 can be increased.

[0080] Additionally, connecting a separate slurry recovery system to the recovery port has other advantages. Generally, the slurry supplied onto the platen 6 (or polishing pad 60) moves to the vicinity of the polishing head 7 as the platen 6 rotates, picks up polishing debris, etc., and is then pushed out and discharged from the outer edge of the platen 6 (or polishing pad 60). On the other hand, some slurry is pushed out and discharged from the outer edge of the platen 6 (or polishing pad 60) as the platen 6 rotates before reaching the polishing head 7. In other words, based on the polishing head 7, slurry that has hardly been used for polishing is often discharged from the outer edge upstream of the platen 6 in the direction of rotation, and based on the polishing head 7, slurry containing polishing debris, etc. is often discharged from the outer edge downstream of the platen 6 in the direction of rotation.

[0081] That is, in the example shown in Figure 16, the slurry recovered from recovery ports 2A and 2B is likely to be cleaner, while the slurry recovered from recovery ports 2C, 2D, and 40A (second slurry recovery nozzle 40) is likely to contain more polishing debris, etc. By collecting these in a separate slurry recovery system, subsequent processing can be minimized. In other words, the cleaner slurries are more likely to be reusable as they are, and by recovering them separately from the other slurries, processing related to reuse can be omitted. Specifically, 20 to 30% of the recovered slurry can be recycled and reused as is, eliminating the need for treatment for reuse.

[0082] In this embodiment, an independent slurry recovery system is connected to each of the four recovery ports, but it is also possible to connect the recovery ports (recovery ports 2A, 2B) upstream of the polishing head 7 in the rotation direction of the platen 6 to one slurry recovery system, and the recovery ports (recovery ports 2C, 2D) downstream of the polishing head 7 to another slurry recovery system. In the case of the annular slurry recovery nozzle 1, the upstream side and downstream side are defined based on the intersection of the line connecting the center of the platen 6 and the center of the polishing head 7 with the outer edge of the platen 6.

[0083] A shut-off unit may be added to the second slurry recovery nozzle 40, and the type thereof is as described in the first to fourth embodiments of the shut-off unit. Also, the second slurry recovery nozzle 40 may be configured to be able to discharge a cleaning agent in the rinsing and cleaning steps. [Explanation of symbols]

[0084] 1...slurry recovery nozzle, 1A...base, 1B...first flange, 1C...second flange, 1-4...opening, 2...slurry piping, 2A, 2B, 2C, 2D, 40A...recovery port, 3...switching valve, 3-1...valve, 3-2...valve, 4...cleaning water piping, 5...platen pan, 6...platen, 7...polishing head, 8...slurry nozzle, 9...slurry, 9-1...slurry, 10...drain, 11...drain piping, 14...cleaning agent, 14-1...cleaning agent, 15...recovery tank, 16...vacuum pump, 20...position adjustment subunit, 21...position adjustment subunit, 22...shutter, 23...valve, 33...valve, 40...second slurry recovery nozzle, 60...polishing pad, W...wafer

Claims

1. A CMP apparatus that supplies a slurry onto a polishing pad and polishes a workpiece held by a polishing head by pressing the workpiece against the polishing pad on a platen, a slurry recovery nozzle provided adjacent to the upper surface of the polishing pad and having an opening facing the outer edge of the polishing pad;

2. 2. The CMP apparatus according to claim 1, further comprising a pressure control unit connected to the slurry recovery nozzle and reducing the pressure inside the slurry recovery nozzle.

3. 2. The CMP apparatus according to claim 1, wherein the slurry recovery nozzle has a groove-shaped cross section in which the opening is formed.

4. 4. The CMP apparatus according to claim 3, wherein the groove has a tapered shape that widens continuously or discontinuously toward the opening.

5. 2. The CMP apparatus according to claim 1, further comprising a shutoff unit that stops the collection of slurry from the slurry collection nozzle.

6. The CMP apparatus according to claim 5 , wherein the shut-off unit includes a shutter that closes the opening.

7. 6. The CMP apparatus according to claim 5, wherein the shut-off unit includes a position adjustment subunit that adjusts the attitude of the slurry recovery nozzle to change the orientation of the opening and / or adjusts the position of the slurry recovery nozzle relative to the platen.

8. 8. The CMP apparatus according to claim 7, wherein the position adjustment subunit slides the slurry recovery nozzle in a direction in which the upper surface faces so that the opening does not intersect with an extension line of a radius of the upper surface.

9. The CMP apparatus according to claim 1 , wherein the slurry recovery nozzle is configured in a circular or partially circular shape along the outer edge of the upper surface.

10. two or more independent slurry recovery systems that recover the slurry via recovery ports are connected to the slurry recovery nozzle; 10. The CMP apparatus according to claim 9, wherein the recovery port of one of the slurry recovery systems is disposed upstream of the recovery port of the other of the slurry recovery systems in the rotation direction of the platen relative to the polishing head.

11. The CMP apparatus according to claim 1 , further comprising a second slurry recovery nozzle that opens toward the upper surface and is disposed within the plane of the upper surface in a plan view.

12. 12. The CMP apparatus according to claim 11, wherein the second slurry recovery nozzle is disposed downstream of the polishing head in the direction of rotation of the platen.

13. Equipped with a controller, 6. The CMP apparatus according to claim 5, wherein the controller controls the shut-off unit to stop the collection of the slurry from the slurry collection nozzle when collection of the slurry is completed.

14. Equipped with a controller, the slurry recovery nozzle is configured to be able to discharge a cleaning agent, When the collection of the slurry is completed, the controller causes the shut-off unit to slide the slurry collection nozzle above the upper surface; The CMP apparatus according to claim 8 , wherein the cleaning agent is discharged from the slurry recovery nozzle.

15. A CMP method in which a slurry is supplied onto a polishing pad, and a workpiece held by a polishing head is pressed against the polishing pad on a platen to be polished, comprising: a slurry recovery nozzle provided adjacent to the upper surface of the polishing pad and having an opening facing the outer edge of the polishing pad;

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