JP2021181157A - CMP device and method - Google Patents

Abstract

To provide a wafer adsorption device and a CMP device capable of strongly adsorbing and holding the entire surface of a wafer.SOLUTION: An air bag 62d expands and pushes the vicinity of the center of an adsorption member 64 downward, and therefore, a suction member 64 is elastically deformed into a convex crown shape downward. An in-table 71 brings a wafer W close to the elastically-deformed adsorption member 64 to bring the wafer W into close contact with the adsorption member 64 sequentially from the vicinity of the center toward the outer periphery.SELECTED DRAWING: Figure 12

Description

The present invention relates to a CMP apparatus and method for CMP polishing a wafer.

In the field of semiconductor manufacturing, a wafer polishing apparatus for flattening a semiconductor wafer (hereinafter referred to as "wafer") such as a silicon wafer is known.

The polishing apparatus described in Patent Document 1 is a polishing apparatus to which chemical mechanical polishing, so-called CMP (Chemical Mechanical Polishing) technology, is applied. In this polishing apparatus, a waiting unit relays between a load / unload portion for transporting a wafer from which a wafer has been taken out from a cassette and a polishing head for polishing the wafer.

The waiting unit is a wafer mounting table with a two-stage upper and lower structure, the upper stage is a load-only wafer mounting table (in-table) that delivers the unpolished wafer to the polishing head, and the lower stage receives the polished wafer from the polishing head. Wafer placement table (out table) dedicated to unloading. When the in-table moves to a predetermined position (load position) where the wafer is delivered to the polishing head, the polishing head descends to attract and hold the wafer, carry the wafer onto the platen, and polish the wafer.

Further, Patent Document 2 discloses a CMP apparatus capable of partially changing the polishing pressure of a wafer. In the polishing head of this CMP device, air is introduced into an air chamber formed between the carrier and the backing film, and air is independently introduced into a plurality of airbags arranged on the lower surface of the carrier. NS. The amount of expansion of the airbag according to the pressure of the air supplied to the airbag locally adjusts the pressing force of the backing film to press the wafer, depending on the placement of the airbag on the backing film that presses the wafer. A pressure distribution can be formed.

In such a polishing head, the wafer is formed by filling the space between the backing film and the wafer with DIW (deionized water) introduced from the suction holes formed in the backing film and sucking the wafer together with the deionized water. It is adsorbed on the backing film.

Japanese Patent No. 3510177 Japanese Patent No. 3683149

However, when the wafer is to be adsorbed on the backing film on which the adsorption holes are not formed as described above, there is a possibility that the adsorbed surface of the wafer may not partially adhere to the backing film. That is, when the wafer is brought close to the backing film, it starts to come into contact with the backing film from the outer periphery of the wafer, the central portion of the wafer does not adhere to the backing film, and there is a problem that the adsorption force of the wafer is lowered.

Therefore, in CMP polishing, a technical problem to be solved in order to firmly adsorb and hold the entire surface of the wafer arises, and an object of the present invention is to solve this problem.

The present invention has been proposed to achieve the above object, and the invention according to claim 1 is held by a wafer suction device that adheres a wafer to a suction member and sucks the wafer, and the suction member. A CMP device including a polishing head for polishing the wafer, the crown forming means for pressing the suction member to elastically deform the pressing position in a convex shape, and the wafer being brought close to the suction member. Further, the present invention provides a CMP apparatus including a wafer transfer means for bringing a part of the wafer ahead of the other part and bringing it into close contact with the suction member.

According to this configuration, the wafer transport means brings the wafer close to the suction member that has been elastically deformed in a convex shape, and causes the portion of the wafer closest to the suction member to precede the other portion and bring it into close contact with the suction member. Since the entire surface of the wafer is in close contact with the suction member, the wafer can be firmly sucked.

In the invention according to claim 2, in addition to the configuration of the invention according to claim 1, the crown forming means presses the substantially center of the suction member downward, and the wafer transport means omits the wafer. Provided is a CMP device that adheres to the suction member in the order from the center to the outer periphery.

According to this configuration, since the wafer adheres to the suction member in the order from substantially the center to the outer periphery, the entire surface of the wafer is uniformly adhered to the suction member, so that the wafer can be stably sucked.

The invention according to claim 3 is a CMP method in which a wafer is brought into close contact with a suction member to suck the wafer, and the wafer held by the suction member is polished by a polishing head, which is provided in the polishing head. A crown forming step in which the crown forming means presses the suction member to elastically deform the pressing position in a convex shape, and the wafer is brought close to the suction member so that a part of the wafer precedes another part. The present invention provides a CMP method including a wafer transfer step of bringing the wafer into close contact with the suction member.

According to this configuration, the wafer is brought close to the suction member that has been elastically deformed in a convex shape, and the portion closest to the suction member of the wafer is brought into close contact with the suction member in front of the other parts, so that the entire surface of the wafer is brought into contact with the suction member. The wafer can be firmly adsorbed because it is in close contact with the wafer.

In the present invention, the portion of the wafer closest to the suction member is brought into close contact with the suction member in advance of the other portion, so that the entire surface of the wafer is brought into close contact with the suction member, so that the wafer can be firmly sucked.

The perspective view which shows typically the wafer polishing apparatus which applied the wafer adsorption apparatus which concerns on one Embodiment of this invention. The vertical sectional view schematically showing the main part of a polishing head. The plan view which shows the polished part. The side view which shows the polished part. The schematic diagram which shows the structure of 2 fluid nozzles. The figure which shows the flow rate distribution in the spray area of 2 fluid nozzles, and the shape of a spray area. A vertical cross section showing the structure of a conventional backing film and a vertical cross section showing the structure of the suction member used in the present invention. The schematic diagram which shows the state in which the adsorption member and the wafer are brought into close contact with each other with the adhesion liquid intervening. The schematic diagram which shows the state in which the adsorption member and a wafer are brought into close contact with each other with a large amount of adhesion liquid intervening. The schematic diagram which shows the state that the adsorption member and the wafer were brought into close contact with each other without the intervention of a close contact liquid. The graph which shows the polishing rate of a wafer polishing apparatus. The schematic diagram which shows the state of passing a wafer between a polishing head and a wafer mounting table. The side view which shows the state of cleaning the suction surface of a suction member. The side view which shows the state of drying the suction surface of a suction member. The plan view which shows the arrangement relation of a polishing part and a cleaning unit.

In the present invention, in order to achieve the purpose of firmly adsorbing and holding the entire surface of the wafer to be adsorbed in CMP polishing, the wafer adsorbing device for adhering the wafer to the adsorbing member to adsorb the wafer and the wafer adsorbing member hold the wafer. A CMP device equipped with a polishing head for polishing a wafer, the crown forming means for pressing the suction member to elastically deform the pressing position in a convex shape, and the wafer being brought close to the suction member to form a wafer. This was achieved by providing a wafer transfer means in which a part of the wafer is brought into close contact with the suction member in front of the other part.

Further, in the present invention, in order to achieve the purpose of firmly adsorbing and holding the entire surface of the wafer to be adsorbed in CMP polishing, the wafer is adhered to the adsorbing member to adsorb the wafer, and the wafer held by the adsorbing member is obtained. In the CMP method of polishing with a polishing head, a crown forming step in which a crown forming means provided on the polishing head presses a suction member to elastically deform the pressing position in a convex shape, and a wafer is brought closer to the suction member. This was realized by including a wafer transfer step in which a part of the wafer is brought into close contact with the suction member in advance of the other part.

Hereinafter, the wafer polishing apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following examples, when the number, numerical value, quantity, range, etc. of the components are referred to, the specific number is used unless it is explicitly stated or the principle is clearly limited to a specific number. It is not limited, and may be more than or less than a specific number.

In addition, when referring to the shape and positional relationship of components, etc., unless otherwise specified or when it is considered that it is not clearly the case in principle, those that are substantially similar to or similar to the shape, etc. are used. include.

In addition, the drawings may be exaggerated by enlarging the characteristic parts in order to make the features easy to understand, and the dimensional ratios and the like of the components are not always the same as the actual ones. Further, in the cross-sectional view, hatching of some components may be omitted in order to make the cross-sectional structure of the components easy to understand.

Further, in the following description, the expressions indicating the directions such as up and down and left and right are not absolute, and are appropriate when each part of the transport holding device of the present invention is drawn, but the posture is appropriate. When is changed, it should be changed and interpreted according to the change in posture.

FIG. 1 is a plan view schematically showing a wafer polishing apparatus 1 according to an embodiment of the present invention. The wafer polishing apparatus 1 is a CMP apparatus and polishes the wafer W flatly. The wafer polishing apparatus 1 includes an index unit 2, a load / unload unit 3, a polishing unit 4, and a cleaning unit 5.

A plurality of cassettes 21 accommodating the wafer W are loaded in the index unit 2, and a robot 22 for transferring the wafer W to the load / unload unit 3 is provided. Further, the robot 22 also receives the cleaned wafer W from the cleaning unit 5 for cleaning the polished wafer W and returns it to the cassette 21.

The load / unload unit 3 includes two upper and lower transfer robots 31 and 32. The transfer robot 31 arranged in the upper stage is for loading the wafer W before polishing. The transfer robot 31 receives the wafer W from the index unit 2, and after centering, transfers the wafer W to the polishing unit 4. The transfer robot 32 arranged in the lower stage is for unloading to transfer the polished wafer W. The transfer robot 32 receives the polished wafer W from the polishing unit 4 and transfers it to the cleaning unit 5.

The polishing unit 4 includes three platens 41, two polishing heads 6, and two waiting units 7.

The platen 41 is formed in a disk shape and is connected to a rotation shaft (not shown) arranged below the platen 41. The platen 41 rotates as the rotation axis rotates. A polishing pad is attached to the upper surface of the platen 41, and a CMP slurry which is a mixture of an abrasive and a chemical is supplied from a nozzle (not shown) on the polishing pad.

The polishing head 6 is configured to be able to move between the platens 41 along the left-right direction of the paper surface of FIG. Further, the polishing head 6 is configured to be vertically movable. The polishing head 6 is formed in a disk shape having a smaller diameter than the platen 41. The polishing head 6 descends when polishing the wafer W and presses the wafer W against the polishing pad.

The waiting units 7 are arranged between the platens 41. The waiting unit 7 includes two upper and lower wafer mounts. The in-table 71 arranged on the upper stage side is for loading the wafer W before polishing. The in-table 71 receives the wafer W before polishing from the transfer robot 31, and delivers the wafer W to the polishing pad 6. The out table 72 arranged on the lower side is for unloading to convey the polished wafer W. The outtable 72 receives the polished wafer W from the polishing head 6 and delivers the wafer W to the transfer robot 32.

The operation of the wafer polishing apparatus 1 is controlled by a control means (not shown). The control means controls each of the components constituting the wafer polishing apparatus 1. The control means is, for example, a computer, and is composed of a CPU, a memory, and the like. The function of the control means may be realized by controlling using software, or may be realized by operating using hardware.

Next, the polishing unit 4 will be described in detail. FIG. 2 is a vertical sectional view schematically showing the polishing head 6.

The polishing head 6 is connected to a rotation shaft 6a arranged above the polishing head 6. The polishing head 6 rotates when the rotation shaft 6a is rotated by driving a motor (not shown). The polishing head 6 includes a head body 61, a carrier 62, a retainer ring 63, and a suction member 64.

The head body 61 is connected to the rotation shaft 6a and rotates together with the rotation shaft 6a. The head main body 61 is connected to a carrier 62 arranged below the head main body 61 via a rotating portion 61a, and the head main body 61 and the carrier 62 rotate in conjunction with each other.

The carrier 62 is provided with airlines 62a arranged at equal intervals on the peripheral edge of the carrier 62. The lower end of the airline 62a is open to the air chamber A formed between the lower surface 62b of the carrier 62 and the suction member 64. The airline 62a is connected to an air supply source as an air supply means (not shown), and air is introduced into the air chamber A via the airline 62a. The pressure of the air supplied to the airline 62a is adjusted by a regulator (not shown).

A carrier pressing means 62c is provided between the head body 61 and the carrier 62. The carrier pressing means 62c is an airbag or the like that is inflated by air supplied from an air supply source (not shown). The pressure of the air supplied from the air source is adjusted by a regulator (not shown). The carrier pressing means 62c presses the wafer W against the platen 41 via the carrier 62 according to the pressure of the supplied air.

An airbag 62d, which will be described later, is provided coaxially on the lower surface 62b of the carrier 62. The airbag 62d is formed in an annular shape having a different diameter. The airbag 62d is fixed to the lower surface 62b of the carrier 62, and is detachably attached to the carrier 62 with a two-component epoxy resin adhesive or the like. The airbag 62d is arranged coaxially with the rotation axis of the polishing head 10 and partitions the air chamber A.

The retainer ring 63 is arranged so as to surround the carrier 62. The retainer ring 63 is fixed to the retainer ring holder 63a with a bolt (not shown). The outer circumference of the suction member 64 is adhered to the inner circumference of the retainer ring holder 63a. The retainer ring holder 63a is attached to the retainer pressing member 63c via the snap ring 63b. A retainer pressing means 63d is provided between the head body 61 and the retainer pressing member 63c. Reference numeral 63e is a cover that covers the upper part of the snap ring 63b.

The retainer pressing means 63c is an airbag or the like that is inflated by air supplied from an air supply source (not shown). The pressure of the air supplied from the air source is adjusted by a regulator (not shown). The retainer pressing means 63c presses the retainer ring 63 against the platen 41 via the retainer pressing member 63c according to the pressure of the supplied air.

The suction member 64 is arranged so as to face the lower surface 62b of the carrier 62. The adsorption member 64 adsorbs and holds the wafer W via the adsorbed water. The details of the suction member 64 will be described later.

FIG. 3 is a plan view of the waiting unit 7. The in-table 71 and the out-table 72 are connected to a rodless cylinder (not shown) via a connecting member 7a. When the rodless cylinder is driven, the in-table 71 and the out-table 72 can move in the vertical direction on the paper surface of FIG.

FIG. 4 is a side view of the waiting unit 7. The polishing head 6 is slidable above the in-table 71 and the out-table 72, receives the wafer W from the in-table 71, and delivers the wafer W to the out-table 72.

Further, the waiting unit 7 includes a two-fluid nozzle 8 and a cleaning unit 9. As shown in FIG. 4, the two-fluid nozzle 8 sprays two fluids containing pure water and compressed air on the suction surface 64a of the suction member 64. The two-fluid nozzle 8 sprays the two fluids so that the spray region of the two fluids overlaps at least a part of the suction member 64 when viewed from below the suction member 64. In this embodiment, the right side of the spray region of the two fluids is detached from the suction member 64. Further, since the spraying region of the two fluids is set to include the center of the suction member 64, the two fluids can be sprayed on the entire suction member 64 by rotating the polishing head 10.

FIG. 5A is a schematic diagram showing the configuration of the two-fluid nozzle 8. FIG. 5B is a schematic view showing a modified example of the two-fluid nozzle 8. 6 (a) and 6 (b) are diagrams showing the flow rate distribution in the spray region of the two-fluid nozzle 8 and the shape of the spray region.

As shown in FIG. 5A, the two-fluid nozzle 8 comprises two fluids formed by mixing 0.4 Mpa clean air (CDA) pressure-adjusted by a regulator 81 and 0.15 Mpa deionized water (DIW). Spray. Further, as shown in FIG. 5B, the spray amount of the two fluids can be adjusted by flowing a part of the deionized water through the drain to lower the water pressure. Reference numeral 82 in FIG. 5B is a needle valve. In this embodiment, the spray amount of the former is 83 mg / sec, while the spray amount of the latter can be reduced to 40 mg / sec.

As shown in FIG. 4, the two-fluid nozzle 8 is arranged below the polishing head 6 and is arranged so as to spray the two fluids diagonally to the suction member 64. In this embodiment, the two-fluid nozzle 8 is tilted at 35 °, and the distance from the two-fluid nozzle 8 to the suction member 64 is set to 315 mm. When the two-fluid nozzle 8 sprays the two fluids perpendicularly to the suction member 64, the two-fluid spray region is formed in a circular shape as shown in FIG. 6A, and the flow rate distribution in the spray region is formed. Peaks in the center. On the other hand, when the two-fluid nozzle 8 sprays the two fluids diagonally to the suction member 64, the spray region of the two fluids is formed in an elliptical shape as shown in FIG. 6 (b), and the spray region is formed in the spray region. The flow distribution becomes gentle.

That is, by adjusting the water pressure of the deionized water supplied to the two-fluid nozzle 81 and the spray angle of the two-fluid nozzle 81 with respect to the adsorption member 64, the size and the spray amount of the two-fluid spray region can be increased or decreased.

FIG. 6A is a vertical cross section showing the structure of a conventional backing film. FIG. 6B is a vertical sectional view showing the structure of the suction member 64.

The suction member 64 is a nap film having a skin layer 64b, and is, for example, a backing film (model number: BPX222) manufactured by Fujibo Ehime Co., Ltd. or the like. In the conventional backing film 100, as shown in FIG. 6A, the skin layer is scraped off and the bore 101 is exposed. As a result, the contact area between the backing film 100 and the wafer W was small, and it was difficult for the wafer W to be adsorbed on the backing film 100. On the other hand, as shown in FIG. 6B, the suction member 64 comes into contact with the wafer W on the entire surface of the skin layer 64b.

Next, a state in which the wafer W is adsorbed to the adsorption member 64 through the contact water supplied by the two-fluid nozzle 8 will be described. FIG. 7A is a schematic view showing a state in which an appropriate amount of the adhesive liquid is applied to the adsorption surface 64a of the adsorption member 64. FIG. 7B is a schematic view showing a state in which the suction member 64 and the wafer W are brought into close contact with each other in the state of FIG. 7A. FIG. 8A is a schematic view showing a state in which the excess adhesive liquid is applied to the surface of the adsorption member 64. FIG. 8B is a schematic view showing a state in which the suction member 64 and the wafer W are brought into close contact with each other in the state of FIG. 8A. FIG. 9A is a schematic view showing a state in which the adhesive liquid is not applied to the surface of the adsorption member 64. FIG. 9B is a schematic view showing a state in which the suction member 64 and the wafer W are brought into close contact with each other in the state of FIG. 9A.

First, as shown in FIG. 7A, the adsorbed water is sprinkled on the adsorption surface 64a of the adsorption member 64. Since the adsorption surface 64a has undulations, the adsorbed water is localized in the recesses of the undulations of the adsorption member 64 even when the adsorbed water is sprinkled on the entire surface of the adsorption surface 64a. That is, a region in which the adsorbed water exists and a region in which the adsorbed water does not exist uniformly exist over the entire surface of the adsorption surface 64a. Further, the adsorbed water is sprinkled with the adsorbed surface 64a facing downward, so that the excess adsorbed water drips down. Further, if the adsorbed member 64 is a water-repellent resin sheet, the adsorbed water stays in the shape of polka dots having a small surface area and a slow evaporation rate, so that a stable water content can be maintained.

Next, as shown in FIG. 7B, when the suction surface 64a of the suction member 64 and the surface to be adsorbed Wa of the wafer W are brought close to each other, the adsorbed water is a gap between the suction surface 64a and the surface to be adsorbed Wa. Spread to. That is, when the wafer W is brought close to the adsorption member 64 in a state where the region where the adsorbed water exists and the region where the adsorbed water does not exist are mixed between the adsorption surface 64a and the surface to be adsorbed Wa, the adsorbed water is adsorbed. It diffuses thinly between the surface 64a and the surface to be adsorbed Wa. Then, due to the surface tension of the adsorbed water, air is pushed out between the adsorbed surface 64a and the adsorbed surface Wa to become a negative pressure, and the adsorbed member 64, which is sufficiently softer than the wafer W, becomes uneven on the adsorbed surface Wa. By elastically deforming so as to follow, the contact area between the suction surface 64a and the surface to be adsorbed Wa increases, and the wafer W is firmly adsorbed to the adsorption member 64 without any gap.

As shown in FIG. 8 (a), when excess adsorbed water is present on the adsorption surface 64a of the adsorption member 64, the undulation of the adsorption surface 64a and the unevenness of the surface to be adsorbed Wa are as shown in FIG. 8 (b). Since a layer of adsorbed water that is sufficiently thicker than that of the above is formed, the adsorption surface 64a and the surface to be adsorbed Wa do not come into direct contact with each other. Is not adsorbed on the adsorption member 64.

Further, as shown in FIG. 9A, if the adsorbed water does not exist on the adsorption surface 64a of the adsorption member 64, as shown in FIG. 9B, even if the wafer W and the adsorption member 64 are brought close to each other, the adsorption member 64 may be brought close to each other. The surface tension of the adsorbed water that brings the wafer W and the adsorption member 64 close to each other does not act, the adsorption member 64 does not elastically deform so as to follow the unevenness of the surface Wa to be adsorbed, and the wafer W adheres to the adsorption member 64 without gaps. Not done.

The amount of adsorbed water is preferably less than 30 mg, more preferably 5 to 10 mg in the case of a 4 inch wafer W, for example.

In this embodiment, the case where the adsorbed water is sprinkled on the adsorbed surface 64a of the adsorbing member 64 has been described as an example, but the same applies even if the adsorbed water is sprinkled on the adsorbed surface Wa of the wafer.

Next, each polishing rate of the wafer polishing apparatus 1 to which the wafer adsorption apparatus 60 is applied and the conventional wafer polishing apparatus is shown in FIG. FIG. 8 is a graph showing the polishing rate when the brittle wafer is CMP polished. Here, a suede pad was used as the polishing pad, and a silica slurry was used as the polishing agent, and CMP polishing was performed on a 4-inch lithium tantalate substrate (thickness: 200 μm).

In a conventional wafer polishing device, when CMP polishing is performed under the polishing conditions of a polishing pressure of 3 psi, a platen rotation speed of 60 rpm, a carrier rotation speed of 63 rpm, and a slurry flow rate of 100 cc / min, the polishing rate is limited to 0.26 μm / min. If it is made larger than this, the wafer W in contact with the retainer ring holder cannot withstand the load in the slurry direction and cracks.

On the other hand, in the wafer polishing apparatus 1, when the polishing conditions were set to a platen rotation speed of 117 rpm, a carrier rotation speed of 120 rpm, and a slurry flow rate of 100 cc / min, and CMP polishing was performed by changing the pressure, the wafer W was attracted to the suction member 64. Therefore, the polishing pressure can be set to a high pressure of 3 psi or more, and the polishing rate can be increased. In this example, a polishing rate of 1.5 μm / min could be obtained at a polishing pressure of 16 psi. In this way, by interposing an appropriate amount of adsorbed water between the adsorption surface 64a of the adsorption member 64 and the adsorbed surface Wa of the wafer W, the adsorption member 64 and the wafer W are firmly adhered to each other, and even a brittle wafer can be used. CMP polishing can be performed at high pressure and high speed.

Next, a procedure for loading the wafer W on the polishing head 6 will be described. 12 (a) to 12 (c) are schematic views showing how the wafer W is handed over from the in-table 71 to the polishing head 6.

First, as shown in FIG. 12A, the in-table 71 on which the wafer W is mounted moves below the polishing head 6. The wafer W is placed on the elevating table 73. The elevating table 73 is provided in the substantially center of the in-table 71 so as to be able to elevate and elevate. The suction surface 64a of the suction member 64 is previously coated with contact water by the two-fluid nozzle 8.

Next, as shown in FIG. 12B, when the airbag 62d is inflated with a weak pressure of 0.3 to 0.5 psi, the airbag 62d presses the vicinity of the center of the suction member 64 downward. As a result, the suction member 64 is elastically deformed into a downwardly convex crown shape that is gently inclined from the center toward the outer circumference.

The in-table 71 brings the wafer W close to the suction member 64 elastically deformed in a crown shape, and first brings the wafer W into close contact with the suction member 64 near the center of the surface Wa to be sucked. After that, as shown in FIG. 12 (c), the elevating table 73 further raises the wafer W, so that the entire surface of the surface to be adsorbed Wa is brought into close contact with the adsorption surface 64a. The pressing position at which the airbag 62d elastically deforms the suction member 64 is preferably substantially in the center of the suction member 64, but is not limited to this.

Since the elevating table 73 is formed to be smaller in diameter by about 20 mm than the wafer W, the suction force of the peripheral edge of the wafer W (10 mm inward from the outer circumference) is weaker than that of the center of the wafer W. As a result, as shown in FIG. 12 (d), when the wafer W is handed over from the polishing head 6 to the elevating table 74 of the out table 72, when the airbag 62d expands, it is held by a relatively weak adsorption force. The wafer W is peeled off from the suction member 64 starting from the portion.

Further, by supplying deionized water or the like to the peripheral edge of the wafer W peeled off from the adsorption member 64, the wafer W can be smoothly peeled off from the suction member 64 by the water flow. As a configuration for supplying deionized water to the peripheral edge of the wafer W in this way, for example, a plurality of water channels toward the adsorption member 64 are provided at equal intervals on the outtable 72, and deionized water of a predetermined pressure is discharged from the water channels. Etc. are conceivable.

Next, the operation of the cleaning unit 9 will be described. FIG. 13 is a side view showing how the suction surface 64a of the suction member 64 is cleaned. FIG. 14 is a side view showing how the suction surface 64a of the suction member 64 is dried. FIG. 15 is a plan view showing the arrangement relationship between the polishing unit 4 and the cleaning unit 9.

The cleaning unit 9 is formed in a disk shape, and a plurality of brushes 91 are erected on the upper surface thereof. The brush 91 is made of a hydrophilic resin such as polyvinyl alcohol (PVA). When cleaning the polishing head 6, the polishing head 6 is lowered until the suction member 64 comes into contact with the brush 91, and the brush 91 is attached to the suction member 64 at a predetermined rotation speed (for example, 20 rpm) for several to several tens of seconds. By sliding the suction surface 64a in contact with the suction surface 64a, the polishing agent residue can be removed without damaging the suction surface 64a.

Further, the cleaning unit 9 includes a cleaning water supply nozzle 92 and a drying nozzle 93. The cleaning water supply nozzle 92 supplies cleaning water such as deionized water to the interface between the brush 91 and the adsorption surface 64a when cleaning the polishing head 6. The drying nozzle 93 dries the lower end of the polishing head 6. Specifically, the polishing head 6 washed with the washing water rises away from the brush 91 and then rotates at a high speed to remove the washing water by centrifugal force. The drying nozzle 93 blows off the remaining cleaning water by discharging clean air toward the lower end of the polishing head 6 that rotates at high speed.

In this way, in the wafer suction device 60 according to the present embodiment, the wafer W is brought close to the suction member 64 whose elevating table 73 is elastically deformed in a convex shape, and the substantially center of the wafer W closest to the suction member 64 is formed. By bringing the wafer W into close contact with the suction member 64 in advance of the other portion, the entire surface of the wafer W is uniformly adhered to the suction member 64, so that the wafer W can be stably sucked.

Further, the present invention can be modified in various ways other than the above as long as it does not deviate from the spirit of the present invention, and it is natural that the present invention extends to the modified ones.

1 ・ ・ ・ Wafer polishing device 2 ・ ・ ・ Index part 3 ・ ・ ・ Load / unload part 4 ・ ・ ・ Polishing part 41 ・ ・ ・ Platen 5 ・ ・ ・ Cleaning part 6 ・ ・ ・ Polishing head 62d ・ ・ ・ Air Bag (retainer ring holder)
63a ・ ・ ・ Retaining holder 64 ・ ・ ・ Suction member 64a ・ ・ ・ Suction surface 7 ・ ・ ・ Waiting unit (wafer transfer means)
71 ・ ・ ・ In table 72 ・ ・ ・ Out table 8 ・ ・ ・ 2 Fluid nozzle 9 ・ ・ ・ Cleaning unit 91 ・ ・ ・ Brush 92 ・ ・ ・ Cleaning water nozzle 93 ・ ・ ・ Drying nozzle A ・ ・ ・ Air chamber V・ ・ ・ Vertical direction W ・ ・ ・ Wafer Wa ・ ・ ・ Surface to be attracted

Claims (3)

A CMP device including a wafer suction device that adheres a wafer to a suction member to suck the wafer, and a polishing head that polishes the wafer held by the suction member.
A crown forming means that elastically deforms the pressing position in a convex shape by pressing the suction member.
A wafer transfer means that brings the wafer closer to the suction member so that a part of the wafer precedes the other portion and is brought into close contact with the suction member.
A CMP device characterized by being equipped with. The crown forming means presses the substantially center of the suction member downward.
The CMP apparatus according to claim 1, wherein the wafer transport means adheres the wafer to the suction member in the order from substantially the center to the outer periphery. A CMP method in which a wafer is brought into close contact with a suction member, the wafer is sucked, and the wafer held by the suction member is polished by a polishing head.
A crown forming step in which the crown forming means provided on the polishing head elastically deforms the pressing position in a convex shape by pressing the suction member.
A wafer transfer step in which the wafer is brought close to the suction member so that a part of the wafer is brought into close contact with the suction member by leading a part of the wafer to another part.
A CMP method comprising.

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