JP2001345298A - Polishing apparatus and method - Google Patents

Abstract

[PROBLEMS] To perform a polishing operation on an outer peripheral portion of an object to be polished such as a substrate on which a film is formed by a series of operations accompanying the original polishing operation, and to efficiently polish the outer peripheral portion. A polishing apparatus is provided. A turntable having a polished surface is provided.
In a polishing apparatus having a top ring 28 for vertically and horizontally movable and holding a polishing object W and pressing a surface to be polished of the polishing object toward the turntable 26, An outer peripheral portion polishing mechanism for polishing the outer peripheral portion of the object to be polished is arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus, and more particularly to a polishing function for polishing a surface of a polishing object such as a semiconductor wafer having a film formed on a surface to a flat and mirror surface, and also to an outer periphery of the polishing object. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus and a polishing method having an outer peripheral portion polishing function for shaving off and removing an unnecessary metal film, particularly, copper (Cu) or the like formed or adhered to a portion.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable movement to use copper (Cu) having a low electric resistivity and a high electromigration resistance instead of aluminum or an aluminum alloy as a metal material for forming a wiring circuit on a semiconductor substrate. Has become. This type of copper wiring is generally formed by embedding copper in a fine recess provided on the surface of a substrate. As a method of forming the copper wiring, there are methods such as CVD, sputtering and plating. In any case, copper is formed on almost the entire surface of the substrate, and unnecessary copper is removed by chemical mechanical polishing (CMP). I am trying to do it.

FIG. 8 shows an example of manufacturing this type of copper wiring board W in the order of steps. As shown in FIG. 8 (a), a copper wiring board W is formed on a conductive layer 1a on a semiconductor substrate 1 on which semiconductor elements are formed. Si
An oxide film 2 made of O ₂ is deposited, a contact hole 3 and a trench 4 for wiring are formed by lithography / etching technology, and a barrier layer 5 made of TiN or the like is formed thereon, and further as a power supply layer for electrolytic plating. The seed layer 7 is formed.

[0004] Then, as shown in FIG.
By applying copper plating to the surface of the semiconductor substrate 1, copper is filled in the contact holes 3 and the trenches 4 of the semiconductor substrate 1, and a copper layer 6 is deposited on the oxide film 2. Thereafter, the copper layer 6 on the oxide film 2 is removed by chemical mechanical polishing (CMP), and the surface of the copper layer 6 and the surface of the oxide film 2 filled in the contact hole 3 and the trench 4 for wiring are removed. Are substantially coplanar. As a result, a wiring composed of the copper layer 6 is formed as shown in FIG.

Here, since the barrier layer 5 is formed so as to cover almost the entire surface of the oxide film 2 and the seed layer 7 is formed so as to cover almost the entire surface of the barrier layer 5, as shown in FIG. A copper sputtered film serving as the seed layer 7 may be present on the outer peripheral portion) or copper (not shown) may be formed on the inner edge (peripheral portion) of the bevel of the substrate and remain without being polished.

Copper, for example, easily diffuses into an oxide film in a semiconductor manufacturing process such as annealing, thereby deteriorating its insulating property, or impairing its adhesiveness to a film to be formed next, and causing peeling from the film. Therefore, it is required that the film be completely removed from the substrate at least before film formation.
Moreover, the outer peripheral portion of the substrate other than the circuit forming portion (here, the outer peripheral portion refers to a region where the edge and the bevel of the wafer are combined, or any portion of the edge / bevel. Edge:
Copper deposited or adhered on the front and back surfaces of the wafer about 5 mm from the outer peripheral edge of the substrate and on the bevel: the side surface of the wafer and the wafer cross section within 0.5 mm from the outer peripheral edge) are unnecessary. Not only the subsequent transfer of the board,
Since it may cause cross-contamination in processes such as storage and processing, it must be completely removed immediately after the copper film forming process and the CMP process.

However, conventionally, for example, an edge polishing apparatus for bare silicon or the like has been generally known, but there has been no polishing apparatus dedicated to an outer peripheral portion of an object to be polished such as a substrate having a film formed on its surface. .

[0008]

Further, for example, when it is attempted to polish the outer peripheral portion of an object to be polished such as a substrate with a bare silicon edge polishing apparatus, this operation is called a polishing operation for the substrate surface. In addition to the fact that it is necessary to perform the work separately in different places, this work is not only troublesome, but also this kind of edge polishing device generally makes the outer peripheral portion of the work come into point contact with the polishing surface at one point along its circumferential direction. Since the polishing is performed while the polishing is performed, the processing speed in the outer peripheral portion polishing is generally slow, and there is a problem that the outer peripheral portion polishing takes time.

The present invention has been made in view of the above, and a polishing operation of an outer peripheral portion of an object to be polished such as a substrate on which a film (particularly a metal film) is formed is a series of operations associated with an original polishing operation of a substrate surface. It is an object of the present invention to provide a polishing apparatus capable of quickly performing the above operation and efficiently polishing the outer peripheral portion. Here, as described above, the substrate surface refers to the surface of the object to be polished, such as a semiconductor wafer, on which the film or wiring is formed.

[0010]

According to a first aspect of the present invention, there is provided a turntable having a polished surface, and a surface to be polished of the object to be polished is held by holding the object to be polished up and down and horizontally movable. A polishing apparatus, comprising: a top ring that presses against a turntable; and an outer peripheral polishing mechanism for polishing an outer peripheral portion of an object to be polished is disposed on a side of the turntable.

Thus, the polishing of the outer peripheral portion of the object to be polished by the outer peripheral portion polishing mechanism arranged on the side of the turntable is performed before and after the original polishing of the polished surface of the object to be polished by the turntable. Work can be done quickly.

[0012] In the invention according to a second aspect, the outer peripheral portion polishing mechanism is disposed at a movable position of the top ring,
2. The polishing apparatus according to claim 1, further comprising an outer peripheral polishing portion provided on an upper surface thereof with an outer peripheral polishing surface that abuts against an outer peripheral portion of the polishing target held by the top ring and performs polishing.

[0013] Thus, after the object to be polished is held by the top ring and pressed against the turntable to perform the original polishing, the object to be polished is pressed against the outer peripheral polishing surface while being held by the top ring to polish the outer peripheral portion. After that, it can be conveyed to the next step. In addition, the polishing target is rotated relative to the polishing portion while the outer peripheral portion of the polishing target is brought into surface contact with the outer peripheral polishing surface over the entire length along the circumferential direction to polish the outer peripheral portion. By doing so, the outer peripheral portion can be efficiently polished with a low surface pressure.

According to a third aspect of the present invention, there is provided a polishing apparatus according to the second aspect, wherein the outer peripheral portion polishing surface is inclined in a direction gradually rising outward with respect to a horizontal plane. Device. Thereby, the inclination angle is arbitrarily set, for example, by the hardness of the material constituting the outer peripheral polishing surface, the outer peripheral shape of the object to be polished, the outer peripheral cut width, the load applied at the time of polishing, etc. During polishing, the lower half of the outer peripheral portion of the polishing target can be reliably brought into contact with the outer peripheral portion polishing surface, or the outer peripheral portion can be polished with an arbitrary cut width.

According to a fourth aspect of the present invention, the outer peripheral portion polishing portion is configured to be rotatable, and the outer peripheral portion polishing portion is formed at a rotation center portion of the outer peripheral portion polishing portion by a centrifugal force caused by the rotation of the outer peripheral portion polishing portion. 4. The polishing apparatus according to claim 2, wherein a polishing liquid supply port for supplying a polishing liquid is provided on the surface. Thereby, the polishing liquid can be supplied to the outer peripheral polishing surface from below the polishing object.

According to a fifth aspect of the present invention, there is provided a polishing method for polishing a surface to be polished by pressing the surface to be polished against the surface to be polished of a turntable with a predetermined force. A polishing method characterized by passing through an outer peripheral portion polishing step of polishing an outer peripheral portion of a polishing object before or after polishing of a polished surface.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a layout diagram showing the overall configuration of a polishing apparatus according to an embodiment of the present invention. In this apparatus, a pair of polishing units 10a and 10b are opposed to one side of a space on a floor having a rectangular shape as a whole. A cassette 12a for accommodating a copper wiring substrate (object to be polished) W on the other end side of which, for example, a circuit is formed in a region excluding the outer peripheral portion of the surface and copper is formed on almost the entire surface thereof;
A pair of loading / unloading units on which 12b is placed is arranged. The transfer robots 14a and 14a are placed on a line connecting the polishing unit and the load / unload unit.
b are arranged to form a transport line. One reversing machine 16 and 18 and two cleaning machines 20a, 20b, 22a and 22 on both sides of the conveying line, respectively.
b is arranged.

In the two polishing units 10a and 10b, devices having basically the same specifications are symmetrically arranged on a transport line, and each of the two polishing units 10a and 10b has a turntable in which a polishing cloth 24 having an upper surface as a polishing surface is adhered to the upper surface. The table 26 includes a table 26, a top ring 28 that holds the substrate W by vacuum suction and presses the substrate W against the polishing cloth 24 of the turntable 26, and a dresser 30 that sharpens the polishing cloth 24. This top ring 28
The dresser 30 is suspended from the free end side of a swing arm 32 and the dresser 30 is suspended from the free end side of another swing arm 34, and can be turned in a horizontal plane.

Further, the substrate W is provided on each transport line side.
Is provided between the pusher 36 and the top ring 28. The outer peripheral polishing portion 38 forms an outer peripheral polishing mechanism with the top ring 28 on the opposite side of the pusher 36 across the turntable 26. Is arranged.

FIG. 2 shows the polishing unit 10a or 10b.
It is sectional drawing which shows the detail of. As shown in FIG. 2, the turntable 26 is connected to a motor (not shown), and is rotatable around its axis 26a as shown by an arrow A.

The top ring 28 is connected to a motor and a lifting / lowering cylinder (not shown), and can move up and down as shown by arrows B and C and can rotate around its axis. On the other hand, it can be pressed with any pressure. Further, the substrate W is attracted to the lower end surface of the top ring 28 by vacuum or the like. Note that a guide ring (retainer ring) 40 for preventing the substrate W from coming off is provided on a lower outer peripheral portion of the top ring 28.

A polishing liquid supply nozzle 42 is provided above the turntable 26, and the polishing cloth 24 adhered to the turntable 26 by the polishing liquid supply nozzle 42.
A polishing liquid is supplied on the top. Around the turntable 26, a frame 4 for collecting polishing liquid and water is provided.
4 are provided, and a gutter 44 a is formed at a lower portion of the frame body 44.

The dresser 30 is located on the side of the polishing pad 24 opposite to the position of the top ring 28, and is configured to be able to dress the polishing pad 24. Dressing liquid used for dressing,
For example, water is supplied from a water supply nozzle 46 extending on the turntable 26. Dresser 30
Is connected to a lifting cylinder and a rotation motor, and can be raised and lowered as shown by arrows D and E, and can rotate around its axis.

The dresser 30 has a disk shape having substantially the same diameter as the top ring 28, and a dressing tool 48
Holding. A hole (not shown) is formed on the lower surface of the dresser 30, that is, a holding surface for holding the dressing tool 48, and this hole communicates with a vacuum source, and
8 is held by suction. The polishing liquid supply nozzle 42 and the water supply nozzle 46 extend to near the rotation center on the upper surface of the turntable 26, and supply the polishing liquid and water to predetermined positions on the polishing pad 24, respectively.

Although this example shows an example in which the polishing surface is constituted by a polishing cloth, the polishing surface may be formed by a surface of a fixed abrasive pad or a grindstone impregnated or fixed with abrasive grains. .

FIG. 3 is an enlarged sectional view showing the top ring 28 and the outer peripheral portion polishing portion 38 in detail. As shown in FIG. 3, the top ring 28 includes a top ring main body 50 and a holding plate 52 having a number of small holes communicating vertically, and a chamber 54 is provided between the top ring main body 50 and the holding plate 52. Is formed. An elastic mat 56 is attached to the lower surface of the holding plate 52. Thus, by evacuating the chamber 54, the substrate W is sucked and held on the lower surface of the holding plate 52 with the elastic mat 56 interposed therebetween. The substrate W is held such that the circuit formation surface on which the film is formed faces downward.

The retainer ring (guide ring) 40
It is located on the outer peripheral surface of the holding plate 52, and when it is lowered (the state shown by the solid line in the drawing), it protrudes downward from the lower surface of the holding plate 52 to form a recess for accommodating the substrate therein. The substrate W is vertically movable so as to expose the outer peripheral portion of the substrate W to the outside (indicated by a chain line).

The top ring 28 is a ball joint 6
The shaft 62 is connected to the lower end of the top ring shaft 62 via a free end 0, and is supported on the free end side of the swing arm 32 so as to be vertically movable and rotatable.

FIG. 4 is a view showing details of the top ring 28. As shown in FIG. 4, the holding plate 52 has a plurality of communication holes 52a opened on the lower surface. It is connected to a vacuum source (not shown) such as a vacuum pump through a joint 64, a communication hole 50 a formed in the top ring main body 50, and a tube 66. Thus, the wafer holding surface 52b of the holding plate 52 can suck the upper surface of the substrate W by vacuum.

The joint 64 has O-rings 6 on the upper and lower outer peripheral portions.
8 and the chamber 54 has communication holes 50a and 52a.
It is configured not to communicate with the. Also joint 6
4 and the holding plate 52 are fitted by a clearance fit so that the deformation of the holding plate 52 is not hindered.

The communication hole 52a is connected to a switching valve (not shown) through a tube 66 extending inside the top ring shaft 62 and a rotary joint (not shown), and the switching valve is appropriately switched. Through hole 52a
Can communicate with a vacuum source, a pressurized air source or a liquid source. Therefore, the wafer holding surface 52b of the holding plate 52 sucks the substrate W in vacuum by setting the communication hole 52a to a pressure lower than the atmospheric pressure by the vacuum source and ejects pressurized air from the communication hole 52a by the pressurized air source. Thus, backside pressure can be applied to the substrate W during polishing. By applying a slight backside pressure to the substrate W during the polishing, it is possible to remove the trace of adsorption that has occurred during the transfer of the substrate W due to vacuum adsorption. In addition, the substrate W can be separated from the wafer holding surface 52b by ejecting the liquid from the communication hole 52a by the liquid source.

The retainer ring 40 is made of a resin material,
A first retainer ring member 40a at a lowermost position that comes into contact with the polishing pad 24, and a second retainer ring member having an L-shaped cross-section above the first retainer ring member 40a and holding the first retainer ring member 40a. 40b. The second retainer ring member 40b is connected at the upper end thereof to the top ring main body 50 in the rotational direction by a pin 72, and the retainer ring 40 rotates integrally with the top ring 28. A bag 74 made of an annular rubber tube is disposed between the retainer ring 40 and the top ring 28. The bag 74 is fixed to the second retaining ring member 40b. Then, the bag 74 is connected to the tube 76.
And a regulator (not shown) connected to a vacuum source, a pressurized air source or a liquid source. Thus, the retainer ring 40 is raised by sucking the interior of the bag 74 by the vacuum source and compressing the same, and is expanded by pressurizing the interior of the bag 74 by the source of pressurized air. It is going to descend.

The top ring shaft 62 has a driving flange 62a, and the rotation of the top ring shaft 62 is transmitted to the top ring 28 by a rotation transmission mechanism 70 including a plurality of pins. The chamber 54 is connected to a vacuum source or a pressurized air source via a tube 71 and a regulator (not shown).

On the other hand, the outer peripheral polishing section 38 has a substantially disk-shaped support 80, and the substrate W
A concave portion 80a having an inclined surface whose diameter gradually increases upward is provided at a position facing the outer peripheral portion. And
A ring-shaped polishing cloth 84 whose surface is an outer peripheral polishing surface 82 is adhered to the inclined surface, whereby the outer peripheral polishing surface 82 is inclined by an angle α with respect to a horizontal plane.

In the case of a wafer on which a pattern to be polished according to the present invention is formed, the outer peripheral portion is polished only on the front surface side (circuit pattern surface) of the wafer because the purpose is to remove the metal film remaining on the outer peripheral portion. Is good. Therefore, as shown in FIG. 3, a desired outer peripheral portion is polished by pressing the wafer from above with the wafer pattern surface which expands upward in diameter and facing downward.

As the polishing cloth 84, for example, SUBA
Nonwoven fabrics such as 400, 600 (Rodel Nitta), I
Closed cell pads (polyurethane foam) such as C1000 (Rodel Nitta) or suede are used,
By inclining the polishing cloth 84 by the angle α, the lower half (wafer surface side) of the outer peripheral portion of the substrate W can be brought into contact with the outer peripheral polishing surface 82 during polishing, or the substrate outer peripheral portion can be cut. The width C ₁ (see FIG. 9) can be set arbitrarily. As the polishing cloth, in particular, Supreme RN
A soft polishing cloth such as (made by Rodel Nitta) is suitable.

The angle α is determined, for example, by the hardness of the material forming the outer peripheral polishing surface 82, the outer peripheral shape of the substrate W, the outer peripheral cut width, the pressing force applied during polishing, and the like. W or abut the lower half of the outer peripheral portion to the outer peripheral portion polishing surface 82 of the, determined optionally so as to adjust the cutting width C _1. For example, with a shallow angle alpha, by selecting a soft material, about 5mm cut width C _1, further set higher, which makes it possible to cope with the plating rest.

This embodiment shows an example in which the outer peripheral polishing surface is constituted by the surface of a polishing cloth. Thus, the use of a polishing cloth and the selection of a soft material can prevent the occurrence of scratches. However, the outer peripheral portion polishing surface may be constituted by the surface of a grindstone impregnated or fixed with abrasive grains. In this case, since the grindstone does not deform, it is possible to cope with the outer peripheral portion shape of the substrate by forming the outer peripheral polishing surface of the grindstone surface into an arc shape, for example, in conformity with the outer peripheral portion shape of the substrate.

The outer peripheral polishing section 38 is connected to the upper end of a rotatable shaft 86 extending vertically. A polishing liquid flow passage 88 extending in the vertical direction is formed at the center of the shaft 86, and a polishing liquid supply port 90 is formed at the center of the support 80 at a position communicating with the polishing liquid flow passage 88. As a result, the polishing liquid 92 discharged from the polishing liquid supply port 90 causes the outer peripheral polishing surface 82
It is supplied to. A cleaning liquid such as pure water or deionized water may flow from the polishing liquid flow path 88 to the polishing liquid supply port 90, or another line for flowing the cleaning liquid may be provided.

Here, as the polishing liquid, an abrasive liquid (slurry) containing abrasive grains is used. For example, when copper is shaved to leave Ta, a copper polishing rate of Ta such as EPC5001 (manufactured by Cabot) is used. If the oxide and low-silicon material (low-K: low dielectric constant interlayer insulating film) is left after removing copper and Ta by 10 times or more, the polishing rate of copper and Ta is that of an oxide film or low-silicon material. It is preferable to select and use one that is at least 10 times higher than the above.

FIG. 5 and FIG. 6 are diagrams showing the outline of the cleaning machine 20a or 20b as a primary cleaning machine. As shown in FIGS. 5 and 6, the washing machine 20a or 20b is provided with a plurality of upright rollers 130 for holding the substrate W, which can be opened and closed around the substrate W. A pair of roll-type scrub cleaning members 1 sandwich the substrate W from above and below.
40a and 140b are arranged so as to be able to contact / retract with the upper and lower surfaces of the substrate W, and around the same, a pure water supply nozzle 142 for supplying pure water to the upper and lower surfaces of the substrate W and a chemical supply for supplying a chemical such as an etchant are provided. Nozzles 144 are provided.

At one end of the scrub cleaning member 140b located on the lower surface side of the substrate W, in this example, a peripheral cleaning member composed of a mohair brush 146 is rotated integrally with the scrub cleaning member 140b. It is provided in.
The mohair brush 146 includes a scrub cleaning member 140b.
A large number of mohairs 154 are scrubbed on a surface of the support 152 having a disc-shaped base portion 148 having a diameter larger than the diameter of the shaft portion 150 and the shaft portion 150 on the shaft portion 150 side.
And extended in the axial direction, and planted in a ring shape.

The scrub cleaning members 140a, 140b
The length and arrangement are set so that the peripheral edge B of the substrate W on the side of the mohair brush 146 is exposed when the substrate W comes into contact with the substrate W. When the scrub cleaning member 140b comes into contact with the lower surface of the substrate W, the mohair brush 146 has the mohair 154 attached to the peripheral portion B of the substrate W projecting outward from the free end side end surface of the scrub cleaning member 140b. The diameter of the base 148, the length of the shaft 150, and the like are set so as to make contact over the entire surface of B.

In this example, the moiré brush 146 is used to form the peripheral edge cleaning member. However, the peripheral edge cleaning member may be composed of a brush made of another material, or a PVA sponge or urethane foam. Good. Further, a mohair brush may be provided at the end of the scrub cleaning member 140a on the upper surface side of the substrate W.

Next, a polishing operation by the polishing apparatus of this embodiment will be described. In this example, by providing two polishing units 10a and 10b, two-stage polishing by series processing (sequential processing) and parallel processing (parallel processing) are possible, but here, the upper part of FIG. The parallel processing using a sequence will be described.

First, the cassette 12 is transferred by the transfer robot 14a.
One substrate W is pulled out from a and passed to the reversing machine 16. The reversing device 16 reverses the substrate W by 180 ° so that the processing surface faces downward, and transports the substrate W after the reversal onto the pusher 36 by the transport robot 14b. The substrate on the pusher 36 is received and held by the top ring 28, and is turned to the polishing position on the turntable 26.

In this state, the substrate W held by the top ring 28 is pressed onto the polishing pad 24 and the turntable 26 is pressed.
By rotating the top ring 28, the lower surface (polishing surface) of the substrate W is rubbed against the polishing pad 24. At this time, by simultaneously supplying a slurry as a polishing liquid from the polishing liquid supply nozzle 42 onto the polishing cloth 24, the polished surface of the substrate W is mechanically polished by abrasive grains in the polishing liquid and a liquid component of the polishing liquid. Polishing is performed by the combined action of the alkali and the chemical polishing action. The polishing liquid used for polishing is scattered out of the turntable 26 by the centrifugal force of the turntable 26, and the polishing liquid at the lower part of the frame 44 is removed.
Collected at 4a.

At this time, by lowering the retainer ring 40, the substrate W is prevented from coming off the lower surface of the top ring 28. When a polishing cloth is used for polishing, the polishing is performed under the supply of a slurry containing abrasive grains. In this case, the same slurry as that used for polishing the outer peripheral portion of the substrate may be used. In the case of a whetstone (fixed abrasive), polishing is performed under the supply of a polishing liquid (water or water and a chemical solution) containing no abrasive.

The polishing is completed when the substrate W has been polished to a predetermined polishing amount. When the polishing is completed, the characteristics of the polishing pad 24 change due to the polishing, and the polishing performance of the next polishing is deteriorated. Therefore, the polishing pad 24 is dressed.

That is, the dressing tool 48 is brought into contact with the polishing pad 24 while the dresser 30 and the turntable 26 holding the dressing tool 48 on the lower surface are rotated, and a predetermined pressure is applied. At this time, water is supplied from the water supply nozzle 46 to the upper surface of the polishing pad 24 at the same time as or before the dressing tool 48 comes into contact with the polishing pad 24. The purpose of supplying water is to wash away the used polishing liquid remaining on the polishing pad 24. Further, the dressing process rubs the dressing tool 48 with the polishing pad 24, and thus has an effect of removing frictional heat generated by the dressing process. The water supplied onto the polishing pad 24 is scattered out of the turntable 26 under the centrifugal force generated by the rotation of the turntable 26, and is collected by the bottom 44 a of the frame 44.

After the completion of the polishing, the top ring 28 is raised, and the substrate W is turned to a position above the outer peripheral polishing portion 38. At the same time, the retainer ring 40 is raised and the substrate W
To expose the outer periphery.

In this state, the outer peripheral portion polishing section 38 is rotated at a rotation speed determined in the finished polishing state of, for example, 20 to 1000 rpm, and the polishing liquid 92 is discharged from the polishing liquid supply port 90 at the same time. While supplying the polishing liquid 92 to the outer peripheral polishing surface 82 by the centrifugal force accompanying the rotation of the outer peripheral polishing unit 38, the top ring 28 is lowered while rotating at a rotation speed of, for example, 100 rpm in the same direction as the polishing unit 38. Then, the outer peripheral portion of the substrate W is brought into contact with the outer peripheral polishing surface 82, and the outer peripheral portion of the substrate W is directed toward the outer peripheral polishing surface 82, for example, at 50K.
By pressing with a predetermined pressing force equal to or less than g, the outer peripheral portion of the substrate W is polished.

After the outer peripheral portion is polished, the top ring 28 is raised, and the substrate W is swung above the pusher 36 to be delivered to the pusher 36.
The upper substrate W is transferred to the washing machine 20a by the transfer robot 14b. That is, when the scrub cleaning members 140a and 140b are located at the upper and lower retracted positions, respectively, at the open position where the roller 130 is retracted outward, the transfer robot 1 transports the substrate W.
The substrate W is transported to a predetermined position inside the roller 130 by 4b, and the roller 130 is advanced to hold the substrate W.

In this state, the substrate W is
Is rotated in the horizontal direction at a low rotation speed of about several tens to 300 rpm, and at the same time, while rotating the scrub cleaning members 140a and 140b, is moved synchronously from the retreat position toward the substrate W to contact the upper and lower surfaces of the substrate W The scrub cleaning members 140a and 140b are rubbed while supplying pure water from the pure water supply nozzle 142 to the upper and lower surfaces of the substrate W to perform scrub cleaning (primary cleaning).

At this time, the mohair brush 146 provided at the end of the scrub cleaning member 140b located on the lower surface side of the substrate W
Rotates integrally with the scrub cleaning member 140b and contacts the peripheral portion B of the substrate W to scrub the peripheral portion B. Since the substrate W is rotated by the roller 130, the entire peripheral portion B of the substrate W is sequentially washed. Further, the peripheral edge B exposed in FIG.
a, 140b, so that it is sufficiently washed. As a result, the region of the peripheral portion B (outer peripheral portion, particularly the bevel portion) of the substrate W whose outer peripheral portion has been polished is cleaned, so that the remaining abrasive liquid and polishing residue may cause particles at a later stage. Is prevented.

Next, if necessary, an etching solution is supplied to the upper and lower surfaces of the substrate W from the chemical solution supply nozzle 144 while changing the rotation speed of the substrate W, and the surface of the substrate W is etched (chemically cleaned). Then, metal ions remaining on the surface of the substrate W are removed, and pure water is further supplied from a pure water supply nozzle 142 to perform replacement with pure water, thereby removing the etching solution. In this manner, the first-stage double-sided cleaning of the substrate W after the polishing is completed by the cleaning machine 20a and the cleaning of the outer peripheral portion (particularly, the bevel portion) of the substrate W are performed, and the transferred robot W is transferred to the transfer robot 14b. And transported to the reversing machine 16.

Then, the substrate inverted by the reversing device 16 is transferred to the cleaning device 22a via the transfer robot 14a.
In the cleaning machine 22a, for example, pure water is sprayed from a pure water rinsing nozzle to perform the second-stage cleaning (finishing cleaning) of the wafer surface, and the wafer is rotated at a high speed and spin-dried. Next, the substrate after the spin drying is transferred to the cassette 12 by the transfer robot 14a.
Return to a.

In this example, one side of the outer peripheral portion of the substrate is polished. However, for example, after polishing one side of the outer peripheral portion of the substrate, the substrate is turned over and the other side is polished. The entire outer peripheral portion may be polished.

In this embodiment, the outer peripheral portion is polished after the CMP of the substrate surface. However, the present invention is not limited to this.
P may be performed. In particular, when polishing debris that affects the polishing of the surface layer appears, the outer peripheral portion of the substrate is polished first, and then the surface film is flattened.

FIG. 7 is a layout diagram showing the overall configuration of a polishing apparatus according to a second embodiment of the present invention.
At the installation position of the washing machine 20a shown in FIG. 1, an outer peripheral polishing unit 38 having the same configuration as that of the above-described embodiment is installed.
An outer peripheral portion polishing mechanism 94 is configured by disposing the top ring 28 having the same configuration as that of the above-described embodiment on the side.

According to this embodiment, similarly to the above-described embodiment, first, the outer peripheral portion of the substrate is polished by the outer peripheral portion polishing mechanism 94, and then the entire surface of the substrate W is polished by the turntable 26. Thereafter, the substrate W is returned to the cassette 12a through a cleaning / drying process, or after the surface of the substrate W is polished by the turntable 26, the outer peripheral portion of the substrate is polished by the outer peripheral polishing mechanism 94. After the drying step, the substrate W can be returned to the cassette 12a.

[0062]

As described above, according to the present invention,
The polishing of the outer periphery of the object to be polished by the outer periphery polishing mechanism arranged on the side of the turntable is quickly performed as a series of operations before and after the original polishing of the surface to be polished by the turntable of the object to be polished. Can be. Moreover, the polishing object is rotated relative to the polishing portion while the outer peripheral portion of the polishing object is brought into surface contact with the outer peripheral polishing surface over the entire length along the circumferential direction, and the outer peripheral portion is polished. By doing so, the outer peripheral portion can be efficiently polished with a low surface pressure.

[Brief description of the drawings]

FIG. 1 is a layout diagram showing an overall configuration of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the polishing unit of FIG. 1 in detail.

FIG. 3 is an enlarged cross-sectional view showing a top ring and an outer peripheral portion polishing portion of FIG. 1 in detail.

FIG. 4 is an enlarged view of a main part of the top ring of FIG. 1;

FIG. 5 shows an outline of the washing machine of FIG. 1, (a) is a perspective view,
(B) is a figure which shows the effect.

FIGS. 6A and 6B are diagrams showing a state during scrub cleaning by the cleaning machine of FIG. 5, wherein FIG. 6A is a front view and FIG.

FIG. 7 is a layout diagram showing an overall configuration of a polishing apparatus according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a manufacturing example of the copper wiring board in order of process.

FIG. 9 is an enlarged cross-sectional view showing an outer peripheral portion after performing CMP on the copper wiring board.

[Explanation of symbols]

10a, 10b Polishing unit 12a, 12b Cassette 14a, 14b Transfer robot 24 Polishing cloth 26 Turntable 28 Top ring 30 Dresser 36 Pusher 38 Outer peripheral polishing part 40 Retainer ring 50 Top ring main body 52 Holding plate 54 Chamber 56 Elastic mat 60 Ball joint 62 top ring shaft 70 rotation transmission mechanism 74 bag 80 support 82 outer peripheral polishing surface 84 polishing cloth 88 polishing liquid flow path 90 polishing liquid supply port 92 polishing liquid 94 outer peripheral polishing mechanism C ₁ cut width W substrate (object to be polished) α angle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yu Ishii 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation (72) Inventor Mitsuhiko Shiragashi 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside Ebara Works (72) Inventor Junji Kunizawa 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Works Co., Ltd. (72) Inventor Hiroyuki Yano 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture In-house (72) Inventor Katsuya Okumura 8 Shingsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 3C058 AA09 AA14 AA18 AB03 AB04 BA07 CB03 DA17

Claims (5)

[Claims] 1. A surface of an object to be polished, comprising: a turntable having a polished surface; and a top ring for holding the object to be polished and pressing a surface to be polished of the object to be polished toward the turntable. A polishing apparatus comprising: a surface polishing mechanism for polishing; and an outer peripheral polishing mechanism for polishing an outer peripheral portion of the object to be polished. 2. The top ring is configured to be vertically movable and horizontally movable, and the outer peripheral portion polishing mechanism is disposed at a movable position of the top ring, and the outer periphery of an object to be polished held on the upper surface by the top ring. The polishing apparatus according to claim 1, further comprising an outer peripheral polishing portion provided with an outer peripheral polishing surface that abuts on the portion to polish. 3. The outer peripheral polishing surface, with respect to a horizontal plane,
3. The polishing apparatus according to claim 2, wherein the polishing apparatus is inclined in a direction gradually rising outward. 4. The outer peripheral polishing section is configured to be rotatable, and supplies a polishing liquid to the outer peripheral polishing surface to a rotation center portion of the outer peripheral polishing section by centrifugal force caused by the rotation of the outer peripheral polishing section. 4. The polishing apparatus according to claim 2, wherein a polishing liquid supply port is provided. 5. A polishing method for polishing a polished surface by pressing a polished surface of an object to be polished against a polished surface of a turntable with a predetermined force, comprising: And a polishing step for polishing an outer peripheral portion of the object to be polished later.