JP2002246343A - Polishing device, semiconductor device-manufacturing method using the same, and semiconductor device manufactured by the manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain edge exclusion to a narrow range by reducing edge sagging generated at the edge section of a substrate and at the same time, reducing the amount of overshoot. SOLUTION: Pluralities of first grooves 61 that are the abrasive channels for spreading abrasive to the polishing surface of a polishing pad 53 are formed lengthwise and crosswise, at the same time, plural second grooves 62, having a narrower width than the first grooves 61, are formed between the adjacent first grooves 61 out of the first grooves 61, 61, and the like. In this case, the first grooves 61, 61, and the like can pile up the abrasive and has width d1 for discharging cutting rubbish, without scratching the surface to be polished on a substrate W, and the second grooves 62, 62, and the like have width d2 for giving appropriate flexibility to the polishing pad 53. A middle member 52, made of a material that is softer than the polishing pad 53, is included between a pad plate 51 and the polishing pad 53.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus for polishing a substrate by bringing a polishing pad into contact with a substrate to be polished and relatively moving the polishing pad, and a method for manufacturing a semiconductor device using the polishing apparatus. And a semiconductor device manufactured by the semiconductor device manufacturing method.

[0002]

2. Description of the Related Art Conventionally, a polishing apparatus for flattening the surface of a substrate such as a semiconductor wafer has a rotating table for holding a substrate to be polished on an upper surface thereof, and a polishing head having a polishing pad attached to a lower surface thereof. A configuration is known in which a polishing head is lowered while rotating both of them to press a polishing pad against a surface to be polished of a substrate, and the polishing head is swung in a contact surface direction to polish the substrate. . Further, in addition to such mechanical polishing, chemical mechanical polishing (Ch) in which a polishing agent (polishing liquid) is supplied to the contact surface between the polishing pad and the substrate to promote the polishing by the chemical action of the polishing agent.
CMP that performs emical Mechanical Polishing (CMP)
Devices are also known.

In a polishing process performed by using such a polishing apparatus, it is necessary to satisfy a predetermined required accuracy with respect to a polishing state of a substrate surface such as flatness and uniformity of a surface to be polished. The polishing pad material (hardness) greatly affects the polishing state of these substrates, and if the polishing pad material is soft, the polishing surface of the polishing pad tends to follow the unevenness of the substrate surface, and the uniformity is reduced. The flatness decreases while improving, and if the material of the polishing pad is made hard, the flatness improves but the uniformity decreases.

[0004] In addition, a demand for edge exclusion is imposed on a substrate to be polished. The edge exclusion refers to a region (width) of the edge (outer edge) portion of the substrate that is not to be evaluated such as uniformity, and it is necessary to keep this within a predetermined range. Regarding the edge exclusion, there is a problem of edge dripping caused when the polishing surface of the polishing pad locally goes around the side surface of the substrate when the polishing pad protrudes from the edge of the substrate (overhangs) during polishing. When the polishing pad protruding from the edge is pulled back to the inside of the substrate, the problem of overshoot in which the polishing surface of the polishing pad is caught on the edge of the substrate to cause a non-contact portion between the polishing pad and the substrate surface at the edge portion. However, these are also affected by the material hardness of the polishing pad.

That is, when the polishing pad is made of a soft material, the polishing pad is bent so as to substantially follow the edge shape of the substrate, so that the edge of the polishing pad becomes large while the amount of overshoot is small. The portion not in contact with the surface is smaller. On the other hand, when the polishing pad is made of a hard material, the polishing pad cannot be bent so as to follow the edge shape of the substrate, so the non-contact portion of the edge portion with the substrate surface becomes large, but the division becomes small. There is an advantage. If the material of the polishing pad is soft as described above, the edge drooping, and if the material is hard, the amount of overshoot increases,
In any case, the edge exclusion is large. However, if the edge exclusion is large, the number of chips that can be cut out from the substrate (semiconductor wafer) is reduced, and a predetermined required standard may not be satisfied. Come.

As a polishing apparatus capable of performing polishing with good flatness and uniformity while compensating for the disadvantage of such a polishing pad made of both hard and soft materials, a polishing apparatus as shown in FIGS. 7A and 7B is used. A polishing pad 153 is provided between the pad 153 and a pad plate 151 holding the polishing pad 153.
There is known one in which an intermediate member 152 made of a softer material is interposed. Here, the polishing pad 153 is made of a hard material, for example, hard foamed polyurethane, and the intermediate member 152 is made of a softer material, for example, an elastic body such as sponge. As a result, the polishing pad 153 is provided with both the characteristics of a hard material and the characteristics of a soft material, and can satisfy the requirement for flatness with the characteristics of a hard material while satisfying the requirement for uniformity with the characteristics of a soft material. become able to. Here, as shown in FIG. 7, a plurality of grooves 16 provided vertically and horizontally on the polishing surface of the polishing pad 153.
Reference numerals 1,161,... Denote abrasive flow paths for distributing the supplied abrasive over the entire polishing surface. The abrasive flow paths allow the abrasive to stay for a certain period of time, and are coated on the substrate to be polished. It has a predetermined width d (for example, 1 mm) enough to discharge shavings without damaging the polished surface.

[0007]

However, even in such a polishing apparatus in which the intermediate member 152 is provided between the polishing pad 153 and the pad plate 151, the polishing pad 153 is made of a hard material. As a result, the edge droop that occurs at the edge of the substrate is small, but FIG.
As shown in FIG. 8, when the polishing head is rebounded from the overhanging state to the inside of the substrate W (the moving direction of the polishing pad 153 with respect to the substrate W at this time is shown in FIG. 8).
The amount of overshoot generated in the middle and the arrow R) is large, and the non-contact portion between the polishing surface of the polishing pad 153 and the surface to be polished of the substrate W becomes large, so that edge exclusion (from the edge in FIG. (The area indicated by the width E) cannot be reduced.

The present invention has been made in view of such a problem, and it is possible to reduce the amount of overshoot while reducing the edge droop generated at the edge of the substrate, and to reduce the edge exclusion in a narrow range. An object of the present invention is to provide a polishing apparatus having a configuration that can be suppressed, a semiconductor device manufacturing method using the polishing apparatus, and a semiconductor device manufactured by the semiconductor device manufacturing method.

[0009]

A polishing apparatus according to the present invention includes a substrate holding member (for example, a substrate holding table 10 in the embodiment) for holding a substrate to be polished, and a substrate holding member held by the substrate holding member. A polishing head having a polishing pad attached thereto so as to face the polishing surface,
The polishing surface of the polishing pad is brought into contact with the surface to be polished of the substrate held by the substrate holding member, and the substrate holding member and the polishing head are relatively moved while an abrasive is interposed between the substrate and the polishing pad. In a polishing apparatus for polishing a substrate by polishing, a plurality of first grooves (for example, the first grooves 61 in the embodiment) for distributing the abrasive on the polishing surface of the polishing pad are formed, and adjacent to the first grooves. One or more second grooves (e.g., 62 in the embodiment) having a width smaller than the first groove are formed between the mating parts.

In the polishing apparatus according to the present invention, a plurality of first grooves for distributing the abrasive are formed on the polishing surface of the polishing pad, and a plurality of first grooves are formed between adjacent ones of the first grooves. A plurality of second grooves having a width smaller than one groove are formed to reduce the bending rigidity of the entire polishing pad. Therefore, the polishing pad easily bends at the edge of the substrate when the polishing pad protrudes from the substrate (when the polishing pad overhangs), and the amount of overshoot at the time of rebound when the polishing head is pulled back inward from the overhanging state is reduced. However, the size is smaller than that of the related art in which such a second groove is not provided. Thereby, the non-contact portion between the polishing surface of the polishing pad and the substrate surface is reduced, and the edge exclusion can be suppressed to a narrow range. Further, by forming the material of the polishing pad from a hard material (for example, hard foamed polyurethane), the edge of the edge of the substrate can be reduced. As described above, according to the polishing apparatus of the present invention, since the edge exclusion can be reduced, the yield rate of non-defective products can be improved. The number of chips that can be output can be increased.

In the above polishing apparatus, it is preferable that an intermediate member made of a material softer than the polishing pad is interposed between the polishing pad and a portion of the polishing head to which the polishing pad is attached. In such a configuration, the intermediate member acts to return the polishing pad to bend at the edge of the substrate, thereby returning the polishing pad to its original position, so that the polishing surface of the polishing pad is parallel to the surface to be polished of the substrate. The degree is higher than when such an intermediate member is not provided. Therefore, the degree of bending of the polishing pad at the edge portion of the substrate can be reduced, and edge exclusion can be further reduced.

Further, a method of manufacturing a semiconductor device according to the present invention includes a step of polishing a substrate surface using a polishing apparatus, wherein the substrate to be polished is a semiconductor wafer. For this reason, according to the method of manufacturing a semiconductor device,
The yield of manufactured semiconductor devices can be improved. The semiconductor device according to the present invention is manufactured by the method for manufacturing a semiconductor device. In a semiconductor device manufactured by the above-described manufacturing method, a substrate having high flatness is used, so that a device with less problems such as poor insulation of wiring and short-circuit is obtained, and a high-performance device is obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a CMP apparatus (chemical mechanical polishing apparatus) 1 which is an embodiment of a polishing apparatus according to the present invention. The CMP apparatus 1 is provided with a substrate holding table 10 capable of detachably holding a substrate (for example, a semiconductor wafer) W to be polished on its upper surface side, and is provided above the substrate holding table 10. And a polishing head 30 to which a polishing pad 53 is attached so as to face the substrate W held by the polishing head 30. In this CMP apparatus 1, the polishing pad 5
The dimension (diameter) 3 is the dimension (diameter) of the substrate W to be polished.
When the polishing pad 53 is in contact with the substrate W and is relatively moved, the entire surface to be polished (upper surface) of the substrate W is polished.

A support frame 20 for supporting the substrate holding table 10 and the polishing head 30 is provided on a horizontal base 21.
A first stage 22 movably provided on a rail (not shown) provided on the base 21 so as to extend in the Y direction (a direction perpendicular to the paper surface); A second frame 24 movably provided on the vertical frame 23, a horizontal frame 25 provided to extend horizontally from the second stage 24, A third stage 26 movably provided on the horizontal frame 25 is provided.

A first electric motor M is provided in the first stage 22.
The first stage 22 can be moved along the rail (that is, in the Y direction) by rotating the first stage 22. A second electric motor M2 is provided in the second stage 24, and the second stage 24 can be moved along the vertical frame 23 (that is, in the Z direction) by rotationally driving the second electric motor M2.
Further, a third electric motor M3 is provided in the third stage 26, and by rotating this third electric motor M3, the third stage 26 can be moved along the horizontal frame 25 (that is, in the X direction). Therefore, the third stage 26 can be moved to an arbitrary position above the substrate holding table 10 by combining the rotation operations of the electric motors M1 to M3.

The substrate holding table 10 is horizontally mounted on the upper end of a rotating shaft 28 provided to extend upward from a table support 27 provided on the base 21. The rotary shaft 28 can be rotated around the Z-axis by rotating a fourth electric motor M4 provided in the table support portion 27, whereby the substrate holding table 10 can be rotated in the XY plane. it can.

The polishing head 30 is attached to a lower end of a spindle 29 provided to extend downward from the third stage 26. This spindle 29 is mounted on the third stage 26
By rotating the fifth electric motor M5 provided therein, the fifth electric motor M5 can be rotated around the Z axis, whereby the entire polishing head 30 can be rotated and the polishing pad 53 can be rotated in the XY plane. The rotation axis of the spindle 29 is assembled so as to be substantially parallel to the rotation axis 28 of the substrate holding table 10.

As shown in FIGS. 2 and 3, the polishing head 30 has a tension flange 31 composed of a disk member 31a detachably attached to the spindle 29 and a cylindrical member 31b detachably attached to the lower surface side of the disk member 31 by bolts B1. A ring member 32 fixed to the lower end of the cylindrical member 31b by a bolt B2;
Disk-shaped drive ring 33 sandwiched between the drive ring 33 and the disk member, a disk-shaped reference plate 41 attached to the lower surface of the drive ring 33, and detachably attached to the lower surface of the reference plate 41 by vacuum suction. And a polishing tool 50 to be used.

The drive ring 33 is composed of a metal drive plate 34 and a rubber diaphragm 35 laminated on the lower surface of the drive plate 34, and circular holes 34a, 35a having substantially the same radius are formed in the center of each. Are formed. As described above, the drive plate 34 and the diaphragm 35 are sandwiched between the tension flange 31 and the ring member 32 and the outer peripheral portions thereof are fixed, but the drive plate 34 has a concentric arc shape having different distances from the center provided therein. Three types of through holes 34b, 34c,
Since it has appropriate flexibility by 34d, it can be slightly deformed in an out-of-plane direction.

A disk-shaped central member 44 having a radius slightly smaller than the circular holes 34a and 35a of the drive ring 33 (of the drive plate 34 and the diaphragm 35) is fixed to the center plate upper surface side of the reference plate 41 by bolts B3. The drive ring 33 centered on the center member 44 is sandwiched between a reference plate 41 and a ring member 45 fixed to the upper surface of the reference plate 41 by bolts B4. As described above, the reference plate 41 is fixed to the tension flange 31 via the drive ring 33, and when the spindle 29 rotates, its rotational force is transmitted. The outer diameter of the flange 41a projecting outward from the outer peripheral portion of the reference plate 41 is formed to be larger than the inner diameter of the flange 32a projecting inward from the inner peripheral portion of the ring member 32. It does not come off from the member 32.

The polishing tool 50 has a disk-shaped pad plate 51 having substantially the same outer diameter as the reference plate 41, a disk-shaped intermediate member 52 mounted on the pad plate 51, and a lower surface of the intermediate member 52. And a circular polishing pad 53. The intermediate member 52 attached to the lower surface of the pad plate 51 is made of a soft material, for example, a sponge-like elastic body, and the polishing pad 53 is made of a hard material, for example, hard foamed polyurethane. Since the polishing pad 53 is a consumable that deteriorates due to polishing, the polishing pad 53 can be detachably attached to the lower surface of the intermediate member 52 (for example, with an adhesive) to facilitate replacement work.

As shown in FIG. 2, inside the reference plate 41, an air suction passage 71 having a plurality of suction openings on the lower surface side.
Are formed, and the air suction passage 71 is
And extends to the inner space S side of the tension flange 31. A suction pipe 72 extending through an air supply passage 80 formed through the center of the spindle 29 is connected to this opening, and the suction pipe 72 is positioned with the pad plate 51 positioned below the reference plate 41. By sucking air from 72, the pad plate 51 can be attached to the reference plate 41 by suction. Here, centering of the pad plate 51 and positioning in the rotational direction are performed by a center pin P1 and a positioning pin P2 provided between the pad plate 51 and the reference plate 41.

FIG. 4 shows the appearance of the polishing tool 50.
FIG. 4A is a bottom view of the polishing pad 53 viewed from the polishing surface side, and FIG. 4B is a side view. As shown in these figures, on the polishing surface of the polishing pad 53, a plurality of first grooves 61 are formed vertically and horizontally as an abrasive flow path for distributing an abrasive described later. A plurality of second grooves 62 each having a smaller width than the first groove 61 are formed between adjacent ones of 61. Here, the first grooves 61, 61,... Have a width d1 enough to retain the abrasive and to discharge the shavings without damaging the polished surface of the substrate W.
(For example, 1 mm), and the second grooves 62, 62,... Have a width d2 (for example, 0.1 mm) that can give the polishing pad 53 appropriate flexibility.

To attach the polishing head 30 to the spindle 29, first, the disk member 31 of the tension flange 31
a is attached to the spindle 29, and the drive ring 3
3 is placed on the ring member 45 with the bolt B4.
Is attached to the reference plate 41. Next, the ring member 32 is attached to the cylindrical member 31b with the bolt B2 in a state where the drive ring 33 to which the reference plate 41 is attached is located at the lower end of the cylindrical member 31b. The cylindrical member 3 to which the reference plate 41 is attached in this manner
The bolt B1 is tightened in a state where 1b is positioned on the lower surface side of the disk member 31a, and the cylindrical member 31b is attached to the disk member 31a (the tension flange 31 is assembled). Finally, the pad plate 51 with the polishing pad 53 attached to the intermediate member 52 is sucked to the lower surface of the reference plate 41.

An air supply passage 80 formed inside the spindle 29 is connected to an air pressure supply line (not shown), and air (high-pressure air) is supplied from the air pressure supply line to form an air supply passage 80 inside the tension flange 31. Can be increased to urge the entire polishing tool 50 downward. By adjusting the magnitude of the air pressure in the internal space S, the contact pressure when the polishing pad 53 is brought into contact with the substrate W can be adjusted as desired.

Further, as shown in FIG.
An abrasive supply pipe 81 connected to an abrasive supply device (not shown) extends therein, and is provided through the center member 44 via a connector 82 located between the spindle 29 and the center member 44. The flow path 83, the flow path 84 penetrating through the center pin P1, and the flow path 8 formed in the pad plate 51
5 and a flow path 86 provided in the intermediate member 52.

In order to polish a substrate using the CMP apparatus 1 having such a configuration, first, a substrate W to be polished is attached by suction to an upper surface of a substrate holding table 10 (at this time, the center of the substrate W The electric motor M4 is driven to drive the substrate holding table 1
Rotate 0. Next, the electric motors M1 to M3 are driven to position the third movement stage 26 above the substrate W, and the spindle 29 is driven by the electric motor M5 to rotate the polishing head 30. Subsequently, the electric motor M2 is driven to lower the third stage 26, and the polishing pad 53 is pressed against the upper surface (the surface to be polished) of the substrate W. When the contact pressure between the substrate W and the polishing pad 53 reaches a predetermined value by adjusting the pressure of the air fed from the above-mentioned air pressure feed line, the electric motors M1 and M2 are driven to move the polishing head 30 in the XY directions (substrate). (The direction of the contact surface between W and the polishing pad 53).

During polishing of the substrate W, an abrasive (liquid slurry containing silica particles) is pumped from the above-mentioned abrasive supply device so that the abrasive is supplied to the lower surface side of the polishing pad 53. To The abrasive supplied to the lower surface side of the polishing pad 53 spreads over the entire polishing surface by using the first grooves 61, 61,... Formed on the polishing surface of the polishing pad 53 as main flow paths. W can be polished efficiently.

As described above, the surface to be polished of the substrate W is rotated by the rotation of the substrate W itself and the polishing head 30 while the abrasive is supplied.
(I.e., the polishing pad 53) is uniformly polished by the rotation and swinging motion. Here, since the reference plate 41 is attached to the tension flange 31 via the flexible drive ring 33 as described above, the reference plate 41 can be slightly deformed in the out-of-plane direction. Even when the degree of parallelism between the rotation axis 28 of the substrate holding table 10 and the rotation axis (spindle 29) of the polishing head 30 is not sufficient, or when there is unevenness (undulation) on the surface of the substrate W, Since the pad plate 51 is flexibly tilted (follows) in response thereto, the contact state between the two is kept good, and the surface (polished surface) of the substrate W is flattened with sufficient accuracy.

When the polishing pad 53 protrudes from the edge of the substrate W (overhangs) due to the swinging (swinging in the XY plane) of the polishing head 30, the polishing pad 53
Is bent at the edge of the substrate W, but the polishing pad 53
Is made of a hard material as described above,
It cannot be deformed to follow the edge shape of. Therefore, when the polishing head 30 is rebounded from the overhang state to the inside of the substrate W (the moving direction of the polishing pad 53 with respect to the substrate W at this time is indicated by an arrow R in FIG. 5). The polishing pad 53 swells (overshoots) in the thickness direction of the substrate W in a state where the polishing pad 53 is in contact with the edge of the substrate W, and a non-contact portion that does not contact the surface of the substrate W is generated as shown in FIG. However, in this CMP apparatus 1, the polishing surface of the polishing pad 53
In addition to the first groove 61 as a flow path for the abrasive, a plurality of second grooves 62 are formed between adjacent ones of the first grooves 61 to reduce the overall bending rigidity and facilitate bending. Therefore, the overshoot amount is smaller than in the conventional configuration in which only the abrasive flow path is provided, and the non-contact portion with the surface of the substrate W, that is, the edge exclusion (in FIG. 5, The area indicated by the width E from the edge) becomes smaller.

In terms of material mechanics, since the bending rigidity is proportional to the cube of the thickness, for example, the original thickness (thickness without grooves) of the polishing pad 53 is 1 mm. Assuming that the depth of the second groove 62 is 0.8 mm, the bending rigidity at the groove portion is 1/5 (= 0.2 / 0.2)
This is reduced to 1/125 which is the cube of 1).

When the second grooves 62, 62,... Are formed in addition to the first grooves 61, 61,... Which are the abrasive flow paths, the contact area of the polishing pad 53 with the substrate W is reduced. However, for example, one side of a region surrounded by the adjacent first grooves 61 (hereinafter referred to as a region A) is set to 5 mm,
The area is defined by second grooves 62, 62,.
If divided, the area of the region A is reduced by about 2 mm ² from 25 mm ^2, and the area is reduced by only about 8%. For each of the two vertical and horizontal divisions, the reduction is 4%. Also, for example, 1
Assuming that the polishing pad 53 has a service life of 250 wafers, a reduction in the area of 8% results in a reduction in the service life of about 20 wafers, and a reduction in the area of 4% results in a reduction in the life of about 10 wafers.

Further, by using a hard material (here, hard foamed polyurethane) as the material of the polishing pad 53 as described above, it is possible to reduce edge droop generated at the edge of the substrate W. As described above, according to the present invention, the edge exclusion can be reduced as compared with the conventional polishing apparatus, and the yield of non-defective products can be improved. Further, if the substrate W is a semiconductor wafer, the number of chips that can be cut out from the wafer increases, so that the manufacturing cost of semiconductor devices can be reduced.

When the polishing tool 50 is pressed against the substrate W by air in the internal space S of the tension flange 31, the intermediate member 52 of the polishing tool 50 is deformed by receiving the pressing force. When the polishing pad 53 overhangs from the edge of the substrate W due to the swing of the head 30 (the swing in the XY plane), the polishing pad 5
3 is bent at the edge of the substrate W as shown in FIG. 5, so that a larger force in the compression direction acts on the intermediate member 52 in the region inside the substrate W near the edge,
On the other hand, in the portion protruding from the edge of the substrate W, a force in the direction of being pulled downward by the polishing pad 53 acts on the intermediate member 52. At this time, the intermediate member 52
In the region inward of the substrate W near the edge of the substrate W, the polishing pad 53 is pressed down, and at a portion protruding from the edge, the polishing pad 53 acts to be pulled up. A force acts in a direction that prevents bending. Thereby, the degree of bending of the polishing pad 53 at the edge portion of the substrate W can be suppressed to be small, and the edge exclusion is further reduced.

Next, an embodiment of a method for manufacturing a semiconductor device according to the present invention will be described. FIG. 6 is a flowchart showing a semiconductor device manufacturing process. When the semiconductor manufacturing process is started, first, in step S200
Then, an appropriate processing step is selected from the following steps S201 to S204, and the process proceeds to any one of the steps.

Here, step S201 is an oxidation step of oxidizing the surface of a semiconductor wafer (hereinafter, referred to as a wafer). Step S202 is a CVD step of forming an insulating film or a dielectric film on the wafer surface by CVD or the like. Step S203 is an electrode forming step of forming electrodes on the wafer by vapor deposition or the like. Step S204 is an ion implantation step of implanting ions into the wafer.

After the CVD step (S202) or the electrode forming step (S203), the process proceeds to step S205. Step S205 is a CMP process. In the CMP process, the polishing apparatus according to the present invention performs planarization of an interlayer insulating film, polishing of a metal film on the surface of a semiconductor device, formation of a damascene by polishing of a dielectric film, and the like.

The CMP step (S205) or the oxidation step
After (S201), the process proceeds to step S206. Step S
206 is a photolithography step. In this step, a resist is applied to the wafer, a circuit pattern is printed on the wafer by exposure using an exposure device, and the exposed wafer is developed. Further, in the next step S207, portions other than the developed resist image are removed by etching.
Thereafter, the resist is removed, and this is an etching step of removing unnecessary resist after etching.

Next, it is determined in step S208 whether all necessary processes have been completed, and if not, step S2
Returning to step 00, the previous steps are repeated to form a circuit pattern on the wafer. If it is determined in step S208 that all steps have been completed, the process ends.

In the method of manufacturing a semiconductor device according to the present invention, the substrate W is polished as a semiconductor wafer in the above-mentioned CMP step using the polishing apparatus according to the present invention. For this reason, the throughput of the CMP process is improved, and a semiconductor device can be manufactured at lower cost than a conventional semiconductor device manufacturing method. Note that the polishing apparatus (CMP apparatus) according to the present invention may be used in a CMP step of a semiconductor device manufacturing process other than the semiconductor device manufacturing process. Further, the semiconductor device manufactured by the semiconductor device manufacturing method according to the present invention is manufactured at a high throughput, so that it is a low-cost semiconductor device.

While the preferred embodiment of the present invention has been described above, the scope of the present invention is not limited to the above. For example, the cross-sectional shapes of the first grooves 61, 61, ... and the second grooves 62, 62, ... formed on the polishing surface of the polishing pad 53 are not limited to the rectangular shape as shown in FIG. It may be V-shaped, U-shaped, trapezoidal, or the like. Further, the shape in the extending direction of the groove is not limited to the lattice shape as shown in FIG. 4A, but may be a concentric shape, a spiral shape, a radial shape (a shape extending from the center to the peripheral portion), or a combination thereof. It does not matter.

In the CMP apparatus 1 shown in the above embodiment, the substrate W and the polishing pad 53 (the polishing head 3
The substrate W is polished by bringing both of them into contact with each other while the both are rotated. However, since the substrate W and the polishing pad 53 may be relatively moved while being brought into contact with each other. Therefore, it is not necessary to rotate both of them, and only one of them may be rotated, or both may not be rotated. Also,
In the above embodiment, a CMP apparatus for polishing a substrate while supplying a liquid slurry containing silica particles has been described as an example. However, the polishing apparatus of the present invention is not limited to such a CMP apparatus, and a substrate polishing apparatus may be used. It can be applied generally.

In addition, the polishing apparatus (C
The MP apparatus 1) has a configuration in which the substrate W to be polished is held on the upper surface side of the substrate holding table 10 and the polishing pad 53 is pressed from above, but the substrate W is replaced with such a configuration. A configuration in which the polishing pad is held on the lower surface side of the substrate holding table and the polishing pad is pressed from below may be employed. Also, in the above embodiment, the second grooves 62 are formed in plurals between the adjacent first grooves 61, 61,..., But the second grooves 62 are formed between the adjacent first grooves 61, 61,. May be formed one by one.

[0044]

As described above, in the polishing apparatus according to the present invention, a plurality of first grooves for distributing the abrasive are formed on the polishing surface of the polishing pad, and the first grooves are formed adjacent to the first grooves. A plurality of second grooves having a width smaller than the first grooves are formed between the mating parts to reduce the bending rigidity of the entire polishing pad. Therefore, the polishing pad easily bends at the edge of the substrate when the polishing pad protrudes from the substrate (when the polishing pad overhangs), and the amount of overshoot at the time of rebound when the polishing head is pulled back inward from the overhanging state is reduced. However, the size is smaller than that of the related art in which such a second groove is not provided. Thereby, the non-contact portion between the polishing surface of the polishing pad and the substrate surface is reduced, and the edge exclusion can be suppressed to a narrow range. Further, by forming the material of the polishing pad from a hard material (for example, hard foamed polyurethane), the edge of the edge of the substrate can be reduced. As described above, according to the polishing apparatus of the present invention, since the edge exclusion can be reduced, the yield rate of non-defective products can be improved, and when the substrate to be polished is a semiconductor wafer, it can be cut out from the wafer. The number of chips can be increased.

In the polishing apparatus, an intermediate member made of a material softer than the polishing pad is preferably interposed between the polishing pad and a portion of the polishing head to which the polishing pad is attached. In such a configuration, the intermediate member acts on the polishing pad that is to be bent at the edge of the substrate so as to return it to its original position, so that the polishing surface of the polishing pad and the surface of the substrate (surface to be polished)
Is higher than when such an intermediate member is not provided. For this reason, the degree of bending of the polishing pad at the edge of the substrate can be reduced,
Edge exclusion can be further reduced.

Further, the method for manufacturing a semiconductor device according to the present invention includes a step of polishing a substrate surface using a polishing apparatus, wherein the substrate to be polished is a semiconductor wafer. For this reason, according to the method of manufacturing a semiconductor device,
The yield of manufactured semiconductor devices can be improved. The semiconductor device according to the present invention is manufactured by the method for manufacturing a semiconductor device. In a semiconductor device manufactured by the above-described manufacturing method, a substrate having high flatness is used, so that a device with less problems such as poor insulation of wiring and short-circuit is obtained, and a high-performance device is obtained.

[Brief description of the drawings]

FIG. 1 is a CM which is an embodiment of a polishing apparatus according to the present invention.
It is a side view which shows the structure of P apparatus.

FIG. 2 is an enlarged cross-sectional view of a peripheral portion of a polishing head in the CMP apparatus.

FIG. 3 is an exploded perspective view of a cross section of a polishing head in the CMP apparatus.

FIG. 4 is a view showing a polishing tool to which a polishing pad is attached, (A) is a bottom view, and (B) is a side view.

FIG. 5 is a partial side view showing a state in which a polishing pad has protruded (overhanged) from a substrate.

FIG. 6 is a flowchart illustrating an example of a semiconductor device manufacturing method according to the present invention.

FIG. 7 is a view showing a conventional polishing tool to which a polishing pad is attached, (A) is a bottom view, and (B) is a side view.

FIG. 8 is a side view showing a state in which a polishing pad protrudes from a substrate (overhangs) in a conventional polishing tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CMP apparatus (polishing apparatus) 10 Substrate holding table (substrate holding member) 20 Support frame 30 Polishing head 50 Polishing tool 51 Pad plate 52 Intermediate member 53 Polishing pad 61 First groove (first groove) 62 Second groove (first groove) 2 groove) W substrate

Claims (4)

[Claims] A substrate holding member for holding a substrate to be polished; and a polishing head having a polishing pad attached thereto so as to face a surface to be polished of the substrate held by the substrate holding member. The polishing surface of the polishing pad is brought into contact with the surface to be polished of the substrate held by the substrate holding member, and the substrate holding member and the polishing pad are interposed between the substrate and the polishing pad with an abrasive interposed therebetween. A polishing apparatus for polishing the substrate by relatively moving a polishing head, wherein a plurality of first grooves for distributing the polishing agent on the polishing surface of the polishing pad are formed; A polishing apparatus, wherein one or more second grooves having a width smaller than the first groove are formed between adjacent ones. 2. An intermediate member made of a material softer than the polishing pad is interposed between a portion of the polishing head to which the polishing pad is attached and the polishing pad. The polishing apparatus according to the above. 3. A method of manufacturing a semiconductor device, comprising: a step of flattening a surface of the semiconductor wafer by using the polishing apparatus according to claim 1; 4. A semiconductor device manufactured by the method of manufacturing a semiconductor device according to claim 3.