JPH11333697A - Dresser system for cmp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform uniform dressing regulation of the polishing surface of a polishing pad, to detect a polishing state containing an uneven surface, and to perform flattening and regulation of the polishing surface according to the wear state. SOLUTION: A dresser system for a CMP device is provided with cylindrical dressers 5a, 5b, and 5c pressed against the polishing surface of a polishing pad 1 and rotatable by a drive part 4 and divided. Based on an uneven surface detected by a flat level measuring part 8, the dressers are individually rotated and controlled and regulated in a narrow range, and regulated to a dressed polishing surface in one-way against the rotation direction of the polishing pad 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dresser system of a CMP apparatus for flattening a layer formed on a semiconductor substrate when manufacturing a semiconductor product having a multilayer structure, and more particularly to a polishing surface adjustment of a polishing pad. Regarding improvement.

[0002]

2. Description of the Related Art In response to demands for higher density and higher integration of semiconductor products, a multilayer structure in which elements are formed hierarchically on a semiconductor substrate has been attempted. In the case of forming this multilayer structure, if the surface (generally, an interlayer insulating film) is not flattened for each layer, irregularities are generated in the upper layer as the layers are stacked. In some cases, the focus margin is lost due to the displacement, and an accurate pattern cannot be drawn, and in some cases, the etching process cannot be performed.

[0003] On the other hand, in the conventional etching process, there are some substances which are difficult to remove due to an etching target. For example, RI
In the etching by the E apparatus, it is difficult to etch Cu which will be used for wiring or the like.

[0004] Therefore, CMP processing utilizing mechanical polishing and chemical reaction is used for flattening the surface of a layer or for such a substance which is difficult to etch.

A CMP apparatus for performing the CMP process presses a moving polishing pad such as a rotation against a workpiece (semiconductor substrate), adds a slurry (abrasive), and performs polishing.

[0006]

In the polishing pad of the above-mentioned CMP apparatus, the surface of the portion pressed against the workpiece as the polishing is performed is worn out, and the polishing surface is polished due to the surface shape of the polished workpiece. Irregularities occur.

In order to maintain the flatness and the polishing efficiency of the polished surface, generally, a disk type dresser 2 as shown in FIG.
The polishing surface is adjusted by rotating and pressing the dresser 2 while rotating the polishing pad 1. The dresser 2 is often provided in a CMP apparatus.

In the adjustment by the dresser 2, since the polishing surface of the polishing pad 1 is polished and adjusted so as to be entirely uniform, even if the polishing surface has a slight unevenness, an excessively large unevenness over the entire surface is required. In some cases, polishing was required. However, in practice, there was no means to confirm whether the adjustment was at a required level over the entire polished surface.

Further, there is no means for confirming whether the degree of the adjustment performed is appropriate for the type of the film to be polished.

[0010] Therefore, such adjustment of the polishing surface is likely to unnecessarily adjust the entire polishing surface of the polishing pad, which shortens the life of the polishing pad, which is originally required.

Further, since the polishing pad 1 and the dresser 2 rotate together, a portion in the reverse rotation direction that passes by the same rotation direction as the rotation direction of the polishing pad is generated on the polishing surface,
The fuzz on the polished surface is different. The difference in the sharpening may cause a difference in the polishing rate to cause uneven polishing, and as a result, affects the flattening of the polished surface of the workpiece. In particular, in a polishing process using a polishing pad whose sharpening has been reduced by the adjustment, the polishing surface is adjusted again in a short period of time in order to lower the polishing efficiency, and the life of the polishing pad is shortened.

Accordingly, the present invention provides a CMP apparatus that performs uniform sharpening adjustment in one direction on a polishing surface of a polishing pad, detects a wear state including irregularities, and flattens and adjusts the polishing surface according to the state. The purpose of the present invention is to provide a dresser system.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a polishing pad which is pressed against a workpiece and rotates to remove the surface of the workpiece by CMP (Cheet).
mical Mechanical Porishing) In the apparatus, a plurality of rotations are performed in a direction perpendicular to a rotation surface of the polishing pad, and pressed against the polishing surface of the polishing pad to flatten the surface and sharpen in one direction. A cylindrical dresser arranged linearly toward the rotation axis, a driving means for applying a desired pressing pressure and rotation to each of the plurality of divided dressers, and a polishing surface of the polishing pad. Provided is a dresser system for a CMP apparatus, comprising: flatness measuring means for detecting unevenness of the surface; and control means for controlling pressing pressure and rotation of the dresser by the driving means based on a result detected by the flatness measuring means. I do.

In the dresser system of the CMP apparatus configured as described above, the cylindrical dresser rotates in a direction perpendicular to the rotation axis surface of the polishing pad and is pressed against the polishing surface to adjust the polishing surface. Adjust to a polished surface that is sharpened along the rotation direction or reverse rotation direction of the pad.

Further, the columnar dresser is rotatably divided into respective portions, and based on the unevenness of the polishing surface of the polishing pad detected by the detecting means, the rotation of each dresser can be changed and adjusted in a narrow portion, An efficient flattening process is performed.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a first embodiment of the present invention, which will be described.

In the present embodiment, the polishing pad 1 is rotated by a driving unit (not shown), and the polishing pad 1 is rotatable so as to be pressed against the polishing surface of the polishing pad 1 to perform flattening and adjustment of fuzzing (sharpening) of the surface. A columnar dresser 3,
A driving unit 4 for pressing and rotating the dresser 3 at a predetermined pressure and rotating the same is provided with a mechanism for raising and lowering the dresser 3 and pressing the dresser 3 against a polishing surface at a desired pressure, for example, a lifting cylinder (not shown).

In this embodiment, uniform polishing is performed on the polishing surface of the rotating polishing pad 1 in the rotation direction. In addition, the dresser 3 may rotate in reverse to adjust the polishing surface of the polishing pad, or may adjust the polishing surface while stopped, depending on the conditions.

According to the present embodiment, since the dresser 3 performs the polishing adjustment in one direction with respect to the polishing surface of the polishing pad 1 and at a predetermined speed, the polishing is flat and sharpened in one direction with respect to the rotation direction. The surface can be adjusted.

Next, FIG. 2 shows a CM according to the second embodiment.
FIG. 3 shows a schematic external configuration of a polishing pad and a dresser system of a P device, and FIG.
explain.

In the first embodiment described above, the polishing surface is flattened and adjusted with one cylindrical dresser. However, when the adjustment portion of the polishing surface of the polishing pad is partially concentrated, In this embodiment, the dresser is divided into a plurality of portions, and furthermore, the dresser is divided into a plurality of portions, irregularities are detected in a narrow range within the polishing surface, and adjustment is performed based on the result. This is an example of realizing flattening and adjustment.

In the present embodiment, the polishing pad 1 is rotated by a driving unit (not shown), and the polishing pad 1 is pressed against the polishing surface of the polishing pad 1 with a predetermined pressure so as to perform adjustment such as flattening and surface sharpening. A cylindrical dresser 5 (5a, 5b, 5c) that is rotatable and divided into three parts, a driving unit 4 that rotates the dresser 5 at a predetermined pressing pressure, and a polishing surface of the polishing pad 1 in contact with or A non-contact sensor 7 for detecting its flatness at a line or a plurality of points, a flat level measuring unit 8 for detecting irregularities in a line from a detection signal detected by the sensor 7, and respective dressers 5a, 5b, 5c Lifting and lowering cylinders 11 for individually controlling the lifting and lowering and generating a desired pressing pressure when pressed against the polished surface; Come, each dresser 5a, 5b, 5c
And a control unit 6 for controlling the rotation of each of them.

In this embodiment, the dresser 5 is described as being divided into three parts. However, it is needless to say that a suitable number of divisions may be made depending on the polishing pad.

In the gap where the above-mentioned divided dressers are connected, it may not be possible to adjust the polishing surface. However, by swinging the connected dresser,
This problem can be avoided.

FIG. 4 shows a specific configuration example of the dresser 5.

In this dresser 5, pipes 9a, 9b, 9c having different diameters are attached and fitted inside cylindrical dressers 5a, 5b, 5c arranged linearly. And attach the gear to the end of the pipe,
By arranging the motors 4a, 4b, 4c in each of them, they can be individually rotated. A belt drive may be used instead of the transmission of the transmission force by the gear.

Further, this configuration example is an example and is not limited. For example, a motor box is arranged outside and a gear is provided so as not to protrude from the outer periphery of each dresser (to avoid touching the polished surface). And rotation may be given by a motor. In addition, various configurations can be realized by a known method.

The operation of the embodiment configured as described above will be described.

For example, assume that the portion A of the polishing pad 1 has a more convex shape than the other portions. In this case, when the sensor 7 detects a convex portion of the polishing pad 1 that is rotating at a constant speed, the convex portion is sent to the flatness level measuring unit 8, an instruction is sent from the control unit 6 to the driving unit 4, and the dresser 5 is pressed against the pad. In this case, the dresser 5b rotates so as to increase the amount of polishing compared to the other dressers 5a and 5c. Note that the timing from the detection of the convex portion to the change of the rotation of the dresser 5 is such that the moving distance with respect to time can be easily obtained since the polishing pad 1 is at a constant rotation. Can be changed.

Next, FIG. 5 shows a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a third embodiment of the present invention and will be described.

In the above-described second embodiment, the divided dressers are connected in a straight line and are arranged toward the rotation axis of the polishing pad. However, in the present embodiment, the divided dresser rotates with the rotating polishing pad. Any one of the dressers is disposed so as to be pressed against the entire surface of the polishing surface, and the rotation is individually controlled.

In the present embodiment, the polishing pad 1 is rotated by a driving unit (not shown), and the polishing pad 1 is rotatable so as to be pressed against the polishing surface of the polishing pad 1 and to perform adjustment such as flattening and surface dressing. A columnar dresser 10 (10a, 10b, 10c) divided into three parts, a driving unit 4 for rotating the dresser 10 at a predetermined pressing pressure, and a contact or non-contact with the polishing surface of the polishing pad 1. A sensor 7 for detecting the degree of flatness in a line or a plurality of points, a flat level measuring unit 8 for detecting unevenness in a line from a detection signal detected by the sensor 7, and an unevenness detected by the flat level measuring unit 8. And a control unit 6 that controls the rotation of each of the dressers 10a, 10b, and 10c based on the above.

In the present embodiment, the dresser 10 is described as being divided into three parts. However, it is needless to say that the number of divisions may be appropriately determined by a polishing pad.

Next, FIG. 6 shows a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a fourth embodiment of the present invention, which will be described.

In this embodiment, a polishing pad 1 which is rotated by a driving unit (not shown) and a conical shape which is rotatable so as to be pressed against the polishing surface of the polishing pad 1 and to perform adjustment such as flattening and surface dressing are provided. Cone type) dresser 11
And a drive unit 4 for rotating the dresser 11 at a predetermined pressing pressure.

In this embodiment, the dresser 11 has a conical shape because the speed of the central portion is different from that of the circumferential side when the polishing pad 1 rotates, so that the dresser surface contacts the polishing surface at the same speed. Shape.

The dresser 11 may rotate in the reverse direction to adjust the polishing surface of the polishing pad, or may adjust the polishing surface while stopped depending on conditions.

According to the present embodiment, since the dresser 11 performs polishing adjustment in one direction and at a predetermined speed with respect to the polishing surface of the polishing pad 1, the polishing is flat and sharpened in one direction with respect to the rotation direction. The surface can be adjusted.

Further, the dresser 11 of this embodiment may be divided into a plurality of parts as in the above-described second and third embodiments, and each may be individually rotatable.

While the above description has been made of an example in which the polishing pad rotates, the present invention can be easily applied to a CMP apparatus which moves in a belt shape.

[0042]

As described above in detail, according to the present invention, uniform sharpening adjustment is performed on the polishing surface of the polishing pad, a wear state including irregularities is detected, and the polishing surface is flattened according to the state. And a dresser system for a CMP apparatus that performs adjustment.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a first embodiment.

FIG. 2 is a view showing a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a second embodiment.

FIG. 3 is a diagram showing a block configuration of the system shown in FIG. 2;

FIG. 4 is a diagram showing a specific configuration example of the dresser shown in FIG. 2;

FIG. 5 is a view showing a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a third embodiment.

FIG. 6 is a view showing a schematic external configuration of a polishing pad and a dresser system of a CMP apparatus according to a fourth embodiment.

FIG. 7 is a diagram showing a conceptual configuration of a disk dresser in a conventional CMP apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Polishing pad 2 ... Disk type dresser 3, 5 (5a, 5b, 5c) ... Dresser 4 ... Drive part 6 ... Control part 7 ... Sensor 8 ... Flatness level measurement part

Claims (5)

[Claims] 1. A CMP (C) method for removing a surface of a workpiece by a polishing pad which is rotated by pressing against the workpiece.
In a mechanical mechanical porishing apparatus, a cylindrical dresser that rotates in a direction perpendicular to the rotation surface of the polishing pad, is pressed against the polishing surface of the polishing pad, flattens the surface, and sharpens in one direction. And a drive means for applying a desired pressing pressure and rotation to the dresser. A dresser system for a CMP apparatus. 2. A CMP apparatus for flatly removing a surface of a workpiece by a polishing pad pressed against the workpiece and rotating, wherein the polishing pad rotates in a direction perpendicular to a rotation surface of the polishing pad, and Pressed against the polishing surface of the pad to flatten its surface and sharpen in one direction, a cylindrical dresser divided into a plurality and arranged linearly on the rotating surface, and each divided into a plurality A driving means for giving a desired rotation to the dresser; a flatness measuring means for detecting irregularities on a polishing surface of the polishing pad; and a driving means for the dresser by the driving means based on a result detected by the flatness measuring means. CM comprising control means for controlling pressing pressure and rotation.
Dresser system for P device. 3. The dresser includes pipes having different diameters fixed and fitted in the rotation axis direction at the center of the inside of each dresser, and each pipe end is provided with a driving unit to be connected. The dresser system according to claim 2, wherein the rotation is performed. 4. A CMP apparatus for flatly removing a surface of a workpiece by a polishing pad pressed against and rotating on the workpiece, wherein the polishing apparatus rotates in a direction perpendicular to a rotation surface of the polishing pad, and A cylindrical shape that is pressed against the polishing surface of the pad to flatten its surface and sharpen in one direction, and is divided into a plurality of portions and arranged to cover the entire polishing surface when the polishing surface rotates. A driving means for applying a desired pressing pressure and rotation to each of the plurality of divided dressers; a flatness measuring means for detecting unevenness of a polishing surface of the polishing pad; and a flatness measuring means. Control means for controlling the pressure and rotation of the dresser by the driving means based on the result obtained.
Dresser system for P device. 5. The dresser system for a CMP apparatus according to claim 1, wherein said dresser is formed in a conical shape.