JP2003173992A - Chemical mechanical polishing equipment - Google Patents

Abstract

[PROBLEMS] To provide a chemical mechanical polishing apparatus capable of uniformly polishing a polished surface of a polishing object and reducing polishing scratches. An object to be polished 16 held by a jig 14 is provided.
In a state in which the polishing surface is in contact with a polishing pad 13 stuck on a surface plate 11 having a conical side surface, the surface plate 11 is rotated while supplying an abrasive 18 from an abrasive pipe 12 arranged as an abrasive supply mechanism. Let it. At this time, the jig 14
Is reciprocated in a direction 20 perpendicular to the contact line formed by the polishing object 16 and the polishing pad 13 and parallel to the polishing surface of the polishing object 16, and further, the rotation direction of the platen 11 is moved by the jig 14. The rotation speed is changed in conjunction with the direction so that the rotation speed of the platen 11 with respect to the polishing target 16 during polishing is kept constant. [Effect] The polishing surface of the object to be polished can be uniformly polished, and polishing scratches can be reduced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present application relates to a chemical mechanical polishing apparatus.

[0002]

2. Description of the Related Art For objects to be polished such as semiconductor wafers, a technique for flattening the step of an insulating film is indispensable in order to meet the demand for a multi-layer wiring structure accompanying the recent higher integration and miniaturization of LSI devices. However, even more strict flatness will be required in the future. Further, polishing scratches caused by polishing adversely affect the structure as the device becomes finer. Therefore, in chemical mechanical polishing, a highly flat and defect-free surface is desired.

Japanese Laid-Open Patent Publication No. 10-71544 discloses a polishing object (semiconductor substrate) placed on a surface plate by spraying a polishing liquid onto a contact surface between a rotating cylindrical drum and a polishing object (semiconductor substrate). ) Is polished. In Japanese Patent Laid-Open No. 10-44029, a jig for holding an object to be polished (wafer) is provided with a bellows joint, and even if the polishing pad surface is inclined during polishing, the bellows joint is arranged below the jig. The holder that holds the object to be polished (wafer) also tilts to follow the object to be polished (wafer).
An apparatus including a mechanism that eliminates a gap between a polishing pad and a polishing pad is described. Japanese Patent Application Laid-Open No. 2000-24914 discloses that a polishing target (wafer) is rotated upward, and a polishing mechanism smaller than the polishing target (wafer) is pressed against the polishing target to rotate the polishing target. Move the upper part of the (wafer) and the polishing member is the object to be polished (wafer)
A device with a mechanism that can be freely tilted to follow the swell is described.

In all of the above conventional techniques, it is possible to uniformly polish an object to be polished in a plane, but the supplied abrasive is likely to accumulate on the surface plate or the object to be polished. As a result, the distribution of the polishing agent on the surface plate or the object to be polished is likely to be non-uniform, and there is room for improvement in order to highly uniformly polish the object to be polished. Further, in all of the above conventional techniques, since abrasion powder generated by polishing of the polishing object is difficult to be removed from the surface plate or the polishing object, polishing scratches easily occur on the polishing surface of the polishing object and there is room for improvement. .

[0005]

As described above, in the above-mentioned conventional techniques, there is room for improvement in highly uniform polishing and reduction of scratches due to polishing. That is, an apparatus capable of highly uniform polishing and reduction of polishing scratches is required. Therefore, in the present invention, the polishing agent is uniformly distributed on the surface plate so that the object to be polished can be uniformly polished, the jig is rotated at a constant rotation speed, and the abrasion powder generated by polishing the object to be polished is generated by the surface plate. The above technical problem is solved by providing a structure of a chemical mechanical polishing apparatus having a mechanism that is easily removed from above or above an object to be polished. This makes it possible to make the polishing surface of the object to be polished uniform and reduce polishing scratches.

[0006]

The concrete means of the present invention for solving the above problems are as follows.

The first means is chemical mechanical polishing provided with a jig for holding an object to be polished, a polishing pad for polishing the object to be polished, a surface plate for rotating the polishing pad, and a polishing agent supply mechanism. In the apparatus, the surface plate has a conical side surface having an inclination of more than 0 degree and less than 90 degrees with respect to the bottom surface of the surface plate, the abrasive supply mechanism is on the rotation axis of the surface plate, and the jig is the object to be polished. It has a mechanism that moves in a direction perpendicular to the contact line made by the polishing pad and parallel to the polishing surface of the polishing object, and the rotation direction of the surface plate works in conjunction with the movement mechanism of the jig that holds the polishing object. It is characterized in that the rotation speed of the surface plate with respect to the object to be polished is always constant due to the change.

A second means is characterized in that, in the first means, the surface plate has a truncated cone side surface.

The third means is characterized in that the polishing agent supply mechanism in the first and second means is provided on the surface plate main body which is cured by the rotary shaft of the surface plate.

A fourth means is characterized in that the jig is rotated at a constant speed in the first to third means.

By this means, the present invention has at least one of the following effects. (1) Since the surface of the polishing plate is inclined, the flow of the polishing agent is less likely to be disturbed, so that the distribution of the polishing agent on the polishing pad can be made uniform, and as a result, the entire polishing surface of the polishing target can be made uniform. Can be polished to. (2) The polishing load (polishing pressure) can be easily fine-tuned according to the fluctuation by making the surface plate a curved surface and making the contact portion with the polishing surface of the object to be polished into a line contact to make the contact area minute. it can. (3) Since the surface plate is inclined, the abrasion powder generated by polishing can be removed from the polishing pad by the liquid flow of the polishing agent, so that polishing scratches can be reduced over the entire polishing surface of the polishing target. (4) By rotating the jig at a constant rotation speed,
It is possible to highly uniformly polish the entire surface of the object to be polished.

Therefore, it is possible to uniformly polish the entire polishing surface of the object to be polished, reduce scratches on the polishing surface of the object to be polished, and further improve the product yield in CMP for semiconductor insulating films.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a perspective view of a chemical mechanical polishing apparatus having a surface 11 having a conical side surface. The sectional view is shown in FIG.

In the first embodiment, as shown in FIGS. 1 and 2, the surface plate 11 has a conical side surface where the bottom surface and the generatrix form an angle of 30 degrees, and the conical side surface of the surface plate 11 is completely coincident therewith. A polishing pad 13 having a size and shape is attached. Further, as a mechanism for supplying the polishing agent 18 onto the polishing pad 13, the polishing agent pipe 12 is used as the rotating shaft 1 of the surface plate 11.
It is arranged vertically above 9.

A jig 14 for holding an object 16 to be polished
Is placed at a position where the polishing surface of the polishing object 16 contacts the polishing pad 13. The jig 14 is an air compression plate 15
And the air 17 in the jig. Although the angle between the bottom surface and the generatrix is 30 degrees as the most effective angle in the embodiment, there is no particular limitation on the tilt angle as long as a uniform distribution of the abrasive can be formed by tilting. Specifically, it can be said that it is larger than 0 degrees and smaller than 90 degrees. This also applies to other embodiments.

Surface plate 1 to which polishing pad 13 is attached
1 rotates about the rotary shaft 19 of the surface plate of FIG. 2 as a rotary shaft. The shape of the surface plate 11 enables a uniform distribution of the polishing agent 18 on the polishing pad 13, and
By combining the polishing agent pipe 12 with the polishing agent pipe 12, a more uniform distribution of the polishing agent is possible. Further, the abrasion powder generated by polishing can be removed from the polishing pad 13 by the liquid flow of the polishing agent 18 supplied from the polishing agent pipe 12. Jig 14
The air compression plate 15 can control the polishing load (polishing pressure) by the pressure of the air 17 on the object to be polished 16. Further, the jig 14 is indicated by an arrow 2 in FIG.
There is a degree of freedom in the direction of 0, and during polishing, the object 16 to be polished and the polishing pad 13 can be reciprocated to a position where they are completely out of contact with each other. While the polishing pad 13 has a curved surface, the polishing surface of the polishing object 16 is a flat surface.
The polished surface of 6 is in line contact (line contact method). Thereby, the object 16 to be polished can be uniformly polished. Therefore, the generatrix on the side surface of the cone in the present specification needs to be a straight line because it is necessary to secure flatness by line contact, and does not include a curve. In the line contact method, the contact area between the polishing pad 13 and the polishing surface of the object 16 to be polished is smaller than that in the surface contact method which is often used in the conventional polishing methods. That is, since the contact area between the polishing pad 13 and the polishing surface of the object 16 to be polished is small, it is difficult to impede the liquid flow of the polishing agent 18, and the distribution of the polishing agent 18 on the polishing pad 13 does not become uneven. In addition, the polishing target 16
Although the contact area fluctuates depending on the polishing location, the contact area is so small that the air compression plate 15 using the air 17 is used.
It is easy to finely adjust the polishing load (polishing pressure) so as to be uniform over the entire polishing surface by controlling the atmospheric pressure.

Therefore, the entire polishing surface of the object 16 to be polished can be uniformly polished and polishing scratches can be reduced. (Embodiment 2) FIG. 3 shows a perspective view of a chemical mechanical polishing apparatus of Embodiment 2, and FIG. 4 shows a sectional view thereof. The bottom surface of the surface plate 11 and the bus bar make an angle of 30 degrees.

In the second embodiment, unlike the first embodiment, as a mechanism for supplying the polishing agent 18 onto the polishing pad 13,
A supply port 21 and a pipe 22 are provided on the main body along the rotating shaft 19 of the surface plate 11. As a result, when the polishing agent 18 is evenly distributed over the entire surface of the polishing pad 13, the polishing agent 18
It is easy to control the supply amount of. This is particularly useful in that the burden of matching the rotary shaft of the surface plate with the supply port can be reduced.

Therefore, as in the first embodiment, the polishing object 16
It is possible to uniformly polish the entire polishing surface and to reduce polishing scratches. (Embodiment 3) FIG. 5 shows a perspective view of a chemical mechanical polishing apparatus of Embodiment 3, and FIG. 6 shows a sectional view thereof.

In the third embodiment, unlike the first and second embodiments, the flat plate 23 is provided at the top of the surface plate 11. In this specification, the shape of the conical side surface in this case is particularly referred to as a truncated cone side surface. Further, the jig 14 for holding the object to be polished 16 moves only on the inclined surface of the truncated cone, and the flat portion 23
The requirement is not to move up. As in the first embodiment, the chemical mechanical polishing apparatus uses the polishing agent pipe 12 as a mechanism for supplying the polishing agent 18 onto the polishing pad 13.
It is arranged vertically above the first rotary shaft 19. as a result,
Since the polishing agent 18 temporarily stays on the flat surface portion 23 due to the surface tension, it is easy to uniformly distribute the polishing agent 18 on the entire surface of the polishing pad 13. Further, it is particularly useful in that the burden of strictly matching the rotary shaft of the surface plate with the supply port can be reduced.

Therefore, like the first and second embodiments, the entire surface of the object 16 to be polished can be uniformly polished, and can be polished without causing scratches. (Embodiment 4) FIG. 7 shows a perspective view of a chemical mechanical polishing apparatus of Embodiment 4, and FIG. 8 shows a sectional view thereof. In the fourth embodiment, similarly to the third embodiment, the flat plate 23 is provided on the uppermost part of the surface plate 11.

A jig 14 for holding an object 16 to be polished
In the same manner as in the third embodiment, it is necessary to move only on the truncated cone slope. Similar to the second embodiment, the chemical mechanical polishing apparatus has a supply port 21 and a pipe 22 arranged on the main body along the rotation axis 19 of the surface plate 11 as a mechanism for supplying the polishing agent 18 onto the polishing pad 13. ing. As a result, the polishing agent 18 temporarily stays on the flat surface portion 23 due to the surface tension, so that the polishing agent 18 can be uniformly distributed over the entire surface of the polishing pad 13, and the amount of the polishing agent 18 supplied can be increased. Easy to control.

Therefore, like the first to third embodiments, the entire polishing surface of the object 16 to be polished can be uniformly polished,
Moreover, polishing scratches can be reduced. (Embodiment 5) FIG. 9 shows a perspective view of a chemical mechanical polishing apparatus of Embodiment 5, and FIG. 10 shows a sectional view thereof.

The chemical mechanical polishing apparatus of Example 5 has a surface plate 11
Has a recess 24 at the top. Although the fifth embodiment shows that the surface plate 11 has a spherical recess, the present invention is not limited to this. It is a necessary condition that the jig 14 for holding the polishing object 16 moves only on the truncated cone slope. As a mechanism for supplying the polishing agent 18 onto the polishing pad 13, the polishing agent pipe 12 is attached to the platen 11.
It is arranged vertically above the rotary shaft 19. As a result, the polishing agent once stays in the depression 24, the overflowing polishing agent 18 flows down on the slope, and the polishing agent 18 can be uniformly distributed on the polishing pad 13 by the centrifugal force generated by the rotation of the surface plate 11. is there. Further, it is particularly useful in that the burden of strictly matching the rotary shaft of the surface plate with the supply port can be reduced. In this specification, the shape of the conical side surface in this case is also included in the truncated conical side surface. This means that the portion to be polished needs to be a straight line, but the upper part of the surface plate that is not subject to polishing does not necessarily have to be a flat surface.

Therefore, as in the first to fourth embodiments, the entire polishing surface of the object 16 to be polished can be uniformly polished and polishing scratches can be reduced. (Sixth Embodiment) FIG. 11 shows a perspective view of a chemical mechanical polishing apparatus of a sixth embodiment, and FIG. 12 shows a sectional view thereof.

The chemical mechanical polishing apparatus of Example 6 is the same as that of Example 5.
Similarly to the above, the surface plate 11 has a depression 24 at the top. Although Example 6 also shows that the surface plate 11 has a spherical depression, the present invention is not limited to this. It is a necessary condition that the jig 14 for holding the polishing object 16 moves only on the truncated cone slope. As a mechanism for supplying the polishing agent 18 onto the polishing pad 13, the platen 11
On the main body along the rotation axis 19 of the supply port 21 and the pipe 2
2 are arranged. As a result, the polishing agent 18 is temporarily depressed 2
4, the overflowing polishing agent 18 flows down on the slope, and the polishing agent 18 can be evenly distributed on the polishing pad 13 by the centrifugal force generated by the rotation of the surface plate 11. Easy to control. Further, it is particularly useful in that the burden of strictly matching the rotary shaft of the surface plate with the supply port can be reduced.

Therefore, as in the first to fifth embodiments, the entire polishing surface of the object 16 to be polished can be uniformly polished and polishing scratches can be reduced. (Embodiment 7) FIG. 13 shows a perspective view of a chemical mechanical polishing apparatus of Embodiment 7, and FIG. 14 shows a sectional view thereof. Plate 1
1 has a conical side surface where the bottom surface and the generatrix form an angle of 30 degrees.

In the seventh embodiment, in addition to the function of the first embodiment, the jig 14 is provided with a mechanism for rotating the jig 25 around the rotary shaft 25 at a constant speed. The shape of the surface plate 11 and the position of the abrasive pipe 12 are not limited to this example.

As a result, the object 16 to be polished can be highly uniformly polished over the entire polishing surface, and polishing scratches can be reduced.

[0030]

According to the present invention, it is possible to polish the entire surface of the object to be polished uniformly and without causing scratches.

[Brief description of drawings]

FIG. 1 is a perspective view of a chemical mechanical polishing apparatus of Example 1.

2 is a sectional view of the chemical mechanical polishing apparatus of Example 1. FIG.

FIG. 3 is a perspective view of a chemical mechanical polishing apparatus of Example 2.

FIG. 4 is a sectional view of a chemical mechanical polishing apparatus of Example 2.

FIG. 5 is a perspective view of a chemical mechanical polishing apparatus of Example 3.

FIG. 6 is a sectional view of a chemical mechanical polishing apparatus of Example 3.

FIG. 7 is a perspective view of a chemical mechanical polishing apparatus of Example 4.

FIG. 8 is a sectional view of a chemical mechanical polishing apparatus of Example 4.

FIG. 9 is a perspective view of a chemical mechanical polishing apparatus of Example 5.

FIG. 10 is a sectional view of a chemical mechanical polishing apparatus of Example 5.

FIG. 11 is a perspective view of a chemical mechanical polishing apparatus of Example 6.

FIG. 12 is a sectional view of a chemical mechanical polishing apparatus of Example 6.

FIG. 13 is a perspective view of a chemical mechanical polishing apparatus of Example 7.

FIG. 14 is a sectional view of a chemical mechanical polishing apparatus of Example 7.

[Explanation of symbols]

11 ... Surface plate, 12 ... Abrasive pipe, 13 ... Polishing pad, 1
4 ... Jig, 15 ... Air compression plate, 16 ... Polishing object, 17
… Air in jig, 18… Abrasive, 19… Rotation axis of surface plate, 2
0 ... Jig movement direction, 21 ... Abrasive supply port, 22 ... Abrasive pipe, 23 ... Planar part, 24 ... Recess, 25 ... Jig rotation axis.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B24B 57/02 B24B 57/02 (72) Inventor Mina Amaba 7-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Hitachi Research Laboratory F-term (reference) 3C047 FF08 GG15 3C058 AA07 AA09 AB01 AC04 CB01 CB02 DA13 DA17

Claims (8)

[Claims] 1. A chemical mechanical polishing apparatus comprising a jig for holding an object to be polished, a polishing pad for polishing the object to be polished, a platen for rotating the polishing pad, and an abrasive supply mechanism. A chemical mechanical polishing apparatus, wherein the surface plate has a conical side surface having an inclination of more than 0 degree and less than 90 degrees with respect to the bottom surface of the surface plate. 2. A chemical mechanical polishing apparatus comprising a jig for holding an object to be polished, a polishing pad for polishing the object to be polished, a surface plate for rotating the polishing pad, and an abrasive supply mechanism. A chemical mechanical polishing apparatus, wherein the surface plate has a truncated cone side surface having an inclination of more than 0 degrees and less than 90 degrees with respect to the bottom surface of the surface plate. 3. The chemical mechanical polishing apparatus according to claim 1, wherein the polishing agent supply mechanism is provided on a surface plate main body along a rotation axis of the surface plate. 4. The chemical mechanical polishing apparatus according to claim 1, wherein the polishing agent supply mechanism is installed on the rotary shaft of the surface plate. 5. The jig has a mechanism for moving in a direction perpendicular to a contact line formed by the object to be polished and the polishing pad and parallel to a polishing surface of the object to be polished.
5. The chemical mechanical polishing device described in 4 above. 6. The chemical mechanical polishing apparatus according to claim 5, wherein the jig is rotated at a constant rotation speed. 7. A surface plate for a chemical mechanical polishing apparatus having a conical side surface or a truncated cone side surface inclined at an angle of more than 0 degree and less than 90 degrees. 8. A chemical mechanical polishing apparatus comprising a jig for holding an object to be polished, a polishing pad for polishing the object to be polished, a platen for rotating the polishing pad, and a polishing agent supply mechanism. The surface plate has a conical side surface or a truncated cone side surface having an inclination of more than 0 degree and less than 90 degrees with respect to the bottom surface of the surface plate, and the polishing agent supply mechanism is installed on a rotation axis of the surface plate. The jig has a mechanism that moves in a direction perpendicular to the contact line formed by the object to be polished and the polishing pad and parallel to the polishing surface of the object to be polished, and rotates the jig at a constant rotation speed. A chemical mechanical polishing apparatus characterized in that a rotation speed of the surface plate with respect to an object to be polished is constant by changing a rotation direction of the surface plate in association with a movement mechanism of the jig.