JP2003179012A - Slurry supply method and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slurry supply method and an apparatus therefor which can prevent clogging of a filter and occurrence of scratch. <P>SOLUTION: The apparatus includes a slurry supply line having a filter 2 provided at the last stage of a piping 1 for slurry supply and a slurry solvent valve 8 connected to the slurry supply line for combining slurry passed through the slurry supply line with solvent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for supplying a slurry in semiconductor polishing, and more particularly to a technology for supplying a slurry (polishing agent) in a CMP technique used for semiconductor manufacturing.

[0002]

2. Description of the Related Art Normally, CMP (Chemical Mechanical Po
(lishing: chemical mechanical polishing) is a method for supplying a polishing agent containing fine particles to the surface of a wafer and pressing a polishing cloth to move the polishing agent to flatten the steps generated in the wafer process step. In order to press the polishing cloth, the fine particles of the abrasive, that is, the slurry to be supplied, need to be highly controlled. This is because when the fine particles are aggregated into large particles, or when foreign matter such as a valve in the supply system is supplied to the wafer surface, scratches that locally scrape the wafer surface occur. In order to prevent this, a filter for removing foreign matter is provided at the final stage of the slurry supply line.

FIG. 6 is a block diagram showing a conventional slurry supply device. In the drawing, the slurry is supplied from the left side of the drawing through a pipe 1, and finally the filter 2 removes the giant particles, and the slurry is discharged onto the polishing platen 4 to which the polishing cloth 3 is attached. The wafer 5 to be polished is pressed against the polishing cloth 3 and is rotated, whereby polishing progresses. When the polishing is completed, the slurry valve 6 is closed. However, if the slurry valve 6 and the slurry after the slurry valve 6 are dried and adhered to cause clogging and scratches, the pure water valve 7 is opened to open the pipe 1 Discharge the slurry inside.

At this time, since the additive in the slurry is diluted, the dispersion effect is reduced, the agglomeration of fine particles is caused, and the filter 2 is clogged and scratched. Further, even when the slurry is flowed after being replaced with pure water to restart the polishing, the slurry flows through the pipe 1 and the filter 2 filled with pure water, so that the addition in the slurry is performed as in the case of the pure water replacement. The agent is diluted and causes agglomeration of fine particles, and the filter 2
Is causing clogging or scratching.

[0005]

As described above, in the case of the conventional slurry supplying apparatus, when the apparatus is in a non-operating state in which the slurry does not flow, the replacement with pure water is performed to prevent the dry adhesion in the filter. There was a problem that the slurry sometimes agglomerated and the filter was clogged. This is to prevent aggregation of fine particles in the slurry,
This is because the solvent is made alkaline or contains an additive, but when it is replaced with pure water, the dispersion effect of these is reduced.

The present invention has been made to solve such conventional problems, and an object thereof is to provide a slurry supply method and an apparatus therefor capable of preventing clogging and scratching of a filter. To do.

[0007]

According to a first aspect of the present invention, there is provided a slurry supply method for supplying a slurry to a polishing platen having a polishing cloth attached thereto through a slurry supply line introduced into a final stage filter. In, the solvent is merged with the slurry flowing through the slurry supply line and is supplied.

In the slurry supply method according to the second aspect of the present invention, pure water is periodically flown through the slurry supply line to replace the solvent with pure water.

In the slurry supply method according to the third aspect of the present invention, as the solvent, an ammonia solution is used in the case of an ammonia-based slurry, and the same dispersant is introduced in pure water in the case of a slurry containing a dispersant. Is used.

According to a fourth aspect of the present invention, there is provided a slurry supply method, wherein the slurry is supplied to a polishing platen having a polishing cloth attached thereto through a slurry supply line introduced into a final filter. To supply the pure water periodically to discharge the slurry, and then to supply the pure water from the movable pure water supply container provided near the discharge port of the slurry supply line to the slurry supply line on a regular basis. It sucks and drains in the opposite direction.

A slurry supply apparatus according to a fifth aspect of the present invention is a slurry supply line having a filter at the final stage of a pipe for supplying the slurry, and a slurry connected to the slurry supply line and flowing through the slurry supply line. And a solvent supply means for merging the solvent.

A slurry supply device according to the invention of claim 6,
A pure water supply means is provided between the filter and the solvent supply means, and supplies pure water periodically.

A slurry supply device according to the invention of claim 7,
The solvent supply means has a slurry solvent valve attached to the pipe of the slurry supply line.

A slurry supply device according to the invention of claim 8;
As the above-mentioned solvent, an ammonia solution is used in the case of an ammonia-based slurry, and the same dispersant is introduced in pure water in the case of a slurry in which a dispersant is introduced.

A slurry supply device according to the invention of claim 9
A slurry supply line in which a filter is provided at the final stage of the pipe to which the slurry is supplied, a pure water supply means connected to the slurry supply line to supply pure water on a regular basis, and the vicinity of the outlet of the slurry supply line A suction and drainage connected to the movable pure water supply container provided in the above and the slurry supply line, for periodically sucking and discharging pure water from the pure water supply container in the opposite direction to the slurry supply line. And means.

The slurry supply device according to the tenth aspect of the present invention, wherein the suction / drainage means comprises a suction / drainage valve attached to a pipe of the slurry supply line, and a pump connected to the suction / drainage valve. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
It will be described with reference to the drawings. Embodiment 1. 1 is a layout diagram showing the configuration of a slurry supply device according to a first embodiment of the present invention. In the figure, 1 is a pipe to which slurry is supplied, 2 is a filter that is attached to the pipe 1 and finally removes giant particles passing through this pipe 1, 3 is a polishing cloth, and 4 is a polishing cloth 3. A polishing platen, 5 is an object to be polished, such as a wafer, 6
Is a slurry valve attached to the pipe 1 in front of the filter 2, and 8 is a slurry solvent valve attached to the pipe 1 between the slurry valve 6 and the filter 2 to merge the slurry solvent with the slurry.

Next, the operation will be described. The slurry is supplied to the pipe 1 from the left side of the drawing, and finally, the filter 2 removes the giant particles and discharges it onto the polishing platen 4 to which the polishing cloth 3 is attached. The wafer 5 which is the object to be polished is pressed against the polishing cloth 3 and is rotated, whereby the polishing progresses. When the polishing is completed, the slurry valve 6 is closed, but if the slurry valve 6 and the subsequent parts of the slurry valve 6 are dried and adhered to the slurry valve 6, clogging and scratches occur, first, the slurry solvent valve 8 is opened. The slurry in the pipe 1 is diluted with the slurry solvent from the slurry solvent valve 8 and discharged. That is, the slurry in the pipe 1 and the filter 2 is substantially replaced with the solvent. In this case, since a solvent that disperses the fine particles is used, the dispersion effect does not decrease, the fine particles do not aggregate, and filter clogging and scratching do not occur.

When the replacement of the slurry in the pipe 1 and the filter 2 with the solvent is completed, the slurry solvent valve 8 is closed. When the polishing is restarted, the slurry valve 6 is opened to flow the slurry into the pipe 1 and the filter 2. However, since the slurry is filled with the solvent, the slurry is promptly replaced with the solvent without agglomeration.

As an example of the solvent of the slurry, an ammonia solution in the case of an ammonia-based slurry and a solution in which the same dispersant is introduced in pure water in the case of a slurry in which a dispersant is introduced can be considered.

In this way, in the present embodiment, it joins the slurry supply system introduced into the final stage filter,
A system for merging the solvent of the slurry is provided, and since the solvent that disperses the fine particles is used as the solvent of the slurry, the dispersion effect does not decrease, and the aggregation of the fine particles is not caused,
It is possible to prevent filter clogging and scratches.

Embodiment 2. FIG. 2 is a layout diagram showing the configuration of the slurry supply device according to the second embodiment of the present invention. In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and duplicate description thereof will be omitted. In this embodiment, the slurry valve 6 and the filter 2 are the same as those in the first embodiment.
A pure water valve 7 for periodically flowing pure water is attached to the pipe 1 behind the slurry solvent valve 8 provided in the pipe 1. Other configurations are the same as those in the first embodiment.

Next, the operation will be described. The slurry is supplied to the pipe 1 from the left side of the drawing, and finally, the filter 2 removes the giant particles and discharges it onto the polishing platen 4 to which the polishing cloth 3 is attached. The wafer 5 to be polished is pressed against the polishing cloth 3 and is rotated, whereby polishing progresses.

When the polishing is completed, the slurry valve 6 is closed. However, if the slurry valve 6 and the slurry after the slurry valve 6 are dried and adhered to the slurry valve 6, clogging and scratches occur, first, the slurry solvent valve 8 is closed. By opening, the slurry in the pipe 1 is diluted with the slurry solvent from the slurry solvent valve 8 and discharged. Since the solvent for dispersing the fine particles is used, the dispersion effect does not decrease, the fine particles do not agglomerate, and the filter clogging and scratches do not occur. When the replacement of the slurry in the pipe 1 and the filter 2 with the solvent is completed, the slurry solvent valve 8 is closed and then the pure water valve 7 is opened.

When the replacement of the solvent in the pipe 1 and the filter 2 with pure water is completed, the pure water valve 7 is closed and the pipe 1 and the filter 2 after the slurry valve 6 are filled with pure water. By periodically opening the pure water valve 7 and flowing pure water, the pipe 1 and the filter 2 are prevented from drying. Since it is replaced with pure water, it is not necessary to use a high-cost slurry or solvent, so that the apparatus can be maintained at low cost even when polishing is not performed for a long time.

To restart polishing, first, the slurry solvent valve 8 is opened to fill the pipe 1 and the filter 2 with the slurry solvent, and then the slurry solvent valve 8 is closed and the slurry valve 6 is opened. Since pure water and the slurry do not mix directly, it is possible to prevent aggregation of the slurry.

FIG. 3 shows the opening / closing timing of each valve.
In this way, in the present embodiment, a system that joins the slurry supply system that is introduced into the final-stage filter, a system that joins the solvent of the slurry, and pure water for periodically flowing pure water to the rear of this system. By providing a system and replacing the slurry in the filter with a solvent, then replacing it with pure water and flowing pure water periodically, it is possible to prevent filter clogging and scratches, and even during long-term suspension. Slurry aggregation can be prevented at low cost.

Embodiment 3. FIG. 4 is a layout diagram showing a configuration of a slurry supply device according to a third embodiment of the present invention. Note that, in FIG. 4, portions corresponding to those in FIG. 2 are denoted by the same reference numerals, and duplicate description thereof will be omitted. In this embodiment, a pure water slurry 9 as a movable pure water supply container is provided at the slurry supply port. In addition, a suction / drainage valve 10 in place of the slurry solvent valve 8 and a pump 11 connected to the suction / drainage valve 10 are provided in front of the pure water valve 7 attached to the pipe 1 in the above-described second embodiment, and the branching just before the filter is performed. Provide a suction line on the line. Other configurations are the same as those in the second embodiment.

Next, the operation will be described. The slurry is supplied to the pipe 1 from the left side of the drawing, and finally, the filter 2 removes the giant particles and discharges it onto the polishing platen 4 to which the polishing cloth 3 is attached. The wafer 5 to be polished is pressed against the polishing cloth 3 and is rotated, whereby polishing progresses.

When the polishing is completed, the slurry valve 6 is closed. However, if the slurry valve 6 and the slurry after the slurry valve 6 are dried and adhered to the slurry valve 6, clogging and scratches occur, first, the pure water valve 7 is closed. The slurry in the pipe 1 is discharged by opening. At this time, since the additive in the slurry is diluted, the dispersion effect is reduced, and the fine particles are aggregated to cause clogging of the filter.
It is necessary to regularly remove the slurry that has aggregated and clogged the filter 2.

Therefore, first, normally, the movable pure water tray 9 in the retracted state as shown in FIG. 4 is moved to the slurry discharging slot as shown in FIG. Next, the suction / drainage valve 10 is opened, and the pump 11 connected to the suction / drainage valve 10 is opened.
Then, the pure water in the pure water tray 9 is sucked. At this time, the agglomerated giant particles captured in the filter 2 by the flow of pure water are discharged toward the pump 11. Thus, by periodically removing the agglomerated giant particles clogging the filter 2, clogging and scratching of the filter 2 are prevented.

As described above, in this embodiment, the suction line is provided in the branch line immediately before the filter, and the movable pure water tray, that is, the pure water supply container is provided in the slurry supply port, and the suction is performed periodically. Prevents filter clogging and scratches by creating a reverse flow from the line and removing slurry solids that have accumulated on the filter next side and housing bottom, that is, by removing agglomerated giant particles that have clogged the filter, etc. can do.

[0033]

As described above, according to the invention of claim 1, in the slurry supply method of supplying the slurry to the polishing platen having the polishing cloth attached thereto through the slurry supply line introduced into the final stage filter, Since the solvent is merged and supplied to the slurry flowing through the slurry supply line, it is possible to prevent clogging of the filter and scratches.

According to the second aspect of the invention, since the pure water is periodically flown through the slurry supply line to replace the solvent with the pure water, it is possible to prevent the filter from being clogged and scratched. There is an effect that the slurry agglomeration can be prevented at a low cost even when stopped for a long period of time.

According to the inventions of claims 3 and 8,
As the solvent, in the case of an ammonia-based slurry, an ammonia solution, and in the case of a slurry in which a dispersant is introduced, the same dispersant introduced in pure water is used, so that clogging of the filter and prevention of scratches occur. There is an effect that it can contribute.

Further, according to the invention of claim 4, in the slurry supply method of supplying the slurry to the polishing platen having the polishing cloth attached thereto through the slurry supply line introduced into the final stage filter, the slurry supply line is provided. Pure water is regularly supplied to discharge the slurry, and then pure water from a movable pure water supply container provided in the vicinity of the discharge port of the slurry supply line is periodically reversed from the slurry supply line. Since it is sucked in the direction and drained, there is an effect that the clogging of the filter and the occurrence of scratches can be prevented.

Further, according to the invention of claim 5, a slurry supply line in which a filter is provided at the final stage of a pipe for supplying the slurry and a slurry which is connected to the slurry supply line and flows through the slurry supply line. Since the apparatus is provided with a solvent supply unit that joins the solvent, there is an effect that it is possible to prevent clogging of the filter and generation of scratches.

Further, according to the invention of claim 6, since the deionized water supply means is provided between the filter and the solvent supply means and supplies deionized water periodically, the filter is clogged and scratched. It is possible to prevent the occurrence of the above-mentioned phenomenon and to prevent the aggregation of the slurry at a low cost even when the operation is stopped for a long time.

Further, according to the invention of claim 7, since the solvent supply means has a slurry solvent valve attached to the pipe of the slurry supply line, it is possible to contribute to the prevention of clogging of the filter and occurrence of scratches. There is an effect.

According to the invention of claim 9, the slurry supply line is provided with a filter at the final stage of the pipe for supplying the slurry, and the slurry supply line is connected to supply pure water regularly. Pure water supply means, a movable pure water supply container provided near the outlet of the slurry supply line, and the pure water from the pure water supply container are connected to the slurry supply line, and the pure water is periodically supplied to the slurry. Since the suction / drainage means for sucking and draining in the direction opposite to the supply line is provided, it is possible to prevent clogging of the filter and generation of scratches.

Further, according to the invention of claim 10, the suction / drainage means comprises a suction / drainage valve attached to the pipe of the slurry supply line, and a pump connected to the suction / drainage valve. There is an effect that it can contribute to the prevention of the occurrence of clogging and scratches.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing an opening / closing timing of each valve in the second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing a third embodiment of the present invention.

FIG. 6 is a configuration diagram showing a conventional thriller supply device.

[Explanation of symbols]

1 pipe, 2 filter, 3 polishing cloth, 4 polishing platen, 5 wafer, 6 slurry valve, 7
Pure water valve, 8 Slurry solvent valve.

Claims (10)

[Claims] 1. A slurry supply method for supplying a slurry to a polishing platen having a polishing cloth attached thereto through a slurry supply line introduced into a final stage filter, wherein a solvent is merged with the slurry flowing through the slurry supply line and supplied. A method for supplying a slurry, characterized in that 2. The slurry supply method according to claim 1, wherein pure water is periodically flown through the slurry supply line to replace the solvent with pure water. 3. As the solvent, an ammonia solution is used in the case of an ammonia-based slurry, and the same dispersant is introduced in pure water in the case of a slurry in which a dispersant is introduced. Alternatively, the slurry supply method described in 2. 4. A slurry supply method of supplying a slurry to a polishing platen having a polishing cloth attached thereto through a slurry supply line introduced into a final stage filter, wherein pure water is supplied to the slurry supply line regularly. The slurry is discharged, and then pure water from a movable pure water supply container provided near the discharge port of the slurry supply line is periodically sucked in a direction opposite to the direction of the slurry supply line so as to be drained. A slurry supply method characterized by the above. 5. A slurry supply line in which a filter is provided at the final stage of a pipe to which the slurry is supplied, and a solvent supply means connected to the slurry supply line for merging the solvent with the slurry flowing through the slurry supply line. A slurry supply device characterized by being provided. 6. The slurry supply apparatus according to claim 1, further comprising a pure water supply unit that is provided between the filter and the solvent supply unit and that regularly supplies pure water. 7. The slurry supply device according to claim 5, wherein the solvent supply means has a slurry solvent valve attached to a pipe of the slurry supply line. 8. The solvent used is an ammonia solution in the case of an ammonia-based slurry, and the same dispersant introduced in pure water in the case of a slurry in which a dispersant is introduced. The slurry supply device according to any one of to 7. 9. A slurry supply line in which a filter is provided at the final stage of a pipe to which slurry is supplied, a pure water supply unit connected to the slurry supply line to supply pure water regularly, and the slurry supply line. A movable pure water supply container provided near the outlet of the line and the slurry supply line are connected, and pure water from the pure water supply container is regularly sucked in the opposite direction to the slurry supply line. A slurry supply device comprising: a suction drainage means for draining the slurry. 10. The slurry supply according to claim 9, wherein the suction / drainage means includes a suction / drainage valve attached to a pipe of the slurry supply line, and a pump connected to the suction / drainage valve. apparatus.