JP2004063846A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the frequency for replacing the filter by elongating the life, by eliminating clogging in filters. <P>SOLUTION: An endless filter 20 is rotated so as to repeatedly pass through a slurry filtering part 30 and a back-cleaning part 40, which are arranged to face a filter surface 20a. If clogging is caused by the filtration of slurry, the filter surface 20a is transferred to the back-cleaning part 40 to regenerate filtering functions. The reproduced filter surface 20a is then transferred to the slurry filtering part 30, to repeat filtration. Thus, by repeatedly performing filtration and reproduction with a single filter, the frequency of changing the filter is suppressed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor device manufacturing technique, and more particularly to a technique effective when applied to a filter used for removing foreign matter in a slurry in a polishing step or the like to eliminate clogging.
[0002]
[Prior art]
The technology described below has been studied by the inventor when researching and completing the present invention, and the outline thereof is as follows.
[0003]
2. Description of the Related Art In a CMP apparatus used for a semiconductor device or the like, a wafer surface or the like is polished using a chemical solution called a slurry and mixed with fine particles. In general, about 10% of the slurry used is substantially used for polishing, and about 90% of the remaining slurry is used, although it depends on the type of film on the surface to be polished and the structure of the CMP apparatus. At present, it is discarded as wastewater.
[0004]
However, for example, the processing cost of a CMP apparatus using a slurry in a semiconductor device is said to be about 1000 $ / W, and 90% of such cost is occupied by the cost of the processing material including the direct material and the consumable parts. Have been. Of the processing material costs, the slurry used for CMP polishing is about 500 $ / W, and the ratio of the slurry cost is extremely large.
[0005]
Therefore, effective use of the slurry is strongly required. In response to such demands, it has been practiced to reduce the amount of waste slurry and reuse the slurry. In such a slurry recycling technique, a major point is how to efficiently remove agglomerated abrasive grains, processing debris, and the like from used slurry.
[0006]
If processing refuse such as polishing refuse generated by CMP polishing or coagulated abrasive grains remains in the regenerated slurry, scratches will be generated by use of the regenerated slurry.
[0007]
Generally, such agglomerated abrasive grains or polishing debris are removed by passing used slurry through a filter. However, in the method using a filter, clogging of the filter necessarily occurs, and periodic filter replacement is required.
[0008]
Filter filtration of waste liquid from the CMP device causes clogging of the filter in a short time, so filter replacement in the slurry recycling technology is frequent, leading to downtime of the slurry recycling device, increase in filter replacement cost, etc. The cost burden of filter maintenance on the operation efficiency and operation cost of the slurry recycling system is extremely large. Therefore, how to effectively eliminate the clogging of the filter has been raised as a major problem.
[0009]
JP-A-2002-1661 discloses a filter structure in which clogging is unlikely to occur. That is, a second filter composed of a solid substance that can pass through the eyes of the first filter and a solid substance that cannot pass through the first filter is provided on a first filter of an organic polymer type, a ceramic type, or the like.
[0010]
The second filter, for example, passes both solids on the first filter by passing drainage containing solids that can pass through the eyes of the first filter and solids that cannot pass through the first filter. It is formed by depositing.
[0011]
When the used slurry from the polishing process such as a CMP apparatus is filtered using the filter including the first filter and the second filter formed by depositing the solid matter, the coagulated abrasive in the slurry is removed. Unwanted substances such as particles and processing wastes are removed in the second filter portion.
[0012]
Unnecessary matter is filtered in the second filter part, and when clogging of the second filter occurs due to such unneeded matter, the first filter is moved by rocking the drainage or the like. The second filter formed by depositing on it collapses to eliminate clogging.
[0013]
Such a configuration eliminates the clogging of the filter from the viewpoint of removing the clogging-causing substance, but by disintegrating the clogged filter portion itself.
[0014]
The second filter that has been disintegrated in this way can be regenerated by passing drainage again as described above, that is, it can eliminate clogging. Further, by providing irregularities on the first filter surface and depositing and forming the second filter having the above configuration on the first filter surface, vibration is applied from the beginning, or air bubbles or the like are formed on the second filter surface. , It is possible to use only the surface layer side of the second filter while collapsing, and by performing the filtering while constantly updating the surface layer of the second filter, the clogging of the second filter is prevented. There is also disclosed a configuration for preventing the generation of.
[0015]
[Problems to be solved by the invention]
However, the present inventor has found that there are the following problems in the above-mentioned slurry regeneration treatment technology.
[0016]
That is, by using the above proposed technique, it is possible to remove foreign substances such as agglomerated abrasive grains and polishing debris in the used slurry while easily performing clogging or eliminating the generated clogging. However, the second filter, which can easily eliminate clogging, needs to be deposited on the first filter to such an extent that it can easily collapse in drainage water. A simple deposition technique is required.
[0017]
In addition, the deposited second filter is always placed in water to keep the deposited filter easily collapsed from the first filter, or remains as it is during the operation stoppage of the apparatus. If the filter is immersed in water, the deposited second filter may be naturally disintegrated. Therefore, special measures to prevent the disintegration by continuing to pass water through the second filter are required. Handling is troublesome.
[0018]
Further, when the clogging is eliminated, the second filter is disintegrated in the drainage to eliminate the clogging, and it is necessary to interrupt the filtration until the second filter is formed each time the second filter is disintegrated.
[0019]
As described above, in the method in which the filter itself is configured to be easily disintegrated and the clogging is eliminated by the disintegration, even if the clogging can be easily eliminated, the operation of the filter regeneration and the filtration operation are performed until the filter is regenerated. They have to be interrupted.
[0020]
In order not to interrupt the filtration, it is conceivable to use a plurality of filters and perform filter regeneration or filter replacement on one filter while continuing filtration on the other filter. Even if the downtime problem is solved, filter maintenance related to filter replacement and filter regeneration cannot be completely eliminated. Filter maintenance work, which is troublesome and time-consuming, will remain.
[0021]
At the same time, the provision of a plurality of filters inevitably increases the device configuration. This is contrary to the demand for downsizing and space saving of the manufacturing apparatus in the semiconductor field, and it is desirable to develop a technology capable of performing processing without employing such a configuration.
[0022]
As long as a filter is used, clogging of the filter cannot be avoided.However, it is difficult to prevent such clogging, or the clogging can be eliminated and the filter can be quickly returned to reduce the filter usage period. If the filter replacement can be made long before it can be considered unnecessary, the cost for filter maintenance can be positively reduced.
[0023]
Further, although some proposals have been made regarding a slurry recycling system, for example, a collection tank, an adjustment tank, and a configuration in which a plurality of filters are used to adjust slurry particle size, adjust concentration, and adjust PH. Such a large tank is provided, has a large throughput of about 1 to 4 CMP apparatuses, and has a large-scale configuration.
[0024]
In particular, since a fixed filter such as a ceramic film, an organic film, and a UF film is used for the filter, clogging is likely to occur, and replacement is required in about two weeks.
[0025]
As described above, it has been pointed out that the conventional slurry recycling system does not sufficiently solve the space problem of the apparatus main body and the cost problem of maintaining the filter, so that the effect based on the reuse by the slurry recycling is weakened. there were.
[0026]
That is, the slurry recycling technology is not yet sufficiently satisfactory in terms of space and cost, and further miniaturization, space saving, and cost reduction are desired.
[0027]
SUMMARY OF THE INVENTION An object of the present invention is to make it possible to quickly remove clogging and return the filter function without replacing the filter when reusing the slurry, when removing clogging of a filter used for removing foreign matter. .
[0028]
Another object of the present invention is to reduce the size of a slurry recycling system.
[0029]
The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0030]
[Means for Solving the Problems]
The following is a brief description of an outline of typical inventions disclosed in the present application.
[0031]
That is, in the present invention, the filtering process is performed on a part of the same filter, the clogging process is performed on the other filter, the filtered portion is turned to the clogging removing process, and the portion subjected to the clogging removing process is processed. By performing the filtering process, the filtering process and the clogging elimination process can be performed in parallel for the same filter, so that the filtering process and the filter regeneration process can be performed without performing the filter replacement. The same filter can be used continuously and used repeatedly while maintaining a constant filtration rate. It is not necessary to replace the filter every time the clogging is eliminated, and a maintenance-free filter configuration can be achieved.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for describing the embodiments, members having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted.
[0033]
(Embodiment 1)
In the present embodiment, a filter mechanism that forms a filter into an endless shape such as a roll, performs a filtering process of slurry in a part of the filter, and performs a clogging elimination process of the filter that has been filtered in another part. explain.
[0034]
FIG. 1 is a perspective view of a main part showing a filter mechanism when the filter is formed in a rotating roll shape. FIG. 2 is an explanatory view showing the filter mechanism from a side cross section in a state where the configuration shown in FIG. 1 is partially changed.
[0035]
As shown in FIG. 1, the filter mechanism 10 includes an endless filter 20 and rollers 11 and 12 for rotating the endless filter 20. One of the rollers 11 and 12 may be configured as a driving roller for rotating a motor, and the other may be configured as a driven roller.
[0036]
For example, the endless filter 20 is formed in a roll shape as shown in FIG. 1 and is rotatably stretched between rollers 11 and 12 separated by a predetermined distance in a belt manner. The endless filter 20 having such a configuration is configured to rotate while being stretched flat between the rollers 11 and 12. The filter 20 is configured as an organic film filter. In the figure, the entire mesh state is omitted by showing the mesh state on a part of the filter surface 20a so that the drawing is easy to see.
[0037]
A slurry filtration unit 30 is provided to face the filter surface 20a which is stretched flat and rotates. In the case shown in FIG. 1, used slurry from a CMP device (not shown) is supplied from the supply pipe 31 toward the filter surface 20a.
[0038]
In the case shown in FIG. 1, the supply of the used slurry is distributed to a plurality of supply pipes 31 using a manifold or the like, so that a wide filtration area can be secured. The supply pipe 31 may be connected to the used slurry discharge side of the CMP apparatus so that the used slurry can be directly supplied to the filter 20 without passing through the recovery tank. Compared to the case where a recovery tank is provided, the space of the device configuration can be remarkably reduced and the efficiency can be improved.
[0039]
However, the supply pipe 31 may be configured to be connected via the buffer tank so that the supply of the used slurry to the filter 20 can be adjusted.
[0040]
As shown in detail in FIG. 2, the supply pipe 31 has a pipe end supported by a pipe end support 32, and a lower surface of the pipe end support 32 slightly floating from the filter surface 20a. It is configured to lightly contact the surface 20a. FIG. 2 shows a state in which the contact is made. By providing the tube end supporting portion 32 in this manner, scattering of the slurry from the tube end to the periphery when the slurry is supplied from the supply tube 31 to the filter surface 20a is prevented. In FIG. 1, the tube end support portion 32 is omitted so that the drawing is easy to see.
[0041]
The tube end supporting portion 32 needs to be made of a material that does not affect the slurry component. ₂ And the like.
[0042]
A slurry receiving portion 33 formed in a substantially dish shape is provided on the back side of the filter surface 20a facing the supply pipe 31. The slurry receiving portion 33 receives the slurry passing through the filter surface 20a and discharges the slurry from the filter mechanism portion 10. I can do it. The discharged slurry may be sent to a slurry recycling step, for example. If recycling is not required, it can be sent to a disposal process.
[0043]
Below the filter surface 20a on which the slurry filtration unit 30 faces, the rotating endless filter 20 is rotated while being flattened between the rollers 11 and 12, and the filter back surface 20b faces upward. ing. A backwash processing unit 40 is provided for the filter back surface 20b.
[0044]
As shown in FIG. 1, the backwashing processing unit 40 is provided with a nozzle 41 as an air blow mechanism so as to cross the filter back surface 20b in the width direction, so that the jet air a can be blown from the nozzle 41 onto the filter back surface 20b. ing. In the drawing, the state of jet air a blowing is shown in a substantially triangular shape.
[0045]
That is, the slurry is filtered by the slurry filtration unit 30, and the jet air a is discharged in a state in which unnecessary substances such as agglomerated abrasive grains in the slurry are captured in the mesh part of the filter 20, that is, in a state where clogging is caused. By spraying on the filter back surface 20b, unnecessary matter is forcibly blown off and separated from the sent filter 20, and clogging is eliminated.
[0046]
In the filter mechanism section 10, as shown in FIG. 1, a disposal section 50 is provided below the backwash section 40. The disposal section 50 has a configuration in which a slope 51 that is directed obliquely downward from the periphery of the endless filter 20 is connected to a disposal port 52, and clogging substances such as agglomerate abrasive grains that have been backwashed are disposed along the slope 51. It flows down and reaches the waste port 52.
[0047]
FIG. 2 has substantially the same configuration as the filter mechanism unit 10 shown in FIG. 1, but is partially different, for example, in the configuration of the slurry receiving unit 33, the backwash processing unit 40, and the disposal processing unit 50.
[0048]
In the case shown in FIG. 2, a slurry pipe 34 is provided below the slurry receiving section 33. The slurry filtered on the filter surface 20a is once received by the slurry receiving section 33, and then flows to the lower slurry pipe 34, so that the slurry can be sent from the slurry pipe 34 to, for example, a PH adjustment processing section. I have.
[0049]
In the case shown in FIG. 2, the configurations of the slurry receiving section 33 and the slurry pipe 34 having such a configuration are set so as to fill the space between the filter surfaces running in parallel between the rollers 11 and 12 in the vertical direction. On the other hand, unlike FIG. 1, the backwash processing section 40 is provided at a position shifted to the side of the slurry receiving section 33. In the case shown in FIG. 2, the backwashing processing unit 40 is provided with the nozzles 41 in the plurality of air supply pipes 42 so that the jet air a can be sprayed over a wide range toward the filter back surface 20 b after the filtering process. It has become.
[0050]
In the configuration shown in FIG. 1, since the configuration of the slurry receiving section 33 and the configuration of the backwashing processing section 40 are configured to be up and down, the gap H between the filter faces running in parallel between the rollers 11 and 12 is inevitable. Must be set high. That is, the rollers 11 and 12 need to have a large diameter.
[0051]
Therefore, as shown in FIG. 2, by re-arranging the slurry receiving section 33 and the backwashing processing section 40 in the horizontal arrangement, the distance H between the upper and lower filter surfaces is shortened, that is, the diameter of the rollers 11 and 12 is reduced. ing. From the viewpoint of promoting downsizing of the filter mechanism 10, the horizontal arrangement shown in FIG. 2 is preferable.
[0052]
In the case shown in FIG. 2, the receiving section 53 is provided in the disposal section 50 so that the agglomerated abrasive grains and the like blown down by the jet air a can be once received by the receiving section 53 and discharged to the disposal port 52. ing.
[0053]
In FIG. 2, foreign substances such as agglomerated abrasive grains and processing waste having a size of about 1 μm or more are indicated by a mesh circle, and recyclable normal slurries are indicated by a shaded display, so that clogging can be easily resolved. As shown in FIG. 2, foreign substances indicated by a mesh circle contained in the used slurry are supplied from the supply pipe 31 of the slurry filtration unit 30 toward the filter surface 20 a, and are captured by the mesh part of the filter 20. You.
[0054]
The captured foreign matter is sent to the backwashing processing unit 40 side with the rotation of the filter 20, and is blown down to the waste processing unit 50 side by the backwashing by spraying the jet air a. The slurry containing normal abrasive grains from which foreign matter has been removed from the used slurry passes through the filter 20, reaches the slurry receiving section 33, and is sent from the slurry pipe as a recyclable slurry.
[0055]
In the above description, a configuration in which jet air is blown from the direction opposite to the filtration direction as the backwashing processing unit 40 has been described. However, other than air, ultrapure water may be blown. Alternatively, air and ultrapure water may be blown.
[0056]
When both air and ultrapure water are sprayed, backwashing with ultrapure water and backwashing with air are performed in this order, so that the filter 20 can be dried when passing through the backwashing processing unit 40, and the slurry filtration processing unit At the time of filtration at 30, filtration without affecting the liquid properties of the slurry can be performed.
[0057]
By providing a filtering mechanism that does not affect the liquid properties of the slurry in this manner, by providing a filter mechanism that is connected to the supply path of the slurry to the CMP device, it is possible to supplement the aggregated abrasive grains that may be included in the new slurry with a new slurry. Can be performed without changing the liquid properties of the liquid.
[0058]
FIG. 3 shows a case where a small-sized slurry recycling apparatus which can be integrated with a CMP apparatus by incorporating a slurry regeneration processing section 60 into the filter mechanism section 10 having the configuration shown in FIG.
[0059]
In the configuration shown in FIG. 3, as the regeneration processing unit 60, the slurry receiving unit 33 is provided with a liquid property measuring unit 61 and a liquid property adjusting unit 62 for monitoring the liquid property such as the concentration and PH of the filtered recovered slurry. I have. As the liquid property adjusting means 62, for example, a means for supplying an adjusting liquid necessary for liquid property adjustment, such as an ultrapure water supply means or an ammonia supply means, may be provided.
[0060]
Based on the concentration and PH information from the liquid property measuring means 61, a required amount of ultrapure water, ammonia and the like are supplied to the slurry collected by the slurry receiving section 33 by the liquid property adjusting means 62, With the slurry pipe 35 provided, the regenerated slurry can be directly supplied to the CMP apparatus.
[0061]
Next, for example, a case where the apparatus having the configuration provided with the regeneration processing unit 60 shown in FIG. 3 is incorporated in a slurry recycling system will be described with reference to FIG. In the case shown in FIG. 4, the new slurry is supplied from the slurry supply device 110 to the CMP device 120. On the downstream side of the CMP device 120, a slurry recycling device 130 provided with the filter mechanism 10 shown in FIG. 3 is provided.
[0062]
The schematic configuration of the CMP apparatus 120 is schematically shown in FIG. That is, in the CMP apparatus 120, as shown in FIG. 5, a polishing pad 123 is provided on a surface plate 122 rotated by a motor 121. A polishing surface of a wafer W provided via a carrier pad 126 is opposed to a wafer carrier 125 rotated by a motor 124 with respect to the surface of the polishing pad 123.
[0063]
In addition, a nozzle 127 connected to a slurry supply device (not shown) by a pipe is provided toward the surface of the polishing pad 123, and the slurry as an abrasive is supplied from the nozzle 127.
[0064]
Using the slurry supplied to the surface of the polishing pad 123 in this manner, the wafer W is polished while the polishing surfaces of the wafer W facing the polishing surface of the polishing pad 123 are rotated with respect to each other, and the polishing surface is planarized. I do.
[0065]
As shown in FIG. 3, the used slurry discharged from the CMP apparatus 120 is coagulated in the slurry through a slurry filtration processing unit 30 at a flat traveling portion of the endless filter 20 formed in a roll shape. Processing chips such as abrasive grains and polishing chips are filtered off.
[0066]
The concentration and PH of the recovered slurry filtered from the filter 20 are checked by the liquid property measuring means 61 in the slurry receiving section 33 as described above, and the collected slurry is passed through the liquid property adjusting means 62 based on the information. Sex adjusted.
[0067]
The recovered slurry having the same liquid property adjustment as the new slurry flows into the slurry pipe 35 from the slurry receiving section 33, passes through the slurry pipe 35, and is supplied to the slurry supply device 110 as a regenerated slurry as shown in FIG. It will be sent and reused.
[0068]
FIG. 6 shows a configuration in which the slurry recycling device 128 is built on the CMP device 120 and integrated with the CMP device 120.
[0069]
In the case shown in FIG. 7, a case is shown in which the slurry recycling device 130 is added between the slurry supply device 110 and the CMP device 120 in the configuration shown in FIG. If such a configuration is adopted, even if agglomerated abrasive grains are mixed in the slurry supplied to the CMP apparatus 120, the removal is performed, and the occurrence of scratches during flattening polishing due to the presence of the agglomerated abrasive grains is prevented beforehand. can do.
[0070]
In the case of used slurry, the liquid property can be adjusted in the subsequent recycling process.Therefore, the liquid property of the used slurry may be changed at the time of filtration for removing foreign substances. In the filter mechanism section 10 provided in the system for supplying to the CMP apparatus 120, unlike the case where foreign substances such as agglomerated abrasive grains are removed from the used slurry, the liquid property of the slurry after filtration must not be changed.
[0071]
In the above-described filter mechanism section 10 according to the present invention, since the backwashing is performed by jet air, the liquid property of the slurry after the filtration does not change, and as shown in FIG. Instead, the slurry recycling apparatus 130 can be provided in the slurry supply path.
[0072]
(Embodiment 2)
In FIGS. 1 to 3 of the first embodiment, the case where the endless filter 20 is formed in a roll shape has been described. In the present embodiment, for example, as shown in FIG. The case of forming a (cylindrical) will be described. In the case of a roll shape, a resin material used for a membrane filter or the like may be considered as the filter material. In the case of a drum shape, a filter structure using quartz may be used.
[0073]
In the case shown in FIG. 8, the rotating roller 13 is provided on the filter surface 20a formed in a drum shape in contact with the peripheral surfaces of the non-filter portions on both ends of the filter 20, and is configured to be rotatable. .
[0074]
A slurry filtration unit 30 is provided on the filter surface 20a so that slurry can be supplied to the filter surface 20a via the tube end support member 32 as described above. By providing the air supply pipe 42 and the nozzle 41, the backwash processing unit 40 can also eliminate clogging with the jet air a.
[0075]
(Embodiment 3)
In the configurations shown in FIGS. 1 to 3 and FIG. 8 of the first and second embodiments, the endless filter 20 is formed in a drum shape (cylindrical shape) on a roll, but as shown in FIG. Alternatively, the endless filter 20 may be formed in a ring shape, and a flat ring surface may be configured as the filter surface 20a to perform the slurry filtering process.
[0076]
In the third embodiment, as shown in FIG. 9A, the entire filter surface 20a can be ensured as a flat surface by forming the filter surface into an endless ring shape. Since the flat surface is widely secured, the filtration surface of the slurry filtration unit 30 can be easily widened.
[0077]
FIG. 9A shows a state in which the slurry filtration processing unit 30 is formed in an arc shape in accordance with the flat ring shape of the filter 20. Similarly, a washing unit 43 and a drying unit 44 are provided in order. In FIG. 9A, the internal configurations of the slurry filtration processing unit 30, the washing unit 43, and the drying unit 44 are omitted for easy viewing. ing.
[0078]
While the filter 20 after the filtration process is being rotated and gradually sent to the washing unit 43 and the drying unit 44, regeneration by washing and drying can be performed.
[0079]
FIG. 9B is a cross-sectional view when the configuration shown in FIG. 9A is cut along a cutting line AA. As shown in FIG. 9B, a used slurry supply pipe 31 is disposed in the slurry filtration section 30 in the transverse direction of the ring-shaped filter 20, and is provided below the supply pipe 31. The used slurry is supplied from the holes to the filter surface 20a in a shower shape.
[0080]
In the cleaning section 43, cleaning is performed by spraying ultrapure water onto the filter surface 20a. In the drying unit 44, the jet air a is blown from above onto the filter surface 20a to be dried. Alternatively, the drying section 44 may be formed in a drying chamber provided with a heater.
[0081]
In the case shown in FIG. 9A, a case where the filter 20 is formed in a ring shape has been described. However, as shown in FIG. 9C, the filter 20 may be formed in a disk shape or the like.
[0082]
In short, if the filter surface is configured to rotate, and if a cleaning processing unit such as a slurry filtration processing unit or a backwash processing unit is arranged on the rotating filter surface, the filtered filter surfaces are sequentially rotated. The filter can be reused while regenerating, and the filter can be used while maintaining the filter function while eliminating clogging for a long period of time without replacing the filter.
[0083]
Since the filtering process and the cleaning process for eliminating clogging can be sequentially performed with the same filter, a maintenance-free configuration that does not substantially require filter replacement can be achieved. Further, the configuration of the filter mechanism can be reduced in size as compared with a configuration in which a plurality of filters are provided, one side performs filter maintenance, and the other side performs a filtering process.
[0084]
From the viewpoint of a method for manufacturing a semiconductor device, the configuration described above can be applied to a polishing step using a slurry such as a CMP apparatus. For example, it can be used in a planarization process by CMP polishing such as a planarization process of an interlayer insulating film, a trench isolation formation process, and a buried metal wiring process in a series of semiconductor device manufacturing processes.
[0085]
For example, a case where the present invention is applied to flattening of an interlayer insulating film of a logic ULSI will be described. A base transistor is formed on a wafer substrate, and SiO (chemical vapor deposition) is formed on the base transistor. ₂ Is deposited to form an interlayer insulating film. The unevenness of the interlayer insulating film is ₂ Is flattened by CMP polishing using a slurry containing as abrasive grains. The slurry used for flattening is sent as used slurry, for example, to a slurry recycling system that goes through each step of the flow shown in FIG. 4, FIG. 6, or FIG.
[0086]
In the slurry recycling system, the used slurry discharged from the CMP apparatus 120 is sent to, for example, a filter mechanism shown in FIG. 1, FIG. 2, or FIG. Grains and processing waste are filtered. At the same time, clogging of the filtration unit is eliminated by backwashing, and the same filter is repeatedly used without changing the filter while maintaining the filter function, and the obtained recycled slurry is supplied to the CMP apparatus 120.
[0087]
It is to be noted that the description of the filtration processing of the used slurry in the filter mechanism unit 10, the clogging removal processing of the filtration processing unit, and the collection of the recycled slurry is omitted.
[0088]
As described above, an Al film is deposited by a sputtering method or the like on the interlayer insulating film planarized in the CMP polishing step of reusing the slurry using a recycling system. Further, patterning by photolithography and patterning by reactive ion etching are performed. SiO2 is formed on the wiring thus formed by CVD. ₂ Is deposited, and an interlayer insulating film is formed again. The interlayer insulating film is planarized by CMP polishing as described above while recycling the slurry.
[0089]
By repeating such a process a required number of times, a semiconductor device having a logic ULSI structure having an interlayer insulating film that has been planarized by CMP and has a slurry recycling process can be manufactured.
[0090]
In addition, the above-described configuration according to the present invention is not limited to the flattening step, and can be applied to, for example, recycling of a slurry for crystal polishing such as silicon crystal of a wafer. Furthermore, the present invention can be effectively applied to a technique for separating a solid dispersed in a liquid from the aggregated solid.
[0091]
As described above, the invention made by the inventor has been specifically described based on the embodiment of the invention. However, the invention is not limited to the embodiment of the invention, and various modifications may be made without departing from the gist of the invention. It goes without saying that it is possible.
[0092]
In the above-described embodiment, the case where the filter is formed in an endless shape has been described. However, a configuration other than the endless shape may be used as a configuration that can be used while constantly regenerating the filtration processing surface. For example, as shown in FIG. 10, a filter 70 formed in a plate shape having a flat plate surface may be reciprocated right and left.
[0093]
In other words, if the washing section 40, the slurry filtering section 30, and the washing section 40 are provided in this order along the plate surface that reciprocates right and left, filtration can be performed while regenerating clogging of the filter surface used in the filtering process. You can continue.
[0094]
In the above description, the configuration in which the filter function can be maintained for a long time in a maintenance-free state has been described by exemplifying application to a CMP apparatus. The present invention can also be applied to a filter mechanism such as a waste liquid treatment device or a chemical liquid supply device that removes foreign substances in a chemical liquid with a filter.
[0095]
【The invention's effect】
The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.
[0096]
In other words, the slurry can be filtered while the clogging is regenerated with the same filter.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a configuration example of a main part of a filter mechanism unit according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating a cross-sectional configuration of a main part of a filter mechanism in a state where a part of the configuration illustrated in FIG. 1 is changed.
FIG. 3 is an explanatory cross-sectional view showing an example in which a regeneration unit is provided in a filter mechanism unit to constitute a slurry recycling apparatus.
FIG. 4 is a flow chart schematically showing a slurry recycling system.
FIG. 5 is an explanatory diagram illustrating a schematic configuration of a CMP apparatus.
FIG. 6 is a flow diagram schematically showing a case where a slurry recycling apparatus is incorporated in a CMP apparatus.
FIG. 7 is a flowchart schematically showing a slurry recycling system in which a slurry recycling mechanism is also provided on the slurry supply side.
FIG. 8 is an explanatory sectional view showing a modification of the endless filter.
9A is an explanatory view illustrating a case where an endless filter is formed in a ring shape, FIG. 9B is a cross-sectional explanatory view thereof, and FIG. 9C is a diagram illustrating an endless filter formed in a disk shape. It is explanatory drawing which shows the case where it did.
FIG. 10 is an explanatory view schematically showing a modified example of a filter mechanism using a filter formed in a reciprocating plate shape.
[Explanation of symbols]
10 Filter mechanism
11 rollers
12 rollers
13 rotating roller
20 Endless filter
20a Filter surface
20b Filter back
30 Slurry filtration section
31 Supply pipe
32 Pipe end support
33 Slurry receiving part
34 Slurry piping
35 Slurry piping
40 Backwash processing section
41 nozzle
42 Air supply pipe
50 Waste treatment department
51 Slope
52 Waste port
60 Playback processing unit
61 Liquid property measuring means
62 Liquid property adjusting means
70 Filter
110 Slurry supply device
120 CMP equipment
121 motor
122 surface plate
123 polishing pad
124 motor
125 wafer carrier
126 carrier pad
127 nozzles
128 Slurry recycling equipment
130 Slurry recycling equipment
a Jet Air

Claims (5)

A method for manufacturing a semiconductor device having a step of eliminating clogging of a filter by a slurry used in a polishing step,
Perform a filtration process of the slurry in a part of the filter, perform a filter clogging elimination process in another part of the filter,
Leaving the filtered filter part to clogging elimination processing, leaving the filter part that has been clogged elimination processing to filtration processing, and repeatedly using the same filter in the filtration processing and the clogging elimination processing A method for manufacturing a semiconductor device, comprising: A method for manufacturing a semiconductor device having a step of eliminating clogging of a filter by a slurry used in a polishing step,
Perform a filtration process of the slurry in a part of the filter formed endless, perform a clogging elimination process in another part of the filter,
Both the filter processing unit and the clogging elimination processing unit, and the filter are relatively moved, and the filter part that has performed the filtration processing is subjected to the clogging elimination processing, and the filter part that has performed the clogging elimination processing is A method of manufacturing a semiconductor device, wherein the same filter is repeatedly used in the filtering process and the clogging elimination process, leaving the process to the filtering process. A method for manufacturing a semiconductor device having a step of eliminating clogging of a filter by a slurry used in a polishing step,
By rotating the filter formed in a roll or drum shape,
Perform a filtration process in a part of the filter, perform a clogging elimination process by backwashing in another part of the filter,
A method for manufacturing a semiconductor device, comprising: repeatedly using a filtered filter portion for clogging elimination processing; and performing a clogging removal filter portion for a filtration process. A method for manufacturing a semiconductor device having a step of eliminating clogging of a filter by a slurry used in a polishing step,
The slurry is supplied to the rotating surface of the filter to perform a filtering process, the clogging process is performed on the rotating surface of the filtered filter, and the same filter is subjected to the filtering process and the clogging removing process. Use repeatedly
A method for manufacturing a semiconductor device, comprising reusing slurry passed through the filter by the filtration process. A method for manufacturing a semiconductor device having a step of eliminating clogging of a filter by a slurry used in a polishing step,
A rotating filter,
A slurry filtration unit facing the rotating surface of the filter,
Using a filter mechanism having a backwashing processing unit facing the back surface of the rotating surface facing the slurry filtration processing unit,
The slurry is supplied by supplying slurry from the slurry filtration unit to the rotating surface of the filter,
For the rotating surface on which the filtration process has been performed, the backwash processing unit performs backwash to eliminate clogging,
A method for manufacturing a semiconductor device, comprising reusing slurry passed through the rotating surface of the filter.

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