JP6971676B2 - Board processing equipment and board processing method - Google Patents

Description

The present disclosure relates to a substrate processing apparatus and a substrate processing method.

A substrate processing apparatus such as a CMP (Chemical Mechanical Polishing) apparatus polishes a substrate using a slurry, and then cleans the substrate. However, the cleaning power in the substrate processing apparatus is not always sufficient, and the substrate is often cleaned using a substrate cleaning apparatus separate from the substrate processing apparatus. Then, there is a problem that the number of substrate processing steps increases.

Japanese Unexamined Patent Publication No. 2008-114183 Japanese Patent No. 3725809

The present disclosure has been made in view of such problems, and an object thereof is to provide a substrate processing apparatus and a substrate processing method capable of sufficiently cleaning a polished substrate with a small number of steps.

According to one aspect of the present disclosure, a polishing unit that polishes a substrate with a polishing liquid, a first cleaning unit that cleans the substrate polished by the polishing unit with sulfuric acid and a hydrogen peroxide solution, and the first cleaning unit. (1) Substrate treatment including a second cleaning section for cleaning the substrate washed by the cleaning section with a basic chemical solution and a hydrogen peroxide solution, and a drying section for drying the substrate washed by the second cleaning section. Equipment is provided.

A first cleaning unit and a second cleaning unit are provided in the substrate processing apparatus. Then, the polishing liquid can be removed by cleaning with the first cleaning unit using sulfuric acid and hydrogen peroxide solution. By cleaning with the second cleaning unit using a basic chemical solution and hydrogen peroxide solution, the components due to sulfuric acid used in the first cleaning unit can be removed. As a result, the polished substrate can be sufficiently cleaned with a small number of steps.

It is desirable not to have a mechanism for drying the substrate after being polished by the polishing portion and before being cleaned by the first cleaning portion.
Further, it is desirable to provide a transport section for transporting the substrate polished by the polishing section to the first cleaning section without drying it.
More preferably, it is provided with a first liquid supply mechanism for spraying a liquid on the substrate being transported by the transport unit.
Further, the transport section is a liquid on a substrate station on which a substrate is placed after being polished by the polishing section and before being cleaned by the first cleaning section, and a substrate mounted on the substrate station. It is desirable to have a second liquid supply mechanism for bathing.
By not drying the polished substrate, the residue on the substrate can be efficiently removed during cleaning by the first cleaning unit.

The first cleaning unit is housed in a first housing provided with a first shutter that can be opened and closed, and the second cleaning unit is housed in a second housing provided with a second shutter that can be opened and closed. It is desirable that the dried portion be housed in a third housing provided with a third shutter that can be opened and closed.
As a result, the sulfuric acid and hydrogen peroxide solution used in the first cleaning section can be suppressed from invading the second cleaning section and the drying section, and the basic chemical solution and hydrogen peroxide solution used in the second cleaning section can be prevented. It is possible to prevent the invasion of the first cleaning part and the drying part.

A third cleaning unit for cleaning the substrate polished by the polishing unit with a basic chemical solution and a hydrogen peroxide solution is provided, and the first cleaning unit cleans the substrate cleaned by the third cleaning unit. It is desirable to do.
It is desirable that the third cleaning unit cleans the substrate by bringing the cleaning member into contact with the substrate while supplying the basic chemical solution and the hydrogen peroxide solution to the substrate.
It is desirable that the second cleaning unit cleans the substrate with a basic chemical solution and hydrogen peroxide solution, and then performs two-fluid jet cleaning.
With these configurations, the detergency is further improved.

The polishing portion may polish the substrate with a polishing liquid containing ceria.
Cleaning by the first cleaning unit can reduce the residual ceria.

Further, according to one aspect of the present disclosure, the substrate is subjected to sulfuric acid and sulfuric acid by a polishing step of polishing the substrate with a polishing liquid by a polishing unit in the substrate processing apparatus and then by a first cleaning unit in the substrate processing apparatus. A first cleaning step of cleaning with a hydrogen peroxide solution, and then a second cleaning step of cleaning the substrate with a basic chemical solution and a hydrogen peroxide solution by a second cleaning unit in the substrate processing apparatus. After that, a substrate processing method including a drying step of drying the substrate is provided by a drying unit in the substrate processing apparatus.

Cleaning with sulfuric acid and hydrogen peroxide solution and cleaning with a basic chemical solution and hydrogen peroxide solution are performed by the first cleaning unit and the second cleaning unit provided in the substrate processing apparatus. As a result, the polished substrate can be sufficiently cleaned with a small number of steps.

After the polishing step, it is desirable to include a transfer step of transporting the substrate from the polishing portion to the first cleaning portion without drying the polished substrate.
By not drying the polished substrate, the residue on the substrate can be efficiently removed during cleaning by the first cleaning unit.

According to one aspect of the present invention, a first cleaning step of cleaning a substrate to which cerium ions are attached with sulfuric acid and a hydrogen peroxide solution, and then a basic chemical solution and a hydrogen peroxide solution are used to clean the substrate. A substrate processing method comprising a second cleaning step of cleaning and then a drying step of drying the substrate is provided.
Cerium ions can be removed by cleaning the substrate with sulfuric acid and hydrogen peroxide solution. After that, sulfuric acid can be removed by washing the substrate with a basic chemical solution and hydrogen peroxide solution.

In the first cleaning step, the substrate to which cerium ions having a cerium concentration of 1.0 × 10 ¹⁰ atms / cm ² or more are attached is washed, and the cerium concentration of the substrate after the drying step is measured by the ICP-MS method. It is desirable that it is below the detection limit.

In the first cleaning step and / or the second cleaning step, the substrate may be heated.

Prior to the first cleaning step, a step of supplying a basic chemical solution and a hydrogen peroxide solution to the substrate to which cerium ions are attached, a step of contacting a rotating sponge member, and a gas and liquid jet. It is desirable to have at least one step of supplying the stream.
By performing such rough cleaning, the cleaning power in a series of substrate cleaning steps is further improved.

The first cleaning step, the second cleaning step, and the drying step are performed in a cleaning tank, and a step of cleaning the inside of the cleaning tank between the first cleaning step and the second cleaning step. It is desirable to include a step of cleaning the inside of the cleaning tank between the second cleaning step and the drying step.
As a result, it is possible to suppress the reaction of the chemical solution (particularly, sulfuric acid and the basic chemical solution).

It is desirable that a polishing step of polishing the substrate with a slurry containing cerium ions is provided before the first cleaning step, and the polished substrate is not dried between the polishing steps and the polishing step.
By not drying the polished substrate, it is possible to suppress the concern of watermark generation and the concern of ceria sticking to the wafer, and the ceria can be removed from the substrate more reliably.

The polished substrate can be sufficiently cleaned with a small number of steps. In addition, the total processing time can be shortened.
In addition, for a substrate polished with ceria, the substrate taken out from the polishing device can be cleaned without being separately cleaned with a separate cleaning device, and without being dried to the end in the same polishing device, so that the cleaning process can be performed. In this case, it is possible to more reliably remove the ceria by cleaning the polished substrate which is polished with ceria and has ceria adhered to it, while suppressing the concern that water marks are generated due to the substrate drying.
Furthermore, the present inventors have studied that cerium abrasive grains have a strong electrical attraction to the substrate, and ceria adhering to the substrate cannot be removed by simply cleaning with a cleaning solution containing an alkaline chemical solution or a surfactant. It turned out in. According to the present invention, such ceria can be more reliably removed from the substrate.

The figure which shows an example of the schematic structure of the substrate processing apparatus schematically. The figure which shows in detail an example of a cleaning apparatus 31-34 and its related part. The flowchart which shows an example of the processing operation of a board processing apparatus. The table which shows the defect number in the substrate W1, W3, W4 after polishing and processing. The table which shows the ^{cerium ion concentration [atms / cm 2} ] in the substrate W1 to W4 after polishing and processing. A table showing the ^{cerium ion concentration [atms / cm 2} ] in the substrates W2 to W4 after the treatment. The table which shows the ^{sulfur ion concentration [atms / cm 2} ] in the substrate W1 to W4 after polishing and processing. The figure which shows the number of defects (the vertical axis on the left side) and the removal rate (the vertical axis on the right side) based on the substrate W11 in the substrate W11 after processing and the substrates W12, W13 after processing. The figure which shows the defect number and removal rate in the case of drying and the case of not drying after the first APM washing. The figure which shows schematically the cleaning apparatus provided in the substrate processing apparatus and performing APM cleaning, SPM cleaning, and drying. It is a figure which shows the state of performing the process of cleaning a substrate by the cleaning apparatus of FIG. 9 in order. It is a figure which shows the state of performing the process of cleaning a substrate by the cleaning apparatus of FIG. 9 in order. It is a figure which shows the state of performing the process of cleaning a substrate by the cleaning apparatus of FIG. 9 in order. It is a figure which shows the state of performing the process of cleaning a substrate by the cleaning apparatus of FIG. 9 in order. It is a figure which shows the state of performing the process of cleaning a substrate by the cleaning apparatus of FIG. 9 in order. It is a figure which shows the state of performing the process of cleaning a substrate by the cleaning apparatus of FIG. 9 in order.

Hereinafter, embodiments according to the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram schematically showing an example of a schematic configuration of a substrate processing apparatus, and may be considered as a schematic top view of the substrate processing apparatus. The board processing devices include a load port 1, one or more polishing units 2, a plurality of cleaning devices 31 to 33, one or a plurality of drying devices 4, transfer units 5 to 9, and substrate stations 10 and 11. , The control unit 12 is provided. Each part other than the load port 1 can be housed in the device 13.

The load port 1 is arranged adjacent to the short side of the apparatus 13, and a substrate cassette for stocking a substrate such as a semiconductor wafer is placed on the load port 1.

The polishing unit 2 is juxtaposed along the long side of the apparatus 13, and the substrate is polished using _{, for example, a slurry containing ceria (CeO 2).} Slurry may remain on the polished substrate. Although the polishing unit 2 is supposed to polish the surface of the substrate, it may be used to polish the bevel of the substrate.

Here, the average particle size (D ₅₀ ) of cerium oxide in the slurry (abrasive) is usually 0.5 to 1.5 μm. The content of cerium oxide is 1 to 10% by mass with respect to the total amount of the abrasive for the substrate. Although cerium oxide abrasive grains have excellent polishing characteristics as compared with conventional silica abrasive grains, they have a characteristic that they tend to settle because of their high specific gravity. It is necessary to adjust the addition amount and pH of the surfactant within the range where the polishing speed of the concave part of the pattern is sufficiently smaller than the polishing speed of the convex part, and therefore the viscosity is 1.0 to 1.4 mPa · s. The viscosity increases with the amount of the surface active agent added, and the viscosity increases with the amount of the surface active agent added. It is desirable to set the pH of the polishing agent to 5.5 to 9 and increase the selection ratio between the polishing rate of the silicon oxide film and the polishing rate of the silicon nitride film.

The cleaning devices 31 to 33 are juxtaposed along the long side of the device 13 opposite to the polishing portion 2, and clean the polished substrate. When the polished substrate is dried, it becomes difficult to remove the residue adhering to the substrate. Therefore, the substrate processing device is used after being polished by the polishing unit 2 and before being cleaned by the cleaning devices 31 to 33. It is desirable not to have a mechanism to dry the substrate. The cleaning by the cleaning devices 31 to 33 will be described in detail later.

The drying device 4 is arranged adjacent to the cleaning device 33 and dries the washed substrate.
The transport unit 5 has a hand for the substrate before cleaning and a hand for the substrate after cleaning, and is arranged between the load port 1, the polishing unit 2 on the load port 1 side, and the drying device 4, and the load port 1 , The transport unit 6 and the drying device 4 can be accessed. The transport unit 5 is, for example, a transport robot, and receives the unprocessed substrate from the load port 1 and delivers it to the transport unit 6. Further, the transport unit 5 takes out the dried substrate from the drying device 4.

The transport unit 6 is arranged along the polishing unit 2 and can access the transport unit 5, the polishing unit 2, and the substrate station 10. The transport unit 6 receives the substrate from the transport unit 5 and feeds it into the polishing unit 2. Further, the transport unit 6 takes out the polished substrate from the polishing unit 2 and places it on the substrate station 10 provided between the transport units 6 and 7.

The transport unit 7 is arranged in an area surrounded by the board station 10 and the cleaning devices 32 and 33, and can access the board stations 10 and 11 and the cleaning devices 32 and 33. The transport unit 7 takes out the substrate that has been polished and placed on the substrate station 10, and places it on the substrate station 11. Further, the transport unit 7 takes out the substrate cleaned by the cleaning device 32 and puts it in the cleaning device 33.

The transport unit 8 is arranged between the cleaning devices 31 and 32, and can access the cleaning devices 31 and 32 and the board station 11. The transport unit 8 takes out the substrate mounted on the substrate station 11 and puts it into the cleaning device 31. Further, the transport unit 8 takes out the substrate cleaned by the cleaning device 31 and puts it in the cleaning device 32. The board station 11 is arranged in the vicinity of the cleaning device 32, and a specific arrangement example will be described later. Further, in the substrate station 11, a pure water supply nozzle (not shown) for supplying pure water to the substrate can be provided so that the substrate does not dry out.

The transport unit 9 is arranged between the cleaning device 33 and the drying device 4, and can access them. The transport unit 9 takes out the substrate cleaned by the cleaning device 33 and puts it in the drying device 4.

The control unit 12 controls each unit in the substrate processing apparatus. For example, the control unit 12 is a processor, and controls the operations of the polishing unit 2, the cleaning devices 31 to 33, the drying device 4, and the transport units 5 to 9 by executing a predetermined program.

The substrate is processed by this substrate processing apparatus as follows. First, the unprocessed substrate mounted on the load port 1 is delivered to the transport unit 6 by the transport unit 5. The transport unit 6 puts the substrate into one of the polishing units 2, and the polishing unit 2 polishes the substrate. The polished substrate is placed on the substrate station 10 by the transport unit 6.

Next, the transfer unit 7 transfers the substrate mounted on the substrate station 10 to the transfer unit 8 via the substrate station 11. The transport unit 8 puts the substrate into the cleaning device 31, and the cleaning device 31 cleans the substrate. The washed substrate is put into the cleaning device 32 by the transport unit 8, and the substrate is cleaned by the cleaning device 32. The washed substrate is put into the cleaning device 33 by the transport unit 7, and the substrate is cleaned by the cleaning device 33.

The washed substrate is put into the drying device 4 by the transport unit 9, and the substrate is dried by the drying device 4. The dried substrate is taken out by the transport unit 5.

The waste liquid of the cleaning liquid is discharged to the outside through a pipe independent of each chamber, so that the atmosphere of other chemical liquids does not come into the chamber.

FIG. 2 is a diagram showing in detail an example of the cleaning apparatus 31 to 34 and related parts thereof, and may be considered as a schematic front view of the substrate processing apparatus.

For example, two cleaning devices 31 are arranged side by side. The cleaning device 31 has a housing 31a having an opening on the transport unit 8 side, a shutter 31b capable of opening and closing the opening, and a cleaning unit 31c housed in the housing 31a. The main cleaning unit 31c performs APM (Ammonium hydrogen-Peroxide Mixture) cleaning as cleaning using a mixed solution of ammonium water and hydrogen peroxide solution. The cleaning unit 31c may only supply the mixed solution to the substrate as APM cleaning, but may perform physical cleaning (scrub cleaning) by contacting a cleaning member such as a roll type sponge while supplying the mixed solution. .. It is desirable that the housing 31a has high resistance to ammonia water and hydrogen peroxide water. Further, it is desirable that an independent exhaust mechanism (not shown) is provided in the housing 31a.

For example, two cleaning devices 32 are arranged side by side. The cleaning device 32 has a housing 32a having openings on the transport unit 8 side and the transport unit 7 side, a shutter 32b capable of opening and closing these openings, and a cleaning unit 32c housed in the housing 32a. .. The main cleaning unit 32c performs SPM (Sulfuric-acid and hydrogen-Peroxide mixture) cleaning as cleaning using a mixed solution of sulfuric acid and hydrogen peroxide solution. It is desirable that the housing 32a has high resistance to sulfuric acid and hydrogen peroxide solution. Further, it is desirable that an independent exhaust mechanism (not shown) is provided in the housing 32a. Then, the board station 11 may be provided between the two cleaning devices 32.

For example, two cleaning devices 33 are arranged side by side. The cleaning device 33 has a housing 33a provided with openings on the transport unit 7 side and the transport unit 9 side, a shutter 33b capable of opening and closing these openings, and a cleaning unit 33c housed in the housing 33a. .. The main cleaning unit 33c performs APM cleaning as cleaning using a mixed solution of ammonia water and hydrogen peroxide water. The cleaning unit 33c may only supply the mixed solution to the substrate as APM cleaning, but may perform physical cleaning (scrub cleaning) with a cleaning member such as a pen-shaped sponge while supplying the mixed solution, or APM. Two-fluid jet cleaning may be performed after cleaning. The housing 33a is preferably made of a material having high resistance to aqueous ammonia or hydrogen peroxide, for example, a PVC material. Further, it is desirable that an independent exhaust mechanism (not shown) is provided in the housing 33a.

For example, two drying devices 4 are arranged side by side. The drying device 4 includes a housing 4a having openings on the transport unit 9 side and the transport unit 5 (see FIG. 1) side, a shutter 4b capable of opening and closing these openings, and a drying unit housed in the housing 4a. It has a portion 4c. The drying unit 4c performs, for example, SRD (Spin Rinse Dry) drying of the substrate. Further, it is desirable that an independent exhaust mechanism (not shown) is provided in the housing 4a.

The transport unit 7 is, for example, a transport robot and has a lower hand 7a and an upper hand 7b. The lower hand 7a conveys a substrate having a relatively high degree of contamination, and the upper hand 7b conveys a substrate having a relatively low degree of contamination. Specifically, the lower hand 7a takes out an unwashed substrate that has been polished by the polishing unit 2 and placed on the substrate station 10 and places it on the substrate station 11. Further, the upper hand 7b takes out the substrate cleaned by any of the cleaning devices 32 and puts it in any of the cleaning devices 33.

The transport unit 8 is, for example, a transport robot, and has a lower hand 8a and an upper hand 8b. The lower hand 8a conveys a substrate having a relatively high degree of contamination, and the upper hand 8b conveys a substrate having a relatively low degree of contamination. Specifically, the lower hand 8a takes out the uncleaned substrate placed on the substrate station 11 and puts it in any of the cleaning devices 31. Further, the upper hand 8b takes out the substrate cleaned by any of the cleaning devices 31 and puts it in any of the cleaning devices 32.

The transport unit 9 is, for example, a transport robot, but it suffices to have one hand 9a in order to transport the cleaned substrate. The hand 9a takes out the substrate cleaned by any of the cleaning devices 33 and puts it in any of the drying devices 4.

Further, a high temperature APM supply source 21, a hydrogen peroxide supply source 22, a high temperature sulfuric acid supply source 23, and a high temperature pure water supply source 24 are provided. These may be outside the device 13. The high temperature APM supply source 21 supplies APM at room temperature to about 80 ° C. to the cleaning devices 31 and 33. The hydrogen peroxide supply source 22 supplies hydrogen peroxide solution at room temperature to the cleaning device 32. The high temperature sulfuric acid supply source 23 supplies sulfuric acid at room temperature to about 80 ° C. to the cleaning device 32. The high temperature pure water supply source 24 can supply pure water at about 75 to 95 ° C. to the cleaning device 32.

Alternatively, an external heat supply source such as an infrared heater is provided inside each of the cleaning devices 31 to 33, and the inside of the cleaning devices 31 to 33 is heated to a high temperature by the heat supplied from the outside to maintain this. The temperature of APM, sulfuric acid and pure water supplied to each cleaning device 31 to 33 from the high temperature APM supply source 21, the high temperature sulfuric acid supply source 23 and the high temperature pure water supply source 24 is set to a lower temperature, for example, room temperature to 40. It can also be set to a temperature of about ° C. With such a configuration, it is possible to use the members such as pipes and pipe joints connected to each cleaning device 31 to 33 from each supply source without ensuring the chemical resistance so much, which is advantageous in terms of device configuration. Will be.

The substrate processing apparatus shown in FIG. 2 is only an example, and the number and arrangement positions of the cleaning apparatus 31 to 33 and the drying apparatus 4, and the configurations of the transport units 7 to 9 and the substrate stations 10 and 11 may be appropriately designed. Further, although the cleaning units 31c and 33c are to be washed with ammonia water, they may be washed with another basic (alkaline) chemical solution and hydrogen peroxide solution.

FIG. 3 is a flowchart showing an example of the processing operation of the substrate processing apparatus. First, the polishing unit 2 polishes the substrate (step S1). When a slurry containing ceria is used for polishing the substrate, ceria may remain on the polished substrate. More specifically, cerium ions having a cerium concentration of 1.0 × 10 ¹⁰ atms / cm ² or more may adhere to the front surface and / or the back surface of the substrate, and such a substrate is washed.

Subsequently, the transport units 6 to 9 put the substrate into one of the cleaning devices 31 without drying the polished substrate (step S2). More specifically, the transport unit 6 takes out the substrate from the polishing unit 2 and places it on the substrate station 10. After that, the lower hand 7a in the transport unit 7 takes out the substrate from the substrate station 10 and places it on the substrate station 11. Next, the lower hand 8a in the transport unit 8 takes out the substrate from the substrate station 11, the shutter 31b in the cleaning device 31 opens, and the substrate is handed over to the cleaning unit 31c through the opening of the housing 31a. After that, the shutter 31b closes.

In order to prevent the substrate from drying, it is desirable to shower the substrate with a liquid shower such as pure water during the transfer of the substrate by the transport units 6 to 8 or at the substrate station 10. In particular, since the substrate stays on the transport units 6 and 7 and the substrate station 10 for a long time, the liquid supply mechanism (not shown) for showering the substrate being transported by the transport units 6 and 7 and the substrate on the substrate station 10 with a shower. ) Is effective. On the other hand, if the staying time of the substrate such as the transport unit 8 is short, it may not be necessary.

The cleaning device 31 discharges APM from the spray nozzle to clean the substrate (step S3). During this time, the shutter 31b in the cleaning device 31 is closed. As a result, it is possible to prevent the APM used in the cleaning device 31 from being mixed with other devices, particularly the cleaning device 32 and the drying device 4. This APM cleaning is a rough cleaning and can be omitted in some cases, but if there are particles that are difficult to remove, it can be treated by rolling or pencil cleaning or by using a two-fluid jet.

When the cleaning by the cleaning device 31 is completed, the transport unit 8 transports the substrate from the cleaning device 31 to any of the cleaning devices 32. More specifically, when the cleaning is completed, the shutter 31b in the cleaning device 31 opens, the upper hand 8b in the transport unit 8 receives the substrate, and then the shutter 31b closes. Then, the shutter 32b on the transport unit 8 side of the cleaning device 32 opens, is delivered to the cleaning unit 32c through the opening of the housing 32a, and then the shutter 32b closes.

Then, the cleaning device 32 discharges SPM from the spray nozzle to clean the substrate (step S4). During this time, the shutter 32b in the cleaning device 32 is closed. As a result, it is possible to prevent the SPM used in the cleaning device 32 from being mixed with other devices, particularly the cleaning devices 31 and 33 and the drying device 4. By SPM cleaning, residues such as particles, ceria and organic substances contained in the slurry are dissolved, and most of them can be removed. In particular, the residue can be efficiently removed by transporting the polished substrate so that it does not dry out.

It is desirable that the cleaning device 32 cleans the substrate with pure water after performing SPM cleaning so that sulfuric acid does not come out from the housing 32a of the cleaning device 32. However, even in that case, the sulfur component due to sulfuric acid may remain on the substrate after SPM cleaning.

When the cleaning by the cleaning device 32 is completed, the transport unit 7 transports the substrate from the cleaning device 32 to any of the cleaning devices 33. More specifically, when the cleaning is completed, the shutter 32b on the transport unit 7 side in the cleaning device 32 opens, the upper hand 7b in the transport unit 7 receives the substrate, and then the shutter 32b closes. Then, the shutter 33b on the transport unit 7 side of the cleaning device 33 opens, is delivered to the cleaning unit 33c through the opening of the housing 33a, and then the shutter 33b closes.

Then, the cleaning device 33 discharges APM from the spray nozzle to clean the substrate (step S5). During this time, the shutter 33b in the cleaning device 33 is closed. As a result, it is possible to prevent the APM used in the cleaning device 33 from being mixed with other devices, particularly the cleaning device 32 and the drying device 4. Most of the sulfur components can be removed by APM cleaning.

When the cleaning by the cleaning device 33 is completed, the transport unit 9 transports the substrate from the cleaning device 33 to any of the drying devices 4. More specifically, when the cleaning is completed, the shutter 33b on the transport unit 9 side of the cleaning device 33 opens, the hand 9a in the transport unit 9 receives the substrate, and then the shutter 33b closes. Then, the shutter 4b in the drying device 4 opens, is passed to the drying unit 4c through the opening of the housing 4a, and then the shutter 4b closes.

Then, the drying device 4 dries the substrate (step S6). When the drying by the drying device 4 is completed, the transport unit 5 takes out the substrate from the drying device 4. More specifically, when the drying is completed, the shutter 4b on the transport unit 5 side of the drying device 4 opens, the washed substrate hand in the transport unit 5 receives the substrate, and then the shutter 4b closes.

As described above, in the present embodiment, by performing SPM cleaning in the substrate processing apparatus and then performing APM cleaning, the substrate can be efficiently cleaned with a small number of steps, and the total processing time can be shortened. That is, by providing the polishing unit 2 and the cleaning devices 32 and 33 in the substrate processing apparatus, SPM cleaning can be performed without drying the polished substrate, and the residue such as ceria contained in the slurry can be sufficiently removed. Further, by performing APM cleaning after SPM cleaning, the sulfur component caused by sulfuric acid used in SPM cleaning can be removed. Further, by storing the cleaning unit 32c for SPM cleaning in the housing 32a and the cleaning units 31c and 33c for APM cleaning in the housings 31a and 33a, respectively, the atmosphere can be created between the cleaning units 31c to 33c. They can be made independent of each other, for example, the sulfur component of SPM is hardly transferred to other processing chambers.

[Experiment 1]
In order to confirm that it is effective to perform APM cleaning after SPM cleaning, the following treatment was performed on the four substrates W1 to W4.

(1) Substrate W1
The surface of the substrate W1 was polished for 60 seconds at a pressure of about 70 hPa using a slurry containing ceria. Then, while supplying pure water, physical cleaning was performed for 60 seconds using a roll-type sponge. As described above, the substrate W1 is not subjected to SPM cleaning or APM cleaning after polishing.

(2) Substrate W2
After performing the same treatment as in (1) above, while rotating the substrate W2, a mixed solution of sulfuric acid (concentration 96%, high temperature) and hydrogen peroxide solution (concentration 30%, room temperature) is supplied for 60 seconds to the substrate. W2 was washed. As described above, the substrate W2 was only cleaned by SPM after polishing.

(3) Substrate W3
After performing the same treatment as in (2) above, the substrate W3 was washed by supplying a mixture of ammonia water, hydrogen peroxide solution and pure water for 30 seconds while rotating the substrate W3. As described above, the substrate W3 was subjected to SPM cleaning and subsequently APM cleaning after polishing.

(4) Substrate W4
After performing the same treatment as in (1) above, the substrate W4 was washed by supplying a mixture of ammonia water, hydrogen peroxide solution and pure water for 60 seconds while rotating the substrate W4. As described above, the substrate W4 was only APM washed after polishing.

FIG. 4 is a table showing the number of defects in the substrates W1, W3, and W4 after polishing and processing. As shown in the figure, the polished substrates W1, W3, and W4 had a defect of about 8,000 to 10,000. In the substrate W4 that has been subjected to only APM cleaning, the number of defects after processing is about 8,500, and the defects are reduced by only about 6%. On the other hand, in the substrate W3 subjected to SPM cleaning and APM cleaning, the number of defects after the treatment was about 2,500, and the defects could be reduced by about 75%.

FIG. 5A is a table showing the ^{cerium ion concentration [atms / cm 2} ] in the substrates W1 to W4 after polishing and treatment. In the figure, the five points of coordinates (0,0), (0,120), (120,0), (0, -120), and (-120,0) on the substrates W1 to W4 are TXRF (Total Reflection). It is the result measured by the X-ray Fluorescence) method.

The cerium ion concentration of the substrate W1 after polishing was about ^{8 * 10 11} [atms / cm ^2]. The cerium ion concentration was about 3 * 10 ¹⁰ [atms / cm ^{2 ] on the substrate W4 that was only APM-cleaned, whereas the detection limit (2 * 10 10} [atms / cm 2] was on the substrates W2 and W3 that were SPM-cleaned. / Cm ² ]) It was possible to reduce it to the following.

FIG. 5B is a table showing the ^{cerium ion concentration [atms / cm 2} ] in the substrates W2 to W4 after the treatment. The figure shows the measurement results by the ICP-MS (Inductively Coupled Plasma Mass Spectrometry) method. In the measurement by the ICP-MS method, the cerium ion concentration was about 5.7 * 10 ¹⁰ [atms / cm ² ] in the substrate W4 that was only APM-cleaned, whereas the substrate W2 that was SPM-cleaned was In W3 detection limit ^{(5 * 10 9 [atms /} cm 2]) could be reduced to below.

As described above, it can be seen that SPM cleaning is effective for removing cerium ions.

FIG. 6 is a table showing ^{sulfur ion concentrations [atms / cm 2} ] in the substrates W1 to W4 after polishing and treatment. In the figure, the five points of coordinates (0,0), (0,120), (120,0), (0, -120), and (-120,0) on the substrates W1 to W4 are TXRF (Total Reflection). It is the result measured by the X-ray Fluorescence) method.

The sulfur ion concentration of the substrate W1 after polishing ^{was about 5.0 * 10 12} [atms / cm ² ], but the sulfur ion concentration of the substrate W2 only ^{subjected to SPM cleaning was 3.6 * 10 13} [atms / cm /]. It rose to ^{cm 2].} Since the substrate W4 without SPM cleaning was ^{about 4.6 * 10 12} [atms / cm ² ], it is considered that sulfur ions caused by sulfuric acid used for SPM cleaning remain on the substrate W2. .. The sulfur ion concentration of the substrate W3 that had been APM washed after SPM washing could be reduced to about ^{6.4 * 10 12} [atms / cm ^2].

As described above, it can be seen that APM cleaning is effective for removing sulfur ions caused by SPM cleaning.

From the above, it was confirmed that the cerium ions contained in the slurry can be removed by SPM washing and the sulfur ions by SPM washing can be removed by APM washing.

In addition, in the above (2), it has been confirmed in another experiment that the number of defects is not so reduced in the washing using only sulfuric acid instead of the SPM washing. Further, in the above (2), it has been confirmed in another experiment that there is no big difference between the case where the mixture of ammonia water, hydrogen peroxide solution and pure water is supplied for 30 seconds and the case where the mixture is supplied for 60 seconds.

[Experiment 2]
In order to confirm that it is more effective to first perform APM cleaning and then perform SPM cleaning and APM cleaning, the following treatments were performed on the three substrates W11 to W13.

(1) Substrate W11
The surface of the substrate W11 was polished for 60 seconds at an average pressure of about 70 hPa using a slurry containing ceria. Then, while supplying a mixture of aqueous ammonia, hydrogen peroxide and pure water, physical washing was performed for 60 seconds using a roll-type sponge. As described above, the substrate W11 was only APM washed after polishing.

(2) Substrate W12
The surface of the substrate W12 was polished for 60 seconds at a pressure of about 70 hPa using a slurry containing ceria. Next, while rotating the substrate W12 at a rotation speed of 50 rpm, a mixed solution of sulfuric acid (concentration 96%, high temperature) and hydrogen peroxide solution (concentration 30%, room temperature) was supplied for 60 seconds to wash the substrate W12. Then, while rotating the substrate W12, a mixture of ammonia water, hydrogen peroxide solution and pure water was supplied for 60 seconds to wash the substrate W12. As described above, the substrate W12 was subjected to SPM cleaning and subsequently APM cleaning after polishing.

(3) Substrate W13
The surface of the substrate W13 was polished for 60 seconds at an average pressure of about 70 hPa using a slurry containing ceria. Then, while supplying a mixture of aqueous ammonia, hydrogen peroxide and pure water, physical washing was performed for 60 seconds using a roll-type sponge. Then, while rotating the substrate W13, a mixed solution of sulfuric acid (concentration 96%, high temperature) and hydrogen peroxide solution (concentration 30%, room temperature) was supplied for 60 seconds to wash the substrate W13. Then, while rotating the substrate W13, a mixture of ammonia water, hydrogen peroxide solution and pure water was supplied for 60 seconds to wash the substrate W13. As described above, the substrate W13 was subjected to APM cleaning after polishing, followed by SPM cleaning, and then APM cleaning.

FIG. 7 is a diagram showing the number of defects (bar graph, vertical axis on the left side) in the substrates W11 to W13 after processing and the removal rate (solid line, vertical axis on the right side) based on the substrate W11. As shown in the substrate W12 in the figure, about 67% of defects could be removed by performing SPM cleaning and APM cleaning after polishing. On the other hand, as shown in the substrate W13 in the figure, by performing APM cleaning, SPM cleaning and APM cleaning after polishing, a defect of about 92% could be removed and the removal rate could be improved.

From the above, it was confirmed that it is more effective to perform APM cleaning first, and then SPM cleaning and APM cleaning.

FIG. 8 is a diagram showing the number of defects and the removal rate when drying is performed after the first APM washing and when drying is not performed. (1) When cleaning in the order of APM cleaning treatment, drying, SPM cleaning treatment, and APM cleaning treatment (bar graph, vertical axis on the left side), and (2) When cleaning in the order of APM cleaning treatment, SPM cleaning treatment, and APM cleaning treatment. A comparison with (bar graph, vertical axis on the right side) is shown. Compared to the case where (1) APM cleaning treatment, drying, SPM cleaning treatment, and APM cleaning treatment are performed in this order, the number of defects is larger when (2) APM cleaning treatment, SPM cleaning treatment, and APM cleaning treatment are performed in this order. It can be seen that the number is small and the removal rate is high. That is, from this figure, the cleaning effect is higher in the case of no drying, that is, in the case of continuous treatment of APM washing, SPM washing and APM washing without drying after CMP, as compared with the case of drying. Was confirmed.

Ceria containing cerium has a strong electric attraction to the substrate and is difficult to remove by simply cleaning with an alkaline chemical solution or a cleaning solution containing a surfactant, but the cleaning power is improved by the above-mentioned cleaning.

In the above-described embodiment, the cleaning devices 31 and 33 for performing APM cleaning, the cleaning device 32 for performing SPM cleaning, and the drying device 4 are separately provided, but among APM cleaning, SPM cleaning and drying. Any two or more processes may be performed in one device. The following embodiments show examples of performing APM cleaning, SPM cleaning and drying in one device.

FIG. 9 is a diagram schematically showing a cleaning device provided in the substrate processing device and performing APM cleaning, SPM cleaning, and drying. This cleaning device includes a chuck (not shown), an arm 51, a cleaning tank cleaning shower 52, and a cleaning tank 53 accommodating them.

The chuck holds and rotates the peripheral edge of the substrate to be cleaned.

The arm 51 is swingable, and specifically, it can move between a cleaning position where the tip of the arm 51 is located above the substrate and a retracted position away from above the substrate. An APM supply nozzle 61, a pure water supply nozzle 62, an H ₂ O ₂ supply nozzle 63, and an SPM supply nozzle 64 facing downward are provided on the lower side of the tip of the arm 51. A pipe 71 having one end connected to an APM supply source (not shown) and the other end connected to the APM supply nozzle 61 passes through the inside of the arm 51. Similar pipes 72 to 74 pass through the other supply nozzles. In FIG. 9, the APM and the like are drawn so as to be supplied only from the upper side of the substrate, but a supply nozzle may be provided on the lower side so that the APM and the like are also supplied from the lower side of the substrate. ..

The cleaning tank cleaning shower 52 is provided on the inner upper part of the cleaning tank 53, and cleaning water (pure water or the like) is supplied to the inside of the cleaning tank 53 to clean the inside of the cleaning tank 53. The cleaning tank 53 is provided with an opening / closing opening (not shown) for loading / unloading the substrate.

10A to 10F are views showing the process of cleaning the substrate by the cleaning apparatus of FIG. 9 in order (pipes 71 to 74 are omitted in each case). Prior to the processing in the main cleaning device, the substrate is polished using the slurry containing ceria in the substrate processing device, and preferably the substrate is conveyed into the main cleaning device without drying the substrate, and the chuck is chucked. Held by. Then, the arm 51 that was in the retracted position moves to the cleaning position.

First, as shown in FIG. 10A, SPM is supplied to the substrate from the SPM supply nozzle 64. As a result, the slurry adhering to the substrate and the organic residue generated during polishing are removed (melted). At this time, the substrate may be heated from an external heat source. By supplying heat from the external heat source onto the substrate in this way, the residue can be more reliably removed from the substrate.

Subsequently, as shown in FIG. 10B, hydrogen peroxide solution is supplied to the substrate from the _{H 2} O _{2 supply nozzle 63.} This removes sulfuric acid in the SPM from the substrate.

Subsequently, as shown in FIG. 10C, pure water or hot water is supplied to the substrate from the pure water supply nozzle 62. As a result, the substrate is rinsed and the chemical solution components are washed away. At this time, the washing water is also supplied from the washing tank washing shower 52 to the inside of the washing tank 53. As a result, the SPM and hydrogen peroxide solution scattered inside the cleaning tank 53 are also removed.

Subsequently, as shown in FIG. 10D, APM is supplied to the substrate from the APM supply nozzle 61. As a result, particles that could not be removed by SPM cleaning are removed. At this time, it is desirable to have a mechanism capable of processing two fluids, a liquid and a gas. At this time, the substrate may be heated from an external heat source. By supplying heat from the external heat source onto the substrate in this way, the residue can be more reliably removed from the substrate. By cleaning the inside of the cleaning tank 53 as shown in FIG. 10C, the reaction between sulfuric acid in SPM and ammonia in APM can be suppressed.

Subsequently, as shown in FIG. 10E, pure water or hot water is supplied to the substrate from the pure water supply nozzle 62. As a result, the substrate is finally rinsed and the chemical solution component is removed.

Subsequently, as shown in FIG. 10F, spin drying is performed while rotating the substrate, and then the dried substrate is carried out from the housing.

Although FIG. 9 shows an example in which the APM supply nozzle 61, the pure water supply nozzle 62, the H ₂ O ₂ supply nozzle 63, and the SPM supply nozzle 64 are provided on one arm 51, various arrangements of the nozzles can be considered. .. For example, the pure water supply nozzle and the H ₂ O ₂ supply nozzle may be supplied from a fixed nozzle. Further, the substrate may be roughly washed prior to the SPM cleaning shown in FIG. 10A. The rough cleaning may be, for example, APM cleaning or two-fluid jet cleaning that supplies a jet stream of gas and liquid. Alternatively, the rough cleaning may be a roll cleaning in which a rotating roll sponge is brought into contact with the substrate.

The above-described embodiments have been described for the purpose of allowing a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the invention is not limited to the described embodiments and should be the broadest scope according to the technical ideas defined by the claims.

1 Load port 2 Polishing unit 31 to 33 Cleaning unit 31a, 32a, 33a Housing unit 31b, 32b, 33b Shutter 31c, 32c, 33c Cleaning unit 4 Drying device 4a Housing unit 4b Shutter 4c Drying unit 5 to 9 Transport unit 10, 11 Board station 12 Control unit 13 Device 21 High temperature APM supply source 22 Hydrogen peroxide supply source 23 High temperature sulfuric acid supply source 24 High temperature pure water supply source 51 Arm 52 Cleaning tank cleaning shower 53 Cleaning tank 61 APM supply nozzle 62 Pure water supply nozzle 63 H ₂ O ₂ Supply Nozzle 64 SPM Supply Nozzle 71-74 Piping

Claims (17)

A polishing part that polishes the substrate with a polishing liquid,
A first cleaning unit, in which sulfuric acid and hydrogen peroxide solution are supplied from a nozzle while the substrate polished by the polishing unit is held and rotated by a substrate holding rotation mechanism, and then cleaned with pure water,
A second cleaning unit that cleans the substrate cleaned by the first cleaning unit with a basic chemical solution and hydrogen peroxide solution while holding and rotating the substrate by the substrate holding rotation mechanism.
A substrate processing apparatus including a drying unit for drying the substrate cleaned by the second cleaning unit. The substrate processing apparatus according to claim 1, which does not have a mechanism for drying the substrate after being polished by the polishing portion and before being cleaned by the first cleaning portion. The substrate processing apparatus according to claim 1 or 2, further comprising a transport unit that transports the substrate polished by the polishing unit to the first cleaning unit without drying. The substrate processing apparatus according to claim 3, further comprising a first liquid supply mechanism for spraying a liquid on the substrate being transported by the transport unit. A substrate station on which a substrate is placed after being polished by the polishing portion and before being cleaned by the first cleaning portion.
The substrate processing apparatus according to any one of claims 1 to 4, further comprising a second liquid supply mechanism for basking a substrate mounted on the substrate station with a liquid. The first cleaning unit is housed in a first housing provided with a first shutter that can be opened and closed.
The second cleaning unit is housed in a second housing provided with a second shutter that can be opened and closed.
The substrate processing apparatus according to any one of claims 1 to 5, wherein the drying portion is housed in a third housing provided with a third shutter that can be opened and closed. A third cleaning unit for cleaning the substrate polished by the polishing unit with a basic chemical solution and a hydrogen peroxide solution is provided.
The substrate processing apparatus according to any one of claims 1 to 6, wherein the first cleaning unit cleans the substrate cleaned by the third cleaning unit. The substrate processing apparatus according to claim 7, wherein the third cleaning unit performs cleaning by bringing a cleaning member into contact with the substrate while supplying a basic chemical solution and a hydrogen peroxide solution to the substrate. The substrate processing apparatus according to any one of claims 1 to 8, wherein the second cleaning unit cleans the substrate with a basic chemical solution and a hydrogen peroxide solution, and then performs two-fluid jet cleaning. The substrate processing apparatus according to any one of claims 1 to 9, wherein the polishing portion polishes the substrate with a polishing liquid containing ceria. The polishing process of polishing the substrate with the polishing liquid by the polishing part in the substrate processing device,
After that, the first cleaning unit in the substrate processing apparatus holds the substrate by the substrate holding rotation mechanism and rotates it while cleaning it with sulfuric acid and hydrogen peroxide solution , and then cleans it with pure water. Process and
After that, a second cleaning step of cleaning the substrate with a basic chemical solution and a hydrogen peroxide solution while holding and rotating the substrate by the substrate holding rotation mechanism by the second cleaning unit in the substrate processing apparatus.
A substrate processing method comprising a drying step of drying the substrate by a drying unit in the substrate processing apparatus. The substrate processing method according to claim 11, further comprising a transfer step of transporting the substrate from the polishing portion to the first cleaning portion without drying the polished substrate after the polishing step. A first cleaning step in which sulfuric acid and hydrogen peroxide solution are supplied from a nozzle while the substrate to which cerium ions are attached is held and rotated by a substrate holding rotation mechanism, and then washed with pure water.
After that, a second cleaning step of cleaning the substrate with a basic chemical solution and a hydrogen peroxide solution while holding the substrate by the substrate holding rotation mechanism and rotating the substrate,
After that, a substrate processing method comprising a drying step of drying the substrate. The substrate processing method according to claim 13, wherein the substrate is heated in the first cleaning step and / or the second cleaning step. Before the first cleaning step, the substrate to which cerium ions are attached is
The process of supplying a basic chemical solution and hydrogen peroxide solution,
The process of bringing the rotating sponge member into contact, and
13. The substrate processing method according to claim 13, comprising at least one step of supplying a jet stream of gas and liquid. The first cleaning step, the second cleaning step, and the drying step are performed in a cleaning tank.
Between the first cleaning step and the second cleaning step, a step of cleaning the inside of the cleaning tank and a step of cleaning the inside of the cleaning tank.
The substrate processing method according to any one of claims 13 to 15, further comprising a step of cleaning the inside of the cleaning tank between the second cleaning step and the drying step. Prior to the first cleaning step, a polishing step of polishing the substrate with a slurry containing cerium ions is provided.
The substrate processing method according to any one of claims 13 to 16, wherein the substrate after polishing is not dried between the polishing step and the second cleaning step.

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