Substrate processing apparatus, substrate processing method, and filter

Abstract

To perform stable patterning for a metal-containing resist film.SOLUTION: A substrate processing apparatus of the present disclosure is used for patterning performed by exposing and developing a metal-containing resist film formed on a substrate. The substrate processing apparatus is provided with a chemical filter comprising a plurality of filter parts arranged side by side toward a downstream side on a channel for supplying gas into the substrate processing apparatus, and each removing different substances in the gas. The plurality of filter parts includes an acid filter part for removing an acidic substance, and a base filter part for removing a basic substance.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus, a substrate processing method, and a filter.

Background Art

[0002] In the manufacturing process of semiconductor devices, various processes are performed by transporting a semiconductor wafer (hereinafter referred to as a wafer), which is a substrate, within a system. For example, as shown in Patent Document 1, a gas that has been purified by passing through a filter is supplied into the system, and the atmosphere in which the wafer is transported and processed is kept clean.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of performing stable patterning on a metal-containing resist film.

Means for Solving the Problems

[0005] The substrate processing apparatus of the present disclosure is a substrate processing apparatus used for patterning performed by exposing and developing a metal-containing resist film formed on a substrate. A chemical filter including a plurality of filter units that respectively remove different substances in the gas is provided in a flow path for supplying gas into the substrate processing apparatus, arranged side by side toward the downstream side. The plurality of filter units include an acid filter unit for removing acidic substances and a base filter unit for removing basic substances.

Effects of the Invention

[0006] The present disclosure can perform stable patterning on a metal-containing resist film.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Mode for Carrying Out the Invention

[0008] Hereinafter, a wafer processing system as a substrate processing apparatus according to the present embodiment will be described with reference to the drawings. In this specification, for elements having substantially the same functional configuration, the same reference numerals are given and redundant description is omitted.

[0009] <Wafer Processing System> First, the configuration of the wafer processing system according to the present embodiment will be described. FIGS. 1 and 2 are a plan view and a front view schematically showing the outline of the configuration of the wafer processing system 1, respectively. In the present embodiment, a case where the wafer processing system 1 is a photolithography processing system that performs a resist film formation process and a development process on a wafer W that is a circular substrate will be described as an example.

[0010] As shown in FIG. 1, the wafer processing system 1 has a cassette station 2 where a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station 3 equipped with a plurality of various processing apparatuses for performing predetermined processing on the wafers W. The wafer processing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 4 for transferring the wafer W between the processing station 3 and an exposure apparatus (not shown) adjacent to the opposite side of the processing station 3 are integrally connected. Note that, as shown in FIG. 1, two processing stations 3 are installed between the cassette station 2 and the interface station 4, but one or three or more processing stations 3 may be installed.

[0011] The cassette station 2 is provided with a plurality of cassette mounting plates 21, wafer transfer apparatuses 22 and 23. The cassette station 2 transfers wafers between the cassette C placed on the cassette mounting plate 21 and the processing station 3 by the wafer transfer apparatus 22 or 23. For this purpose, the wafer transfer apparatuses 22 and 23 are each provided with a drive mechanism in directions such as the X direction, the Y direction, the vertical direction, and the rotation around the vertical axis (θ direction) as required, and may be provided with drive mechanisms in all directions. At least one of the wafer transfer apparatuses 22 and 23 can transfer the cassette C and the wafers, and can also perform a wafer transfer operation with the processing station 3. The wafer transfer operation with the processing station 3 is, for example, to transfer wafers between a third block G3 including a transfer apparatus accessible by the wafer transfer apparatus 33 in the processing station 3 described later. The third block G3 may be provided with a plurality of transfer apparatuses (not shown) arranged in the vertical direction.

[0012] Note that an inspection apparatus (not shown) for inspecting the wafer W may be provided at a position accessible by either of the wafer transfer apparatuses 22 and 23.

[0013] The processing station 3 is provided with a plurality of blocks, for example, three blocks G1, G2, and G4, namely the first, second, and fourth blocks. Also, as shown in FIG. 2, a plurality of layers 31 each including the first and second blocks G1 and G2 are stacked in the vertical direction. For example, the first block G1 is provided on the front side of the processing station 3 (the negative X-direction side in FIG. 1), and the second block G2 is provided on the back side of the processing station 3 (the positive X-direction side in FIG. 1). The fourth block G4 is provided on the interface station 4 side of the processing station 3 (the positive Y-direction side in FIG. 1) or at the connection portion with another adjacent processing station 3. The fourth block G4 may include a plurality of transfer devices arranged in the vertical direction. Further, the aforementioned third block G3 may be provided within the processing station 3.

[0014] A plurality of processing devices, for example, a patterning film forming device and a development processing device (both not shown in the figure) are arranged in the first block G1. As the patterning film forming device, for example, in addition to a resist film forming device, an antireflection film forming device can be included.

[0015] For example, a plurality of processing devices are arranged side by side in the horizontal direction. Note that the number, arrangement, and type of these processing devices can be arbitrarily selected.

[0016] In these patterning film forming devices and development processing devices, for example, it is performed by supplying a predetermined processing liquid or a predetermined gas onto the wafer W. In this way, in the patterning film forming device, formation of a resist film used as a mask when forming a pattern of the lower layer film, and formation of an antireflection film or the like for efficiently performing light irradiation processing such as exposure processing are performed. On the other hand, in the development processing device, a part of the exposed resist film is removed to form the uneven shape as the mask.

[0017] For example, in the second block G2, heat treatment apparatuses (not shown) for performing heat treatment such as heating and cooling of the wafer W are provided side by side in the vertical and horizontal directions. Also in the second block G2, although not shown in any figure, a hydrophobization treatment apparatus for performing a hydrophobization treatment to enhance the fixing property between the resist liquid and the wafer W, and a peripheral exposure apparatus for exposing the outer peripheral portion of the wafer W are provided side by side in the vertical direction (Z direction in FIG. 2) and the horizontal direction. The number and arrangement of these heat treatment apparatuses, hydrophobization treatment apparatuses, and peripheral exposure apparatuses can also be arbitrarily selected.

[0018] As shown in FIG. 1, a wafer transfer region 32 is formed in the region sandwiched between the first block G1 and the second block G2 in a plan view. In the wafer transfer region 32, for example, a wafer transfer apparatus 33 is disposed.

[0019] The wafer transfer apparatus 33 has, for example, a transfer arm 33a that is movable in the Y direction, the front-rear direction, the θ direction, and the vertical direction. The wafer transfer apparatus 33 moves within the wafer transfer region 32 and can transfer the wafer W to predetermined apparatuses in the surrounding first block G1, second block G2, third block G3, and fourth block G4. When there are a plurality of processing stations 3 as shown in FIG. 1, the wafer transfer apparatus 33 provided in the processing station 3 located on the interface station 4 side can transfer the wafer W to predetermined apparatuses in the fifth block G5 described later in addition to the first, second, and fourth blocks G1, G2, and G3.

[0020] For example, as shown in FIG. 2, a plurality of wafer transfer apparatuses 33 are arranged vertically. One wafer transfer apparatus 33 can transfer the wafer W to a predetermined apparatus located at the height of a plurality of upper layers 31 among the plurality of vertically stacked layers 31. For a predetermined apparatus located at the height of a plurality of layers 31 located below those layers 31, another wafer transfer apparatus 33 can transfer the wafer W. A plurality of wafer transfer regions 32 are provided so as to enable such transfer of the wafer W. Note that the number of wafer transfer apparatuses 33 and the number of layers 31 corresponding to one wafer transfer apparatus 33, such as providing one wafer transfer apparatus 33 for each layer 31, can be arbitrarily selected.

[0021] Further, a shuttle transfer device (not shown) may be provided in the wafer transfer area 32, or the first block G1 or the second block G2. The shuttle transfer device linearly transfers the wafer W between a space adjacent to one side of the processing station 3 and another space adjacent to the opposite side thereof.

[0022] The interface station 4 is provided with a fifth block G5 including a plurality of transfer devices, and wafer transfer devices 41 and 42. The interface station 4 transfers the wafer W using the wafer transfer device 41 or 42 between the fifth block G5 where the wafer W is transferred by the wafer transfer device 33 and the exposure machine. For this purpose, the wafer transfer devices 41 and 42 are each provided with a drive mechanism in directions such as the X direction, the Y direction, the vertical direction, and the rotation around the vertical axis (θ direction) as required, and may be provided with drive mechanisms in all directions. At least one of the wafer transfer devices 41 and 42 can support the wafer W and transfer the wafer W between the transfer device in the fifth block G5 and the exposure device.

[0023] A cleaning treatment device for cleaning the surface of the wafer W and the above-described peripheral exposure device may be provided at a position accessible by either of the wafer transfer devices 41 and 42 within the interface station 4.

[0024] The inspection device may be provided in the cassette station 2 as described above, but may also be provided at a position accessible by any of the transfer arms (33, 41, 42 in FIG. 1 or FIG. 2) provided inside the processing station 3 and the interface station 4, respectively.

[0025] The above wafer processing system 1 is provided with a control device 100. The control device 100 is, for example, a computer and has one or more control circuits and a program storage unit (not shown) so as to be able to execute processing by a program. The program storage unit stores a program for controlling the processing of the wafer W in the wafer processing system 1. Further, the program storage unit also stores a program for controlling the operations of the drive systems of the above-described various processing devices, transfer devices, etc., to realize wafer processing in the wafer processing system 1. Note that the above program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control device 100. Instructions (each step) are incorporated into the installed program so that control signals are output to each part of the wafer processing system 1, and the transfer of the substrate by each wafer transfer device and the operations of each processing device are controlled by these control signals.

[0026] <Operation of Wafer Processing System> The wafer processing system 1 is configured as described above. Next, an example of wafer processing performed using the wafer processing system 1 configured as described above will be described.

[0027] First, a cassette C containing a plurality of wafers W is carried into the cassette station 2 of the wafer processing system 1 and placed on the cassette mounting plate 21. Next, each wafer W in the cassette C is sequentially taken out by the wafer transfer device 22 or 23 and transferred to the transfer device of the third block G3.

[0028] The wafer W conveyed to the transfer device of the third block G3 is supported by the wafer transfer device 33 and conveyed to the hydrophobization treatment device provided in the second block G2, where the hydrophobization treatment is performed. Next, the wafer transfer device 33 conveys it to the resist film forming device to form a resist film on the wafer W, and then conveys it to the heat treatment device for pre-baking treatment, and then conveys it to the transfer device of the fifth block G5. When there are multiple processing stations 3 as shown in FIGS. 1 and 2, the wafer W is placed once in the transfer device of the fourth block G4 before being conveyed to the transfer device of the fifth block G5, and then transferred between the multiple wafer transfer devices 33. Also, the wafer W may be conveyed to the peripheral exposure device by the wafer transfer device 33 as needed for exposure treatment of the peripheral portion of the wafer.

[0029] The wafer W conveyed to the transfer device of the fifth block G5 is conveyed to the exposure device by the wafer transfer devices 41 and 42 and subjected to exposure treatment in a predetermined pattern. Note that the wafer W may be washed by the cleaning treatment device before the exposure treatment.

[0030] The exposed wafer W is conveyed to the transfer device of the fifth block G5 by the wafer transfer devices 41 and 42. Then, it is conveyed to the heat treatment device by the wafer transfer device 33 for post-exposure baking treatment.

[0031] The wafer W after post-exposure baking treatment is conveyed to the developing device by the wafer transfer device 33 and developed. After the development is completed, the wafer W is conveyed to the heat treatment device by the wafer transfer device 33 for post-bake treatment.

[0032] After that, the wafer W is conveyed to the transfer device of the third block G3 by the wafer transfer device 33, and then conveyed to the cassette C on the predetermined cassette mounting plate 21 by the wafer transfer device 22 or 23 of the cassette station 2. Thus, a series of photolithography processes are completed.

[0033] Note that the wafer processing system (substrate processing system) in the present disclosure is not limited to the configurations and operations described above. For example, in the form of the above implementation, it has been described that the wafer W is transferred between the interface station 4 and the exposure apparatus, but it does not necessarily have to be directly connected to the exposure apparatus. In that case, for example, after the wafer W is transported from the cassette station 2 to the processing station 3 and the necessary processing is performed, it is transported back to the cassette station 2 for external unloading. Also, those that are not necessary among the processing apparatuses mentioned may not be provided, or the processing in those apparatuses may not be performed.

[0034] <Regarding the resist film> In the resist film forming apparatus of the wafer processing system 1, a resist film made of a metal-containing resist is formed. More specifically, for example, a film of a metal oxide resist (Metal Oxide Resist: MOR) is formed. Note that the above metal-containing resist contains metal as a constituent component of the resist, and does not mean a resist that contains metal only as an impurity. The metal that is a constituent component of this resist is, for example, tin (Sn). And this resist film made of MOR is developed after being exposed using light of an appropriate wavelength such as EUV (Extreme Ultra Violet) in the exposure apparatus, thereby forming a pattern (patterning). In the following description, unless otherwise specifically mentioned, the resist film is a resist film made of MOR.

[0035] The wafer processing system 1 is provided in the air atmosphere in a clean room in a semiconductor manufacturing factory. In order to suppress the scattering of particles inside the system, the wafer processing system 1 takes in the air around the system and supplies the air in a predetermined direction to form an air flow. However, the resist film made of MOR is modified by reacting with various components contained in the air, and the line width (Critical Dimension: CD) of the formed resist pattern changes. In the evaluation test described later, an acidic substance, more specifically acetic acid, is shown as an example of the component that changes the CD.

[0036] The wafer processing system 1 is provided with a chemical filter for removing chemical substances in the gas. As described above, the air taken into the wafer processing system 1 passes through the chemical filter and forms an air flow within the system. Since this chemical filter is composed of a plurality of filter sections for removing different substances, various types of chemical substances that can change the CD of the resist pattern can be removed from the air supplied into the wafer processing system 1. Therefore, the variation in CD between the wafers W of the same lot is suppressed, and a stable patterning process is performed on each wafer W to prevent the deviation of CD from the allowable range.

[0037] <Arrangement Example of Chemical Filter> A description will be given with reference to the schematic front view of the wafer processing system 1 in FIG. 3. The cassette station 2, the processing station 3, and the interface station 4 are each provided with a housing 20, 30, 40, and the interiors of the housings 20, 30, 40 are configured as spaces partitioned from each other. In the spaces partitioned in this way, the above-described conveyance path of the wafer W and each device for performing processing and placement on the wafer W are provided, and the wafer W is conveyed between the stations 2 to 4 through openings (not shown) formed in the housings 20 to 40.

[0038] A fan 51 is provided above each of the housings 20, 30, 40. Further, each of the housings 20, 30, 40 is provided with a flow path 52 extending downward from the fan 51, and a chemical filter 5 is provided at the downstream end of the flow path 52, which is the ceiling portion of the housing. In the figure, 52A is a flow path forming member for forming the flow path 52. Due to the action of the fan 51, air is taken into the flow path 52 from the outside of the wafer processing system 1, and this air further flows toward the downstream side of the flow path 52. By such a flow, the air is supplied to the chemical filter 5 from above and passes through the chemical filter 5, and is discharged from below the chemical filter 5. The air from which various chemical substances have been removed by passing through the chemical filter 5 in this way forms a downward air flow within the housing.

[0039] <Configuration Example of Chemical Filter> FIG. 4 is a longitudinal side view of the chemical filter 5. In addition, the arrows in this FIG. 4 and each figure showing the configuration of the chemical filter described later indicate the flow direction of the gas passing through the chemical filter. The chemical filter 5 includes an acid filter section 53 for removing acidic substances, a base filter section 54 for removing basic substances, and an organic filter section 55 for removing organic substances. The acid filter section 53, the base filter section 54, and the organic filter section 55 are laminated in this order toward the upstream side of the flow path 52. In this example, the thicknesses (sizes in the gas flow direction) of the acid filter section 53, the base filter section 54, and the organic filter section 55 are the same as each other.

[0040] These acid filter section 53, base filter section 54, and organic filter section 55 may be collectively described as filter sections 53 to 55. In this example, since the flow path 52 is formed in the Z direction (vertical direction), the lamination direction of the filter sections 53 to 55 is also the Z direction.

[0041] The filter sections 53 to 55 will be described in more detail. These filter sections 53 to 55 are filter materials having a removing action on the above-described respective substances. The organic filter section 55 is constituted by, for example, activated carbon, and can adsorb and remove various organic substances such as hydrocarbons, alcohols, ketones, esters, and aromatic compounds. The base filter section 54 is constituted by, for example, an ion exchanger so as to be able to remove various amines and ammonia as the above-described basic substances. This ion exchanger is, for example, a strongly acidic cation exchanger having a sulfonic acid group as a functional group. The acid filter section 53 is constituted by, for example, an ion exchanger so as to be able to remove various organic acids such as acetic acid and various inorganic acids such as hydrochloric acid, hydrofluoric acid, nitric acid, and sulfuric acid as the above-described acidic substances. This ion exchanger is, for example, a strongly basic anion exchanger having a quaternary ammonium group as a functional group.

[0042] For example, each of the filter units 53 to 55 has a plate-like body and is structured to have a number of small holes that communicate from one main surface of the plate to the other main surface so as to allow the supplied gas to pass through. A specific example of such a structure is a honeycomb structure. As described above, for the acid filter unit 53 and the base filter unit 54 which are ion exchangers, for example, an ion exchange resin may be used to form such a structure.

[0043] Note that instead of having such a configuration, the filter units 53 to 55 may be formed into a plate shape (including a sheet shape) by making a fabric, knitted fabric, or non-woven fabric using fibers containing components for removing the above-described chemical substances. In that case, the above-described small holes are gaps formed between the fibers. When using fibers in this way, for the acid filter unit 53 and the base filter unit 54, they may be configured using ion exchange fibers as the ion exchanger. For the organic filter unit 55, it may be configured with activated carbon fibers.

[0044] <Action and Effect of Chemical Filter> As described above, in the chemical filter 5, the organic filter unit 55, the base filter unit 54, and the acid filter unit 53 are provided toward the downstream side. By providing each filter unit with a different object to be removed in this way, the air that has passed through the chemical filter 5 has various chemical substances that cause fluctuations in the CD of the pattern formed on the resist film removed, and is supplied to the transfer path of the wafer W in the wafer processing system 1 and to each device that processes and places the wafer W. Therefore, as described above, it is possible to stabilize the CD of the pattern in the resist film.

[0045] Incidentally, in a patterning film forming apparatus, EBR (Edge Bead Removal) is performed in which an organic solvent is supplied to the peripheral portion of the wafer W after film formation to remove unnecessary portions, or pre-wetting treatment is performed in which an organic solvent is supplied to the wafer W before film formation to enhance the wettability with respect to the processing liquid for forming the film. For example, this organic solvent may contain PGMEA (Propylene glycol monomethyl ether acetate), and it is conceivable that a trace amount of PGMEA leaks outside the wafer processing system 1 and is supplied to the chemical filter 5 by the fan 51.

[0046] The operation of the chemical filter 5 when PGMEA is supplied as an organic substance will be described with reference to FIGS. 5 to 8. In FIGS. 5 to 8, PGMEA in the atmosphere is shown as 61. For some time after a new chemical filter 5 is attached to the wafer processing system 1, the PGMEA 61 supplied to the chemical filter 5 is collected by the organic filter section 55 provided as the filter section on the most upstream side in the chemical filter 5, and thus is not released from the chemical filter 5 (FIG. 5).

[0047] However, if the supply of this PGMEA 61 and other organic substances to the chemical filter 5 continues and the amount collected in the organic filter section 55 becomes large, the adsorption and removal performance of the organic filter section 55 for newly supplied organic substances decreases, and this performance falls below the allowable range. That is, the organic filter section 55 reaches the end of its life (FIG. 6). Then, the PGMEA 61 supplied to the chemical filter 5 passes through the organic filter section 55 and is supplied to the base filter section 54. By the action of the base filter section 54, the PGMEA 61 is decomposed, and acetic acid (shown as 62 in the figure) is generated (FIG. 7). As described above, the acetic acid 62 causes the CD of the pattern of the resist film that is MOR to fluctuate. However, since an acid filter section 53 is provided on the downstream side of the base filter section 54 where the acetic acid 62 is generated in this way, the acetic acid 62 is removed by the action of this acid filter section 53 (FIG. 8), and it is prevented from being released from the chemical filter 5.

[0048] The operation of the chemical filter 5 shown in FIGS. 5 to 8 will be further described. The chemical filter 5 includes filter sections 53 to 55, and as described above, since it can remove various chemical substances, it is advantageous in suppressing CD variations of the resist pattern. However, when the height of the space where the chemical filter 5 is installed is limited, due to the configuration having filter sections which are a plurality of types of filter media, the thickness of each of the filter sections 53 to 55 will be relatively small. Since the length of the life of the filter sections 53 to 55 depends on the thickness, there may be cases where it is difficult to extend the life of each of the filter sections 53 to 55.

[0049] Therefore, when the concentration of organic substances around the wafer processing system 1 is high, as shown in FIGS. 5 and 6, the organic filter section 55 reaches the end of its life relatively early, and acetic acid 62 which becomes a factor for varying the CD of the resist pattern from PGMEA 61 is generated. However, in the chemical filter 5, since the base filter section 54 and the acid filter section 53 are arranged in order toward the downstream side on the downstream side of the organic filter section 55, as described with reference to FIGS. 7 and 8, the release of acetic acid 62 from the chemical filter 5 is prevented.

[0050] Therefore, even if the wafer processing system 1 is placed in an environment where the concentration of organic substances around the wafer processing system 1 is relatively high and the life of the organic filter section 55 becomes relatively short, it is not essential to replace the chemical filter 5 before this life expires. That is, according to the configuration of the chemical filter 5, when provided in the wafer processing system 1, it is possible to prevent the replacement frequency from becoming high. This reduces the frequency of a state where the transfer and processing of the wafer W in the wafer processing system 1 are stopped for the replacement, and thus the reduction in the productivity of the wafer processing system 1 is suppressed.

[0051] <Second Embodiment of Chemical Filter> Next, another example of the chemical filter installed in the wafer processing system 1 instead of the chemical filter 5 will be described. FIG. 9 is a longitudinal side view of the chemical filter 5A which is the second embodiment. For the chemical filter 5A, an organic filter portion 55 is not provided, and it is composed of a base filter portion 54 and an acid filter portion 53 which are laminated on each other. Regarding the arrangement order of the base filter portion 54 and the acid filter portion 53, similar to the chemical filter 5, the acid filter portion 53 is located on the downstream side of the flow path 52 so that acetic acid 62 generated in the base filter portion 54 can be removed by the acid filter portion 53. As described in the explanation of the chemical filter 5, since the lower side of the flow path 52 where the chemical filter is provided in the wafer processing system 1 is the downstream side, the acid filter portion 53 is disposed below the base filter portion 54.

[0052] As described above, the organic filter portion 55 is not provided in the chemical filter 5A. Therefore, when selecting and providing the chemical filter 5 or the chemical filter 5A in the space at a predetermined height in the flow path 52, the thickness of the acid filter portion 53 and / or the thickness of the base filter portion 54 can be made larger for the chemical filter 5A. Regarding the chemical filter 5A shown in this FIG. 10, the thickness is the same as that of the chemical filter 5 shown in FIG. 4, and the thickness of each of the acid filter portion 53 and the base filter portion 54 is larger for the chemical filter 5A than for the chemical filter 5. An example of the relationship between the thicknesses of the filter portions between the chemical filters will be further described later.

[0053] <Third Embodiment of Chemical Filter> FIG. 10 is a longitudinal side view of the chemical filter 5B which is the third embodiment. For the chemical filter 5B, similar to the chemical filter 5, the acid filter portion 53, the base filter portion 54, and the organic filter portion 55 are laminated and configured. In the direction of the downstream side of the flow path 52, the order is the acid filter portion 53, the organic filter portion 55, and the base filter portion 54.

[0054] In the chemical filter 5B, the thickness of the organic filter section 55 is greater than the thickness of the acid filter section 53 and the thickness of the base filter section 54. By setting the thickness in this way, the period from the start of use of the chemical filter 5B until the organic filter section 55 reaches the end of its life becomes long. During this long period, even if PGMEA 61 is supplied to the chemical filter 5B, it does not reach the base filter section 54. Therefore, the generation of acetic acid 62 in the base filter section 54 and the release of the acetic acid 62 from the chemical filter 5B are prevented. Thus, for this chemical filter 5B as well, even when used in an environment with a relatively high organic matter concentration, similar to the chemical filter 5, the replacement frequency can be suppressed.

[0055] In addition, even if organic substances other than PGMEA or compounds generated by reactions such as decomposition of this organic substance affect the CD of the resist pattern, if the thickness of the organic filter section 55 is large like that of this chemical filter 5B, the organic substance can be collected over a long period. That is, even when organic substances other than PGMEA cause fluctuations in the CD of the resist pattern, according to the configuration of the chemical filter 5B in which the relationship between the thicknesses of the filter sections 53 to 55 is the above-described relationship, it is preferable because the replacement frequency of the chemical filter 5B can be suppressed. Regarding the chemical filter 5 described with reference to FIG. 4 as well, the replacement frequency may be further suppressed by making the thickness of the organic filter section 55 greater than the thickness of the acid filter section 53 and the thickness of the base filter section 54.

[0056] <Another example of the arrangement of the chemical filter> Regarding each chemical filter, although it has been shown to be arranged in the flow path 52 through which the atmosphere forming the downward airflow passes, it is not limited to such an arrangement. FIG. 11 shows an example in which the chemical filter 5 is provided in the flow path 71 provided in the side wall of the cassette station 2. By the fan 72, the atmosphere taken in from the outside of the wafer processing system 1 flows laterally through the flow path 71 and passes through the chemical filter 5, forming a lateral airflow within the housing 20. Therefore, the filter units 53 to 55 are arranged side by side horizontally. As shown in the example of FIG. 11, the system configuration is not limited to supplying gas to the chemical filter from above, and the installation direction of the chemical filter and the gas supply direction through the chemical filter can be arbitrarily set. At other stations other than the cassette station 2, a chemical filter may be provided so that the gas flowing horizontally within the housing passes through it.

[0057] Also, FIG. 12 shows an example in which a gas supply system 73 is connected to the wafer processing system 1. The gas supply system 73 is a system provided outside the wafer processing system 1 and includes a supply mechanism 74 that supplies a gas adjusted to be within a predetermined range with respect to temperature and humidity. The gas supply system 73 and the processing apparatus 70 provided in the processing station 3 are connected via a pipe 75. In the gas supply system 73, the chemical filter 5 is arranged in the flow path 76 provided on the upstream side of the pipe 75, and the gas supplied from the supply mechanism 74 passes through the chemical filter 5 and is supplied to the processing station 3 via the pipe 75.

[0058] The gas whose temperature and humidity are adjusted in this way is an inert gas such as, for example, N2 gas. The processing apparatus 70 to which this inert gas is supplied includes a housing 77, a processing space for processing the wafer W is formed inside the housing 77, and the inert gas is supplied to this processing space. Therefore, this processing space is formed inside the housing 30 of the processing station 3 by the housing 77 and is a space partitioned from the wafer transfer region 32 to which air is supplied from the chemical filter 5 on the ceiling portion. Examples of the processing apparatus 70 include a patterning film forming apparatus and a heating apparatus.

[0059] Note that the inert gas supplied from the gas supply system 73 via the chemical filter 5 is not limited to being supplied to the processing apparatus for the wafer W. For example, in the processing station 3, it is assumed that a standby device for waiting a plurality of wafers W in a standby space partitioned from the wafer transfer region 32 by being surrounded by the housing 77 is provided. The inert gas may be supplied to this standby space. The standby device may be provided at a station other than the processing station 3 such as the cassette station 2. Further, the supply destination of this inert gas may be the cassette mounting plate 21 of the cassette station 2, and the inert gas is supplied into the cassette C in which the wafer W waits through a gas supply port (not shown) of the cassette mounting plate 21. The cassette C is a transfer container called, for example, a FOUP (Front Opening Unify Pod), and is configured to enable gas supply from the outside to the inside. As described above, the supply destination of the inert gas from the gas supply system 73 is not limited to the processing station 3.

[0060] In FIGS. 11 and 12, an example using the chemical filter 5 was given. However, instead of the chemical filter 5, chemical filters 5A, 5B, or each of the chemical filters described below may be used. And for this gas supply system 73 as well, instead of the chemical filter 5, chemical filters 5A, 5B, or the chemical filters described below may be used. Note that, as shown in the example of FIG. 12, the gas supplied to each chemical filter is not limited to air, and regarding the installation position of the chemical filter, it may be away from the transfer path of the wafer W or the housing that stores the processing apparatus 70.

[0061] <Further Configuration Example of Chemical Filter> FIG. 13 is a longitudinal side view of the chemical filter 5C which is a fourth embodiment. The chemical filter 5C is configured in the same manner as the chemical filter 5, with the organic filter section 55, the base filter section 54, and the acid filter section 53 arranged in line toward the downstream side of the flow path 52. However, gaps 57 and 58 are respectively formed between the organic filter section 55 and the base filter section 54, and between the base filter section 54 and the acid filter section 53. Therefore, for the chemical filter 5C, a configuration is adopted in which a gap is provided between one filter section and another filter section arranged next to the one filter section when looking at the flow path 52 from the downstream side. In the figure, 59 is a cylindrical frame that surrounds the side circumferences of the filter sections 53 to 55 and forms the flow path 52, and supports the filter sections 53 to 55 so that the gaps 57 and 58 are formed. In the example shown in FIG. 13, the gaps 57 and 58 have the same width, but this width may be different from each other. FIG. 14 shows an example in which the width of the gap 57 is smaller than the width of the gap 58.

[0062] In this way, the adjacent filter sections of the filter sections 53 to 55 may not be in contact with each other. However, as described above, the life of the filter section depends on the thickness. From the perspective of arranging the chemical filter in the limited chemical filter arrangement space in the system and providing it so that the life of each filter section becomes long, it is preferable that the adjacent filter sections are in contact with each other.

[0063] FIG. 15 is a side view of the chemical filter 5D according to the fifth embodiment. Similar to the chemical filter 5C, this chemical filter 5D is configured such that the organic filter section 55, the base filter section 54, and the acid filter section 53 are arranged side by side toward the downstream side of the flow path 52. However, since the flow path 52 is formed in the lateral direction, the filter sections 53 to 55 are also arranged side by side in the lateral direction. And the filter sections 53 to 55 are arranged in the frame 59 relatively far apart from each other. It can also be seen that the widths of the gaps 57 and 58 described in FIGS. 13 and 14 are formed relatively large.

[0064] As shown in the example of FIG. 15, the filter sections are not necessarily close to each other and may be relatively far apart. Even in such a case where they are relatively far apart, it is assumed that the chemical filter is constituted by each filter section from the filter section arranged on the most upstream side in the flow path (the organic filter section 55 in this example) to the filter section arranged on the most downstream side (the acid filter section 53 in this example).

[0065] FIG. 16 is a side view of the chemical filter 5E according to the sixth embodiment. This chemical filter 5E has substantially the same configuration as the chemical filter 5C shown in FIG. 13, but the difference is that projections 50 are provided on the base filter section 54 and the acid filter section 53. The projections 50 project from each of the upstream side and the downstream side of the flow path 52, and unevenness is formed on the main surfaces of the base filter section 54 and the acid filter section 53 by these projections 50, so that the surface area on the main surfaces becomes relatively large, thereby enhancing the removal performance of chemical substances. Note that the projections 50 are not projections inevitably formed in the manufacturing process of the filter section, and their height is, for example, 0.5 mm or more.

[0066] Incidentally, in the chemical filter 5E, the protrusion 50 formed on the opposing surface 54A of the base filter section 54 facing the acid filter section 53 and the protrusion 50 formed on the opposing surface 53A of the acid filter section 53 facing the base filter section 54 do not overlap with each other when viewed in the gas flow direction. Therefore, it is preferable that the width of the gap 58 between the acid filter section 53 and the base filter section 54 is prevented from increasing, thereby preventing the chemical filter 5E from becoming larger in size.

[0067] In the chemical filter 5E, the organic filter section 55 is not provided with the protrusion 50, but the protrusion 50 may also be provided on the organic filter section 55 in the same manner as the base filter section 54 and the acid filter section 53. Note that the thicknesses of the filter sections 53 to 55 in the case of providing the protrusion 50 in this way are the thicknesses in the portions where the protrusion 50 is not provided.

[0068] As shown in the example of the chemical filter 5E, the filter sections 53 to 55 are not necessarily flat like the examples of the chemical filters 5, 5A to 5D. FIG. 17 shows a longitudinal side view of a chemical filter 5F which is a seventh embodiment as an example of another chemical filter in which the filter sections 53 to 55 are not flat. Each of the filter sections 53 to 55 in this chemical filter 5F is formed in a wavy shape in side view by making a plate shape in which a mountain-folded portion and a valley-folded portion are repeated from one end side to the other end side. In the example of FIG. 17, by making folds, the filter sections 53 to 55 have a so-called pleated shape, but it may also have a shape that draws a wavy curve in side view due to the absence of folds.

[0069] By making the filter sections 53 to 55 wavy in side view as described above, the surface area on the side facing the upstream side of the flow path 52 can be increased, and the removal performance of chemical substances can be enhanced. In the example of FIG. 16, gaps 57 and 58 are provided between the filter sections 53 to 55, but a configuration in which the gaps 57 and 58 are not provided may also be used.

[0070] FIG. 18 is a longitudinal side view of the chemical filter 5G according to the seventh embodiment. This chemical filter 5G is configured substantially the same as the chemical filter 5C in FIG. 13, but the difference is that the gap 57 between the filter parts 54 and 55 is not provided.

[0071] Due to the variation in the supply amount of the organic matter at various locations in the organic filter part 55, some positions reach the end of their lifespan earlier than other positions. Assuming that PGMEA 61 is supplied from such a position to the base filter part 54. That is, it is assumed that PGMEA 61 is locally supplied to the base filter part 54 from some positions in the organic filter part 55. In that case, acetic acid 62 is generated at a local position in the base filter part 54 and is released toward the acid filter part 53 as indicated by the relatively thick arrow in the figure. However, this acetic acid 62 diffuses through the gap 58 between the acid filter part 53 and the base filter part 54, suppressing the supply to the local position of the acid filter part 53. That is, by providing the gap 58, it is possible to prevent the local position in the acid filter part 53 from reaching the end of its lifespan earlier than other positions and being unable to remove acetic acid 62. As a result, the replacement frequency of the chemical filter 5G can be suppressed.

[0072] In addition, for each of the above-described chemical filters provided with the gap 58 between the base filter part 54 and the acid filter part 53 in the same manner as this chemical filter 5G, the same effects as those of the chemical filter 5G described above can be obtained. Also, when providing the gap 57 between the organic filter part 55 and the base filter part 54 as in the chemical filter 5C in FIG. 13, PGMEA 61 also diffuses through the gap 57 and is then supplied to the base filter part 54. Therefore, it is preferable because it can more reliably suppress the shortening of the lifespan of the local position of the acid filter part 53 described above.

[0073] <Installation of Different Chemical Filters within the Same System> Incidentally, among the chemical filters described above, the same chemical filter may be provided in the wafer processing system 1, or different chemical filters may be provided. Appropriate chemical filters can be selected and arranged in consideration of the size of the installation space for the chemical filters at various locations within the system and the concentration of each chemical substance around the installation location. More specifically, the chemical filters provided in the flow paths connected to each of the spaces partitioned from each other may have different configurations. Hereinafter, such an example will be described with reference to the drawings.

[0074] In the example shown in FIG. 19, in the wafer processing system 1, the chemical filter 5A described in FIG. 9 is provided in the flow path 52 (first flow path) at the ceiling of the cassette station 2, and the chemical filter 5 described in FIG. 4 is provided in the flow path 52 (second flow path) at the ceiling of the processing station 3. Then, air is supplied to the chemical filter 5A (first chemical filter) and the chemical filter 5 (second chemical filter) from the atmosphere into the housing 20 which is the first space and the housing 30 which is the second space, respectively.

[0075] In this example, in anticipation of a high concentration of various organic substances around the processing station 3 where an organic solvent is used, in order to enhance the removal effect, the chemical filter 5 including the organic filter section 55 is provided at the ceiling of the processing station 3. On the other hand, anticipating that the concentration of organic substances around the cassette station 2 is lower than that around the processing station 3, the chemical filter 5A not including the organic filter section 55 is provided at the ceiling of the cassette station 2. Since it does not include the organic filter section 55, for the chemical filter 5A, the acid filter section 53 and the base filter section 54 are configured to be relatively thick so that the installation space is effectively utilized, thereby achieving an extended service life. Specifically, with respect to the thickness of each of the acid filter section 53 and the base filter section 54, the chemical filter 5A is configured to be larger than the chemical filter 5, thus achieving an extended service life of the chemical filter 5A in this way.

[0076] FIG. 20 shows another installation example. In the wafer processing system 1 of FIG. 20, it is assumed that the processing station 3 has a greater height of the installable area for the chemical filter. Chemical filters 5 are provided at the ceiling portions of the cassette station 2 and the processing station 3, respectively. However, in order to effectively utilize the above-mentioned installable area, the thickness of the organic filter portion 55 is greater for the chemical filter 5 in the processing station 3 than for the chemical filter 5 in the cassette station 2. Thereby, the chemical filter 5 in the processing station 3 is made to have a longer life.

[0077] FIG. 21 shows yet another installation example. In this example, a chemical filter 5 is provided at the ceiling portion of the cassette station 2, while a chemical filter 5B having a greater thickness of the organic filter portion 55 shown in FIG. 10 than the thicknesses of other filter portions is provided at the ceiling portion of the processing station 3, so that the chemical filter in the processing station 3 may have a longer life.

[0078] As described above, it is possible to make it different whether the chemical filters provided at different positions in the wafer processing system 1 include the organic filter portion 55, to make the arrangement order in the flow path of the included filter portions different, or to make the thickness of any one of the included filter portions different.

[0079] Regarding making the thickness of the filter section different between chemical filters at different positions in the wafer processing system 1, an example where the thickness of the organic filter section 55 is different has been shown. However, the thickness of the base filter section 54 and / or the acid filter section 53 may be made different. Also, for convenience of explanation, assuming that the concentration of organic substances is higher around the processing station 3, an organic filter section 55 is provided in the processing station 3, or a chemical filter in which the organic filter section 55 has a long life is arranged. However, the arrangement is not limited to such. That is, the chemical filter described as being arranged in the processing station 3 may be arranged in the cassette station 2, and the chemical filter described as being arranged in the cassette station 2 may be arranged in the processing station 3. And although the configuration of the chemical filter is shown to be different between the cassette station 2 and the processing station 3, the configuration of the chemical filter may be made different between other stations.

[0080] <System split configuration> As described above, the wafer processing system 1, which is a substrate processing apparatus, performs a series of patterning from the formation of a patterned film to development. However, the system configuration is not limited to such. A plurality of device parts responsible for different parts of this series of patterning are provided in the clean room. Then, the cassette C is sequentially transported between the device parts by the transport mechanism in the clean room, and the wafer W taken out from the cassette C is transported within each device part and processed, so that it may be configured as a wafer processing system in which patterning processing is performed. The substrate processing apparatus is an apparatus that allows the wafer W carried out from the cassette C to be processed and returned to the cassette C again. Therefore, each of the plurality of device parts corresponds to a substrate processing apparatus. As such, the substrate processing apparatus may be configured as a device part responsible for a part of the patterning process, and the chemical filter described above may be provided in each device part.

[0081] Regarding the device unit, if it is a device unit not connected to the exposure apparatus, it may be provided with a cassette station 2 for transporting the wafer W between the inside of the device unit and the cassette C, and a processing station 3, and only the necessary processing apparatuses among the above-described processing apparatuses may be provided in the processing station 3. Further, if it is a device unit connected to the exposure apparatus, it may be provided with a cassette station 2 and an interface station 4, and the wafer W may be transported between the cassette C and the exposure apparatus via these cassette station 2 and interface station 4. When performing processes other than exposure in the device unit, a processing station 3 may also be provided.

[0082] Incidentally, patterning may be a process of repeating PEB (Post Exposure Bake) and development. The second and subsequent PEBs and development are processes for shaping the pattern formed on the resist film by the first PEB and development, and the above-described chemical filters can also be applied to the device unit that performs the second and subsequent PEBs and development. Incidentally, the patterning process is a process from forming the resist film of MOR to developing this resist film. However, when repeating PEB and development in this way, the development here corresponds to the last development. When repeating PEB and development, it is assumed that the etching process of the film (lower layer film) in the lower layer of the resist film is not performed until the shaping is completed. That is, the process from forming the resist film to performing the last development before performing the etching of the lower layer film for the first time corresponds to patterning.

[0083] It has been described that the inert gas that has passed through the chemical filter described as each example may be supplied to the cassette C or the standby device provided in the station. In a system that performs patterning by a plurality of device units, adopting a configuration in which the inert gas is supplied in this way is preferable because it is possible to suppress the deterioration of the resist film due to the wafer W waiting for a long time in the cassette C of one device unit even if the access to one device unit by the transfer mechanism is delayed. Note that the purpose is not to make the wafer W wait for transfer to different device units, but rather to more surely suppress the deterioration of the resist film before it is transferred to the destination when transferring the wafer W within the same device unit. Therefore, the cassette C and the standby device may be supplied with an inert gas.

[0084] Incidentally, although the materials constituting the filter units 53 to 55 have already been exemplified, it is only necessary that each can remove different chemical substances, and thus the exemplified ones are not limited. For example, for the acid filter unit 53, activated carbon to which a basic substance such as potassium carbonate is attached may be used, and for the base filter unit 54, activated carbon to which an acidic substance such as phosphoric acid is attached may be used. Also, the filter units 53 to 55 are not limited to having the structure described above. For example, a structure in which a large number of granular activated carbons are sandwiched by a nonwoven fabric to form a layer may be used. And the substrate to be processed is not limited to being a wafer, and may be, for example, a substrate for manufacturing a flat panel display or a mask substrate for manufacturing a mask for exposure. Therefore, a rectangular substrate may be processed.

[0085] <Supplementary Note on MOR> A supplementary explanation will be given for the resist film of MOR. In the resist film, from the Sn atoms at the sites exposed by the exposure apparatus, the ligands coordinated to the Sn atoms are desorbed, and a large number of Sn atoms from which the ligands have been desorbed are bonded to each other via oxygen (O) atoms. That is, Sn is oxidized to form a crosslinked structure, and a structure of -Sn-O-Sn-O-Sn-O- is formed in the exposed region of the resist film. Note that the ratio of Sn atoms to O atoms in the crosslinked structure is not necessarily 1:1 in this way. By the formation of this crosslinked structure, the exposed sites are insolubilized with respect to the developing fluid, and PEB promotes the formation of this crosslinked structure. At the time of development, the unexposed regions where the crosslinked structure is not formed will be removed.

[0086] <Another configuration example of the wafer processing system> FIG. 22 shows a plan view of the wafer processing system 1A. The wafer processing system 1A is configured in substantially the same manner as the wafer processing system 1, and hereinafter, the description will focus on the differences from the wafer processing system 1. In the description of this wafer processing system 1A, the side where the cassette station 2 is located and the side where the interface station 4 is located are defined as the left side and the right side, respectively, and the side where the first block G1 is located and the side where the second block is located are defined as the front side and the rear side, respectively.

[0087] A chemical filter 5H is provided in each of the cassette station 2, the processing station 3, and the interface station 4 instead of the chemical filter 5. Further, the gas supply system 73 described in FIG. 12 is connected to the wafer processing system 1A. Also in the flow path 76 of this gas supply system 73, a chemical filter 5H is provided instead of the chemical filter 5.

[0088] The chemical filter 5H provided at each station is provided in the flow path 82 of a rectangular cylindrical body 81 whose interior is configured as a gas flow path 82. Similar to the chemical filter 5, the chemical filter 5H includes an acid filter section 53, a base filter section 54, and an organic filter section 55, but the order of arrangement of these filter sections is different from that of the chemical filter 5. Details of the chemical filter 5H will be described later.

[0089] In the cassette station 2, the cylindrical body 81 is provided at a position above the cassette mounting plate 21 on the left side wall constituting the housing 20, and the upstream side of the flow path 82 formed by the cylindrical body 81 faces leftward and faces the external space of the housing 20. In each processing station 3, the cylindrical body 81 is provided on the upper wall constituting the housing 30, the upstream side of the flow path 82 formed by the cylindrical body 81 faces upward, and faces the external space of the housing 30. In the interface station 4, the cylindrical body 81 is provided so as to protrude forward and backward from the front side wall and the rear side wall of the housing 40, respectively. The upstream side of the flow path 82 formed by the front cylindrical body 81 faces forward, and the upstream side of the flow path 82 formed by the rear cylindrical body 81 faces backward, and each faces the external space of the housing 40.

[0090] In this way, the cylindrical bodies 81 each provided with the chemical filter 5H are provided at stations 2, 3, and 4. And for each of stations 2, 3, and 4, intake of the atmosphere outside the wafer processing system 1A through the chemical filter 5H provided at the station and supply of the atmosphere into the housings 20, 30, and 40 constituting the station are performed. This intake and supply of the atmosphere are performed by a fan 51 provided on the downstream side of the chemical filter 5H in the air flow path formed at each station.

[0091] Further, a filter 90 for removing foreign matter from the atmosphere is provided on the downstream side of the fan 51 in the air flow path, and the atmosphere is supplied into the housing through the filter 90. This filter 90 is, for example, a ULPA (Ultra Low Penetration Air) filter. As described above, for each station, a flow path in which the chemical filter 5H, the fan 51, and the filter 90 are located downstream is formed, and the above-described cylindrical body 81 forms a part of the flow path. Hereinafter, for convenience, the filter 90 may be described as the foreign matter removal filter 90.

[0092] The processing station 3 will be further described. In the wafer transfer area 32 of the processing station 3, air is supplied from above through a flow path provided in the above-described housing 30 and including the chemical filter 5H, the fan 51, and the foreign matter removal filter 90. Then, for each processing apparatus 70 included in the first block G1 and the second block G2, gas adjusted in terms of temperature and humidity is supplied from the gas supply system 73 as illustrated in FIG. 12 through the chemical filter 5H of the gas supply system 73.

[0093] Subsequently, the cassette station 2 will be described in detail with reference to the longitudinal front view of FIG. 23 and the cross-sectional plan view of FIG. 24. Also, the configurations of the chemical filter 5H and the cylindrical body 81 will be described in more detail. The cylindrical body 81 is configured such that a metal cylindrical body 81A and a cylindrical body 81B are connected to each other in the axial direction of the cylinder through a connecting member 83. The cylindrical body 81A forms the upstream side of the flow path 82, and the cylindrical body 81B forms the downstream side of the flow path 82. The connecting member 83 is an elastic member formed in an annular shape along the circumferences of the cylindrical bodies 81A and 81B, and specifically, for example, a packing.

[0094] The chemical filter 5H is configured by arranging an organic filter section 55, an acid filter section 53, and a base filter section 54 in this order toward the downstream side of the flow path 82. The organic filter section 55 and the acid filter section 53 are provided within the cylinder 81A, and the base filter section 54 is provided within the cylinder 81B. In this example, the organic filter section 55 is a sheet containing activated carbon, the acid filter section 53 is a sheet containing impregnated activated carbon, and the base filter section 54 is a sheet containing a cation exchange resin. Each of these sheets is formed by weaving fibers and is arranged so as to partition the flow path 82 into an upstream side and a downstream side. And each filter section configured as a sheet in this way is bent into a pleated shape as described with reference to FIG. 17.

[0095] Regarding the peaks formed by folding the sheet in this way, if the distance in the direction of the flow path 82 between adjacent tops is defined as the apparent thickness L, in this example, in order to extend the service life of the base filter section 54, the apparent thickness L of the base filter section 54 is larger than the apparent thickness L of the organic filter section 55 and the acid filter section 53. Note that, by the apparent thickness L becoming relatively large in this way, the volume of the space between the folds formed by the sheet of the base filter section 54 also becomes relatively large. As a result, the pressure loss when the gas passes through the region where the base filter section 54 is provided in the flow path 82 becomes low. Therefore, assuming that the base filter section 54 in the case of a flat shape has a relatively high pressure loss, from the viewpoint of reducing the pressure loss of the flow path 82 in addition to the viewpoint of extending the service life of the base filter section 54, it is effective to set the relationship of the apparent thickness L of each filter section to the relationship described above.

[0096] In this example, since the apparent thickness L of the base filter section 54 is increased, the cylindrical body 81 is relatively long. Since forming the cylindrical body 81 integrally may increase the difficulty of manufacturing and processing due to its size, as described above, the cylindrical body 81 is composed of cylindrical bodies 81A and 81B which are separate members from each other, and these cylindrical bodies 81A and 81B are connected via a connecting member 83. When providing each filter section 53 - 55 in such a cylindrical body 81, by providing the connecting member 83, the space formed between the acid filter section 53 and the base filter section 54 increases by the thickness of this connecting member 83. As in the example described with reference to FIG. 18, this space is utilized, and the air that has passed through the acid filter section 53 diffuses and is supplied to the base filter section 54, so it is preferable because a decrease in the life at a local position of the base filter section 54 is suppressed.

[0097] In the cassette station 2, a plurality of, for example, three cylindrical bodies 81 are provided side by side in the front - rear direction at the same height. Each cylindrical body 81 is arranged within the housing 20 that constitutes the cassette station 2 such that its axis extends left - right, and as described above, the upstream side of the flow path 82 opens to the left - hand side wall of the housing 20.

[0098] On the right side of each cylindrical body 81, a suction housing 84 is provided. The suction housing 84 forms a longitudinally long space 85 partitioned from the surroundings, and the downstream side of the flow path 82 of each cylindrical body 81 is connected to the space 85. In the suction housing 84, two fans 51 are provided such that their rotation axes extend in the left - right direction, and these fans 51 are located spaced apart front - rear on the right - hand side of the space 85. Each fan 51 can suck the flow path 82 of each cylindrical body 81 through the space 85. Therefore, the flow paths of a plurality of cylindrical bodies 81 are sucked by one fan 51.

[0099] On the right side of the suction housing 84, the upstream ends of two ducts 86 are provided side by side in the front-rear direction and are respectively connected to the suction housing 84. Of the two fans 51, the air sucked by the rear fan 51 is supplied to the flow path 87 in the rear duct 86, and the air sucked by the front fan 51 is supplied to the flow path 87 in the front duct 86. The downstream side of each duct 86 extends downward and then bends to extend leftward. The lower side of the portion where each duct 86 extends leftward is open. And a foreign matter removal filter 90 is provided so as to block the open portion of the duct 86 from below, and thus, the downstream end of the flow path 87 is located as a flat space above the foreign matter removal filter 90. Therefore, as shown in FIG. 23, the flow path 87 is in an L shape lying on its side in a front view, and the chemical filter 5H is located above the foreign matter removal filter 90.

[0100] The air supplied from the outside of the wafer processing system 1A by the fan 51 to the flow path 87 in the duct 86 through the chemical filter 5H is supplied downward through the foreign matter removal filter 90. The lower region of the foreign matter removal filter 90 where the air is supplied in such a manner is the region where the wafers W are conveyed by the wafer transfer devices 22 and 23.

[0101] In this way, a flow path is formed from the chemical filter 5H to the foreign matter removal filter 90 by the cylindrical body 81, the suction housing 84, and the duct 86, and this flow path is bent so as to be in a U shape lying on its side. The chemical filter 5H includes the filter portions 53 to 55 and is larger than a chemical filter having a configuration including only one or two of the filter portions 53 to 55. However, as described above, by bending the flow path, even when the chemical filter 5H is arranged, an increase in the size of the flow path in the left-right direction is prevented. In other words, due to the flow path configuration of this example, a relatively large chemical filter 5H can be installed in the flow path direction without increasing the size of the flow path left and right.

[0102] Next, the interface station 4 will be described with reference to the side view of FIG. 25. This FIG. 25 shows the interface station 4 as viewed from the right side. In the rear side within the housing 40 of the interface station 4 in this example, a plurality of processing devices 70 are stacked and provided. The processing performed by this processing device 70 is not limited, but for example, it is a process of cleaning the wafer W before exposure by an exposure device. In this interface station 4, the flow paths are formed such that the air inhaled from different chemical filters 5H is supplied to different regions. The supply destination of the air that has passed through the chemical filter 5H of the rear cylindrical body 81 is the processing device 70. And the supply destination of the air that has passed through the chemical filter 5H of the front cylindrical body 81 is the region where the wafer transfer devices 41, 42 outside the processing device 70 move.

[0103] The front end of the cylindrical body 81 provided at the rear of the housing 40 is connected to a duct 91 that extends obliquely upward from the side wall of the housing 40 in a side view. Through this duct 91, the flow path 82 within the cylindrical body 81 and the flow path 94 formed by a flow path forming member 93 provided inside the housing 40 communicate with each other. In the downstream direction of the flow path 94, a fan 51 and a foreign matter removal filter 90 are provided. The downstream end of the flow path forming member 93 is configured as, for example, a duct and is connected to each processing 70. With the above configuration, the air taken into the housing 40 through the rear chemical filter 5H by the fan 51 in the flow path 94 is supplied to each processing device 70 through the foreign matter removal filter 90.

[0104] The rear end of the cylindrical body 81 provided in front of the housing 40 is connected to the side wall of the housing 40. The flow path 82 within the cylindrical body 81 and the flow path 96 formed by a flow path forming member 95 provided inside the housing 40 communicate with each other. In the downstream direction of the flow path 96, a fan 51 and a foreign matter removal filter 90 are provided. With the above configuration, the air taken into the housing 40 through the front chemical filter 5H by the fan 51 in the flow path 96 is supplied to the movement region of the wafer transfer devices 41, 42 through the foreign matter removal filter 90.

[0105] Regarding the interface station 4, a chemical filter 5H may be provided at the upper part of the housing 40 of the station in the same manner as the processing station 3. However, as described above, by providing the chemical filter 5H on the side of the housing 40, it is possible to prevent the cylindrical body 81 from protruding from the upper wall of the housing 40. As a result, the height of the interface station 4 can be suppressed. For example, when a component of the exposure apparatus is located above the interface station 4, it is effective that the height of the interface station 4 is suppressed in order to prevent interference with the component.

[0106] When providing the cylindrical body 81 provided with the chemical filter 5H in this way on the side wall of the housing 40, if the cylindrical body 81 interferes with the member provided on the side wall of the housing 40, a duct 91 is interposed between the cylindrical body 81 and the housing 40 as exemplified by the cylindrical body 81 on the rear side. By doing so, the interference may be prevented. Therefore, the duct 91 may not be provided if there is no such interfering object, and may be provided between the cylindrical body 81 on the front side and the wall portion of the housing 40 if necessary. Also, in this interface station 4, the supply destination of the air that has passed through the chemical filter 5H on the rear side is the processing apparatus 70, and the supply destination of the air that has passed through the chemical filter 5H on the front side is the transfer area of the wafer W. However, depending on the arrangement position of the processing apparatus 70 in the housing 40 and the like, the supply destination of the air may be set as appropriate. Therefore, air may be supplied to the processing apparatus 70 through the chemical filter 5H on the front side.

[0107] In FIG. 23, the organic filter section 55 and the acid filter section 53 are shown as being separated from each other, but they may be in contact with each other. Also, in this example, the apparent thickness L of the base filter section 54 among the filter sections 53 to 55 is larger than the apparent thickness L of the other filter sections, but it is not limited to such a setting. Depending on the environment in which the wafer processing system 1A is installed, the filter section with a larger apparent thickness L may be determined. Further, it is not limited to making the apparent thickness L of only a specific filter section larger than the apparent thickness L of the other filter sections. And when the thickness of each filter section L is relatively small, the cylindrical body 81 is not limited to being constituted by the cylindrical bodies 81A and 81B, and may be constituted by only the cylindrical body 81B as shown in FIG. 26. Note that the arrangement order of the filter sections 53 to 55 is not limited to the examples shown in FIGS. 23 and 26, and may be the arrangement order described as other examples heretofore.

[0108] In the configuration example of the wafer processing system 1 described above prior to this wafer processing system 1A, the chemical filter is located on the downstream side of the fan 51. However, a configuration in which the chemical filter is located on the upstream side of the fan 51 as in this wafer processing system 1A may be adopted. Also, although the foreign matter removal filter 90 is not shown in the wafer processing system 1, it may be provided in the same manner as in this wafer processing system 1.

[0109] Examples have been shown in which the chemical filters 5 and 5H are provided in the wafer processing system for forming a resist film by MOR and in the gas supply system 73 attached to this wafer processing system, but the chemical filters 5 and 5H are not limited to being provided in such systems. Specifically, the chemical filters 5 and 5H may be mounted in a wafer processing system for forming a resist film using a chemically amplified resist and in the gas supply system 73 attached to this wafer processing system. The wafer processing system for forming a chemically amplified resist film can be configured in the same manner as the wafer processing system described above, for example, except for the difference in the type of resist supplied to the wafer W.

[0110] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. Without departing from the scope and spirit of the appended claims, the above embodiments may be omitted, substituted, changed, and combined in various forms.

[0111] <Evaluation Test> When performing patterning on the wafer W, a gas containing an organic compound is supplied to a partial region (referred to as the first region) on the surface of the wafer W at any stage, and a test is conducted to compare the CD sizes between the pattern formed in the first region and the pattern formed in the second region where the gas is not supplied. The gas was supplied at any one of the first to fourth stages. The first stage is before forming a resist film composed of MOR, the second stage is after forming the resist film and before exposure by an exposure apparatus, the third stage is after exposure and before PEB, and the fourth stage is after PEB and before development. In this evaluation test, development and PEB were not repeated.

[0112] Also, in this evaluation test, an exposure apparatus using KrF (krypton fluoride) as a light source was used. And for the gas of the organic compound to be supplied, it was changed for each wafer W. Specifically, gases obtained from each of a mixed solution of PGMEA and acetic acid, PGMEA, acetic acid, a mixed solution of propylene glycol monomethyl ether and PEGMEA, hexamethyldisilazane, cyclohexanone, methyl ethyl ketone, and acetone were supplied. For the mixed solution of PEGMEA and acetic acid, those having a weight percentage of acetic acid contained of 2%, 5%, and 40% were used respectively.

[0113] As a result of the evaluation test, for the wafers W to which the gas obtained from the mixture of PEGMEA and acetic acid or the gas of acetic acid was supplied in the second, third, or fourth stage, the CD sizes were different between the first region and the second region. More specifically, for those to which the gas containing acetic acid was supplied in the second or third stage, the CD of the first region was smaller than the CD of the second region. For those to which the gas containing acetic acid was supplied in the fourth stage, the CD of the first region was larger than the CD of the second region. For the other wafers W, no clear difference in the CD size was observed between the first region and the second region. From the results of this evaluation test, it is presumed that acetic acid contributes to the variation in the CD of the pattern. Therefore, as described as an example, it is effective to include the organic filter part 55 in the chemical filter, and to arrange the acid filter part 53 and the base filter part 54 in the order described in the embodiment so as to prevent the release of acetic acid generated from the decomposed PGMEA.

Explanation of Signs

[0114] W Wafer 1 Wafer processing system 5 Chemical filter 53 Acid filter part 54 Base filter part

Claims

1. In a substrate processing apparatus used for patterning performed by exposing and developing a metal-containing resist film formed on a substrate, a chemical filter including a plurality of filter units for removing different substances in the gas is provided in a flow path for supplying gas into the substrate processing apparatus, arranged side by side toward the downstream side, wherein the plurality of filter units include an acid filter unit for removing an acidic substance and a base filter unit for removing a basic substance.

2. The substrate processing apparatus according to claim 1, wherein the acid filter unit is provided on the downstream side of the base filter unit.

3. The plurality of filter units include an organic filter unit for removing organic substances in the gas, and the substrate processing apparatus according to claim 2, wherein the organic filter unit is provided on the upstream side of the base filter unit in the flow path.

4. The plurality of filter units include an organic filter unit for removing organic substances in the gas, and the substrate processing apparatus according to claim 1, wherein the acid filter unit, the organic filter unit, and the base filter unit are provided in this order toward the downstream side.

5. As the chemical filter, a first chemical filter and a second chemical filter provided in a first flow path and a second flow path for supplying the gas to different spaces in the substrate processing apparatus are provided, wherein between the first chemical filter and the second chemical filter, at least one of the presence or absence of an organic filter unit for removing organic substances in the gas, the order in which the filter units are arranged, and the thickness of the filter units having the same removal target is different.

6. Only the first chemical filter of the first chemical filter and the second chemical filter includes the organic filter unit, and the substrate processing apparatus according to claim 5, wherein for the acid filter unit or the base filter unit, the thickness in the second chemical filter is greater than the thickness in the first chemical filter.

7. A gap is provided between one filter unit among the plurality of filter units and another filter unit provided next to the one filter unit when looking at the flow path toward the downstream side.

8. In a substrate processing method for patterning by exposing and developing a metal-containing resist film formed on a substrate, A step of supplying, into a substrate processing apparatus for performing the patterning, a gas that has passed through a chemical filter including a plurality of filter units arranged side by side toward the downstream side in a flow path and each removing different substances in the gas. A substrate processing method, wherein the plurality of filter units include an acid filter unit for removing an acidic substance and a base filter unit for removing a basic substance. **Claim 9** In a chemical filter used in a substrate processing apparatus that performs patterning by exposing and developing a metal-containing resist film formed on a substrate, the chemical filter includes a plurality of filter units arranged side by side toward the downstream side in a flow path for supplying a gas into the substrate processing apparatus and each removing different substances in the gas, wherein the plurality of filter units include an acid filter unit for removing an acidic substance and a base filter unit for removing a basic substance.

Images