Substrate processing method, substrate processing apparatus and storage medium

Abstract

The invention provides a substrate processing method, a substrate processing apparatus, and a storage medium for forming a good pattern on a metal-containing resist film. A substrate processing method for patterning a resist film formed on a substrate by exposing and developing the resist film, the substrate processing method including a step of performing an auxiliary process for adjusting the moisture adhesiveness of a formation surface for forming the resist film in the substrate before forming the metal-containing resist film on the substrate.

Description

Technical Field

[0001] The invention relates to a substrate processing method, a substrate processing device and a storage medium. Background Art

[0002] When manufacturing semiconductor devices, a semiconductor wafer (hereinafter referred to as a wafer) is photolithographically processed. In the case of using a chemically amplified resist solution, for example, a device for forming a resist film on a wafer, developing the resist film after exposure, and hydrophobizing the resist film is shown in patent document 1. The hydrophobizing is processed by supplying HMDS (hexa methyl disiloxane) gas to the surface of the wafer to perform hydrophobizing, thereby suppressing the resist film from peeling off from the surface of the wafer.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-004804 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technology capable of forming a good pattern on a metal-containing resist film.

[0008] Technical solutions for solving technical problems

[0009] The substrate processing method of the present invention is a substrate processing method for patterning by exposing and developing a resist film formed on a substrate, comprising the following steps: before forming the resist film containing metal on the above-mentioned substrate, performing auxiliary treatment to adjust the moisture adhesion of the forming surface of the substrate for forming the resist film.

[0010] Effects of the Invention

[0011] According to the present invention, a good pattern can be formed on a metal-containing resist film. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. 1 is a top view showing a substrate processing system according to an embodiment.

[0013] Figure 2 It is a longitudinal sectional front view showing the above-mentioned substrate processing system.

[0014] Figure 3 It is a longitudinal sectional side view showing an apparatus for performing a hydrophobic treatment in the above-mentioned substrate processing system.

[0015] Figure 4This is a graph showing the temperature change of the substrate during the above-mentioned hydrophobic treatment.

[0016] Figure 5 It is a schematic diagram showing the chemical changes in the resist.

[0017] Figure 6 It is a schematic diagram showing the chemical changes of metals that undergo dehydration condensation after exposure.

[0018] Figure 7 This is a diagram for explaining the timing of wafer processing and transportation in each module.

[0019] Figure 8 This is a graph showing the results of Evaluation Test 1.

[0020] Fig. 9 This is a graph showing the results of Evaluation Test 2.

[0021] Description of Reference Numerals

[0022] 10A Hydrophobic treatment module

[0023] 10B Development Module

[0024] 10E Pressure Reduction Module

[0025] R0 resist film

[0026] W chip. DETAILED DESCRIPTION

[0027] <Substrate processing system>

[0028] Below, refer to Figure 1 Top view and Figure 2 The substrate processing system 1 including the substrate processing device of the present embodiment as a module is described with reference to the longitudinal sectional front view of FIG. In addition, in this specification, the elements having substantially the same functional structure are marked with the same reference numerals and repeated descriptions are omitted. The substrate processing system 1 is a system for performing photolithography on a wafer W, for example, a system for forming a resist film on the wafer W and developing it.

[0029] Moreover, the substrate processing system 1 is formed by connecting the box station S1, for example, two processing stations S2 and the interface station S3 in a row in the horizontal direction. Afterwards, the direction along the row of these stations S1 to S3 is set as the left-right direction. In addition, the left-right direction is the direction along the X direction described later, sometimes recorded as the X direction, sometimes the direction orthogonal to the X direction when viewed from above is called the Y direction, the direction orthogonal to the X direction and the Y direction is called the Z direction, and the Z direction is called the up-down direction. In addition, the substrate processing system 1 is arranged in a clean room of atmospheric pressure (normal pressure). Except for the processing in a part of the modules described later, the wafer W is transported and processed under atmospheric pressure.

[0030] The box station S1 is configured to be able to carry in and out a box C storing a plurality of wafers W. The processing station S2 includes a plurality of various processing modules 10A to 10D for performing predetermined processing on the wafers W. The interface station S3 is configured to be connected to an exposure machine (not shown) on the side opposite to the side connected to the processing station S2, and to be able to transfer the wafers W between the exposure machine and the processing station S2. In addition, the processing station S2 is provided with two stations between the box station S1 and the interface station S3, but it may also be provided with one station or more than three stations.

[0031] The cassette station S1 is provided with a cassette mounting table 41, conveying devices 42, 43, and a tower T1. The tower T1 includes a plurality of transfer modules TRS arranged in the vertical direction, and the towers T2 and T3 described later are similarly configured. In addition, the tower T1 may also be provided in the processing station S2.

[0032] The cassette stage 41 is configured to be able to mount a cassette C as a transport container for wafers W. The transport devices 42 and 43 are configured to be able to transport wafers W between the cassette C on the cassette stage 41 and the processing station S2. Specifically, the transport devices 42 and 43 each include a drive mechanism in the X direction, the Y direction, the Z direction, and around the vertical axis (θ direction) as required, and may also include a drive mechanism in all directions. The drive mechanism is the same in the transport devices 44, 53, and 54 described later.

[0033] Furthermore, at least one of the transfer devices 42 and 43 can transfer the wafer W to the cassette C, and at least the other can transfer the wafer W to the processing station S2. The transfer of the wafer W to the processing station S2 refers to, for example, transferring the wafer W to a tower T1 accessible to the transfer device 44 in the processing station S2 described later. In addition, in the cassette station S1, an inspection device (not shown) for inspecting the wafer W may be provided at a position accessible to either of the transfer devices 42 and 43.

[0034] like Figure 2As shown, each processing station S2 includes, for example, eight layers 45 stacked in the vertical direction, first and second blocks G1 and G2 arranged in each of the layers 45, and a tower T2 arranged in a manner extending in the vertical direction on these layers 45. The tower T2 is arranged at the boundary position between the two processing stations S2 and S2. In the towers T1 and T2, the temperature adjustment module SCPL and the handover module TRS are respectively arranged at a height corresponding to each layer 45. Each handover module TRS is configured to be accessed by a corresponding conveying device to temporarily place a wafer W for handover of the wafer W, and each temperature adjustment module SCPL is configured to include a storage portion for storing the wafer W, and can adjust the temperature of the stored wafer W.

[0035] The first block G1 is arranged on the front side of the processing station S2 ( Figure 1 The second block G2 is arranged on the back side of the processing station S2 ( Figure 1 In the first block G1, a plurality of liquid processing modules are arranged, for example, a plurality of coating modules (resist film forming modules) 10B and a developing module 10D for coating a resist liquid to form a resist film, and in addition to these, a module for forming an anti-reflection film is sometimes included. These coating modules 10B, developing modules 10D and other processing modules are arranged in a horizontal direction in each layer 45, and the number, arrangement and type of these processing modules can be arbitrarily selected.

[0036] The coating module 10B and the developing module 10D, for example, supply a predetermined processing liquid onto the wafer W to perform various processes. Thus, in the coating module 10B, a resist film used as a mask when forming a pattern of a film on the lower layer side, an anti-reflection film for efficiently performing a light irradiation process such as an exposure process, etc. are formed. In the developing module 10D, for example, a portion of the resist film that is not irradiated with light during the exposure process is removed through and the mask is formed.

[0037] In the second block G2, a heat treatment module 10C for performing heat treatment such as heating and cooling of the wafer W, a hydrophobic treatment module 10A as a substrate processing device, and a peripheral exposure module (not shown) for exposing the outer periphery of the wafer W are arranged side by side in the vertical direction and the horizontal direction. The number and arrangement of these heat treatment modules 10C, hydrophobic treatment modules 10A, and peripheral exposure modules can also be arbitrarily selected.

[0038] like Figure 1As shown, in a region sandwiched between the first block G1 and the second block G2 in a plan view, a conveying region 51 is provided. The conveying region 51 is a space extending in the X direction at the center of each layer 45 in the Y direction and provided from the uppermost layer 45 to the lowermost layer 45. In the conveying region 51, for example, a plurality of conveying devices 44 can be arranged in a row in the Z direction or the X direction.

[0039] The conveyor 44 provided at the processing station S2 on the cassette station S1 side can move within the conveyance area 51 to convey the wafer W to each module in the surrounding first block G1, second block G2, towers T1, and T2. The conveyor 44 provided at the processing station S2 on the interface station S3 side can move within the conveyance area 51 to convey the wafer W to each module in the surrounding first block G1, second block G2, towers T2, and T3.

[0040] The conveying device 44 is, for example, Figure 2 As shown, a plurality of conveying devices 44 are arranged up and down. For example, the upper conveying device 44 is configured to be able to convey wafers W to each module at the height of the four layers 45 located on the upper side, and the lower conveying device 44 is configured to be able to convey wafers W to each module at the height of the four layers 45 located on the lower side. It is configured so that wafers W are appropriately conveyed to each module arranged in a manner to surround the conveying area 51 by using such a plurality of conveying devices 44. In addition, the number of conveying devices 44 and the number of layers 45 that can be conveyed by one conveying device 44 can be arbitrarily selected, such as providing the conveying device 44 for each layer 45.

[0041] In addition, a shuttle transport device (not shown) may be provided in the transport region 51 or the first block G1 or the second block G2. The shuttle transport device transports the wafer W linearly between a space adjacent to one side of the processing station S2 and another space adjacent to the other side thereof.

[0042] The interface station S3 is provided with a tower T3 and conveying devices 53 and 54 which are arranged near the tower T3 and can be raised and lowered. The interface station S3 uses the conveying devices 53 and 54 to convey wafers W between the tower T3 and the exposure machine. At least one of the conveying devices 53 and 54 can support the wafer W and convey the wafer W between the delivery module TRS in the tower T3 and the exposure machine.

[0043] In addition, at the interface station S3, a cleaning device for cleaning the surface of the wafer W and the above-mentioned peripheral exposure machine may be provided at a position accessible by either of the conveying devices 53 and 54. The inspection device may be provided at the cassette station S1 as described above, but may also be provided at the processing station S2 and the interface station S3. In this case, the conveying arm ( Figure 1 , Figure 2 44, 53, 54) in the accessible locations.

[0044] Taking the above processing modules 10A to 10D as an example, first refer to Figure 3 The structure of the hydrophobic treatment module 10A is described in detail. The hydrophobic treatment module 10A includes a hot plate 11 in which a heater is embedded and a processing container 12 surrounding the hot plate 11. By supplying a hydrophobic gas to a wafer W placed on the hot plate 11, a hydrophobic treatment is performed on the upper surface of the wafer W. The upper surface is a formation surface on which a resist film is to be formed later, and therefore contacts the resist film. Moreover, the upper surface is a surface formed by a lower film that is etched using the resist film as a mask after the resist pattern is formed.

[0045] Furthermore, the processing container 12 includes a container body 13 and a top plate 14. The container body 13 includes a lower covering portion 13A covering the lower portion of the hot plate 11, and a lower side wall 13B protruding upward from the periphery of the lower covering portion 13A and surrounding the side periphery of the hot plate 11. The top plate 14 is raised and lowered relative to the container body 13 by a lifting mechanism 15, and moves between a lower position (the position shown in the figure) in which a processing space is formed to process the wafer W and an upper position in which no processing space is formed and the wafer W is delivered to the hot plate 11. Although not shown in the figure, three pins are provided on the hot plate 11, and the three pins extend out and sink into the upper surface of the hot plate 11 when the top plate 14 is in the upper position, thereby delivering the wafer W between the conveying device 44 moved onto the hot plate 11 and the hot plate 11.

[0046] The lower center portion of the top plate 14 is formed into a circular protrusion 14A by bulging downward, and a plurality of release ports 14B are provided at intervals on the side of the protrusion 14A in the circumferential direction thereof. Hydrophobic gas is supplied to the release port 14B from a gas supply mechanism 16 disposed outside the processing container 12, and the hydrophobic gas released from the release port 14B flows from the center of the wafer W to the peripheral portion on the surface of the wafer W heated by the hot plate 11. A plurality of exhaust ports 14C and 14D connected to an exhaust mechanism 17 such as a vacuum pump are formed on the lower surface of the top plate 14 at a position closer to the peripheral side than the protrusion 14A. Thus, the atmosphere in the processing container 12 can be appropriately exhausted from the exhaust ports 14C and 14D, and the suction of the atmosphere outside described later can be performed.

[0047] The hydrophobic gas is, for example, composed of a silane coupling agent, and a more specific example is HMDS gas. The supply source 16A of the gas supply mechanism 16 has a storage portion of HMDS liquid and a gasification portion for gasifying the liquid to generate HMDS gas. The supply and stop of HMDS gas from the release port 14B are switched by opening and closing of a valve V1 inserted in a flow path 16B connecting the gas supply mechanism 16 and the top plate 14. Moreover, the gas supply mechanism 16 is connected to the flow path 16B, and for example includes a purge gas supply source 16C for supplying nitrogen.

[0048] The peripheral edge of the top plate 14 protrudes downward, and the lower surface forms an upper side wall 18 in contact with the lower side wall 13B. On the lower surface of the upper side wall 18, a plurality of suction ports 18A are provided at intervals in the circumferential direction of the upper side wall 18. Each suction port 18A extends along the radial direction of the top plate 14. When the top plate 14 is located at the lower position, the suction port 18A of the top plate 14 is close to the lower side wall 13B, and the atmosphere outside the processing container 12 is sucked from the suction port 18A.

[0049] When the HMDS gas is supplied, for example, the exhaust is not performed from the exhaust port 14C but from the exhaust port 14D, so that the HMDS gas flows toward the peripheral portion of the wafer W, flows into the suction port 18A together with the external gas, and is removed from the exhaust port 14D. When the hydrophobic treatment is completed, that is, the supply of the HMDS gas is completed, the supply of the purge gas is started from the purge gas supply source 16C, for example. During the supply of the purge gas, the exhaust is also performed from the exhaust ports 14C and 14D.

[0050] The other processing modules 10B to 10D are briefly touched upon, centering on the differences from the hydrophobic treatment module 10A. The coating module 10B and the developing module 10D are configured to include a loading portion that absorbs and holds the central portion of the back side of the wafer W, a rotating mechanism that rotates the loading portion, and a nozzle that supplies a processing liquid to the front side of the wafer W, and can supply the processing liquid to the entire surface of the wafer W. The coating module 10B supplies a resist liquid as a processing liquid to the wafer W, and forms a resist film by spin coating. The developing module 10D applies a developing liquid as a processing liquid to develop the resist film.

[0051] The resist liquid applied by the coating module 10B is a metal-containing resist, more specifically a metal oxide resist (Metal Oxide Resist, MOR). In addition, the above-mentioned metal-containing resist contains metal as a constituent component of the resist, and does not refer to a resist containing only impurities. The metal as a constituent component of the resist is, for example, tin (Sn). Unless otherwise specified below, the resist is MOR. The MOR is, for example, a negative resist, and the formed resist film is exposed, for example, using EUV (Extreme ultraviolet). The hydrophobic treatment performed by the above-mentioned hydrophobic treatment module 10A is an effective auxiliary treatment when forming a pattern by exposing and developing the resist film, and the reason for performing this auxiliary treatment will be explained later.

[0052] A plurality of heat treatment modules 10C are stacked up and down in the second block G2, and a plurality of heat treatment modules 10C are arranged side by side. Moreover, the heat treatment module 10C includes a hot plate for heating the wafer W placed thereon. Sometimes, the heat treatment performed on the wafer W after the resist film is formed and before exposure using these heat treatment modules 10C is described as PAB (Post Apply Bake), the heat treatment performed after exposure and before development is described as PEB (Post Exposure Bake), and the heat treatment performed after development is described as HB (Hard Bake).

[0053] The above substrate processing system 1 is provided with a control device 100. The control device 100 is, for example, a computer, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the wafer W in the substrate processing system 1. In addition, the program storage unit also stores a program in which a step group is incorporated, and the step group is used to control the actions of the above-mentioned various processing devices, conveying devices and other driving systems to realize the processing of the wafer W in the substrate processing system 1. In addition, the above-mentioned program can also be recorded in a computer-readable storage medium and installed in the control device 100 from the storage medium.

[0054] <Operation of the substrate processing system>

[0055] The operation of wafer processing performed by the substrate processing system 1 configured as described above will be described.

[0056] First, a box C containing a plurality of wafers W is sent to the box station S1 of the substrate processing system 1 and placed on the box loading table 41. Next, each wafer W is taken out from the box C in sequence by using any one of the conveying devices 42 and 43, and is transported to any one of the handover modules TRS in the tower T1. The wafer W transported to the handover module TRS is supported by the conveying device 44 and transported to the hydrophobic treatment module 10A of the second block G2 for hydrophobic treatment. The hydrophobic treatment in the hydrophobic treatment module 10A is described in detail below.

[0057] Before conveying the wafer W, the hot plate 11 of the hydrophobic treatment module 10A is heated by a heater to a set temperature B of, for example, 80°C to 120°C. The wafer W is fed between the container body 13 and the top plate 14 at the upper position, and the wafer W is placed on the hot plate 11. Then, the top plate 14 is lowered to the lower position to form a processing space. Then, the valve V1 is opened at a specified opening, and HMDS gas is supplied from the gas supply mechanism 16 to the processing space at a specified flow rate. The HMDS gas flows in a manner that diffuses from the central side of the wafer W toward the outer peripheral edge portion above the wafer W, and the surface of the wafer W (the formation surface of the resist film described above) is hydrophobized.

[0058] As the supply time of HMDS gas of hydrophobization treatment time, it is preferably less than 10 seconds as shown in the evaluation test described later.Through such a relatively short time of hydrophobization treatment, the hydrophobization degree of the surface of the wafer W is adjusted to the desired degree.The adjustment of the hydrophobization degree (that is, the adjustment of the moisture adhesion of the formation surface of the resist film) is described in detail.The hydrophobization performed as described above is to replace the hydroxyl group as the hydrophilic group present on the surface of the wafer W with the processing of the hydrophobic group as (CH3)3-SiO, and the adjustment of the above-mentioned moisture adhesion refers to stopping the supply of HMDS gas to the wafer W under the state of remaining unreacted hydroxyl groups, so that the reaction is stopped.Therefore, the adjustment refers to assuming that the HMDS gas is continuously supplied, and the supply of HMDS gas is stopped when the state of the replacement of the hydrophobic group is further carried out, so that the above-mentioned substitution reaction is stopped.Therefore, when observing the contact angle of water relative to the surface of the wafer W, the above-mentioned hydrophobization treatment time is set to be able to obtain a contact angle smaller than the contact angle obtained when the supply of HMDS gas for a time longer than the hydrophobization treatment time is carried out. Specifically, for example, the hydrophobic treatment time in the hydrophobic treatment module 10A is set so that the contact angle with respect to pure water becomes 30 degrees or more and less than 65 degrees.

[0059] in addition, Figure 4 Relationship between the temperature and time of the wafer W placed on the hot plate 11 when the hydrophobic treatment is performed as described above is represented, the solid line portion of the graph represents the actual temperature change of the wafer W, and the dotted line portion represents the imaginary temperature change. The horizontal axis of the curve graph is the time when the wafer W is placed on the hot plate 11 and is set to 0 seconds, and the vertical axis is the temperature of the wafer W. By placing the wafer W on the hot plate 11, the temperature of the wafer W rises. Assuming that the placement time is relatively long, the temperature of the wafer W reaches the set temperature B of the hot plate 11 as shown in the dotted line portion of the curve graph. That is, the temperature rise is saturated at the set temperature B. Time t0 is the set time when the valve V1 for supplying and cutting off HMDS gas to the processing container 12 is opened, and time t1 is the set time when the valve V1 is closed. Therefore, the time from time t0 to time t1 is the hydrophobic treatment time.

[0060] As already mentioned, for the purpose of adjusting the adhesion of water on the surface of the wafer W, the hydrophobic treatment time is relatively short. Therefore, the moment t1 is the moment before the temperature of the wafer W reaches the set temperature B of the hot plate 11, and the temperature change H1 from the placement of the wafer W on the hot plate 11 and the start of heating to the moment t1 is, for example, less than 60°C. In addition, for example, as described above, the substrate processing system 1 is configured in a clean room, so that the temperature of the wafer W at the start of the heating is the set temperature of the clean room. Then, after the moment t1, a purge gas is supplied into the processing container 12 to raise the top plate 14 to an upper position, and at the moment t2, the pins are raised so that the wafer W leaves the hot plate 11, and the heating of the wafer W is stopped. Since the hydrophobic treatment time is short, the moment t2 is also the same as, for example, the moment t1, and is the moment before the wafer W reaches the set temperature B.

[0061] The reason why the hydrophobic treatment of the resist film forming surface of the wafer W is a limiting treatment as described above is to make the shape of the resist pattern good, shorten the time for PEB, and reduce the necessary exposure amount. Regarding this, as described later, the treatment and transportation of the wafer W after leaving the hot plate 11 are explained. In the following, reference is also made to the schematic diagram showing the change of the resist, that is, Figure 5 , Figure 6 The wafer W is transported to the outside of the processing container 12 by the transport device 44. Then, the wafer W is transported to the temperature control module SCPL and adjusted to a predetermined temperature. Thereafter, the wafer W is transported to the loading portion of the coating module 10B by the transport device 44, and the resist liquid is supplied to the nozzle from the storage portion (not shown).

[0062] In the state stored in the storage unit, if Figure 5 As shown on the left side, the compound 60 constituting the resist has a structure including a core 61 containing a metal, an OR group (R part is, for example, an alkyl group) bonded to the core 61, and a ligand 62 as an organic ligand. A resist liquid is supplied from a nozzle to a wafer W to form a resist film R0. The resist film R0 is formed on the surface of the wafer W whose moisture adhesion is adjusted and the moisture content is reduced as described above, so that the amount of water permeating and mixing from the surface to the resist film R0 can be suppressed. Therefore, the amount of moisture contained in the resist film R0 can be suppressed.

[0063] When the (resist solution) is supplied to the wafer W to form a film, the OR group in the compound 60 is hydrolyzed to become a hydroxyl group by contacting with a trace amount of water in the atmosphere. The compound 60 thus converted to have a hydroxyl group is shown as compound 60A. Figure 5 The wafer W having the resist film R0 formed thereon is transported to the heat treatment module 10C and subjected to a heat treatment (PAB). The compound 60A undergoes dehydration condensation before the end of the PAB. Figure 5As shown on the right side of , a cluster compound 64 is formed. The cluster compound 64 includes a core 63 composed of a metal oxide and a plurality of ligands 62 located around the core 63 .

[0064] The wafer W after PAB is transported to the delivery module TRS of the tower T2 by the transport device 44, and is transported to the delivery module of the tower T3 by the transport device 44 of the processing station S2 on the interface station S3 side.

[0065] The wafer W transported to the transfer module of tower T3 is transported to the exposure machine by the transport devices 53 and 54, and is exposed in a predetermined pattern. Through this exposure, in the exposure area R1 of the resist film R0, the ligand 62 in the cluster compound 64 is separated from the core 63, and hydrogen is bonded to the core 63 instead. Figure 6 In the upper part, for convenience, the cluster compound that has changed in this way is indicated by 66, and hydrogen in the cluster compound 66 is indicated by 67. In addition, the non-exposed region R2 is still composed of the cluster compound 64.

[0066] The exposed wafer W is transported to the transfer module TRS of the tower T3 by the transport devices 53 and 54. After that, it is transported to the heat treatment module 10C by the transport device 44 to perform PEB. By reacting with moisture in the atmosphere before the completion of PEB, the hydrogen 67 in the cluster compound 66 is replaced by the hydroxyl group 68, and the cross-linking reaction caused by the dehydration condensation between the cluster compounds 66 using the hydroxyl group 68 is advanced. Figure 6 The series of reactions is schematically shown at the tip of the dot-dash arrow in the middle of FIG. The cluster compound 66 is polymerized by the series of reactions, and the exposed region R1 becomes insoluble in the developer.

[0067] The wafer W after PEB reaction is transported to the developing module 10D by the transport device 44 for development. By supplying the developing solution, the non-exposed area R2 that has not been subjected to the insolubilization treatment is dissolved and removed. Figure 6 As shown in the lower part of the figure, a resist pattern is formed on the resist film R0. After the development, the wafer W is transported to any heat treatment module 10C by the transport device 44 to perform HB. After that, the wafer W is transported to the transfer module of the tower T1 by the transport device 44, and transported to the box C of the specified box mounting table 41 by any wafer transport device 42 or 43 of the box station S1. In this way, a series of photolithography is completed.

[0068] In order to explain the effect of the hydrophobic treatment in the photolithography, the following describes the reactions that are inferred to occur when the photolithography is performed without the hydrophobic treatment. Since the hydrophobic treatment is not performed, the resist film R0 is formed in a state where there is a lot of water on the surface of the wafer W. Therefore, a lot of water penetrates or mixes into the resist film R0 from the surface of the wafer W. Since the water contained in the resist film R0 becomes more, the water Figure 5 In addition to the hydrolysis of the OR group described above, part of the ligand 62 is also released from the core 61 and the core 63, so that part of the cluster compound 64 is in a state where part of the ligand 62 that should have been originally present is released.

[0069] In this way, the cluster compounds 64 from which the ligands 62 have been detached are bonded to each other using the sites from which the ligands 62 have been detached, thereby replacing the ligands 62 before the resist film R0 is exposed. Figure 6 When the combination is formed by the cluster compound 64 from which only a part of the ligand 62 is separated, since the ligand 62 remaining in the cluster compound 64 is a relatively high atomic group, the ligand 62 will interfere and prevent the metal-containing cores 63 from being closely arranged. Therefore, with regard to the combination, Figure 6 When the reaction up to PEB progresses normally as described above, the obtained polymer has lower insolubility in the developer.

[0070] Therefore, in the case where a large number of such combinations are formed before exposure, in order to cause Figure 6 In the reaction described in the above, it is necessary to ensure the insolubility of the exposed area R1 during development by making the cluster compound 64 remaining in the resist film R0 progress more. Specifically, it is necessary to make the exposed area R1 insoluble in the developer by making the exposure amount during exposure larger so that the ligand 62 is separated from more cluster compounds 64, or making the PEB time longer so that the cross-linking reaction progresses further.

[0071] On the other hand, when the ligand 62 does not separate from the cluster compound 64 before exposure, Figure 6 As shown in the figure, when the ligand 62 is detached by exposure, the ligand 62 does not hinder the coordination of the core 63 when it is bonded to the core 63, so the core 63 can be arranged in a close manner. Therefore, with regard to the above-mentioned hydrophobic treatment, by preventing the ligand 62 from being unnecessarily detached before exposure, when the exposure area R1 is made insoluble (insoluble in the developer), the exposure amount ratio in the exposure machine can be reduced (that is, the sensitivity of the reaction of the resist film R0 to exposure is increased), or the time required for PEB can be shortened. These effects are also the effects obtained from the evaluation test below.

[0072] In addition, as described in the evaluation test below, it was confirmed that excessive hydrophobic treatment would cause the non-exposed area R2 to become insoluble in the developer (i.e., the contrast of the pattern would decrease). It is believed that this is caused by excessive sensitivity to exposure due to the hydrophobic treatment. In other words, it is believed that the resist film R0 becomes insoluble (insoluble in the developer) even by a very small amount of light. Therefore, Figure 3 , Figure 4 As described in , the wafer W is subjected to a restricted hydrophobic treatment, so that the exposed region R1 is reliably rendered insoluble in the developer and the solubility of the non-exposed region R2 is ensured, thereby achieving an effect of obtaining a good pattern shape of the resist film R0.

[0073] In addition, the substrate processing system 1 in the present invention is not limited to the structure and action described above. For example, the wafer W after PAB can be transported to the peripheral exposure machine by the transport device 44 as needed to perform exposure processing on the peripheral portion of the wafer W, and the wafer W can also be cleaned by a cleaning device after PAB and before exposure. In addition, for example, in the above-mentioned embodiment, the case of handing over the wafer W between the interface station S3 and the exposure machine is described, but it is not necessary to be directly connected to the exposure machine. In this case, for example, after the wafer W is transported from the box station S1 to the processing station S2 and necessary processing is performed, it is transported to the box station S1 again for external delivery. That is, instead of performing the above-mentioned series of photolithography on the wafer W after being sent out from the box C and before being sent in, the box C can be transported to multiple devices in sequence, and the wafer W is processed by each device, thereby performing a series of photolithography.

[0074] Moreover, the formation of the lower film can also be carried out by the substrate processing system 1. In this case, after the coating solution is applied by a coating module 10B different from the coating module 10B for resist film formation, the wafer W is heated by a heat treatment module 10C different from the heat treatment module 10C for resist film heating, and then the above-mentioned hydrophobic treatment and subsequent treatments are carried out. In addition, unnecessary devices in the devices cited as processing devices may not be provided, or the treatment in the device may not be carried out. In addition, the above-mentioned configuration positions of various modules are not necessary requirements, and they may also be appropriately configured at different positions. In this case, the conveying path of the wafer W is appropriately conveyed from one module to other modules using conveying devices 42, 44, 53, 54, towers T1 to T3, etc. in accordance with the order of the above-mentioned processing.

[0075] <Decompression module>

[0076] In the above, the hydrophobic treatment module 10A is described as an example of a substrate processing apparatus, but the auxiliary treatment performed by the auxiliary treatment module is not limited to the hydrophobic treatment, and may be other auxiliary treatments for reducing the amount of water attached to the surface of the wafer W. The following describes a decompression module 10E that performs a decompression treatment as other auxiliary treatment.

[0077] The decompression module 10E is, for example, arranged at a position described as setting the hydrophobic treatment module 10A instead of the hydrophobic treatment module 10A. Moreover, the decompression module 10E includes a processing container 12, for example, in the same manner as the hydrophobic treatment module 10A, but the suction port 18A is not formed on the top plate 14. When the top plate 14 is located at a lower position, the container body 13 and the top plate 14 are in close contact, forming a closed processing space in the processing container 12. Then, the exhaust port 14C opens at any position of the wall surface of the processing container 12 forming the processing space, and the processing space is exhausted by the exhaust mechanism 17 to form a decompression space. The exhaust mechanism 17 and the exhaust port 14C are equivalent to the decompression part.

[0078] In addition, the container body 13 is provided with a stage for placing the wafer W without having a temperature adjustment function, for example, in place of the hot plate 11. Furthermore, the gas supply mechanism 16 of the decompression module 10E is configured to supply low-humidity gas, and to supply the low-humidity gas from the release port 14B and exhaust the gas from the exhaust port 14C. The low-humidity gas is a gas having a humidity lower than that of the clean room in which the substrate processing system 1 is installed, and is, for example, an inert gas such as nitrogen or argon, or dry air.

[0079] When the wafer W is placed on the stage, a closed processing space is formed. By exhausting the processing container 12, the pressure of the closed space in the processing container is reduced from normal pressure to become a reduced pressure space, and the moisture attached to the surface of the wafer W is vaporized and separated from the wafer W. Next, by supplying low-humidity gas from the injection port 14B, the re-adhesion of moisture is prevented, and the pressure of the closed space is restored to normal pressure. Then, the processing container 12 is opened and the wafer W is sent out. In this way, the amount of water attached to the wafer W during the formation of the resist film is suppressed. In addition, the adjustment of the adhesion of water on the surface of the wafer W includes not only a process of reducing the adhesion of water by hydrophobic treatment, but also a process of directly reducing the amount of water attached as described above.

[0080] However, since the treatment for suppressing the amount of water adhesion is included, for example, in the hydrophobic treatment module 10A described above, the hydrophobic gas may not be supplied and only the wafer W may be heated to remove moisture. However, when the wafer W is cooled and returned to room temperature in the coating module 10B, moisture around the wafer W may adhere to the wafer W again. Therefore, in the case of performing the heating treatment in this way, for example, a structure capable of supplying low-humidity gas into the processing container 12 is adopted as in the decompression module 10E, and cooling is performed using the low-humidity gas.

[0081] In addition, this heating is heating performed separately from the PAB performed to form the lower film of the resist film. That is, the PAB for the lower film, which is performed by heating and evaporating the solvent in the lower film after the lower film is formed under the resist film such as the anti-reflection film by applying the chemical solution, is a process different from the PAB. In other words, the heating is performed after the PAB for the lower film is performed and the wafer W is received by the conveying device.

[0082] In addition, in the case of removing moisture by decompression treatment or heat treatment, by making the space for conveying the wafer W from the treatment to the coating of the resist film low-humidity, for example, it is possible to suppress moisture from adhering to the surface again. Specifically, for example, for the conveying area and module for conveying the wafer W by the conveying device forming the space, the above-mentioned low-humidity gas can be supplied to the conveying area of ​​the wafer W. In addition, in the case of performing hydrophobic treatment, it is also possible to make the space for conveying the wafer W low-humidity like this, and more reliably suppress the moisture attached to the wafer W from being supplied to the resist film. In addition, as an adjustment of the adhesiveness of moisture, in the case of removing moisture from the surface of the wafer W by decompression treatment or heat treatment, there is no limit to the amount of moisture remaining on the surface of the wafer W after the treatment. That is, it is possible to treat in a way that a part of the moisture attached to the wafer W remains, or it is possible to treat in a way that all or substantially all of the moisture is removed from the surface of the wafer W.

[0083] However, assuming that the wafer W (wafer W2) that has been processed is transported to the coating module 10B as described above in the decompression module 10E, when another wafer W (wafer W1) is being processed in the coating module 10B that is the transport destination, before the wafer W1 can be transported out of the coating module 10B, for example, the transport device waits in front of the coating module 10B while holding the wafer W2, delaying the transport of the wafer W2 to the coating module 10B. If the delay time of the transport varies between wafers W in the same batch, there is a possibility that the pattern shape will vary due to the variation in the amount of moisture in the atmosphere attached to the wafer W.

[0084] Below, also refer to Figure 7The timing diagram is explained. In order to suppress the deviation of the above-mentioned pattern shape, the deviation of the time T0 from the moment when the decompression treatment of the decompression module 10E is completed (set as s11) to the moment when the wafer W is sent to the coating module 10B (set as s12) is suppressed. In addition, the time from when the wafer W is sent to the coating module 10B to the start of the treatment is constant, so the time T0 from the moment s11 to the moment when the formation of the resist film is started (set as s13) is made consistent. The time s11 when the treatment of the decompression module 10E is completed refers to the timing when the processing container 12 is opened due to the rise of the top plate 14 (that is, the timing when the wafer W is exposed to the external gas of the processing container 12). In addition, suppressing the deviation of the time T0 from the moment s11 to the moment s12 in the wafers W in the same batch, for example, means that the deviation of the time T0 converges to less than 10 seconds, and preferably the deviation of the time T0 is 0 seconds. The variation in the time T0 is suppressed by adjusting the processing start time (set to s10) of the decompression module 10E.

[0085] When the wafer W is placed on the mounting table of the decompression module 10E, the control device 100 calculates the time s14 after the prescribed processing time in the decompression module 10E + the prescribed time required for the transport from the decompression module 10E to the coating module 10B has passed since the time s0 of the placement. Then, at the time s14, it is determined whether there is a wafer W previously transported to the coating module 10B in the coating module 10B, which is the transport destination of the wafer W. In the case where it is determined that there is no wafer W, the decompression treatment is started quickly. In the case where it is determined that there is a wafer W, the time TT required from the time s14 to the transport of the wafer W from the coating module 10B is calculated. On the other hand, after the time determined corresponding to the time TT has passed since the time s0 when it is determined that there is a wafer W, the decompression treatment of the wafer W is started. The time determined corresponding to the TT may also be TT itself.

[0086] In this way, for each wafer W in the batch, the processing start time s10 in the decompression module 10E is determined according to the timing of feeding into the coating module 10B, and the deviation of the time T0 is suppressed as described above. In addition, the timing of starting the processing of the coating module 10B corresponds to the feeding timing, so it can also be said that the determination of the decompression processing start time s10 is carried out according to the timing of starting the processing of the coating module 10B. By determining the processing start time s10 in this way, the stagnation of the wafer W being transported to the coating module 10B is eliminated, and the deviation of the time T0 is suppressed. In addition, the various calculations, judgments, and decisions for determining the timing of starting the decompression processing are implemented by the control device 100.

[0087] In addition, the processing start time s10 of the decompression module 10E refers to the time when the processing container 12 is made into a closed space and the decompression is started. In addition, when the hydrophobic treatment module 10A is set instead of the decompression module 10E, the timing of the start of the processing can also be adjusted in the same way. The processing start time s10 in the hydrophobic treatment module 10A is the time when the valve V1 is opened to supply the hydrophobic gas to the wafer W, and the processing completion time s11 is the time when the valve V1 is closed. Therefore, Figure 4 The times t0 and t1 shown correspond to Figure 7 The processing starts at time s10 and the processing is completed at time s11. However, the hydrophobic treatment is a treatment to prevent the adhesion of water, so the shape change of the pattern caused by the re-adhesion of water is less likely to occur compared with the decompression treatment in the decompression module 10E, so Figure 7 The delivery control described in is particularly effective when the process is performed in the decompression module 10E.

[0088] As described above, the wafer W is transported to the temperature control module SCPL for temperature control before being transported to the coating module 10B. Figure 7 The conveyance of the wafer W will be described by assuming that, for example, a plurality of temperature adjustment modules SCPL are provided so that the conveyance of the wafer W from the decompression module 10E to the temperature adjustment module SCPL does not stagnate.

[0089] As the silane coupling agent contained in the gas supplied by the hydrophobic treatment module 10A, in addition to HMDS, for example, trimethylsilyldimethylamine (TMSDMA), trimethylsilyldiethylamine (TMSDEA), dimethyl (dimethylamino) silane (DMSDMA), 1,1,3,3-tetramethyldisilane (TMDS), polysilazane, siloxane, they can be used. In addition, about these silane coupling agents, it is not limited to supply to the wafer W in the state of gas, and it is also possible to supply to the wafer W in the state of liquid. For example, it is also possible to use the coating of spin coating in the same manner as the resist. However, as described above, if hydrophobicization progresses excessively, the shape of the pattern produces an undesirable situation, so the concentration of the silane coupling agent in the liquid is appropriately adjusted.

[0090] In addition, the formation of the resist film by liquid treatment is described, but it is not limited to liquid treatment. For example, a module with the same structure as the hydrophobic treatment module 10A can also be used to supply the gas used for film formation of the resist film instead of the hydrophobic gas, thereby forming the resist film. In addition, the processing recorded using the processing liquid for development, the formation of the lower film, etc. is also the same as the formation of the resist film, and the processing gas can be supplied instead of the processing liquid for processing.

[0091] In addition, regarding the configuration position of the hydrophobic treatment module 10A and the coating module 10B, as described above, in addition to being arranged in the first block G1, it can also be arranged in the second block G2 described as placing the thermal treatment module 10C. In addition, regarding the hydrophobic treatment module 10A, for example, it can be arranged in the tower T1 of the box station S1, or it can be a device structure that transports the wafer W that has been hydrophobized at the box station S1 to the processing station S2, and forms a resist film at the processing station S2. In addition, regarding each module including the hydrophobic treatment module 10A and the coating module 10B, it can also be arranged at a position that can be accessed by each conveying device other than the position illustrated above. The number and configuration layout of the conveying device are not limited to the examples shown in this disclosure, and can also be appropriately set.

[0092] The hydrophobic treatment module 10A is further described. An example is given in which the wafer W is placed on the hot plate 11 to heat it. However, the heating unit for heating the wafer W is not limited to the hot plate 11. For example, the heating unit may be an LED, and the wafer W may be heated by irradiating light from the LED. In this case, for example, Figure 4 As shown in FIG. 1 , the supply of the hydrophobizing gas is stopped before the wafer W reaches the set temperature B at which the temperature rise is saturated.

[0093] Since it is sufficient to perform hydrophobicization on the surface of the wafer W only occasionally (sparsely), Figure 4 In the embodiment, the hydrophobic treatment is stopped before the wafer W reaches the set temperature B (i.e., the temperature change of the wafer W is suppressed), so that the wafer W can be quickly sent out from the hydrophobic treatment module 10A, thereby increasing the productivity (throughput) of the substrate processing system 1. However, when the wafer W is heated by the hot plate 11 or the LED, it is not limited to this, and the hydrophobic gas may be supplied to the wafer W after reaching the set temperature B to perform the hydrophobic treatment. Moreover, the substrate processed in the present technology is not limited to the wafer W, but may also be other substrates such as substrates for manufacturing flat panel displays.

[0094] Various evaluation tests performed in connection with the technology of the present invention will be described.

[0095] [Evaluation Test 1]

[0096] In evaluation test 1, as described in the embodiment, multiple wafers W are subjected to hydrophobic treatment, formation of resist film R0, exposure, PEB, development, and HB using EUV, and the residual film amount (the size of the film thickness of the residual resist film) of exposure area R1 is measured. In the above-mentioned series of processes, the exposure amount is changed between wafers W, and the relationship between the exposure amount and the residual film amount is investigated according to the measurement result. In addition, the hydrophobic treatment time (the time for supplying hydrophobic gas) is set to any one of 10 seconds, 30 seconds, and 60 seconds. The test performed by setting the hydrophobic treatment time to 10 seconds, 30 seconds, and 60 seconds is set to evaluation test 1-1, 1-2, and 1-3 respectively. In addition, exposure uses an exposure machine with a KrF (krypton fluoride) light source, and the time for performing PEB is set to 60 seconds.

[0097] Figure 8 It is a chart summarizing the results of evaluation test 1, with the exposure amount set on the horizontal axis and the residual film amount set on the vertical axis, and the horizontal axis and the vertical axis are marked with a certain scale. As shown in the chart, in any of the evaluation tests 1-1 to 1-3, the residual film amount varies greatly with the value A of the exposure amount as the boundary. When the exposure amount is the same between the evaluation tests 1-1 to 1-3, there is no big difference in the residual film amount. Therefore, it is confirmed that the difference in the hydrophobic treatment time between the evaluation tests 1-1 to 1-3 does not affect the insolubility reaction of the resist film in the exposed area to the developer.

[0098] Thus, regarding the exposure area R1, no significant difference was found between the evaluation tests 1-1 to 1-3. However, in the evaluation tests 1-2 and 1-3, it was confirmed that a so-called bridging defect was generated in which a protrusion was formed in the non-exposure area R2 in a manner that connected the protrusion of the pattern formed in the exposure area R1. In the evaluation test 1-1, no bridging defect was found. Therefore, according to the evaluation test 1, it was confirmed that in the case of excessive hydrophobic treatment (i.e., the contact angle of the formation surface of the resist film with respect to pure water becomes too high), an unnecessary reaction will proceed in the non-exposure area R2, and a normal pattern may not be formed.

[0099] For the sake of convenience, the exposure amount that becomes the boundary value of the residual film amount that changes greatly in the range above this value and in the range below this value, such as the value A of the curve, is referred to as the insoluble exposure amount. As shown in the results of the evaluation test 2 later, for the case where the above-mentioned series of treatments from the hydrophobic treatment to HB is performed and the case where the hydrophobic treatment is not performed in the series of treatments, the Figure 8Such a graph showing the relationship between the exposure amount and the residual film amount. Regarding the insoluble exposure amount of the graph, the case of hydrophobization treatment is smaller than the case of not hydrophobization treatment. That is, it is confirmed that by performing hydrophobization treatment, the resist film described in the embodiment becomes insoluble in the developer with a relatively small exposure amount. According to the difference caused by the presence or absence of such hydrophobization treatment and the result of evaluation test 1, it is known that the hydrophobization treatment time is preferably shorter, for example, less than 10 seconds. In addition, as described in the embodiment, it is inferred that it is effective to perform hydrophobization treatment occasionally (sparsely).

[0100] [Evaluation Test 2]

[0101] In this evaluation test, the influence of the presence or absence of hydrophobic treatment on the exposure sensitivity of the resist film and the influence of the PEB time on the exposure sensitivity were confirmed. In evaluation test 2-1, a series of treatments were performed in the same manner as in evaluation test 1, with the hydrophobic treatment time being 10 seconds and the PEB time being 60 seconds. In evaluation tests 2-2, 2-3, and 2-4, the PEB time was set to 120 seconds, 300 seconds, and 60 seconds, respectively, and no hydrophobic treatment was performed. In addition, the wafer W was treated in the same manner as in evaluation test 2-1. Then, using each wafer W after treatment, a graph showing the relationship between the exposure amount and the residual film amount was obtained in the same manner as in evaluation test 1.

[0102] Fig. 9 Represent this chart.According to this chart, the resist film of the wafer W of evaluation test 2-1 becomes insoluble (insoluble in developer) with less than 20% exposure amount of the resist film of the wafer W of evaluation test 2-4 processed under the same conditions except not being hydrophobized.Therefore, it can be known that by hydrophobizing of the present invention, the exposure sensitivity of resist film improves.And, according to the chart, the residual film amount during the exposure amount larger than the insoluble exposure amount in evaluation test 2-1 is less than the residual film amount during the exposure amount larger than the insoluble exposure amount in evaluation test 2-4.It is speculated that this is because a large amount of cross-linking reactions occur by hydrophobizing, and the resist film shrinks.

[0103] In addition, the relationship between the size of the insoluble exposure amount is Evaluation Test 2-4>2-2>2-3. That is, the longer the time for PEB is performed, the smaller the insoluble exposure amount is. Moreover, the size of the residual film amount at the exposure amount above the insoluble exposure amount is Evaluation Test 2-3<2-2<2-4. Therefore, it is speculated that as the time for PEB becomes longer, the cross-linking reaction progresses. Moreover, with respect to Evaluation Test 2-2, a 60-second long PEB was performed instead of the hydrophobic treatment in comparison with Evaluation Test 2-1, but between Evaluation Tests 2-1 and 2-2, the size of the residual film amount at the exposure amount above the insoluble exposure amount and the unnecessarily hydrophobic exposure amount is roughly the same. That is, it can be seen that the same effect as the 60-second PEB is obtained by performing a hydrophobic treatment. Therefore, it is confirmed that by performing a hydrophobic treatment, the time for PEB can be shortened. As described in Evaluation Test 1, the time required for the hydrophobic treatment is short. Therefore, the results of the evaluation tests 1 and 2 show that the hydrophobic treatment can shorten the time required for PEB and shorten the time required to complete HB on the wafer W, thereby improving productivity.

[0104] In addition, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The above-mentioned embodiments may be omitted, replaced, changed, and combined in various ways without departing from the scope and spirit of the invention.

Claims

1. A substrate processing method, characterized in that: The substrate processing method is used to perform patterning by exposing and developing a resist film formed on a substrate: The substrate processing method includes the following steps: before forming the metal-containing resist film on the substrate, performing an auxiliary process for adjusting the moisture adhesion of a formation surface of the substrate for forming the resist film.

2. The substrate processing method according to claim 1, characterized in that: The auxiliary treatment is a hydrophobic treatment of the formation surface.

3. The substrate processing method according to claim 2, characterized in that: The auxiliary treatment makes the contact angle of pure water on the formation surface be greater than or equal to 30 degrees and less than 65 degrees.

4. The substrate processing method according to claim 2 or 3, characterized in that: The auxiliary treatment is a treatment in which a treatment gas for hydrophobic treatment is supplied to the formation surface and the substrate is heated by a heating unit. The temperature change of the substrate from the start of the hydrophobic treatment to the end of the hydrophobic treatment is 60° C. or less.

5. The substrate processing method according to claim 1, characterized in that: The auxiliary process is a process of removing the moisture from the formation surface by depressurizing the inside of a process container in which the substrate is placed to form a reduced pressure space.

6. The substrate processing method according to claim 1, characterized in that: The method includes adjusting a timing of starting the auxiliary process according to a timing of starting the formation of the resist film.

7. The substrate processing method according to claim 6, characterized in that: The following steps are involved: When the auxiliary processing and the formation of the resist film are performed sequentially on a plurality of the substrates, the timing for starting the auxiliary processing of each substrate is determined so as to suppress the time difference between the substrates from the timing for ending the auxiliary processing to the timing for starting the formation of the resist film.

8. A substrate processing device, characterized in that: The substrate processing device processes a substrate, and the substrate can be patterned by forming a resist film, and then exposing and developing the resist film. The substrate processing apparatus performs an auxiliary process for adjusting moisture adhesion of a formation surface of the substrate for forming the resist film before forming the resist film containing metal on the substrate.

9. The substrate processing device according to claim 8, characterized in that: The auxiliary treatment is a hydrophobic treatment of the formation surface.

10. The substrate processing device according to claim 8, characterized in that: The substrate processing device comprises: a processing container in which the substrate can be disposed; and A decompression unit is configured to decompress the interior of the processing container to form a decompression space in order to remove the moisture from the formation surface.

11. A storage medium storing a computer program used in a substrate processing device, characterized in that: The computer program includes a group of steps for executing the substrate processing method according to claim 1.

Images