JP2017006863A - Substrate processing method, program and computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly form a prescribed pattern on a substrate in a substrate processing method using a block copolymer including hydrophilic and hydrophobic polymers.SOLUTION: A substrate processing method includes forming a plurality of circular patterns on a wafer W by a polystyrene film 404; applying a block copolymer onto the wafer W; and phase-separating the block copolymer into a hydrophilic polymer 411 and a hydrophobic polymer 412. The molecular weight percentage of the hydrophilic polymer 411 is controlled to 20 to 40% so that the hydrophilic polymer 411 is arrayed in a cylindrical shape, and the diameter of a circular pattern by the polystyrene film 404 is set to 2(L-R) or less when defining a pitch between the hydrophilic polymers 411 as L, and the radius of the hydrophilic polymer 411 as R.SELECTED DRAWING: Figure 16

Description

  The present invention relates to a substrate processing method using a block copolymer comprising a hydrophilic (polar) polymer having hydrophilicity (polarity) and a hydrophobic (nonpolar) polymer having hydrophobicity (no polarity). The present invention relates to a program and a computer storage medium.

  For example, in a semiconductor device manufacturing process, for example, a resist coating process is performed by applying a resist solution on a semiconductor wafer (hereinafter referred to as “wafer”) as a substrate, and a predetermined pattern is exposed on the resist film. A photolithography process for sequentially performing an exposure process and a development process for developing the exposed resist film is performed, and a predetermined resist pattern is formed on the wafer. Then, using the resist pattern as a mask, an etching process is performed on the film to be processed on the wafer, and then a resist film removing process is performed to form a predetermined pattern on the film to be processed.

  By the way, in order to increase the capacity of a DRAM or the like, it is required to increase the density of the hole pattern constituting the capacitor in the DRAM. For this reason, miniaturization of the resist pattern has been advanced, and for example, the light of the exposure process in the photolithography process has been shortened. However, there are technical and cost limitations to shortening the wavelength of the exposure light source, and it is difficult to form a fine resist pattern on the order of several nanometers, for example, only by the method of advancing the wavelength of light. is there.

  Thus, a wafer processing method using a block copolymer composed of a hydrophilic polymer (hydrophilic polymer) and a hydrophobic polymer (hydrophobic polymer) has been proposed (Patent Document 1). In such a method, a hole pattern is formed on the wafer, for example, at a position corresponding to the hexagonal close-packed structure in plan view. Specifically, on the wafer, a circular pattern is formed as a base with a hydrophilic film at a part of the position corresponding to the hexagonal close-packed structure, and a block copolymer is applied on the patterned wafer. . When the block copolymer is phase-separated into a hydrophilic polymer and a hydrophobic polymer, the circular pattern having hydrophilicity that has been formed as a base functions as a guide, and has a cylindrical shape so as to be in contact with the upper surface of the pattern. A hydrophilic polymer is arranged. At the same time, starting from this cylindrical hydrophilic polymer, the hydrophilic polymers are autonomously and regularly arranged sequentially at positions corresponding to the hexagonal close-packed structure.

  Thereafter, for example, by removing the hydrophilic polymer, a fine hole pattern is formed on the wafer by the hydrophobic polymer. Then, the processing target film is etched using the hydrophobic polymer pattern as a mask to form a predetermined pattern on the processing target film.

JP2007-31568A

  By the way, in the manufacturing process of a semiconductor device, when forming a metal wiring, a cut pattern may be formed by cutting a part of a line and space pattern made of metal such as copper. In the formation of this cut pattern, a predetermined dot pattern is formed on the upper layer of the pattern to be cut, and etching is performed using this pattern as a mask.

  With the miniaturization of semiconductor devices, the dot pattern is also required to be miniaturized. Therefore, a method for forming a fine dot pattern by using the hole pattern forming method using the block copolymer described above has been studied.

  However, when forming a hole pattern with a block copolymer, for example, as in Patent Document 1, when a circular pattern formed of a hydrophilic film is used as a guide, the diameter of the guide is several nm from a desired value. When shifted, the cylindrical hydrophilic polymer is not properly arranged at a position corresponding to the hexagonal close-packed structure. Therefore, in the method of Patent Document 1, it is necessary to control the diameter of the guide with an accuracy of several nm, and there is a problem that the process margin is very small.

  The present invention has been made in view of such points, and an object of the present invention is to appropriately form a predetermined pattern on a substrate in substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer. It is said.

In order to achieve the above object, the present invention provides a method for treating a substrate using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer, and a part thereof formed on the substrate. A neutral layer forming step of forming a neutral layer on the base film having a predetermined pattern from which the substrate has been removed, and a hydrophobic region within the region where the base film is removed in the substrate after the neutral layer forming step. A coating film pattern forming step of forming a circular, elliptical or rounded rectangular pattern with a conductive coating film, and a block copolymer coating for coating the block copolymer on the substrate on which the coating film pattern is formed A step of separating the block copolymer into the hydrophilic polymer and the hydrophobic polymer; and selectively removing the hydrophilic polymer from the phase-separated block copolymer. The polymer has a remer removal step, and the ratio of the molecular weight of the hydrophilic polymer in the block copolymer is such that, in the polymer separation step, the columnar first hydrophilic polymer is formed on the pattern of the hydrophobic coating film. It is adjusted to 20% to 40% so that the columnar second hydrophilic polymer is arranged in a region other than the hydrophobic coating film, and the pattern by the hydrophobic coating film is
(1) In the case of a circle, the diameter of the pattern is 0.8 to 1.5 times the theoretical value of the pitch between the adjacent second hydrophilic polymers. (2) In the case of an ellipse or a rounded rectangle The length in the longitudinal direction of the pattern is (A + n) L ₀ , and the length of the widest portion in the short direction is (0.8 to 1.5) L _0.
It is characterized by being set to. Here, A is an arbitrary constant in the range of 0.7 to 1.3, L ₀ is based on the ratio of the molecular weight of the hydrophilic polymer in the block copolymer, and between the adjacent second hydrophilic polymers. Pitch, n is a natural number.

  In pattern formation using a block copolymer, a guide is generally formed on the base with a film having a small energy difference from the polymer whose arrangement is to be controlled, out of a hydrophilic polymer and a hydrophobic polymer, and applied on the block. By phase-separating the copolymer, the polymer is autonomously arranged at a position corresponding to the guide. On the other hand, the present inventors have found that the arrangement of the polymer can be controlled also by forming a guide with a film having a large energy difference from the polymer to be arranged. Specifically, for example, when controlling the arrangement of a cylindrical hydrophilic polymer, when a circular guide is formed by a film having a large energy difference from the hydrophilic polymer that is the polymer to be arranged, that is, a hydrophobic film , Hydrophobic polymer is attracted on the guide, but since there is a certain amount of hydrophilic polymer in the block copolymer, it is hydrophilic in the center of the region where the hydrophobic polymer is attracted. It was found that the polymer was aligned.

The present invention is based on such knowledge, and a pattern having a predetermined shape is formed by a hydrophobic coating film in a region where the base film is removed, and the molecular weight of the hydrophilic polymer is a predetermined ratio on the pattern. The block copolymer adjusted to 1 is applied, and then the block copolymer is phase-separated. As a result, if the pattern of the hydrophobic coating film is circular, the cylindrical hydrophilic polymer is autonomously arranged at a position corresponding to the center of the circular pattern. Further, if the pattern of the hydrophobic coating film is an ellipse or a rounded rectangle, a plurality of columnar hydrophilic polymers are arranged along the longitudinal direction with respect to the center position in the longitudinal direction of the pattern. Therefore, the hole pattern by the hydrophobic polymer can be formed at a desired position by selectively removing the hydrophilic polymer from the block copolymer after phase separation. Then, by performing an etching process using the hole pattern of the hydrophobic polymer as a mask, for example, a part of the pattern formed in the lower layer of the base film can be cut to form a desired cut pattern. In the present invention, the diameter of the pattern formed by the hydrophobic coating film may be 0.8 to 1.5 times the pitch between the second hydrophilic polymers when the pattern is circular. In the case of a rounded rectangle, A is an arbitrary constant in the range of 0.7 to 1.3, and L ₀ is based on the ratio of the molecular weight of the hydrophilic polymer in the block copolymer, between the second hydrophilic polymers. If the pitch and n are natural numbers, the length in the longitudinal direction of the pattern is (A + n) L ₀ , and the length of the widest portion in the short direction is (0.8 to 1.5) L ₀ . Therefore, as in Patent Document 1, a very large process margin can be ensured as compared with the case where a hydrophilic film is used to control the arrangement of the cylindrical hydrophilic polymer. Therefore, according to the present invention, a predetermined pattern can be appropriately formed on a substrate in substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer.

According to another aspect of the present invention, there is provided a method for treating a substrate using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer, wherein the neutral layer is formed on the substrate. And a coating film pattern forming step of forming an elliptical or rounded rectangular pattern with a hydrophobic coating film at a predetermined position on the substrate after the neutral layer forming step, and a pattern of the coating film is formed. A block copolymer coating step of coating the block copolymer on the substrate, a polymer separation step of phase-separating the block copolymer into the hydrophilic polymer and the hydrophobic polymer, and the phase-separated block A polymer removal step of selectively removing the hydrophilic polymer from the copolymer, and the ratio of the molecular weight of the hydrophilic polymer in the block copolymer is determined by the polymer separation step. In such a manner, the columnar first hydrophilic polymer is arranged on the pattern of the hydrophobic coating film, and the columnar second hydrophilic polymer is arranged in a region other than the hydrophobic coating film, respectively. adjusted to 20% to 40%, the length in the longitudinal direction of the oval or rounded rectangle by the hydrophobic coating film, the (a + n) L _0, length of the widest portion in the widthwise direction, (0.8 to 1.5) L ₀ is set. Here, A is an arbitrary constant in the range of 0.7 to 1.3, L ₀ is determined by the ratio of the molecular weight of the hydrophilic polymer in the block copolymer, and between the adjacent second hydrophilic polymers. The theoretical value of pitch, n is a natural number.

  The molecular weight ratio of the hydrophilic polymer in the block copolymer may be 32% to 34%.

  The hydrophilic polymer may be polymethyl methacrylate, and the hydrophobic polymer may be polystyrene.

  The coating film may be a polystyrene film.

  According to another aspect of the present invention, there is provided a program that operates on a computer of a control unit that controls the substrate processing system so that the substrate processing method is executed by the substrate processing system.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

  According to the present invention, a predetermined pattern can be appropriately formed on a substrate in substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer.

It is a top view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a front view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a rear view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is the flowchart explaining the main processes of wafer processing. It is explanatory drawing of the longitudinal cross-section which shows a mode that the pattern of the line and space, the protective layer, and the hard mask layer were formed on the wafer. It is explanatory drawing of planar view which shows a mode that the pattern by the hard mask layer was formed. It is explanatory drawing of the longitudinal cross-section which shows a mode that the antireflection film, the neutral layer, and the resist film were formed on the wafer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the resist pattern was formed on the neutral layer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the polystyrene film was formed on the resist pattern. It is explanatory drawing of the longitudinal cross-section which shows a mode that the pattern by the polystyrene film was formed on the neutral layer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer was apply | coated on the wafer. It is explanatory drawing of the plane which shows a mode that the block copolymer was phase-separated into the hydrophilic polymer and the hydrophobic polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer was phase-separated into the hydrophilic polymer and the hydrophobic polymer. It is explanatory drawing of the plane which shows the relationship between the diameter of the pattern of a polystyrene film, and arrangement | positioning of a hydrophilic polymer. It is explanatory drawing of the plane which shows arrangement | positioning of the hydrophilic polymer at the time of making the diameter of the pattern of a polystyrene film excessive. It is explanatory drawing of the longitudinal cross-section which shows a mode that the cylindrical hydrophilic polymer was arranged by the conventional method. It is explanatory drawing of the longitudinal cross-section which shows a mode that the hydrophilic polymer was selectively removed from the block copolymer after a phase separation. It is explanatory drawing of the longitudinal cross-section which shows a mode that the pattern of the line and space was etched. It is explanatory drawing of the plane which shows the relationship between arrangement | positioning of the pattern of a polystyrene film, and arrangement | positioning of a hydrophilic polymer. It is explanatory drawing of the plane which shows the relationship between arrangement | positioning of the pattern of a polystyrene film, and arrangement | positioning of a hydrophilic polymer. It is explanatory drawing of the plane which shows the relationship between arrangement | positioning of the pattern of a polystyrene film, and arrangement | positioning of a hydrophilic polymer. It is explanatory drawing of the plane which showed the area | region which cut | disconnects the pattern of the line and space, and the said pattern. It is explanatory drawing of the plane which showed the arrangement | positioning of the pattern of a line and space, and a hydrophilic polymer and hydrophobic polymer. It is explanatory drawing of the plane which shows the state which cut | disconnected the pattern of the line and space. It is explanatory drawing of the longitudinal cross-section which shows the state which formed the polystyrene film after removing the neutral layer, and removed the resist pattern after that.

  Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing an outline of the configuration of a substrate processing system 1 that performs the substrate processing method according to the present embodiment. 2 and 3 are a front view and a rear view, respectively, schematically showing the outline of the internal configuration of the substrate processing system 1. The substrate processing system 1 according to the present embodiment is, for example, a coating and developing processing system. In the present embodiment, a predetermined cut pattern is formed by cutting a line-and-space pattern formed in advance on the upper surface of the wafer W. This will be described as an example.

  As shown in FIG. 1, the substrate processing system 1 includes a cassette station 10 in which a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station 11 having a plurality of various processing apparatuses for performing predetermined processing on the wafers W. And an interface station 13 that transfers the wafer W to and from the exposure apparatus 12 adjacent to the processing station 11 is integrally connected.

  The cassette station 10 is provided with a cassette mounting table 20. The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21 on which the cassette C is mounted when the cassette C is carried into and out of the substrate processing system 1.

  As shown in FIG. 1, the cassette station 10 is provided with a wafer transfer device 23 that is movable on a transfer path 22 that extends in the X direction. The wafer transfer device 23 is also movable in the vertical direction and the vertical axis direction (θ direction), and includes a cassette C on each cassette mounting plate 21 and a delivery device for a third block G3 of the processing station 11 described later. The wafer W can be transferred between the two.

  The processing station 11 is provided with a plurality of, for example, four blocks G1, G2, G3, and G4 having various devices. For example, the first block G1 is provided on the front side of the processing station 11 (X direction negative direction side in FIG. 1), and the second block is provided on the back side of the processing station 11 (X direction positive direction side in FIG. 1). Block G2 is provided. A third block G3 is provided on the cassette station 10 side (Y direction negative direction side in FIG. 1) of the processing station 11, and the interface station 13 side (Y direction positive direction side in FIG. 1) of the processing station 11 is provided. Is provided with a fourth block G4.

  For example, in the first block G1, as shown in FIG. 2, a plurality of liquid processing apparatuses, for example, a developing apparatus 30 for developing the wafer W, an organic solvent supply as a polymer removing apparatus for supplying an organic solvent onto the wafer W Apparatus 31, antireflection film forming apparatus 32 for forming an antireflection film on wafer W, neutral layer forming apparatus 33 for forming a neutral layer by applying a neutral agent on wafer W, resist solution on wafer W A resist coating device 34 for forming a resist film by applying a coating film, a coating film forming device 35 for applying a hydrophobic coating liquid on the wafer W to form a hydrophobic coating film, and a resist film removing liquid on the wafer W The resist removal device 36 for removing the resist film by supplying the block copolymer and the block copolymer coating device 37 for coating the block copolymer on the wafer W are stacked in order from the bottom.

  For example, the developing device 30, the organic solvent supply device 31, the antireflection film forming device 32, the neutral layer forming device 33, the resist coating device 34, the coating film forming device 35, the resist removing device 36, and the block copolymer coating device 37 are Three are arranged side by side in the horizontal direction. The number and arrangement of these liquid processing apparatuses can be arbitrarily selected.

  In these liquid processing apparatuses, for example, spin coating for applying a predetermined coating liquid onto the wafer W is performed. In spin coating, for example, a coating liquid is discharged onto the wafer W from a coating nozzle, and the wafer W is rotated to diffuse the coating liquid to the surface of the wafer W.

  Note that the block copolymer applied on the wafer W by the block copolymer coating device 37 is a first polymer in which the first monomer and the second monomer are linearly polymerized (the weight of the first monomer). A polymer (copolymer) having a polymer) and a second polymer (polymer of the second monomer). A hydrophilic polymer having hydrophilicity (polarity) is used as the first polymer, and a hydrophobic polymer having hydrophobicity (nonpolarity) is used as the second polymer. In the present embodiment, for example, polymethyl methacrylate (PMMA) is used as the hydrophilic polymer, and for example, polystyrene (PS) is used as the hydrophobic polymer. The ratio of the molecular weight of the hydrophilic polymer in the block copolymer is about 20% to 40%, and the ratio of the molecular weight of the hydrophobic polymer in the block copolymer is about 80% to 60%. The block copolymer is obtained by making a copolymer of these hydrophilic polymer and hydrophobic polymer into a solution with a solvent.

  Moreover, the neutral layer formed on the wafer W by the neutral layer forming apparatus 33 has an intermediate affinity for the hydrophilic polymer and the hydrophobic polymer. In the present embodiment, for example, a random copolymer or an alternating copolymer of polymethyl methacrylate and polystyrene is used as the neutralizing agent. In the following, the term “neutral” means having an intermediate affinity for the hydrophilic polymer and the hydrophobic polymer.

  For example, in the second block G2, as shown in FIG. 3, a heat treatment apparatus 40 for performing heat treatment of the wafer W, an ultraviolet irradiation apparatus 41 for irradiating the wafer W with ultraviolet light, an adhesion apparatus 42 for hydrophobizing the wafer W, A peripheral exposure device 43 that exposes the outer peripheral portion of the wafer W, and a polymer separation device 44 that phase-separates the block copolymer applied on the wafer W by the block copolymer coating device 37 into a hydrophilic polymer and a hydrophobic polymer Are arranged side by side in the horizontal direction. The heat treatment apparatus 40 includes a hot plate for placing and heating the wafer W and a cooling plate for placing and cooling the wafer W, and can perform both heat treatment and cooling treatment. The polymer separation device 44 is also a device that performs heat treatment on the wafer W, and the configuration thereof is the same as that of the heat treatment device 40. The ultraviolet irradiation device 41 includes a mounting table on which the wafer W is mounted, and an ultraviolet irradiation unit that irradiates the wafer W on the mounting table with ultraviolet light having a wavelength of 172 nm, for example. The number and arrangement of the heat treatment apparatus 40, the ultraviolet irradiation apparatus 41, the adhesion apparatus 42, the peripheral exposure apparatus 43, and the polymer separation apparatus 44 can be arbitrarily selected.

  For example, in the third block G3, a plurality of delivery devices 50, 51, 52, 53, 54, 55, and 56 are provided in order from the bottom. The fourth block G4 is provided with a plurality of delivery devices 60, 61, 62 in order from the bottom.

  As shown in FIG. 1, a wafer transfer region D is formed in a region surrounded by the first block G1 to the fourth block G4. In the wafer transfer region D, for example, a plurality of wafer transfer devices 70 having transfer arms that are movable in the Y direction, the X direction, the θ direction, and the vertical direction are arranged. The wafer transfer device 70 moves in the wafer transfer area D and transfers the wafer W to a predetermined device in the surrounding first block G1, second block G2, third block G3, and fourth block G4. it can. Further, in the wafer transfer region D, a shuttle transfer device 80 that transfers the wafer W linearly between the third block G3 and the fourth block G4 is provided.

  The shuttle transport device 80 is movable linearly in the Y direction, for example. The shuttle transfer device 80 moves in the Y direction while supporting the wafer W, and can transfer the wafer W between the transfer device 52 of the third block G3 and the transfer device 62 of the fourth block G4.

  As shown in FIG. 1, a wafer transfer apparatus 100 is provided next to the third block G3 on the positive side in the X direction. The wafer transfer apparatus 100 has a transfer arm that is movable in the X direction, the θ direction, and the vertical direction, for example. The wafer transfer device 100 can move up and down while supporting the wafer W, and can transfer the wafer W to each delivery device in the third block G3.

  The interface station 13 is provided with a wafer transfer device 110 and a delivery device 111. The wafer transfer device 110 has a transfer arm that is movable in the Y direction, the θ direction, and the vertical direction, for example. The wafer transfer device 110 can transfer the wafer W between each transfer device, the transfer device 111, and the exposure device 12 in the fourth block G4, for example, by supporting the wafer W on a transfer arm.

  The substrate processing system 1 is provided with a control unit 300 as shown in FIG. The control unit 300 is a computer, for example, 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. The program storage unit also stores a program for controlling the operation of driving systems such as the above-described various processing apparatuses and transfer apparatuses to realize wafer processing in the substrate processing system 1. The program is recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), or a memory card. May have been installed in the control unit 300 from the storage medium.

  Next, wafer processing performed using the substrate processing system 1 configured as described above will be described. FIG. 4 is a flowchart showing an example of main steps of such wafer processing.

First, a cassette C storing a plurality of wafers W is carried into the cassette station 10 of the substrate processing system 1, and each wafer W in the cassette C is sequentially transferred to the transfer device 53 of the processing station 11 by the wafer transfer device 23. . As described above, a line-and-space pattern E as shown in FIG. 5 is formed in advance on the upper surface of the wafer W in the wafer W in the present embodiment. The pattern E is formed of a wiring metal such as copper. Further, on the upper surface of the pattern E, a protective layer F as a first hard mask made of, for example, an SOC (spin-on-carbon) film and an etching hard mask layer HM as a second hard mask are formed in this order from the bottom. ing. The hard mask layer HM has a predetermined pattern J formed by partially removing the hard mask layer HM, and includes a metal such as Ti and Ta and a metal compound such as TiN and TaN. It is a metal hard mask. The pattern J formed on the hard mask layer HM is a pattern including a circular hole portion Ja having a diameter Q in plan view as shown in FIG. 6, for example. 5 is a longitudinal sectional view of a portion indicated by a one-dot chain line AA in FIG. In addition, the base film in the present invention is composed of at least one of the protective layer F that is the first hard mask or the hard mask layer HM that is the second hard mask. In other words, only the protective layer F may be provided as the base film, only the hard mask layer HM may be provided, or both the protective layer F and the hard mask layer HM may be provided. If the protective layer F and the hard mask layer HM have a two-layer structure as in the present embodiment, the pattern J is formed at least on the upper hard mask layer HM. In addition to the carbon-containing film such as the SOC film, an SiO ₂ film, a SiON film, a Si-containing antireflection film such as SiARC, or the like can be used as the base film that is a hard mask. Further, the carbon-containing film is not limited to a film formed by coating such as an SOC film, and for example, an amorphous carbon film formed by a CVD (Chemical Vapor Deposition) apparatus or the like may be used.

  The hole portion Ja of the pattern J is arranged so that the center position of a region where a part of the pattern E is cut in a process described later and the center position of the pattern J substantially coincide with each other in plan view. At this time, the distance P between the centers of the adjacent adjacent hole portions Ja is set to a predetermined value or more. The setting of the diameter Q and the distance P of the hole portion Ja will be described later.

  Next, the wafer W is transferred to the heat treatment apparatus 40 and the temperature thereof is adjusted, and then transferred to the antireflection film forming apparatus 32 to form an antireflection film 400 on the wafer W as shown in FIG. 7 (FIG. 4). Step S1). Thereafter, the wafer W is transferred to the heat treatment apparatus 40, heated, and the temperature is adjusted.

  Next, the wafer W is transported to the neutral layer forming apparatus 33, and a neutral agent is applied on the antireflection film 400 of the wafer W to form a neutral layer 401 as shown in FIG. Layer formation step, step S2 in FIG. Thereafter, the wafer W is transferred to the heat treatment apparatus 40, heated, and the temperature is adjusted.

  Next, the wafer W is transferred to the adhesion device 42 and subjected to an adhesion process. Thereafter, the wafer W is transported to the resist coating unit 34, and a resist solution is applied onto the neutral layer 401 of the wafer W to form a resist film 402 as shown in FIG. Thereafter, the wafer W is transferred to the heat treatment apparatus 40 and pre-baked. Thereafter, the wafer W is transferred to the peripheral exposure device 43 and subjected to peripheral exposure processing.

  Next, the wafer W is transferred to the exposure apparatus 12 by the wafer transfer apparatus 110 of the interface station 13 and subjected to exposure processing. Thereafter, the wafer W is transferred to the heat treatment apparatus 40 and subjected to post-exposure baking, and then transferred to the developing apparatus 30 for development processing. After completion of the development, the wafer W is transferred to the heat treatment apparatus 40 and subjected to a post baking process. Thus, as shown in FIG. 8, a predetermined resist pattern 403 is formed by the resist film 402 on the neutral layer 401 of the wafer W (step S3 in FIG. 4). The resist pattern 403 in the present embodiment has substantially the same shape as the pattern J formed by the hard mask layer HM, and has a diameter Q at a position substantially the same as the position where the hole portion Ja of the hard mask layer HM is formed. Hole portion 403a is formed. In other words, the arrangement of the hole portions 403a of the resist pattern 403 in a plan view substantially matches the arrangement of the hole portions Ja of the hard mask layer HM shown in FIG.

  Next, the wafer W is transferred to the coating film forming apparatus 35. In the coating film forming apparatus 35, a hydrophobic coating liquid is supplied onto the wafer W on which the resist pattern 403 is formed. The hydrophobic coating solution means a hydrophilic polymer and a hydrophobic polymer in the block copolymer supplied by the block copolymer coating device 37 that have a small energy difference between the hydrophobic polymer and the hydrophobic polymer. Yes. In the present embodiment, the hydrophobic coating liquid applied by the coating film forming apparatus 35 is, for example, a solution of polystyrene in a solvent form. As a result, as shown in FIG. 9, a polystyrene film 404 is formed on the resist pattern 403 as a hydrophobic coating film (step S4 in FIG. 4).

  Next, the wafer W is transferred to the resist removing device 36. In the resist removing device 36, a resist removing liquid is supplied onto the wafer W, and the resist pattern 403 by the resist film 402 is removed. As the resist removing solution, for example, a mixed solution of an organic amine and a polar solvent is used. When the resist pattern 403 is removed, the polystyrene film 404 formed in the hole portion 403a of the resist pattern 403 remains on the neutral layer 401. As a result, as shown in FIG. 10, a pattern having a diameter Q substantially the same as that of the hole portion 403a is formed at the location where the hole portion 403a of the resist pattern 403 is formed on the neutral layer 401 of the wafer W by the polystyrene film 404. Is formed (coating film pattern forming step, step S5 in FIG. 4).

  Next, the wafer W is transferred to the block copolymer coating device 37. In the block copolymer coating device 37, as shown in FIG. 11, the block copolymer 410 is coated on the wafer W (block copolymer coating step; step S6 in FIG. 4).

  Next, the wafer W is transferred to the polymer separation device 44 and subjected to heat treatment at a predetermined temperature. Thereby, the block copolymer 410 on the wafer W is phase-separated into a hydrophilic polymer and a hydrophobic polymer (polymer separation step; step S7 in FIG. 4). Here, as described above, the molecular weight ratio of the hydrophilic polymer in the block copolymer 410 is 20% to 40%, and the molecular weight ratio of the hydrophobic polymer is 80% to 60%. In general, when the neutral layer 401 is uniformly formed on the entire surface of the wafer W, the hydrophilic polymer of the phase-separated block copolymer has a cylindrical shape perpendicular to the upper surface of the wafer W, and is viewed in plan view. Are arranged autonomously at positions corresponding to the hexagonal close-packed structure. The hydrophobic polymer is phase-separated so as to surround the hydrophilic polymer.

  In this embodiment, since the polystyrene film 404 is formed on the neutral layer 401, the hydrophobic polymer 412 after the phase separation has an energy difference larger than that of the neutral layer 401, for example, as shown in FIG. They are drawn onto the small polystyrene film 404 and arranged so as to be in contact with the polystyrene film 404. On the other hand, the hydrophilic polymer 411 existing in the block copolymer 410 at a ratio of 20% to 40% is also autonomously arranged at a more stable energy position. In this case, the hydrophilic polymer 411 is attracted onto the polystyrene film 404. The position of the center of the hydrophobic polymer 412 is the most energetically stable position. As a result, as shown in FIG. 12, the hydrophilic polymer 411 is arranged at a position corresponding to the center of the circular polystyrene film 404. At this time, since the energy difference between the hydrophilic polymer 411 and the polystyrene film 404 is large, a gap Z may be formed between the hydrophilic polymer 411 and the polystyrene film 404. In FIG. 12, for convenience, the code of the hydrophilic polymer arranged at the position corresponding to the center of the circular polystyrene film 404 is “411a”, and the code of the other hydrophilic polymer is “411b”. Hereinafter, the hydrophilic polymer denoted by “411a” is referred to as a first hydrophilic polymer, and the hydrophilic polymer denoted by “411b” is referred to as a second hydrophilic polymer.

Then, when the first hydrophilic polymer 411a is phase-separated above the center position of each polystyrene film 404, for example, as shown in FIG. 13, the first hydrophilic polymer 411a (circle with hatching shown in FIG. 13). The second hydrophilic polymer 411b is arranged at substantially equal intervals around the base point so as to be stable in terms of energy. As a result, the first hydrophilic polymer 411a and the second hydrophilic polymer 411b are autonomously arranged at positions substantially corresponding to the hexagonal close-packed structure. In the present embodiment, the hole portion Ja of the pattern J of the hard mask layer HM shown in FIG. 6 is arranged at a position corresponding to the hexagonal close-packed structure. As a result, as shown in FIG. as illustrates the case where the pitch between each and each adjacent first hydrophilic polymer 411a second hydrophilic polymer 411b are arranged in a fixed hexagonal close-packed structure at L _0.

Note that the pitch L ₀ and the diameters of the first hydrophilic polymer 411a and the second hydrophilic polymer 411b are interaction parameters between the hydrophilic polymer 411 and the hydrophobic polymer 412 constituting the block copolymer 410. This is determined by a certain χ (chi) parameter and the molecular weight of each polymer. In this embodiment, the pitch L ₀ will be described as being consistent with a theoretical value determined by a value such as the χ parameter.

  Next, the setting of the diameter Q of the circular pattern by the polystyrene film 404, that is, the diameter Q of the hole portion 403a of the resist pattern 403 will be described. As shown in FIG. 11, when the block copolymer 410 on the neutral layer 401 having a polystyrene film 404 formed on a part thereof is phase-separated, the hydrophobic surface having a small energy difference is present on the upper surface of the polystyrene film 404 as described above. The hydrophilic polymer 411 having a large energy difference is arranged at the position where it is not in contact with the polystyrene film 404 as much as possible and at the center of the hydrophobic polymer 412 drawn on the polystyrene film 404. Therefore, if the diameter Q of the pattern of the circular polystyrene film 404 is approximately the same as the diameter of the cylindrical first hydrophilic polymer 411a, the first hydrophilic polymer 411a corresponds to the center of the hydrophobic polymer 412. Arrange in position.

  However, if the diameter Q is set excessively, the arrangement of the first hydrophilic polymer 411a is affected. The influence on the arrangement of the first hydrophilic polymer 411a will be specifically described with reference to FIG.

As described above, the second hydrophilic polymer 411b corresponds to a hexagonal close-packed structure based on the first hydrophilic polymer 411a located on the center of the polystyrene film 404, for example, as shown in FIG. Array. In this case, the pitch between the first hydrophilic polymer 411a adjacent the second hydrophilic polymer 411b is the above-described L _0. However, when the diameter Q of the pattern of the circular polystyrene film 404 becomes large and, for example, overlaps with the second hydrophilic polymer 411b in a plan view, in other words, the radius of the second hydrophilic polymer 411b is R and In this case, when the diameter Q of the pattern of the polystyrene film 404 is larger than 2 (L ₀ -R), the arrangement of the second hydrophilic polymer 411b is changed. More specifically, for example, as shown in FIG. 15, the pitch L ₀ between the hydrophilic polymers 411a and 411b is arranged at a position where the pitch is approximately 2√3 / 3, and the first hydrophilic polymer 411a is Instead of being on the center of the polystyrene film 404, they are arranged, for example, in the form of an equilateral triangle within the range of the polystyrene film 404 having a diameter Q. When the diameter Q of the pattern of the polystyrene film 404 is increased from the state of FIG. 14 so as to overlap with the second hydrophilic polymer 411b, the portion where the second hydrophilic polymer 411b is arranged in FIG. This is because the energy difference from the hydrophilic polymer 411 is increased, and the hydrophobic polymer 412 is arranged. As shown in FIG. 15, when the value of the diameter Q is increased, the arrangement of the first hydrophilic polymer 411 a that is most stable in terms of energy is not the center of the pattern of the polystyrene film 404 but the hydrophobic polymer 412. It appears as a regular triangle within the range corresponding to the circular pattern. As a result, the first hydrophilic polymer 411a is arranged at a position deviated from the center position of the polystyrene film 404, and the arrangement (orientation) in the rotational direction of the first hydrophilic polymer 411a arranged in an equilateral triangle is also included. It becomes impossible to control. Therefore, in order to arrange the first hydrophilic polymer 411a in a desired arrangement, the diameter Q of the pattern of the polystyrene film 404 is preferably 2 (L ₀ -R) or less.

From the viewpoint of arranging the first hydrophilic polymer 411a in a desired arrangement, that is, in the center position of the polystyrene film 404, it is not necessary to provide a lower limit for the diameter Q of the pattern of the polystyrene film 404. According to the inventors, the value of the gap Z formed between the first hydrophilic polymer 411a and the polystyrene film 404 shown in FIG. 12 becomes smaller as the diameter Q of the circular pattern formed by the polystyrene film 404 becomes smaller. Has been confirmed to increase. Therefore, it is preferable that the gap Z is as small as possible from the viewpoint of using the hydrophobic polymer 412 as an etching mask in the subsequent etching process. And according to the inventors, to the gap Z than the desired value has been confirmed that it is preferable that the diameter Q approximately 0.8 times the desired pitch L _0. Therefore, in order to arrange the first hydrophilic polymer 411a in a desired arrangement, the pattern diameter Q of the polystyrene film 404 is 2 (L ₀ -R) or less and approximately 0.8 times or more of the pitch L _0. It is preferable.

When the desired pitch between the hydrophilic polymers 411 is L ₀ , the diameter Q of the pattern of the polystyrene film 404 is preferably 2 (L ₀ -R) or less as described above. As a result of intensive research, when the ratio of the molecular weight of the hydrophilic polymer 411 in the block copolymer 410 is about 20% to 40%, in order to stably arrange the hydrophilic polymers 411 at the pitch L ₀ , , the diameter Q of the pattern of the polystyrene film 404 is more preferably it was confirmed that less 1.5 times the desired pitch L _0. Therefore from this result, when forming the hydrophobic polymer 412 an etching mask for forming a hole pattern, the diameter Q is the desired pitch L ₀ of the cylindrical pattern with a hydrophilic polymer 411 substantially 0.8 It can be said that it is more preferable to set the magnification to 1.5 times. Therefore, for example, when the pitch L ₀ between the hydrophilic polymers 411 is 40 nm, the diameter Q may be about 32 nm to 60 nm, and a process margin of about 30 nm can be secured.

Further, in the pattern J of the hard mask layer HM, the distance P between the centers of adjacent hole portions Ja adjacent to each other, in other words, between the circular patterns formed by the polystyrene film 404, the first hydrophilic polymer 411a is made of polystyrene. from the viewpoint of arrangement in the center of the circular pattern by film 404, it is preferable to set longer than the pitch L ₀ between the hydrophilic polymer 411. The reason for this will be described later.

  On the other hand, as disclosed in Patent Document 1, when a circular pattern with a hydrophilic coating film is used as a guide for arranging the hydrophilic polymers 411, the process for the pattern diameter Q as described above is used. The margin is very small. Specifically, as shown in FIG. 16, when the guide is formed by the hydrophilic coating film 420, the first hydrophilic polymer 411a after phase separation is arranged so as to be in contact with the coating film 420 having a small energy difference. Therefore, when the diameter Q is larger than the diameter of the desired hydrophilic polymer 411, it becomes a truncated cone shape in which the diameter expands downward. When the diameter Q is excessive, the first hydrophilic polymer 411a is not exposed on the upper surface of the hydrophobic polymer 412, and has a substantially truncated cone shape. In such a case, in etching using the hydrophobic polymer 412 as a mask, it becomes impossible to process with a desired dimension. Therefore, the diameter Q needs to be approximately the same as or smaller than the diameter of the cylindrical hydrophilic polymer 411 after phase separation. However, generally, there is an unavoidable error of about 5 nm in the dimension (CD: Critical Dimension) of the resist pattern 403, but the diameter of the cylindrical hydrophilic polymer 411 is about 20 nm to 30 nm. For the diameter of the polymer 411, this error is so large that it cannot be ignored. Therefore, when forming the hydrophilic coating film 420, there is almost no process margin for the diameter Q, and it is extremely difficult to control the diameter Q of the coating film 420 in accordance with the diameter of the hydrophilic polymer 411. This difference in process margin is the reason why the polystyrene film 404 is used as a guide for arranging the first hydrophilic polymer 411a in this embodiment.

  After the block copolymer 410 is phase-separated by the polymer separation device 44, the wafer W is transferred to the ultraviolet irradiation device 41. The ultraviolet irradiation device 41 irradiates the wafer W with ultraviolet rays to break the polymethyl methacrylate bond chain, which is the hydrophilic polymer 411, and causes the polystyrene, which is the hydrophobic polymer 412, to undergo a crosslinking reaction (step of FIG. 4). S8).

  Next, the wafer W is transferred to the organic solvent supply device 31. In the organic solvent supply device 31, a polar organic solvent (polar organic solvent) is supplied to the wafer W. For example, IPA (isopropyl alcohol) is used as the polar organic solvent. As a result, the hydrophilic polymer 411 whose bond chain has been cut by ultraviolet irradiation is dissolved by the organic solvent, and the hydrophilic polymer 411 is selectively removed from the wafer W (polymer removal step; step S9 in FIG. 4). As a result, a hole pattern 430 is formed by the hydrophobic polymer 412 as shown in FIG.

Thereafter, the wafer W is transferred to the delivery device 50 by the wafer transfer device 70,
Thereafter, the wafer is transferred to the cassette C of the predetermined cassette mounting plate 21 by the wafer transfer device 23 of the cassette station 10.

  Thereafter, the cassette C is transported to an etching processing apparatus (not shown) provided outside the substrate processing system 1, and the neutral layer 401, the antireflection film 400, the protective layer F, and the pattern are formed using the hydrophobic polymer 412 as a mask. E is etched. At this time, since the hard mask layer HM is formed on the upper surface of the protective layer F, as shown in FIG. 18, a portion where the hard mask layer HM is not formed, in other words, a circular shape is formed by the polystyrene film 404. The hole pattern 430 is transferred to the pattern E only in the portion where the pattern (2) has been formed (step S10 in FIG. 4). Thereby, a desired cut pattern can be formed. During etching, the hydrophobic polymer 412 and the polystyrene film 404 remain in the hole pattern 430 formed by the first hydrophilic polymer 411a, but the gap Z and the thickness of the polystyrene film 404 are appropriately adjusted. Thus, processing that is not different from the hole pattern 430 corresponding to the second hydrophilic polymer 411b can be performed. As the etching processing apparatus, for example, an RIE (Reactive Ion Etching) apparatus is used. That is, in the etching processing apparatus, dry etching for etching a film to be processed such as a hydrophilic polymer or an antireflection film is performed by a reactive gas (etching gas), ions, or radicals.

  Thereafter, the wafer W is etched again, and the hydrophobic polymer 412, the neutral layer 401, and the antireflection film 400 on the wafer W are removed. Thereafter, the wafer W is unloaded from the etching processing apparatus, and a series of wafer processing ends.

According to the above embodiment, a circular pattern with a predetermined diameter is formed on the wafer W by the polystyrene film 404 which is a hydrophobic film, and then the block copolymer 410 is applied, and then the block Since the copolymer 410 is phase-separated, the columnar first hydrophilic polymer 411 a is autonomously arranged at a position corresponding to the center of the circular pattern formed by the polystyrene film 404. At this time, the diameter of the circular pattern formed by the polystyrene film 404 may be 0.8 to 1.5 times the pitch L ₀ between the hydrophilic polymers 411. Compared to the case where a hydrophilic film is used to control the disposition of the conductive polymer, a very large process margin can be secured. Therefore, according to the present invention, a predetermined pattern can be appropriately formed on a substrate in substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer.

  In the above embodiment, the ratio of the molecular weight of the hydrophilic polymer is about 20% to 40%. According to the present inventors, the ratio between the first hydrophilic polymer 411a and the polystyrene film 404 is From the viewpoint of setting the value of the gap Z formed in a desired value, the ratio of the molecular weight of the hydrophilic polymer 411 in the block copolymer 410 is 32% to 34%, and the ratio of the molecular weight of the hydrophobic polymer 412 is It has been confirmed that it is more preferably 68% to 66%. More specifically, when the circular pattern by the polystyrene film 404 is used as a guide, when the block copolymer 410 is heat-treated for phase separation, the hydrophilic polymer 411 does not come into contact with the polystyrene film 404 and is energetic. First, it moves above the center of the polystyrene film 404, which is a stable position. That is, as shown in FIG. 12, the island of the first hydrophilic polymer 411a floats in the sea of the hydrophobic polymer 412. On the other hand, when the second hydrophilic polymer 411b is arranged around the first hydrophilic polymer 411a, the first hydrophilic polymer 411a above the center portion of the polystyrene film 404 becomes adjacent to the second hydrophilic polymer 411b. The diameter of the upper surface of the first hydrophilic polymer 411a is reduced so that the distance between and the first hydrophilic polymer 411a becomes constant (energeticly stable), and changes to a substantially cylindrical shape as a whole. Even if the diameter of the upper surface of the first hydrophilic polymer 411a is reduced, the volume of the island of the first hydrophilic polymer 411a does not change. Move to. That is, the value of the gap Z is determined by the degree of downward movement of the first hydrophilic polymer 411a in the thickness direction of the wafer W. The volume of the islands of the first hydrophilic polymer 411a is one of the factors that determine how much the first hydrophilic polymer 411a moves downward in the thickness direction of the wafer W. The volume of the island of one hydrophilic polymer 411a depends on the ratio of the molecular weight of the hydrophilic polymer in the block copolymer 410. Therefore, the value of the gap Z can be adjusted by adjusting the ratio of the molecular weight of the hydrophilic polymer in the block copolymer 410. According to the present inventors, the value is set to 32% to 34% as described above. It is preferable.

In addition to the ratio of the molecular weight of the hydrophilic polymer in the block copolymer 410, the factor determining the gap Z includes the film thickness of the block copolymer 410 formed in step S6. According to the above, it has been confirmed that this film thickness is preferably about 0.4 to 0.6 times the desired pitch L ₀ between the hydrophilic polymers 411.

In the above embodiment, the hole portion Ja of the pattern J of the hard mask layer HM is arranged at a position corresponding to the hexagonal close-packed structure, so that, for example, as shown in FIG. The case where the hydrophilic polymer 411a and the second hydrophilic polymer 411b are autonomously arranged at positions substantially corresponding to the hexagonal close-packed structure has been described as an example, but the arrangement of the holes Ja, in other words, by the polystyrene film 404 The circular pattern is not necessarily arranged at a position corresponding to the hexagonal close-packed structure. By appropriately setting the diameter Q of the circular pattern formed by the polystyrene film 404, the first hydrophilic polymers 411a are arranged at the center positions of the circular patterns, and the first film is disposed around the polystyrene film 404. The second hydrophilic polymer 411b is arranged with the hydrophilic polymer 411a as a starting point, but when the arrangement of the circular pattern by the polystyrene film 404 is shifted from the position corresponding to the hexagonal close-packed structure, in other words, adjacent to each other. If the pitch between the first hydrophilic polymer 411a is not an integral multiple of the theoretical value of the pitch L ₀ of the second hydrophilic polymer 411b, the second to be arranged around the first hydrophilic polymer 411a The pitch L ₀ between the hydrophilic polymers 411b is also different from the theoretical value. However, in the phase separation of the block copolymer 410, since the arrangement of the first hydrophilic polymer 411a is first determined as described above, the arrangement of the first hydrophilic polymer 411a is the arrangement of the second hydrophilic polymer 411b. It is not affected by. Therefore, regardless of the arrangement state of the second hydrophilic polymer 411b, the first hydrophilic polymer 411a can be arranged at a desired position, that is, at the center of the circular pattern formed by the polystyrene film 404 in this embodiment. Since the hard mask layer HM is formed at a position corresponding to the second hydrophilic polymer 411b, the second hydrophilic polymer 411b is used when performing the etching process using the hydrophobic polymer 412 as a mask in step S10. Even if the arrangement of the pattern is not controlled, it does not affect the pattern E under the hard mask layer HM.

In the above embodiment, the polystyrene film 404 functioning as a guide has a circular shape, but the polystyrene film 404 may have an elliptical shape or a rounded rectangular shape, for example. For example, when a line-and-space pattern E to be cut is formed by using double patterning or the like, the pitch between the centers of the pattern E is set so as not to be substantially different from the pitch L ₀ between the hydrophilic polymers 411. There may be.

In such a case, it is conceivable to form a pattern of circular polystyrene film 404 with a pitch L _0, for example, as shown in FIG. 19, to form a pattern of polystyrene film 404 with a pitch L _0, the pattern with each other It may overlap. Then, the first hydrophilic polymer 411a, rather than arranged in the center of each circular pattern L _0, the most in the pattern of the polystyrene film 404 became shaped substantially 8 by partially overlapping Arrange in an energetically stable position. In FIG. 19, a pitch L ₀ in the range of polystyrene film 404 first hydrophilic polymer 411a is描図a state in which sequence example became shaped substantially 8. In such a case, as in the case where the diameter Q of the polystyrene film 404 is excessive, the arrangement of the first hydrophilic polymer 411a cannot be controlled to a desired position. In other words, the circular pattern by polystyrene film 404, for example by forming a cut pattern in a position Tonaria' in pitch L ₀ is sometimes difficult. In addition, this is the above-described distance P between the centers of the adjacent hole portions Ja adjacent to each other in the pattern J of the hard mask layer HM (the distance between circular patterns formed by the polystyrene film 404), and the pitch L ₀ between the hydrophilic polymers 411. This is why it is set longer.

Therefore, the present inventors have conceived that when the cut pattern is formed at the pitch L ₀ , the pattern formed by the polystyrene film 404 is an elliptical shape or a rounded rectangular shape. This will be specifically described below.

According to the present inventor, for example, as shown in FIG. 20, when a rounded rectangular pattern 440 is formed by the polystyrene film 404, the longitudinal length K of the rounded rectangular shape and the short length around the middle position CL of the B, the first hydrophilic polymer 411a and along the longitudinal direction is confirmed to be arranged with a pitch L _0.

At this time, if the length B in the short direction is excessive, the length B in the short direction is the same as in the case where the diameter Q of the circular pattern formed by the polystyrene film 404 as illustrated in FIG. A plurality of first hydrophilic polymers 411a are arranged within the range, and it is difficult to control the position where the first hydrophilic polymers 411a are arranged. It has been confirmed by the present inventors that the first hydrophilic polymer 411a can be arranged in a line along the longitudinal direction by setting it to 0.8 to 1.5 times ₀ . The set value 0.8 to 1.5 times the pitch L ₀ is the same as the range of the diameter Q of the circular pattern formed by the polystyrene film 404, and the length B in the short direction is set to such a value. By doing so, it is possible to prevent a plurality of the first hydrophilic polymers 411a from being arranged in the lateral direction.

In addition, the length K in the longitudinal direction is set to (A + n) L ₀ so that two or more first hydrophilic polymers 411a can be arranged in a line along the longitudinal direction of the pattern 440. It has been confirmed by the inventors. Here, A is an arbitrary constant in the range of 0.7 to 1.3, and n is a natural number. This set value will be described.

According to the present inventors, when the length K in the longitudinal direction of the pattern 440 is insufficient, the first hydrophilic polymer 411a is substantially angular along the longitudinal direction of the pattern 440 as shown in FIG. It has been confirmed that they are arranged in a round rectangular shape. This is considered to be because when the first hydrophilic polymer 411a has no space for phase separation at the pitch L ₀ in the longitudinal direction of the pattern 440, the substantially rounded rectangular shape is the most energy stable shape. It is done. Therefore, the present inventors diligently studied, and by making the length K in the longitudinal direction longer than the pitch L ₀ by A × L ₀ , the two first hydrophilic properties are included in the rounded rectangular pattern 440. thereby arranging a plurality of polymer 411a with a pitch L ₀ is confirmed. Further, the length K each time longer by minute pitch L _0, the first hydrophilic polymer 411a be arranged in the pattern 440 has been confirmed to be increased by one. From this knowledge, by setting the length K in the longitudinal direction to (A + n) L ₀ discretely, two or more first hydrophilic polymers 411a can be arranged in a line along the longitudinal direction of the pattern 440. I found something. When the value of n is 1, two first hydrophilic polymers 411a are arranged in the pattern 440, and when the value of n is 2, the first hydrophilic polymer 411a is in the pattern 440. Are arranged in three. Therefore, the number of the first hydrophilic polymers 411a arranged in the longitudinal direction is “n + 1” with respect to (A + n) L ₀ having a length K in the longitudinal direction. Further, when the value of n is an even number, the odd number of first hydrophilic polymers 411a are arranged in the pattern 440. In such a case, the first hydrophilic polymer 411a is arranged at the center of the position CL, since the first hydrophilic polymer 411a spaced apart by a position CL and the pitch L ₀ is more sequences, it is possible to appropriately control the placement of the first hydrophilic polymer 411a.

Although FIG. 20 illustrates the case where the pattern 440 formed by the polystyrene film 404 is rounded rectangular, the pattern 440 may be elliptical. When using an oval pattern, the length K of the major axis is set to (A + n) L ₀ as in the case of using a rounded rectangle, and the width B in the short direction is the widest in the short direction. By setting the length of the portion, that is, the minor axis to (0.8 to 1.5) L ₀ , the same effect as when the pattern 440 has a rounded rectangular shape can be obtained.

  In this way, by using the rounded rectangular or elliptical pattern 440, for example, a line-and-space pattern E having a pitch L0 as shown in FIG. 22 is cut at a region M indicated by a broken line in FIG. Is formed, the hole portion Ja of the hard mask layer HM is formed in a range overlapping the region M in plan view. In the case shown in FIG. 22, the shape of the hole portion Ja includes not only a circular shape but also an elliptical shape or a rounded rectangular shape. By doing so, the pattern 440 by the polystyrene film 404 is formed in the hole part Ja in process S5. Also in this case, the pattern 440 includes not only a circular shape but also an elliptical shape or a rounded rectangular shape.

  Then, after the block copolymer 410 is applied in step S6 and then the block copolymer 410 is phase-separated in step S7, the first hydrophilic polymer 411a is located at a position corresponding to the region M as shown in FIG. And the hydrophobic polymer 412 are phase-separated and arranged. At this time, a plurality of first hydrophilic polymers 411a are arranged in a region M formed in a rounded rectangular shape. In FIG. 23, in order to clarify the positional relationship between the pattern E and the first hydrophilic polymer 411a, the neutral layer 401, the antireflection film 400, the protective layer F, and the hard mask layer HM, such as the pattern E and the first mask, are shown. The one interposed between the first hydrophilic polymer 411a and the second hydrophilic polymer 411b are not shown.

  Then, after removing the hydrophilic polymer 411 in step S9, an etching process is performed using the hydrophobic polymer 412 as a mask in step S10, thereby cutting a desired portion of the pattern E as shown in FIG. Can be formed.

Note that when the elliptical or rounded rectangular pattern 440 is used, the pitch of the line-and-space pattern E may not match the pitch L ₀ between the hydrophilic polymers 411. In such a case, the χ parameter is changed by appropriately adjusting the ratio of the molecular weight of the hydrophilic polymer 411 and the hydrophobic polymer 412 in the block copolymer 410, the concentration of the solvent for making the block copolymer 410 into a solution, and the like. It is preferable to match the pitch of the pattern E with the pitch L ₀ between the hydrophilic polymers 411.

  In the above embodiment, after forming the resist pattern 403 having the hole portion 403a, the polystyrene film 404 is applied on the resist pattern 403, and then the resist pattern 403 is removed, whereby the polystyrene film 404 is formed on the neutral layer 401. However, the method of forming the circular pattern by the polystyrene film 404 is not limited to the contents of the present embodiment. For example, a polystyrene film 404 is applied on the neutral layer 401, then a resist pattern 403 is formed on the polystyrene film 404, and the polystyrene film 404 is etched using the resist pattern 403 as a mask. A pattern by the polystyrene film 404 may be formed.

  Further, the polystyrene film is not necessarily formed on the upper surface of the neutral layer 401. For example, after forming a resist pattern 403 on the neutral layer 401 in step S3 as shown in FIG. 4, the neutral layer 401 is removed by etching using the resist pattern 403 as a mask, and then the polystyrene film 404 is formed in step S4. You may make it apply | coat. In this case, by removing the resist pattern 403 in step S5, a polystyrene film 404 can be formed directly on the antireflection film 400, for example, as shown in FIG. Also in this case, since the polystyrene film 404 and the neutral layer 401 are directly exposed on the upper surface of the wafer W, the first hydrophilic polymer 411a is arranged at a desired position using the polystyrene film 404 as a guide. Can do.

  In the above embodiment, since the case where the resist pattern 403 is transferred to the pattern E on the wafer W has been described as an example, the hard mask layer HM is formed on the wafer W in advance. The present invention can also be applied when forming a hole-shaped pattern. In such a case, the hard mask layer HM is not necessarily formed.

  In the above embodiment, the SOC film is used as the protective layer F and the metal hard mask is used as the hard mask layer HM. However, for example, SiARC is used as the protective layer F and the SOC film is used as the hard mask layer HM. It may be. For example, when the hole pattern 430 is transferred to the pattern E by etching in step S10 by using the protective layer F as the inorganic film SiARC and the hard mask layer HM as the organic film SOC film, the protective layer F and the hard layer are hardened. The etching selection ratio with respect to the mask layer HM can be increased. Further, since the protective layer F is made of SiARC, the protective layer F also functions as an antireflection film, and therefore, for example, the step S1 of forming the antireflection film on the upper surface of the hard mask layer HM can be omitted. As a result, the throughput of wafer processing can be improved.

  In the above embodiment, the removal of the resist pattern 403 in the step S5 and the removal of the hydrophilic polymer 411 in the step S9 are performed by so-called wet treatment. However, the technique for removing the resist pattern 403 and the hydrophilic polymer 411 is the present method. For example, the above-described dry etching or the like may be used. That is, instead of the resist removing device 36 and the organic solvent supply device 31 as the polymer removing device, a dry etching device may be used.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood. The present invention is not limited to this example and can take various forms. The present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than a wafer or a mask reticle for a photomask.

  The present invention is useful when a substrate is treated with a block copolymer including, for example, a hydrophilic polymer having hydrophilicity and a hydrophobic polymer having hydrophobicity.

DESCRIPTION OF SYMBOLS 1 Substrate processing system 30 Developing apparatus 31 Organic solvent supply apparatus 32 Antireflection film forming apparatus 33 Neutral layer forming apparatus 34 Resist coating apparatus 35 Coating film forming apparatus 36 Resist removing apparatus 37 Block copolymer coating apparatus 40 Heat treatment apparatus 41 Ultraviolet irradiation Device 42 Adhesion device 43 Peripheral exposure device 44 Polymer separation device 300 Control unit 400 Antireflection film 401 Neutral layer 402 Resist film 403 Resist pattern 404 Polystyrene film 410 Block copolymer 411 Hydrophilic polymer 412 Hydrophobic polymer E Pattern F Protective layer HM hard mask layer W wafer

Claims (8)

A method of treating a substrate using a block copolymer comprising a hydrophilic polymer and a hydrophobic polymer,
A neutral layer forming step of forming a neutral layer on the base film having a predetermined pattern formed on the substrate and partially removed;
In the substrate after the neutral layer forming step, a coating film pattern forming step of forming a circular, elliptical or rounded rectangular pattern with a hydrophobic coating film in the region where the base film is removed;
A block copolymer coating step of coating the block copolymer on the substrate on which the pattern of the coating film is formed;
A polymer separation step of phase-separating the block copolymer into the hydrophilic polymer and the hydrophobic polymer;
A polymer removal step of selectively removing the hydrophilic polymer from the phase-separated block copolymer;
The ratio of the molecular weight of the hydrophilic polymer in the block copolymer is such that, in the polymer separation step, the first hydrophilic polymer in a columnar shape on the pattern by the hydrophobic coating film is other than the hydrophobic coating film. And adjusted to 20% to 40% so that the cylindrical second hydrophilic polymer is arranged in the region of
The pattern by the hydrophobic coating film is
(1) In the case of a circle, the diameter of the pattern is 0.8 to 1.5 times the theoretical value of the pitch between the adjacent second hydrophilic polymers. (2) In the case of an ellipse or a rounded rectangle The length of the pattern in the longitudinal direction is (A + n) L ₀ , and the length of the widest portion in the lateral direction is (0.8 to 1.5) L _0.
A substrate processing method, wherein
A: Arbitrary constant L _{0 in} the range of 0.7 to 1.3: Theoretical value of the pitch between the adjacent second hydrophilic polymers determined by the ratio of the molecular weight of the hydrophilic polymer in the block copolymer n: natural number A method of treating a substrate using a block copolymer comprising a hydrophilic polymer and a hydrophobic polymer,
A neutral layer forming step of forming a neutral layer on the substrate;
A coating film pattern forming step of forming an elliptical or rounded rectangular pattern with a hydrophobic coating film at a predetermined position on the substrate after the neutral layer forming step;
A block copolymer coating step of coating the block copolymer on the substrate on which the pattern of the coating film is formed;
A polymer separation step of phase-separating the block copolymer into the hydrophilic polymer and the hydrophobic polymer;
A polymer removal step of selectively removing the hydrophilic polymer from the phase-separated block copolymer;
The ratio of the molecular weight of the hydrophilic polymer in the block copolymer is such that, in the polymer separation step, the first hydrophilic polymer in a columnar shape on the pattern by the hydrophobic coating film is other than the hydrophobic coating film. And adjusted to 20% to 40% so that the cylindrical second hydrophilic polymer is arranged in the region of
The length in the longitudinal direction of the oval or rounded rectangle by the hydrophobic coating film is (A + n) L ₀ , and the length of the widest portion in the short direction is (0.8 to 1.5). characterized in that it is set to L _0, the substrate processing method.
A: Arbitrary constant L _{0 in} the range of 0.7 to 1.3: Theoretical value n of the pitch between the second hydrophilic polymers determined by the ratio of the molecular weight of the hydrophilic polymer in the block copolymer: Natural number Prior to the coating film pattern forming step, a neutral layer removing step of removing a portion of the neutral layer formed on the substrate corresponding to the region from which the base film has been removed is further provided. The substrate processing method according to claim 1. The substrate processing method according to claim 1, wherein a ratio of the molecular weight of the hydrophilic polymer in the block copolymer is 32% to 34%. The hydrophilic polymer is polymethyl methacrylate;
The substrate processing method according to claim 1, wherein the hydrophobic polymer is polystyrene. The substrate processing method according to claim 1, wherein the hydrophobic coating film is a polystyrene film. A program that operates on a computer of a control unit that controls the substrate processing system so that the substrate processing method according to any one of claims 1 to 6 is executed by the substrate processing system. A readable computer storage medium storing the program according to claim 7.

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