JP5837525B2 - Substrate processing method, program, and computer storage medium - Google Patents

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 the manufacturing process of a semiconductor device, for example, a resist coating process for coating a resist solution on a semiconductor wafer (hereinafter referred to as “wafer”) to form a resist film, an exposure process for exposing a predetermined pattern on the resist film, A photolithography process for sequentially performing a development process for developing the exposed resist film is performed to form a predetermined resist pattern 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.

  Incidentally, in recent years, in order to further increase the integration of semiconductor devices, it is required to make the pattern of the film to be processed finer. 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.

  Therefore, a wafer processing method using a block copolymer composed of two types of block chains (polymers), hydrophilic and hydrophobic, has been proposed (Patent Document 1). In such a method, first, a neutral layer having an intermediate affinity for two types of polymers is formed on a wafer. Then, a so-called line-and-space guide pattern is formed on the neutral layer by using, for example, a resist. Thereafter, a block copolymer is applied onto the neutral layer, and the block copolymer is phase-separated into two types of polymers, hydrophilic and hydrophobic, to form a lamella structure. Thereafter, by selectively removing one of the polymers by, for example, etching or the like, a fine pattern is formed on the wafer by the other polymer. Then, the processing target film is etched using the polymer pattern as a mask to form a predetermined pattern on the processing target film.

JP 2008-36491 A

  By the way, one of the wafer processes using the lamellar structure as described above is to narrow the width of a trench formed by, for example, a linear resist pattern. Specifically, as shown in FIG. 22, a resist pattern 601 is formed on a wafer W having a neutral layer 600 formed on the surface thereof, and a block polymer is applied to the space portion of the resist pattern 601. The hydrophilic polymer 602 and the hydrophobic polymer 603 are separated. Then, as shown in FIG. 23, for example, by selectively removing the hydrophilic polymer 602, a trench 610 having a width narrower than the space portion formed by the resist pattern 601 is formed.

  However, in order to properly form a lamella structure as shown in FIG. 22, the width of the space portion of the resist pattern 601 is formed such that an odd number of hydrophilic polymers 602 and hydrophobic polymers 603 are arranged alternately. There is a need to. If the width of the space portion of the resist pattern 601 is not such that the hydrophilic polymer 602 and the hydrophobic polymer 603 are arranged in an odd number for some reason, there is a problem that a lamellar structure cannot be formed properly. Therefore, it is desired to develop a technique capable of stably narrowing the trench width even when the width of the space portion varies.

  The present invention has been made in view of the above points, and is stable even if the width of the space portion of the guide pattern fluctuates in substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer. The purpose is to narrow the trench width.

  To achieve the above object, the present invention provides a method for treating a substrate using a block copolymer comprising a first polymer having polarity and a second polymer having no polarity, Forming a coating film on the substrate, and forming a guide pattern having a linear line portion and a linear space portion in plan view by the coating film; and for the substrate after the guide pattern is formed A block copolymer coating step for coating the block copolymer, a polymer separation step for phase-separating the block copolymer into the first polymer and the second polymer, and the phase-separated block copolymer It has a polymer removal step of selectively removing the first polymer from the coalescence, and the film thickness of the block copolymer applied in the block copolymer application step is (1) When the exposed surface exposed from the space portion of the guide pattern has polarity, the pattern pitch by the first polymer and the second polymer after phase separation is 1 to 1.5 times (2) When the exposed surface exposed from the space portion of the guide pattern has no polarity, it is 0.5 to 1 times the pattern pitch of the first polymer and the second polymer after phase separation, The molecular weight ratio of the first polymer in the coalescence is 20% to 40%.

  According to the present invention, the film thickness of the block copolymer applied to the substrate is changed depending on whether or not the exposed surface has polarity. The ratio of the molecular weight of the first polymer in the block copolymer is 20% to 40%. Thereby, after the phase separation, the semi-cylindrical first polymer is arranged on the upper surface of the second polymer and parallel to the substrate, or the cylindrical first polymer is arranged in the second polymer parallel to the substrate. Can be arranged. At this time, the first polymer is automatically arranged at the center of the space portion even if the width of the space portion of the guide pattern due to, for example, a resist pattern fluctuates. Then, by selectively removing the first polymer, for example, the upper surface of the second polymer can be depressed downward. As a result, the recessed portion of the second polymer is first removed, for example, by etching the second polymer. Thereby, for example, a fine trench can be formed by the second polymer between the guide patterns such as a resist pattern without being affected by the variation in the width of the space portion.

  When the exposed surface exposed from the space portion of the guide pattern has no polarity and the film thickness of the block copolymer applied in the block copolymer coating step is 1 times the pattern pitch, or When the exposed surface exposed from the space portion of the guide pattern has polarity and the film thickness of the block copolymer applied in the block copolymer application step is 1.5 times the pattern pitch, In the polymer removal step, the first polymer and the second polymer are irradiated with energy rays after the phase separation of the first polymer and the second polymer, and then a predetermined treatment liquid is supplied to the substrate, thereby the first polymer. May be removed by dissolution.

  In the second polymer, the first polymer is arranged in a columnar shape or a semi-cylindrical shape in parallel with the upper surface of the substrate and in parallel with the line portion of the guide pattern, and the width of the space portion is It may be larger than the diameter of the first polymer in a columnar or semi-cylindrical shape.

  The exposed surface exposed from the space portion of the guide pattern has polarity, and the exposed surface may be either a silicon oxide film or an antireflection film formed on the lower surface of the coating film.

  The first polymer may be polymethyl methacrylate and the second polymer may be polystyrene.

  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 in order to cause the substrate processing system to execute the substrate processing method.

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

  According to the present invention, in substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer, the trench width can be stably reduced even if the width of the space portion of the guide pattern varies. .

It is a top view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a side view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a side view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer apply | coated on the wafer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer apply | coated on the wafer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer apply | coated on the wafer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the 1st polymer was selectively removed. It is explanatory drawing of the longitudinal cross-section which shows a mode that the 2nd polymer was etched by predetermined thickness. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer apply | coated on the wafer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer apply | coated on the wafer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer apply | coated on the wafer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the 2nd polymer was etched by predetermined thickness. 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 antireflection film was 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 antireflection film. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer was apply | coated to the space part of the resist pattern. It is explanatory drawing of the longitudinal cross-section which shows a mode that the block copolymer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the plane which shows a mode that the block copolymer was phase-separated into the 1st polymer and the 2nd polymer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the 1st polymer was selectively removed. It is explanatory drawing of the longitudinal cross-section which shows a mode that the 2nd polymer was etched by predetermined thickness. It is explanatory drawing of the longitudinal cross-section which shows the pattern formed with a 1st polymer and a 2nd polymer when the film thickness of a block copolymer is increased. 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 in the conventional wafer process. It is explanatory drawing of the longitudinal cross-section which shows a mode that the pattern of the hydrophobic polymer was formed on the wafer in the conventional wafer process.

  Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing an outline of a configuration of a substrate processing system 1 for performing substrate processing according to the present embodiment. 2 and 3 are side views showing an outline of the internal configuration of the substrate processing system 1.

  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, for example, four cassette mounting plates 21 on which the cassette C is mounted when the cassette C is carried in 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, and a cleaning apparatus 31 for cleaning the wafer W by applying an organic solvent onto the wafer W are provided. An anti-reflection film forming device 32 for forming an anti-reflection film on the wafer W, a resist coating device 34 for applying a resist solution on the wafer W to form a resist film, and a block copolymer for applying a block copolymer on the wafer W. Polymer coating devices 35 are stacked in order from the bottom.

  For example, the developing device 30, the cleaning device 31, the antireflection film forming device 32, the resist coating device 34, and the block copolymer coating device 35 are arranged side by side in the horizontal direction. The number and arrangement of the developing device 30, the cleaning device 31, the antireflection film forming device 32, the neutral layer forming device 33, the resist coating device 34, and the block copolymer coating device 35 can be arbitrarily selected.

  In the developing device 30, the cleaning device 31, the antireflection film forming device 32, the resist coating device 34, and the block copolymer coating device 35, for example, spin coating for applying a predetermined coating solution 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.

  The block copolymer applied on the wafer W by the block copolymer coating device 35 has a first polymer and a second polymer. A hydrophilic polymer that is a polar (hydrophilic) polymer is used as the first polymer, and a hydrophobic polymer that is a non-polar (hydrophobic) polymer is used as the second polymer. In the present embodiment, for example, polymethyl methacrylate (PMMA) is used as the hydrophilic (polar) polymer, and polystyrene (PS) is used as the hydrophobic (nonpolar) polymer. In addition, the ratio of the molecular weight of the hydrophilic polymer in the block copolymer is 20% to 40%, preferably 12 to 30%. The molecular weight ratio of the hydrophobic polymer in the block copolymer is 80% to 60%, more preferably 88% to 70%. The block copolymer is a polymer in which a hydrophilic polymer and a hydrophobic polymer are linearly combined.

  For example, in the second block G2, as shown in FIG. 3, the block copolymer coated on the wafer W by the heat treatment apparatus 40 and the block copolymer coating apparatus 35 for performing the heat treatment of the wafer W is converted into a hydrophilic polymer and a hydrophobic polymer. A polymer separation device 41 for phase-separating into a functional polymer, an adhesion device 42 for hydrophobizing the wafer W, a peripheral exposure device 43 for exposing the outer periphery of the wafer W, and an ultraviolet irradiation device 44 for irradiating the wafer W with ultraviolet rays They 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 41 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. Further, the number and arrangement of the heat treatment apparatus 40, the polymer separation apparatus 41, the adhesion apparatus 42, the peripheral exposure apparatus 43, and the ultraviolet irradiation 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 a peeling process described later in the substrate processing system 1. The program is recorded on a computer-readable storage medium such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnetic optical desk (MO), or memory card. Or installed in the control unit 300 from the storage medium.

  Next, in describing wafer processing performed using the substrate processing system 1 configured as described above, first, the principle of wafer processing according to the present embodiment will be described.

  In the block copolymer having the first polymer having polarity and the second polymer having no polarity, for example, the molecular weight ratio of the first polymer is 20% to 40%, and the molecular weight ratio of the second polymer is 80%. % To 60%, the pattern formed after the block copolymer is phase-separated into the first polymer and the second polymer is a pattern in which the first polymer is arranged in a cylindrical shape in the second polymer. It becomes. And the columnar pattern by the 1st polymer after this phase separation differs in the direction of arrangement by the state of the application surface on wafer W to which a block copolymer is applied.

  When the coating surface on which the block copolymer is applied has, for example, an equivalent energy difference with respect to both the first polymer and the second polymer, the cylindrical pattern by the first polymer after phase separation is: In the second polymer, they are arranged perpendicular to the application surface. When the first polymer is arranged perpendicularly to the coating surface in this way, it usually has an equivalent energy difference with respect to both the first polymer and the second polymer. A neutral layer having an intermediate affinity for the polymer is formed on the wafer. And the said neutral layer is used as an application surface which apply | coats a block copolymer.

On the other hand, when the block polymer is applied on an application surface having a small energy difference from the polymer of either the first polymer or the second polymer, the first polymer and the second polymer after phase separation are applied. These polymers are arranged in parallel to the application surface. Specifically, when the block copolymer is applied on a nonpolar surface, for example, as shown in FIG. 4, for example, the first polymer 400 (polymer having polarity) after phase separation is polar. Since the energy difference from the coated surface not having the thickness is larger than that of the second polymer 401 (polymer having no polarity), the wafer W is arranged so as not to contact the coated surface W ₀ . In other words, the second polymer 401 is arranged so as to be in contact with the application surface W _0, and the first polymer 400 is arranged in a cylindrical shape in the second polymer 401. At this time, the first polymer 400 is parallel to the coating surface W ₀ of the wafer W. Further, the interval between the columnar first polymers 400 is also equal. This is because the first polymer 400 and the second polymer 401 move autonomously so that the energy difference at the interface between the first polymer 400 and the second polymer 401 is equal throughout the pattern. As shown in FIG. 4, when the pitch of the pattern in which the first polymer 400 is arranged in a columnar shape parallel to the wafer W in the second polymer 401 is L ₀ , the first polymer 400 is applied to the application surface W _0. that the thickness of the block copolymer if it is L _0, to form such patterns.

Next, description will be made of a case where the thickness of the block copolymer to be applied to the wafer W, and the L _0/2 which is half of the pitch L ₀ of the pattern. The thickness of the block copolymer and L _0/2, when the then the block copolymer is phase separation, for example, as shown in FIG. 5, the second polymer 401 is layered on the coated surface W ₀ of the wafer W The first polymer 400 is arranged in layers on the second polymer 401. However, in general, the first polymer 400 has a smaller energy difference from the second polymer 401 than the energy difference from the atmosphere. Therefore, as shown in FIG. 6, the first polymer 400 has a semicircular shape in a cross-sectional view so that the contact area with the atmosphere is minimized.

When the first polymer 400 is selectively removed, as shown in FIG. 7, the upper surface of the second polymer 401 has a shape recessed in a semicircular shape downward. In the selective removal of the first polymer 400, for example, when the first polymer 400 is polymethyl methacrylate which is a hydrophilic polymer, when the wafer W is irradiated with, for example, ultraviolet rays as an energy ray, polymethacrylic acid is used. As the methyl bonding chain is cleaved, the second polymer 401, which is, for example, the hydrophobic polymer polystyrene, undergoes a crosslinking reaction. Thereafter, when, for example, isopropyl alcohol (IPA), which is a polar organic solvent, is supplied to the wafer W, the first polymer 400, which is a hydrophilic polymer whose bond chain is cut by ultraviolet irradiation, is dissolved and selectively removed. On the other hand, the second polymer 401 remains on the coating surface W ₀ of the wafer W with the upper surface thereof being recessed in a semicircular shape. In addition, the wavelength of the irradiated ultraviolet light is, for example, 172 nm or 222 nm. In addition to ultraviolet rays, for example, electron beams can be used as energy rays.

Next, when the remaining second polymer 401 is isotropically etched for a predetermined time by dry etching such as RIE (Reactive Ion Etching), for example, on the coating surface W ₀ , the film thickness of the second polymer 401 decreases. As shown in FIG. 8, the depressed portion of the second polymer 401 is first removed, and the portion that has not been depressed remains as it is. As a result, the trench 401a is formed by the second polymer 401 remaining by a predetermined thickness. At this time, the remaining thickness of the second polymer 401 is smaller than L _0/2 by etching.

  Here, the present inventors pay attention to the property that the distance between the semi-cylindrical first polymers 400 is also equal, and the space portion of a so-called line-and-space resist pattern having a line portion and a space portion. The inventors have conceived that the width is set to be larger than the diameter of the semi-cylindrical first polymer 400 so that one semi-cylindrical first polymer 400 is arranged. In this case, since the first polymer 400 is autonomously arranged in the center of the space portion, even if the width of the space portion of the resist pattern does not become a predetermined width due to some trouble, the first polymer 400 is still left in the space. It can be arranged in the center of the part. Then, as shown in FIG. 8, by removing the first polymer 400 and partially removing the second polymer, the width of the trench due to the resist pattern can be narrowed. This is an overview of the principles of the present invention.

Note in the above example has been described in the case of applying the block copolymer on the coated surface W ₀ having no polarity, when applying the block copolymer on the coated surface W ₀ having polarity is applied Even if the film thickness of the block copolymer is the same, the patterns of the first polymer 400 and the second polymer 401 are different. Specifically, when the coating surface W ₀ is polar and the block copolymer is applied at a thickness that is half the pattern pitch L ₀ , the first polymer 400 after phase separation is as shown in FIG. And arranged in layers on the coating surface W ₀ where the energy difference is small. The second polymer 401 is arranged in layers on the upper surface of the first polymer 400. In such a case, the first polymer 400 is stable in contact with the coating surface W _0, and therefore, unlike the case shown in FIG. 6, it does not have a semi-cylindrical shape at this point. That is, if the coating surface W ₀ has a polarity, when the thickness of the block copolymer L _0/2, semicylindrical pattern of the first polymer 400 is not formed.

Therefore, if the film thickness of the block copolymer to be applied is the same as the pattern pitch L ₀ , as shown in FIG. 10, the first polymer 400 is divided into two layers on the application surface W ₀ side and the atmosphere side. The second polymer 401 is sandwiched between the two layers of the first polymer 400. Then, as described above, the first polymer 400 arranged on the upper surface of the second polymer 401 has the upper surface of the second polymer 401 as shown in FIG. 11 in order to minimize the contact area with the atmosphere. Arrange in a semi-cylindrical shape. Therefore, if the coating surface W ₀ is a surface having a polarity, the thickness of the block copolymer to be applied to the application surface W ₀ is the same city as the pattern pitch L _0, is applied surface W ₀ is the surface having the polarity In this case, if the film thickness of the block copolymer is half of the pattern pitch L _0, a semicylindrical pattern of the first polymer 400 can be arranged on the surface of the second polymer 401.

Further, in the above, as shown in FIG. 6, if the first polymer 400 is semi-cylindrical shape, i.e., thickness of the block copolymer to be applied to the application surface W ₀ is, the coating surface W ₀ The case where the surface has polarity is described as L ₀ , and the case where the coating surface W ₀ is a surface having no polarity is described as being 1 / 2L _{0. As} shown in FIG. Even when the polymer 400 is cylindrical, it is possible to reduce the width of the trench by the resist pattern as described above. When the first polymer 400 has a cylindrical shape, when the coating surface W ₀ is a surface having polarity, the thickness of the block copolymer is 3 / 2L ₀ and the coating surface W ₀ is a surface having no polarity. In some cases it is L ₀ .

In such a case, for example, as shown in FIG. 12, the second polymer 401 is first etched by dry etching until the first polymer 400 is exposed. Thereafter, the exposed first polymer 400 is irradiated with ultraviolet light, and then isopropyl alcohol is supplied, so that the top surface of the second polymer 401 is recessed downward as shown in FIG. Can be left in. In FIG. 12, an example is shown where a surface coating surface W ₀ of the wafer W has no polarity, the case applied surface W ₀ is a surface having a polarity, the block copolymer except for the point thickness is 3 / 2L _0, the same as in the case of FIG. 12.

  The substrate processing method according to the present embodiment is based on the above knowledge. Next, wafer processing performed using the substrate processing system 1 will be described. FIG. 13 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. .

  Next, the wafer W is transferred to the heat treatment apparatus 40 by the wafer transfer apparatus 70, and the temperature is adjusted. Thereafter, the wafer W is transferred to the antireflection film forming apparatus 32 by the wafer transfer apparatus 70, and an antireflection film 410 is formed on the wafer W as shown in FIG. 14 (step S1 in FIG. 13). 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 delivery device 54 by the wafer transfer device 100. Thereafter, the wafer W is transferred to the adhesion device 42 by the wafer transfer device 70 and subjected to an adhesion process. Thereafter, the wafer W is transferred to the resist coating device 34 by the wafer transfer device 70, and a resist solution is applied onto the antireflection film 410 of the wafer W to form a resist film. Thereafter, the wafer W is transferred to the heat treatment apparatus 40 by the wafer transfer apparatus 70 and pre-baked. Thereafter, the wafer W is transferred to the delivery device 55 by the wafer transfer device 70.

  Next, the wafer W is transferred to the peripheral exposure device 43 by the wafer transfer device 70 and subjected to peripheral exposure processing. Thereafter, the wafer W is transferred to the delivery device 56 by the wafer transfer device 70. Next, the wafer W is transferred to the transfer device 52 by the wafer transfer device 100 and transferred to the transfer device 62 by the shuttle transfer device 80.

  Thereafter, 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.

Next, the wafer W is transferred from the exposure apparatus 12 to the delivery apparatus 60 by the wafer transfer apparatus 110. Thereafter, the wafer W is transferred to the heat treatment apparatus 40 by the wafer transfer apparatus 70 and subjected to post-exposure baking. Thereafter, the wafer W is transferred to the developing device 30 by the wafer transfer device 70 and developed. After the development is completed, the wafer W is transferred to the heat treatment apparatus 40 by the wafer transfer apparatus 70 and subjected to a post-bake process. Thus, a predetermined resist pattern 411 is formed as a guide pattern on the antireflection film 410 of the wafer W as shown in FIG. 15 (step S2 in FIG. 13). In the present embodiment, the resist pattern 411 is a so-called line-and-space pattern having a line portion 411a and a space portion 411b. The width of the space portion 411b is set so that one columnar or semi-columnar first polymer 400 is disposed in the space portion 411b. Further, the height of the resist pattern 411 is the same as the pattern pitch L ₀ of the block copolymer 412 as will be described later.

Next, the wafer W is transferred to the block copolymer coating device 35 by the wafer transfer device 70. In the block copolymer coating device 35, the block copolymer is supplied to the wafer W, and as shown in FIG. 16, the block copolymer 412 is coated in the space portion 411b of the resist pattern 411 (step S3 in FIG. 13). ). In this case, the thickness of the line portion 411a of the resist pattern 411 is because it is _{L 0,} also becomes _{L 0} coated thickness of the block copolymer 412 in the space portion 411b.

  Next, the wafer W is transferred to the polymer separation device 41 by the wafer transfer device 70. In the polymer separator 41, the wafer W is heat-treated at a predetermined temperature. Then, as shown in FIGS. 17 and 18, the block copolymer 412 on the wafer W is phase-separated into a first polymer 400 which is a hydrophilic polymer and a second polymer 401 which is a hydrophobic polymer (FIG. 13 steps S4).

Here, as described above, in the block copolymer 412, the molecular weight ratio of the first polymer 400 is 20% to 40%, and the molecular weight ratio of the second polymer 401 is 80% to 60%. In this embodiment, the coating surface W ₀ coated with the block copolymer 412, in other words, the exposed surface exposed from the space portion 411 b of the resist pattern 411 is the antireflection film 410, and this antireflection The membrane 410 is a hydrophilic (polar) membrane. Then, in step S4, as shown in FIGS. 17 and 18, the first polymer 400 is arranged in layers on the antireflection film 410 side, and is arranged in a semi-cylindrical shape on the upper surface of the second polymer 401.

  Thereafter, the wafer W is transferred to the ultraviolet irradiation device 44 by the wafer transfer device 70 and irradiated with ultraviolet rays (step S5 in FIG. 13). As a result, the first polymer 400 is cleaved at the bond chain and becomes soluble in, for example, an organic solvent.

Then, the wafer W is transferred to the cleaning apparatus 31 by the wafer transfer apparatus 70, the first polymer 400 is soluble in an organic solvent by being washed with an organic solvent, as shown in FIG. 19, the second polymer 401 Is selectively removed from the upper surface (step S6 in FIG. 13). At this time, the first polymer 400 arranged on the upper surface of the antireflection film 410 remains as it is.

  Thereafter, the wafer W is transferred to the delivery device 50 by the wafer transfer device 70 and then 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 transferred to an etching processing apparatus provided outside the substrate processing system 1, and the second polymer 402 is dry-etched (step S7 in FIG. 13). At this time, the first polymer 400 arranged between the second polymer 401 and the antireflection film 410 is also etched in the same manner. As a result, as shown in FIG. 20, a trench 401a is formed by the second polymer 401 between the line portions 411a of the resist pattern 411. Then, the antireflection film 410 and the wafer W are etched using the second polymer 401 as a mask, and a predetermined pattern is formed on the wafer W.

According to the above embodiment, the film thickness of the block copolymer 412 applied to the wafer W is changed according to whether or not the coating surface W ₀ to which the block copolymer 412 is applied has polarity. Further, the ratio of the molecular weight of the first polymer 400 in the block copolymer 412 is set to 20% to 40%. Therefore, by separating the block copolymer 412, the semi-cylindrical first polymer 400 can be arranged in parallel with the upper surface of the second polymer and the upper surface of the wafer W. At this time, even if the width of the space portion 411b of the guide pattern formed by the resist pattern 411 or the like fluctuates to such a degree that a predetermined arrangement cannot be achieved, for example, by the lamellar structure, the first polymer 400 It arranges autonomously in the center of the part 411b. Then, by selectively removing the semi-cylindrical first polymer 400, for example, the upper surface of the second polymer 401 can be depressed downward. As a result, for example, by etching the second polymer 401, the recessed portion of the second polymer 401 is first removed. Thereby, for example, a fine trench can be formed by the second polymer 401 in the center portion of the resist pattern 411 without being affected by the variation in the width of the space portion 411b.

In the above embodiment, an example in which the first polymer 400 is arranged in a semi-cylindrical shape on the upper surface of the second polymer has been described. However, as described above, the first polymer 400 is replaced with the second polymer. It may be arranged in a columnar shape inside 401. However, when the first polymer 400 is formed in a semi-cylindrical shape on the upper surface of the second polymer 401, the first polymer 400 is selectively removed by dry etching the first polymer 400. Therefore, it is more preferable to form the first polymer 400 in a semi-cylindrical shape on the upper surface of the second polymer 401. In other words, when the coating surface W ₀ to which the block copolymer 412 is applied has polarity, the film thickness of the block copolymer 412 is L _0, and when the coating surface W ₀ has no polarity, the thickness of the copolymer 412 and more preferably to _L 0/2.

In addition, when the film thickness of the block copolymer 412 is further increased, as shown in FIG. 21, for example, the second polymer 401 is sandwiched between the first polymer 400 and the semicircular shape. Columnar first polymers 400 are arranged. Figure 21 is描図an example of a state on the coating surface W ₀ having no polar 3L _0/2 of the by coating the block copolymer 412 is phase-separated in thickness. At this time, the first polymers 400 are arranged in an equilateral triangle shape in cross-sectional view so that the distances between the first polymers 400 are equal. Therefore, when viewed in a plan view, the first polymer 400 having a columnar shape and the first polymer 400 having a semi-columnar shape are alternately arranged, so that a trench formed by the second polymer 401 cannot be formed properly. Therefore, the film thickness of the block copolymer 412 needs to be a film thickness that prevents the semi-columnar first polymer 400 from being arranged above the columnar first polymer 400. Specifically, if the coating surface W ₀ of block copolymer 412 is applied has a polarity, the thickness of the block copolymer 412 1 to 1.5 times the pitch L ₀ of the pattern, the coated surface When W ₀ has no polarity, the thickness of the block copolymer 412 needs to be 0.5 to 1 times the pitch L ₀ .

  In the above embodiment, the width of the space portion 411b of the resist pattern 411 is set so that one semi-columnar or columnar first polymer 400 is arranged, but the width of the space portion 411b is set. Is not limited to the contents of the present embodiment. For example, the width of the space portion 411b may be set so that two or more first polymers 400 are arranged, and how the space portion 411b width is set can be arbitrarily set. In any case, if the width of the space portion 411b is larger than the diameter of the semi-cylindrical or cylindrical first polymer 400 so that one first polymer 400 is arranged in the space portion 411b, The polymers 400 are arranged in the space portion 411b at regular intervals in a plan view.

In the above embodiment, the coating surface W ₀ having a polarity is the antireflection film 410 formed on the wafer W. However, as the coating surface W ₀ having a polarity, for example, a silicon oxide film or the like may be formed on the wafer W. It may be another hydrophilic film formed. Further, the coating surface W ₀ having no polarity may be a hydrophobic film such as a polystyrene film formed on the wafer W, for example. However, when the coated surface W ₀ has the same energy difference with respect to both the first polymer 400 and the second polymer 401, that is, the coated surface W ₀ has the first polymer 400 and the second polymer 401. As described above, since the first polymer 400 is arranged perpendicular to the coating surface W ₀ , the neutral layer is made of the block copolymer. can not be used as a coating surface W _0.

  In the above embodiment, the first polymer 400 is selectively removed by, for example, wet etching using an organic solvent. However, the first polymer 400 may be selectively removed by dry etching. .

  In the above embodiment, as shown in FIGS. 4 and 12, when the first polymer 400 is arranged in a columnar shape parallel to the wafer W in the second polymer 401, Although an example in which the first polymer is irradiated with ultraviolet rays after the polymer 401 has been dry-etched has been described, the ultraviolet rays may be irradiated before the second polymer 401 is dry-etched. In such a case, the second polymer 401 may be dry-etched after the ultraviolet irradiation, or isopropyl alcohol may be supplied after the ultraviolet irradiation and then the dry etching may be performed. According to the present inventors, even when isopropyl alcohol is supplied after ultraviolet irradiation and before dry etching, isopropyl alcohol penetrates into the second polymer, and the first polymer 400 can be dissolved.

By supplying isopropyl alcohol after ultraviolet irradiation and before dry etching, the throughput of wafer processing can be improved. That is, when isopropyl alcohol is supplied after dry etching, the first polymer 400 is removed by isopropyl alcohol, and then dry etching is performed again in step S7. Therefore, the wafer is interposed between the substrate processing system 1 and an external etching processing apparatus. W exchanges will occur twice. In this regard, if the first polymer 400 is dissolved in advance by supplying isopropyl alcohol before dry etching,
After the second polymer is removed by dry etching in the etching processing apparatus, it is not necessary to transfer the wafer W from the etching processing apparatus to the substrate processing system 1 for removing the first polymer 400 again.

  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 device 31 Cleaning device 32 Antireflection film forming device 33 Neutral layer forming device 34 Resist coating device 35 Block copolymer coating device 40 Heat treatment device 156 Block copolymer supply unit 190 Mixer 300 Control unit 400 1 polymer 401 second polymer 410 antireflection film 411 resist pattern 412 block copolymer W wafer W ₀ coated surface

Claims (7)

A method of treating a substrate using a block copolymer comprising a first polymer having polarity and a second polymer having no polarity, comprising:
Forming a coating film on the substrate, and forming a guide pattern having a linear line portion and a linear space portion in plan view by the coating film; and
A block copolymer application step of applying the block copolymer to the substrate after the guide pattern is formed;
A polymer separation step of phase-separating the block copolymer into the first polymer and the second polymer;
A polymer removal step of selectively removing the first polymer from the phase-separated block copolymer;
The film thickness of the block copolymer applied in the block copolymer application step is:
(1) When the exposed surface exposed from the space portion of the guide pattern has polarity, the pattern pitch by the first polymer and the second polymer after phase separation is 1 to 1.5 times (2) When the exposed surface exposed from the space portion of the guide pattern does not have polarity, it is 0.5 to 1 times the pattern pitch of the first polymer and the second polymer after phase separation,
The substrate processing method according to claim 1, wherein a ratio of the molecular weight of the first polymer in the block copolymer is 20% to 40%. The first polymer is arranged in a columnar shape or a semicylindrical shape in the second polymer, parallel to the upper surface of the substrate and parallel to the line portion of the guide pattern,
The substrate processing method according to claim 1, wherein a width of the space portion is larger than a diameter of the first polymer having the columnar shape or the semi-columnar shape. When the exposed surface exposed from the space portion of the guide pattern has no polarity and the film thickness of the block copolymer applied in the block copolymer coating step is 1 times the pattern pitch, or When the exposed surface exposed from the space portion of the guide pattern has polarity and the film thickness of the block copolymer applied in the block copolymer application step is 1.5 times the pattern pitch,
In the polymer removal step, the first polymer and the second polymer are irradiated with energy rays after the phase separation of the first polymer and the second polymer, and then a predetermined treatment liquid is supplied to the substrate, thereby the first polymer. The substrate processing method according to claim 1, wherein the substrate is dissolved and removed. The exposed surface exposed from the space portion of the guide pattern has polarity,
The substrate processing method according to claim 1, wherein the exposed surface is one of a silicon oxide film and an antireflection film formed on a lower surface of the coating film. The first polymer is polymethyl methacrylate;
The substrate processing method according to claim 1, wherein the second polymer is polystyrene. A program that operates on a computer of a control unit that controls the substrate processing system to cause the substrate processing system to execute the substrate processing method according to claim 1. A readable computer storage medium storing the program according to claim 6.

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