JP2014187103A - Substrate processing apparatus, substrate processing method, program and computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately form a predetermined pattern on a substrate in a substrate processing using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer.SOLUTION: A block copolymer 404 is applied over the upper surface of a first neutral layer 400 on a wafer W, and a neutral agent is applied over the upper surface of the block copolymer 404, thereby forming a second neutral layer 405. By subjecting the wafer W, which has been provided with the second neutral layer 405 on the block copolymer 404, to a heat treatment, the block copolymer 404 is phase separated into a hydrophilic polymer 406 and a hydrophobic polymer 407. The neutral agent does not dissolve the block copolymer 404, and prevents oxygen from reaching the block copolymer 404 during the heat treatment.

Description

  The present invention relates to a substrate processing apparatus using a block copolymer including a hydrophilic (polar) polymer having hydrophilicity (polarity) and a hydrophobic (nonpolar) polymer having hydrophobicity (no polarity). The present invention relates to a substrate processing method, 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.

  Thus, a wafer processing method using a block copolymer composed of two types of block chains (polymers) has been proposed (Patent Document 1). In this method, first, a neutral layer having an intermediate affinity for two types of polymers is formed on a wafer, and a guide pattern is formed on the neutral layer by using, for example, a resist. Then, a block copolymer is apply | coated on a neutral layer and a block copolymer is phase-separated. 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, the block copolymer described above is gradually phase-separated by heat treatment at a predetermined temperature or more, and the polymer after phase separation is arranged in a predetermined shape. Further, in order to promote the bonding of the polymer and increase the length of the pattern by the polymer, it is necessary to diffuse the polymer. For this purpose, it is necessary to perform heat treatment at a higher temperature.

  However, when the heat treatment temperature is increased in order to lengthen the pattern by the polymer, it has been confirmed that the higher the temperature and the longer the heat treatment time, the more the variation in the pattern by the polymer after phase separation occurs.

  As a result of intensive investigations by the present inventors, it was confirmed that the variation in the pattern is caused by the oxidation of the polymer of the block copolymer by heat treatment, and if this oxidation can be prevented, a uniform pattern can be formed. It was.

  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. And

  To achieve the above object, the present invention provides a method for treating a substrate using a block copolymer comprising a first polymer and a second polymer, wherein the first polymer and the second polymer are processed. A neutral layer forming step for forming on the substrate a neutral layer having an intermediate affinity for the polymer, and a block copolymer for applying the block copolymer to the substrate on which the neutral layer is formed. A polymer coating step, and a polymer separation step of heat-treating a substrate having a coating film formed on the block copolymer to phase-separate the block copolymer into the first polymer and the second polymer; And supplying a coating solution that does not dissolve the block copolymer on the block copolymer before the polymer separation step and prevents oxygen from reaching the block copolymer during the heat treatment in the polymer separation step. Coating film It is characterized by having a coating film forming step of forming.

  According to the present invention, before the polymer is separated, the block copolymer is not dissolved on the block copolymer, and the coating prevents oxygen from reaching the block copolymer during the heat treatment during polymer separation. Since the film is formed, oxidation of the block copolymer can be prevented. Moreover, since the coating solution does not dissolve the block copolymer, the block copolymer and the coating solution are not mixed at the interface between the coating film and the block copolymer. As a result, variation in the pattern due to the polymer due to oxidation can be suppressed, and a predetermined pattern can be appropriately formed on the substrate.

  The coating film formed in the coating film forming step may have an intermediate affinity for the first polymer and the second polymer.

  The coating film formed by the coating film forming apparatus may be soluble in an organic solvent.

  The coating film may be an acrylic film containing fluorine.

  The coating film may be formed by moving a coating liquid supply nozzle having a coating liquid discharge port larger than the diameter of the substrate relative to the substrate.

  The molecular weight ratio of the first polymer in the block copolymer may be 40% to 60%.

  The first polymer may be a hydrophilic polymer having hydrophilicity, and the second polymer may be a hydrophobic polymer having hydrophobicity.

  The hydrophilic polymer may be polymethyl methacrylate, and the hydrophobic 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 yet another aspect, the present invention provides a system for processing a substrate using a block copolymer including a first polymer and a second polymer, wherein the first polymer and the second polymer are combined with each other. A neutral layer forming apparatus for forming a neutral layer having an intermediate affinity on a substrate, and a block copolymer for applying the block copolymer to the substrate on which the neutral layer is formed A coating apparatus, a coating film forming apparatus for further applying a coating liquid on the block copolymer to form a coating film, and heat-treating the substrate on which the coating film is formed on the block copolymer, to thereby form the block A polymer separation device for phase-separating the copolymer into the first polymer and the second polymer, and the coating film formed by the coating film forming device does not dissolve the block copolymer And the polymer separator It is characterized in that oxygen in the heat treatment at is what prevents reaching the block copolymer.

  The coating film formed by the coating film forming apparatus may have an intermediate affinity for the first polymer and the second polymer.

  The coating film formed by the coating film forming apparatus may be soluble in an organic solvent.

  The coating film may be an acrylic film containing fluorine.

  The coating film forming apparatus may be a coating liquid supply nozzle provided in the block copolymer coating apparatus.

  A coating liquid nozzle moving mechanism that moves the coating liquid supply nozzle relative to the substrate may be provided, and the coating liquid supply nozzle may have a discharge port that is larger than the diameter of the substrate.

  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 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 a longitudinal cross-sectional view which shows the outline of a structure of a block copolymer coating apparatus. It is a cross-sectional view which shows the outline of a structure of a block copolymer coating apparatus. It is a perspective view which shows the outline of a structure of a coating nozzle. 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 and the 1st neutral layer 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 wafer. It is explanatory drawing of the longitudinal cross-section which shows a mode that the exposed surface of the 1st neutral layer on a wafer was hydrophilized. It is explanatory drawing of the longitudinal cross-section which shows a mode that the resist pattern was removed. 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 longitudinal cross-section which shows a mode that the 2nd neutral layer was apply | coated on the block copolymer. 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 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 longitudinal cross-section which shows a mode that the hydrophilic polymer and the 2nd neutral layer were selectively removed.

  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. A film to be processed (not shown) is formed in advance on the wafer processed by the substrate processing system 1.

  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 antireflection film forming device 32 for forming an antireflection film on the wafer W, a neutral layer forming device 33 for applying a neutral agent on the wafer W to form a neutral layer, and a resist solution on the wafer W Then, a resist coating device 34 for forming a resist film and a block copolymer coating device 35 for coating a block copolymer on the wafer W are stacked in order from the bottom.

  For example, 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 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 neutral layer forming device 33, the resist coating device 34, and the block copolymer coating device 35, for example, a spin for applying a predetermined coating solution onto the wafer W. Coating 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 configuration of these liquid processing apparatuses will be described later.

  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. The ratio of the molecular weight of the hydrophilic polymer in the block copolymer is 40% to 60%, and the ratio of the molecular weight of the hydrophobic polymer in the block copolymer is 60% to 40%. The block copolymer is a polymer in which a hydrophilic polymer and a hydrophobic polymer are linearly combined.

  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 neutral layer. 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, 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.

  Next, the configuration of the above-described block copolymer coating device 35 will be described. As shown in FIG. 4, the block copolymer coating device 35 includes a processing container 120 in which a loading / unloading port (not shown) for the wafer W is formed on the side surface.

  A spin chuck 130 that holds and rotates the wafer W is provided in the processing container 120. The spin chuck 130 has a horizontal upper surface, and a suction port (not shown) for sucking the wafer W, for example, is provided on the upper surface. By suction from the suction port, the wafer W can be sucked and held on the spin chuck 130.

  The spin chuck 130 has a chuck drive mechanism 131 including a motor, for example, and can be rotated at a predetermined speed by the chuck drive mechanism 131. Further, the chuck drive mechanism 131 is provided with a lift drive source such as a cylinder, and the spin chuck 130 can move up and down.

  Around the spin chuck 130, a cup 132 that receives and collects the liquid scattered or dropped from the wafer W is provided. A discharge pipe 133 that discharges the collected liquid and an exhaust pipe 134 that exhausts the atmosphere in the cup 22 are connected to the lower surface of the cup 132.

  As shown in FIG. 5, a rail 140 extending along the Y direction (left and right direction in FIG. 5) is formed on the X direction negative direction (downward direction in FIG. 5) side of the cup 132. The rail 140 is formed, for example, from the outside of the cup 132 in the Y direction negative direction (left direction in FIG. 5) to the outside in the Y direction positive direction (right direction in FIG. 5). An arm 141 is attached to the rail 140.

  A block copolymer supply nozzle 142 that discharges the block copolymer to the wafer W as shown in FIGS. 4 and 5 is supported on the arm 141. The arm 141 is movable on the rail 140 by a nozzle driving unit 143 shown in FIG. Thereby, the block copolymer supply nozzle 142 can move from the standby part 144 installed outside the Y direction positive direction side of the cup 132 to above the center part of the wafer W in the cup 132, and further, The wafer can be moved in the radial direction on the surface. The arm 141 can be moved up and down by a nozzle driving unit 143, and the height of the block copolymer supply nozzle 142 can be adjusted. As shown in FIG. 4, the block copolymer supply nozzle 142 is connected to a block copolymer supply device 145 that supplies a block copolymer to the block copolymer supply nozzle 142.

  As shown in FIGS. 5 and 6, for example, the block copolymer supply nozzle 142 has an elongated shape as a whole, and has a main body portion 142a whose length J is larger than at least the diameter of the wafer W, for example. doing. A slit-like discharge port 142b having a predetermined length D and a predetermined width G larger than the diameter of the wafer W is formed along the longitudinal direction of the main body 142a on the lower end surface of the main body 142a. Therefore, the block copolymer can be applied to the entire surface of the wafer W by moving the block copolymer supply nozzle 142 relative to the wafer W.

  Further, another arm 150 is attached to the rail 140. A neutral agent nozzle 151 for supplying a neutral agent is supported on the other arm 150.

  The other arm 150 is movable on the rail 140 by the nozzle driving unit 152 shown in FIG. 5, and the neutral agent nozzle 151 is provided on the outer side of the cup 132 on the Y direction negative direction side. To the center of the wafer W in the cup 132. Further, the other arm 150 can be raised and lowered by the nozzle driving unit 152, and the height of the neutral agent nozzle 151 can be adjusted. As shown in FIG. 4, the neutral agent nozzle 151 is connected to the neutral agent supply device 160 to the neutral agent nozzle 151. The neutral agent nozzle 151 has the same configuration as the block copolymer supply nozzle 142. That is, the neutral agent nozzle 151 has an elongated shape as a whole, and its length is at least larger than the diameter of the wafer W.

  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, wafer processing performed using the substrate processing system 1 configured as described above will be described. FIG. 7 is a flowchart showing an example of main steps of such wafer processing.

  First, a cassette C containing a plurality of wafers W is carried into the cassette station 10 of the coating and developing treatment apparatus 2 and placed on a predetermined cassette placing plate 21. Thereafter, the wafers W in the cassette C are sequentially taken out by the wafer transfer device 23 and transferred to the transfer device 53 of the processing station 11.

  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 400 is formed on the wafer W as shown in FIG. 8 (step S1 in FIG. 7). 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 heat treatment apparatus 40 by the wafer transfer apparatus 70, and the temperature is adjusted. Thereafter, the wafer W is transferred to the neutral layer forming device 33 by the wafer transfer device 70, and a first neutral layer 401 is formed on the entire surface of the wafer W as shown in FIG. 8 (step S2 in FIG. 7). . Thereafter, the wafer W is transferred to the heat treatment apparatus 40, heated, temperature-controlled, and then returned to the delivery apparatus 53.

  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 first neutral layer 401 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 402 is formed on the neutral layer 401 of the wafer W as shown in FIG. 9 (step S3 in FIG. 7).

  In this embodiment, the resist pattern 402 is a so-called line-and-space resist pattern having a straight line portion 402a and a straight space portion 402b in plan view. Note that the width of the space portion 402b is set so that a hydrophilic polymer and a hydrophobic polymer are alternately arranged in odd-numbered layers in the space portion 402b as described later.

  The wafer W on which the resist pattern 402 is formed is transferred to the ultraviolet irradiation device 44 by the wafer transfer device 70. In the ultraviolet irradiating device 44, the exposed surface of the neutral layer 401 exposed from the space portion 402b of the resist pattern 402 is irradiated with ultraviolet rays as shown in FIG. At this time, ultraviolet rays having a wavelength of 172 nm are irradiated. Then, the exposed surface of the neutral layer 401 is oxidized and hydrophilized (step S4 in FIG. 7). Hereinafter, the region of the neutral layer 401 thus made hydrophilic may be referred to as a hydrophilic region 403.

  As a result of intensive studies by the inventors, it has been found that the wavelength of ultraviolet light for forming the hydrophilic region 403 in the neutral layer 401 may be 300 nm or less. Specifically, when an ultraviolet ray having a wavelength of 300 nm or less is irradiated, active oxygen can be generated from oxygen in the processing atmosphere, and the exposed surface of the neutral layer 401 is oxidized and hydrophilized by this active oxygen. In addition, in order to generate | occur | produce active oxygen more easily, it turns out that it is better to use ozone as a process atmosphere. In particular, when the wavelength of ultraviolet rays is 172 nm, not only when ozone is used as a processing atmosphere, but also when the processing atmosphere is an air atmosphere, active oxygen can be efficiently generated from oxygen in the air atmosphere. I know.

  Next, the wafer W is transferred to the cleaning device 31 by the wafer transfer device 70. In the cleaning device 31, an organic solvent is supplied onto the wafer W, and the resist pattern 402 on the wafer W is removed as shown in FIG. 11 (step S5 in FIG. 7). Then, in the neutral layer 401, the surface of the hydrophilic region 403 has hydrophilicity, and the surface of other regions has neutrality. And the surface of the neutral layer 401 is maintained flat. Thereafter, the wafer W is transferred to the delivery device 50 by the wafer transfer device 70.

  Next, the wafer W is transferred to the delivery device 55 by the wafer transfer device 100. Thereafter, 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 supply nozzle 142 is moved from one end of the wafer W to the other end by the nozzle driving unit 143, and the neutral layer 401 on the wafer W is moved as shown in FIG. A block copolymer 404 is applied to the entire surface (step S6 in FIG. 7).

  Next, in the block copolymer coating device 35, the neutral agent nozzle 151 moves from one end of the wafer W after coating the block copolymer 404 to the other end, and the neutral agent is placed on the block copolymer 404. Supplied. As a result, the second neutral layer 405 is formed on the entire surface of the block copolymer 404 of the wafer W without mixing the block copolymer 404 and the neutral agent (see FIG. 13). 7 step S7).

  The neutral agent supplied from the neutral agent nozzle 151 does not dissolve the block copolymer, and will be described later in the step of phase-separating the block copolymer 404 into a hydrophilic polymer and a hydrophobic polymer by heat treatment. It is required that oxygen present in the heat treatment atmosphere does not reach the interface between the second neutral layer 405 and the block copolymer 404. As long as these requirements are satisfied, the neutral agent used in the block copolymer coating device 35 and the neutral agent used in the neutral layer forming device 33 may be the same. Specific examples of the neutral agent that does not dissolve the block copolymer 404 include, for example, a solution in which a polymer such as Si (Me) -OH is dissolved in pure water as a solvent, for example, tetramethylammonium hydroxide (TMAH). There is a solution in which the solubility of a polymer in pure water is increased by adding a polar solvent such as isopropyl alcohol (IPA). And by adjusting the addition amount of the solvent which has polarity, it has the intermediate | middle affinity with respect to both the hydrophilic polymer and hydrophobic polymer of a block-shaped polymer. The ratio of pure water to the solvent added for imparting polarity is about 20: 1 to 2.5: 1 in volume ratio. Further, the ratio of the solvent, in this case, pure water or pure water to which the solvent is added, and the polymer is about 99: 1 to 33: 1 in weight ratio. The polymer used for the neutral agent is not limited to Si (Me) -OH, and may be arbitrarily selected as long as it can be dissolved in, for example, pure water as a solvent or a mixed solution of pure water and a polar solvent. Is possible.

  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. 14 and 15, the block copolymer 404 on the wafer W is phase-separated into a hydrophilic polymer 406 and a hydrophobic polymer 407 (step S8 in FIG. 6). At this time, since the upper surface of the block copolymer 404 is covered with the second neutral layer 405, the upper surface of the second neutral layer 405 is oxidized by oxygen present in the heat treatment atmosphere, but the second intermediate layer 405 is oxidized. Oxygen does not reach the interface between the conductive layer 405 and the block copolymer 404. In addition, since a neutral agent that does not dissolve the block copolymer is used, the block copolymer and the neutral agent are mixed at the interface between the second neutral layer 405 and the block copolymer. Nor. As a result, the block copolymer 404 can be appropriately phase-separated into the hydrophilic polymer 406 and the hydrophobic polymer 407 while suppressing variation in pattern due to the polymer due to oxidation.

  Here, as described above, in the block copolymer 404, the molecular weight ratio of the hydrophilic polymer 406 is 40% to 60%, and the molecular weight ratio of the hydrophobic polymer 407 is 60% to 40%. Then, in step S8, as shown in FIGS. 14 and 15, the hydrophilic polymer 406 and the hydrophobic polymer 407 are phase-separated into a lamellar structure. In FIG. 15, a cross section of the lower surface of the second neutral layer 405 is depicted in order to express the state of the hydrophilic polymer 406 and the hydrophobic polymer 407 after phase separation. In addition, since the width of the space portion 402b of the resist pattern 402 is formed to a predetermined width in the step S3 described above, the hydrophilic polymer 406 and the hydrophobic polymer 407 are formed on the hydrophilic region 403 of the neutral layer 401. Alternatingly arranged in odd layers, for example, three layers. Specifically, since the surface of the hydrophilic region 403 has hydrophilicity, the hydrophilic polymer 406 is disposed in the middle of the hydrophilic region 403, and the hydrophobic polymers 407 and 407 are disposed on both sides thereof. And the hydrophilic polymer 406 and the hydrophobic polymer 407 are alternately arrange | positioned also on the other area | region of the neutral layer 401. FIG.

  Thereafter, the wafer W is transferred again to the ultraviolet irradiation device 44. Then, the wafer W is irradiated with ultraviolet rays to cut the bond chain of polymethyl methacrylate, which is the hydrophilic polymer 406, and to crosslink the polystyrene, which is the hydrophobic polymer 407. At this time, the binding chain of the second neutral layer 405 is also broken. Thereafter, the wafer W is transferred again to the cleaning device 31, and the organic solvent supply device 31 supplies, for example, IPA, which is a polar organic solvent, to the wafer W. As a result, the hydrophilic polymer 406 and the second neutral layer 405 whose bond chains are cut by ultraviolet irradiation are dissolved, and the second neutral layer 405 and the hydrophilic polymer 405 are selectively selected as shown in FIG. (Step S9 in FIG. 7). Thereby, a predetermined pattern by the hydrophobic polymer 407 is formed.

  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 transported to an etching processing apparatus provided outside the substrate processing system 1, and the first neutral layer 401, the antireflection film 400, and the film to be processed on the wafer W using the hydrophobic polymer 407 as a mask. Is etched. Thereby, a predetermined pattern is formed on the film to be processed (step S10 in FIG. 6). 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 hydrophobic polymer 407 and the antireflection film 400 are removed, and a series of wafer processing ends.

  According to the above embodiment, in the step S7 before the phase separation of the polymer, the block copolymer 404 is not dissolved on the block copolymer 404, and oxygen is blocked during the heat treatment for polymer separation. Since the second neutral layer 405 is formed as a coating film that prevents reaching the copolymer, it is possible to prevent the block copolymer 404 from being oxidized by oxygen in the atmosphere during the heat treatment in step S8. In addition, the neutral agent that forms the second neutral layer 405 does not dissolve the block copolymer 404, so that the block copolymer 404 and the intermediate at the interface between the second neutral layer 405 and the block copolymer 404 are not included. It does not mix with sex agents. Therefore, variations in the pattern of the hydrophilic polymer 406 and the hydrophobic polymer 407 due to oxidation can be prevented, and a predetermined fine pattern can be appropriately formed on the wafer W. As a result, in the step S10, the processing target film can be appropriately etched using the pattern as a mask, and a predetermined pattern can be formed on the processing target film.

  Further, since the upper surface of the block copolymer 404 is covered with the second neutral layer 405, the block copolymer 404 is in a state where both the upper surface and the lower surface thereof are in contact with the neutral layer. As a result, it is possible to prevent an energy difference from occurring between the upper and lower interfaces of the block copolymer 404, so that the hydrophilic polymer 406 and the hydrophobic polymer 407 can be arranged uniformly in the thickness direction of the wafer W.

  In the above embodiment, in step S4, the exposed surface of the first neutral layer 401 is irradiated with ultraviolet rays to make the exposed surface hydrophilic, thereby forming the hydrophilic region 403. The hydrophilic region 403 is made hydrophilic. Although used as a guide after phase separation of the polymer 406 and the hydrophobic polymer 407, how to form a guide for phase separation of the hydrophilic polymer 406 and the hydrophobic polymer 407 is limited to this embodiment. It is not something. For example, a resist pattern may be used as a guide and can be arbitrarily selected.

  In the above embodiment, the neutral layer is used as the coating film covering the upper surface of the block copolymer 404. However, the neutral layer is not necessarily required. Any film can be used as long as it does not dissolve the block copolymer 404 and can prevent oxygen from reaching the block copolymer 404 during the heat treatment in step S8. Can be selected. For example, a so-called top coat agent, which is an acrylic film containing fluorine applied to the upper surface of a resist film in a photolithography process, may be used. Since the topcoat agent is soluble in TMAH, which is an organic solvent, the second neutral layer 405 can be easily removed. In addition, that oxygen can be prevented from reaching the block copolymer 404 does not mean that the coating film covering the upper surface of the block copolymer 404 is not oxidized, but the coating film itself is oxidized. Even in this case, it means that oxygen is not transmitted to the second neutral layer 405 which is the base.

  The coating film covering the upper surface of the block copolymer 404 is a film formed on the lower surface of the block copolymer 404 in order to prevent an energy difference between the upper and lower interfaces of the block copolymer 404. It is desirable to use a film having a small energy difference from the above. That is, when the underlying film on the lower surface of the block copolymer 404 is the first neutral layer 401 as in this embodiment, the film formed on the upper surface of the block copolymer 404 is also a neutral layer. For example, when the underlying film on the lower surface of the block copolymer 404 is a film having polarity, it is desirable that the film formed on the upper surface of the block copolymer 404 is also a film having the same polarity. By doing so, the energy difference in the upper and lower interfaces of the block copolymer 404 can be eliminated, and the influence on the phase separation between the hydrophilic polymer 406 and the hydrophobic polymer 407 can be minimized. As a result, the hydrophilic polymer 406 and the hydrophobic polymer 407 can be arranged uniformly over the thickness direction of the wafer W.

  In the above embodiment, the block copolymer 404 and the neutral agent are applied to the wafer W using the block copolymer supply nozzle 142 and the neutral agent nozzle 151 in which the discharge ports 142b larger than the diameter of the wafer W are formed. Although applied, the method of applying the block copolymer 404 and the neutralizer is not limited to the contents of the present embodiment. For example, when a so-called spin coat is used for application of the block copolymer 404 and the neutral agent, the block copolymer 404 and the neutral agent are temporarily mixed, but the second neutral layer 405 is formed. If a material that does not dissolve the block copolymer 404 is used as the property agent, the second neutral layer 405 and the block copolymer 404 are separated due to the difference in specific gravity with time, so that they do not mix. . When spin coating is used, for example, the block copolymer 404 is formed by the block copolymer coating device 35, and then the solvent is evaporated by heat treatment with the heat treatment device 40, and then the second neutral layer 405 is formed. You may make it form. In such a case, the temperature of the heat treatment is not higher than the temperature at which the solvent is evaporated but the block copolymer 404 is not phase-separated and oxidized. By doing so, it is possible to more reliably prevent the second neutral layer 405 and the block copolymer 404 from being temporarily mixed.

  In the above embodiment, the second neutral layer 405 and the hydrophilic polymer 406 are removed by the organic solvent, but may be dry etching.

  In the above embodiment, the block copolymer 404 and the second neutral layer 405 are formed in the block copolymer coating device 35. For example, the block copolymer coating device 35 is Separately, a neutral agent coating device as a coating film forming device for forming the second neutral layer 405 may be provided.

  In the above embodiment, the block copolymer 404 on the wafer W is phase-separated into a hydrophilic polymer 406 and a hydrophobic polymer 407 having a lamellar structure. However, in the wafer processing method of the present invention, the block copolymer 404 is The present invention can also be applied to the case where the so-called cylindrical polymer hydrophilic polymer 406 and hydrophobic polymer 407 are phase-separated.

  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 2 Coating development processing apparatus 3 Etching processing apparatus 30 Developing apparatus 31 Alkaline solution supply apparatus 32 Antireflection film forming apparatus 33 Neutral layer forming apparatus 34 Resist coating apparatus 35 Block copolymer coating apparatus 40 Heat treatment apparatus 202-205 Etching apparatus 300 Controller 400 Neutral layer 401 First resist film 402 Antireflection film 403 Second resist film 404 Block copolymer W wafer

Claims (22)

A method of treating a substrate using a block copolymer comprising a first polymer and a second polymer,
A neutral layer forming step of forming on the substrate a neutral layer having an intermediate affinity for the first polymer and the second polymer;
A block copolymer application step of applying the block copolymer to the substrate on which the neutral layer is formed;
A polymer separation step in which a substrate having a coating film formed on the block copolymer is heat-treated to phase-separate the block copolymer into the first polymer and the second polymer;
Supplying a coating solution that does not dissolve the block copolymer on the block copolymer before the polymer separation step and prevents oxygen from reaching the block copolymer during the heat treatment in the polymer separation step. And a coating film forming step of forming a coating film. The substrate processing method according to claim 1, wherein the coating film formed in the coating film forming step has an intermediate affinity for the first polymer and the second polymer. 3. The substrate according to claim 2, wherein the coating liquid for forming the coating film is obtained by dissolving a predetermined polymer in pure water or a liquid obtained by adding a solvent that imparts polarity to pure water. Processing method. The substrate processing method according to claim 3, wherein the solvent of the coating solution is pure water. The substrate processing method according to claim 3, wherein an organic solvent having a polarity or an alkaline solution is added to the pure water. The substrate processing method according to claim 1, wherein the coating film formed by the coating film forming apparatus is soluble in an organic solvent. The substrate processing method according to claim 6, wherein the coating film is an acrylic film containing fluorine. The coating film is formed by moving a coating liquid supply nozzle having a coating liquid discharge port larger than the diameter of the substrate relative to the substrate. Substrate processing method. The substrate processing method according to claim 1, wherein the molecular weight ratio of the first polymer in the block copolymer is 40% to 60%. The substrate according to claim 1, wherein the first polymer is a hydrophilic polymer having hydrophilicity, and the second polymer is a hydrophobic polymer having hydrophobicity. Processing method. The hydrophilic polymer is polymethyl methacrylate;
The substrate processing method according to claim 10, wherein the hydrophobic polymer is polystyrene. 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 claim 1. A readable computer storage medium storing the program according to claim 12. A system for processing a substrate using a block copolymer comprising a first polymer and a second polymer,
A neutral layer forming apparatus for forming on the substrate a neutral layer having an intermediate affinity for the first polymer and the second polymer;
A block copolymer coating device for coating the block copolymer on the substrate on which the neutral layer is formed;
A coating film forming apparatus for forming a coating film by further applying a coating solution on the block copolymer;
A polymer separator for heat-treating a substrate having a coating film formed on the block copolymer to phase-separate the block copolymer into the first polymer and the second polymer;
The coating film formed by the coating film forming apparatus does not dissolve the block copolymer and prevents oxygen from reaching the block copolymer during the heat treatment in the polymer separation apparatus. A substrate processing system as a feature. The substrate processing system according to claim 14, wherein the coating film formed by the coating film forming apparatus has an intermediate affinity for the first polymer and the second polymer. 15. The substrate according to claim 14, wherein the coating liquid for forming the coating film is obtained by dissolving a predetermined polymer in pure water or a liquid obtained by adding a solvent that imparts polarity to pure water. Processing system. The substrate processing system according to claim 16, wherein the solvent of the coating solution is pure water. The substrate processing system according to claim 16, wherein an organic solvent having a polarity or an alkaline solution is added to the pure water. The substrate processing system according to claim 14, wherein the coating film formed by the coating film forming apparatus is soluble in an organic solvent. The substrate processing system according to claim 19, wherein the coating film is an acrylic film containing fluorine. 21. The substrate processing system according to claim 14, wherein the coating film forming apparatus is a coating liquid supply nozzle provided in the block copolymer coating apparatus. A coating liquid nozzle moving mechanism for moving the coating liquid supply nozzle relative to the substrate;
The substrate processing system according to claim 21, wherein the coating liquid supply nozzle has a discharge port larger than a diameter of the substrate.

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