TW201802908A - Substrate processing method and substrate processing device - Google Patents

Abstract

An object of the invention is to provide a method which, when using a spin coating method to coat a wafer with a coating liquid of a block copolymer, is capable of obtaining a block copolymer with a uniform film thickness, even when a reduced amount of the coating liquid is supplied. The substrate processing method of the present invention is a method of processing a substrate using a block copolymer that contains a hydrophilic polymer and a hydrophobic polymer, the method including a step of supplying a prewetting liquid L1 containing a solvent for the block copolymer coating liquid to a substrate W, thereby forming a liquid film F2 of the prewetting liquid in a circular shape concentric with the substrate W, and a step, performed after a step, of supplying a block copolymer coating liquid L2 to the substrate W and spinning the substrate W to form a thin film of the block copolymer.

Description

Substrate processing method and substrate processing device

The present invention relates to a substrate processing method and a substrate using a block copolymer containing a hydrophilic (polar) hydrophilic (polar) polymer and a hydrophobic (non-polar) hydrophobic (non-polar) polymer. Processing device.

In a manufacturing process of, for example, a semiconductor device, a photolithography process is performed, and this photolithography process is sequentially performed on, for example, a semiconductor wafer (hereinafter referred to as a “wafer”) by applying a resist solution to form a resist of the resist film. A liquid coating process, an exposure process for exposing a predetermined pattern on the resist film, a development process for developing the exposed resist film, and the like, and a predetermined resist pattern is formed on the wafer. Next, using this resist pattern as a photomask, an etching process is performed on the film to be processed on the wafer, and thereafter, a resist film is removed, etc. to form a predetermined pattern on the film to be processed.

In recent years, in order to achieve higher integration of semiconductor devices, miniaturization of the above-mentioned processed film has been required. Therefore, the miniaturization of the resist pattern has been developed, for example, a technique for shortening the wavelength of light of the exposure process of the photolithography process has been developed. However, the short wavelength of the exposure light source has technical and cost limits. If only the method of developing the short wavelength of light is developed, it is difficult to form, for example, a minute resist pattern in the order of several nanometers.

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 this method, first, a guide portion is formed on the wafer with, for example, a resist pattern. Thereafter, the block copolymer is coated on a wafer, and the block copolymer is subjected to a heat treatment to separate the block copolymer into a hydrophilic polymer and a hydrophobic polymer. Thereafter, the wafer is irradiated with ultraviolet rays to perform a polymer modification treatment, and an organic solvent is supplied to the wafer, whereby the hydrophilic polymer can be selectively removed. In addition, the method of coating the block copolymer on the wafer uses a so-called spin coating method, which supplies the coating solution of the block copolymer to the center of the surface of the wafer while it is being rotated, and inserts the substrate with a centrifugal force. The segment copolymer is diffused on the wafer, thereby coating the coating solution of the block copolymer. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-232621

[Problems to be Solved by the Invention] Since a high quality is required for a block copolymer to be coated on a wafer, a coating solution for the block copolymer is extremely effective. Therefore, the application amount of the coating solution of the block copolymer is preferably a small amount. In addition, once the coating amount is small, it is difficult to spread the coating solution of the block copolymer to the end of the wafer by a spin coating method. The solution to this problem is to consider the application of a drug-saving solution (pre-wet solution) before applying the coating solution of the block copolymer. Since the flowability of the coating liquid of the block copolymer can be improved by applying the pre-wet liquid, the supply amount of the coating liquid can at least extend the coating liquid to the end of the wafer.

However, the present inventors have confirmed that in the above method of applying a pre-wetting liquid before applying a coating solution of a block copolymer, the occurrence of The following questions. That is, it was confirmed that when the coating liquid of the pre-wet liquid and the block copolymer was discharged to the center portion of the wafer, and the pre-humid liquid was applied to the wafer by the spin coating method, the embedded liquid was dried when the coating liquid was dried. The film thickness of the segment copolymer is locally thinned at the center of the wafer. In order to obtain the desired pattern of the processed film, the film thickness of the block copolymer needs to be uniform throughout the wafer, and the uniformity of the film thickness of the block copolymer is far more stringent than that of a resist.

The present invention has been made in view of this point, and an object thereof is to obtain uniformity even when the supply amount of the coating liquid is small when the coating solution of the block copolymer is applied to a wafer by a spin coating method. The film thickness of the block copolymer. [Means to solve the problem]

In order to achieve the foregoing object, the present invention is a substrate processing method for processing a substrate using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer, which includes a pre-wet liquid film formation process and a block copolymer film formation process. In the pre-wet liquid film forming process, a pre-wet liquid containing a solvent of the coating solution of the block copolymer is supplied to the substrate to form a liquid film of the pre-wet liquid; the block copolymer film forming process is performed in the After the pre-wet liquid film formation process, the coating solution of the block copolymer is supplied to the substrate, and the substrate is rotated to form a thin film of the block copolymer. The pre-wet liquid film formation process includes the pre-wet liquid film formation process. The wet liquid film is formed into a ring-shaped ring film forming process concentric with the substrate.

According to the present invention, since the pre-wetting liquid is supplied before the coating liquid for the block copolymer is supplied, the consumption of the coating liquid for the block copolymer can be suppressed. In addition, since the liquid film of the pre-wetting liquid containing the solvent of the coating solution of the block copolymer is formed into a ring shape, the thin film of the block copolymer at the center portion of the wafer can be prevented from being locally thin, and uniformity can be formed. Film thickness of block copolymer film.

For example, in the annular film formation process, a nozzle for supplying the pre-wetting liquid is arranged at a predetermined position on the outer periphery of the substrate, and the substrate is made in a state where the pre-wetting liquid is supplied from the nozzle. After one rotation, the liquid film of the pre-wet liquid is formed into the annular shape.

The distance from the center of the substrate to the nozzle should be greater than 3.3% of the radius of the substrate and less than 40% of the radius.

The pre-wet liquid film formation process preferably includes a pre-wet liquid film diffusion process, which rotates the substrate at a rotation speed faster than the rotation speed of the substrate of the annular film formation process, so that the substrate is formed as The liquid film of the ring-shaped pre-wet liquid expands toward the outer periphery of the substrate.

The substrate processing method preferably includes a drying process for drying the film of the block copolymer.

In the process of forming the block copolymer film, it is preferable to supply the coating solution of the block copolymer to the central portion of the substrate.

The film thickness of the thin film of the block copolymer is preferably 100 nm or less.

The viscosity of the coating solution of the block copolymer is preferably 3 cP or less.

According to another aspect of the present invention, a program is provided that operates on a computer that controls a control section of a substrate processing system to cause the substrate processing system to execute the substrate processing method.

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

Yet another aspect of the present invention is a substrate processing system that uses a block copolymer containing a hydrophilic polymer and a hydrophobic polymer to process a substrate, and includes a coating solution for supplying the block copolymer to form the insert. A block copolymer coating device for a film of a segmented copolymer; the block copolymer coating device includes a first nozzle for supplying a pre-wetting solution of a solvent containing a coating solution of the block copolymer to the substrate, and The coating solution of the block copolymer is supplied to a second nozzle of the substrate; the block copolymer coating device supplies the pre-wet liquid to the substrate from the first nozzle, and forms a connection with the substrate on the substrate. The concentric annular liquid film of the pre-wet liquid of the substrate is supplied from the second nozzle to the substrate after forming the liquid film of the pre-humid liquid from the second nozzle to form the block. Copolymer film.

For example, the block copolymer coating device arranges the first nozzle at a predetermined position on the outer periphery of the substrate, and rotates the substrate once while the pre-wetting liquid is supplied from the first nozzle. To form a liquid film of the annular pre-wet liquid.

The distance from the center of the substrate to the first nozzle should be greater than 3.3% of the radius of the substrate and less than 40% of the radius.

The block copolymer coating device preferably rotates the substrate at a rotation speed faster than the rotation speed of the substrate when the liquid film of the ring-shaped pre-wetting liquid is formed, so that the ring-shaped pre-wet The liquid film of the liquid expands in the outer peripheral direction of the substrate.

The block copolymer coating device preferably rotates the substrate and dries the film of the block copolymer.

The block copolymer coating apparatus preferably supplies the coating solution of the block copolymer from the second nozzle to a center portion of the substrate.

The film thickness of the thin film of the block copolymer is preferably 100 nm or less.

The viscosity of the coating solution of the block copolymer is preferably 3 cP or less. [Effect of the invention]

According to the present invention, when a coating solution of a block copolymer using a predetermined solvent is applied to a wafer by a spin coating method, even when the supply amount of the coating solution is small, a uniform film thickness can be obtained. Paragraph copolymer.

[Embodiments for Implementing the Invention] Hereinafter, embodiments of the present invention will be described. FIG. 1 is an explanatory plan view showing the outline of the configuration of a substrate processing system 1 that implements a substrate processing method according to this embodiment. In addition, in this specification and the drawings, elements having substantially the same functional structure are denoted by the same reference numerals, and redundant descriptions are omitted.

The substrate processing system 1 includes a coating processing device 2 that performs a solution processing such as photolithography processing on a wafer as a substrate, and an etching processing device 3 that performs etching processing on a wafer.

FIG. 2 is a plan explanatory view of the coating processing apparatus 2, and FIGS. 3 and 4 are a front view and a rear view, respectively, schematically showing the outline of the internal structure of the substrate processing system 1. The coating processing apparatus 2 of this embodiment performs solution processing such as coating processing and development processing.

As shown in FIG. 2, the coating processing apparatus 2 has a structure in which the cassette station 10 for carrying in and out a cassette C containing a plurality of wafers W and having a predetermined processing for the wafer W are provided. The processing stations 11 of the plurality of various processing apparatuses and the interface station 13 for transferring the substrate W between the processing station 11 and the adjacent exposure apparatus 12 are integrally connected.

A cassette mounting table 20 is provided at the cassette station 10. The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21 for mounting the cassette C when the cassette C is carried in and out of the substrate processing system 1.

As shown in FIG. 2, the wafer cassette station 10 is provided with a wafer transfer device 23 that can move freely on a transfer path 22 extending in the X direction. The wafer transfer device 23 can also move freely in the vertical direction and around the vertical direction (θ direction), and can be used as a transfer device between the cassette C on each cassette mounting plate 21 and the third block G3 of the processing station 11 described later. Between wafers W.

The processing station 11 is provided with a plurality of devices having various devices, for example, four blocks G1, G2, G3, and G4. For example, a first block G1 is provided on the front side of the processing station 11 (the negative direction side in the X direction in FIG. 2), and a second block G2 is provided on the back side of the processing station 11 (the positive direction side in the X direction in FIG. 2). . A third block G3 is provided on the cassette station 10 side of the processing station 11 (the negative direction side in the Y direction in FIG. 2), and on the interface station 13 side of the processing station 11 (the positive direction side in the Y direction in FIG. 2). There is a fourth block G4.

For example, in the first block G1, as shown in FIG. 3, a plurality of solution processing devices such as a developing device 30 for developing a resist pattern formed on a wafer W by developing a resist solution are sequentially stacked from below, The neutral agent is applied to the wafer W after forming the resist pattern to form a neutral layer. The neutral layer forming device 31 is configured to apply an organic solvent to the wafer W after the neutral layer is formed to clean the wafer W. The cleaning device 32 is a block copolymer coating device 33 that applies a block copolymer to the wafer W.

For example, three imaging devices 30, a neutral layer forming device 31, a cleaning device 32, and a block copolymer coating device 33 are arranged in line in the horizontal direction. In addition, the number and configuration of these solution processing devices can be arbitrarily selected.

In addition, in these solution processing apparatuses, spin coating is performed in which a predetermined coating liquid is applied on, for example, the wafer W. In spin coating, for example, the coating liquid is discharged onto the wafer W from a coating nozzle, and the wafer W is rotated to spread the coating liquid onto the surface of the wafer W. The structure of these solution processing apparatuses is mentioned later.

In addition, the block copolymer contained in the coating liquid coated on the wafer W by the block copolymer coating device 33 is a first polymer having a first monomer and a second monomer polymerized into a linear chain ( A polymer of the first monomer) and a polymer (copolymer) of the second polymer (the polymer of the second monomer). The first polymer uses a hydrophilic (polar) hydrophilic polymer, and the second polymer uses a hydrophobic (non-polar) hydrophobic polymer. In this embodiment, for example, polymethyl methacrylate (PMMA) is used as the hydrophilic polymer, and polystyrene (PS) is used as the hydrophobic polymer, that is, polystyrene (PS) -polymethacrylic acid is used, for example. Methyl Ester (PMMA) block copolymer (PS-b-PMMA). The molecular weight ratio of the hydrophilic polymer of the block copolymer is about 20% to 40%, and the molecular weight ratio of the hydrophobic polymer of the block copolymer is about 80% to 60%. In addition, the coating solution of the block copolymer (hereinafter referred to as the BCP coating solution) makes the block copolymer of the hydrophilic polymer and the hydrophobic polymer into a solution form by a solvent. When PS-b-PMMA is used as the block copolymer, propylene glycol methyl ether acetate (PGMEA) can be used as a solvent.

In this embodiment, a single solvent is used as the solvent of the BCP coating liquid. In this BCP coating solution, the solute, that is, the ratio of the block copolymer to the solvent is less than 10%. In addition, as described later, the block copolymer coating device 33 forms a pre-wet liquid film on the wafer W, and then discharges the BCP coating liquid onto the wafer to form a thin film of the block copolymer.

The neutral layer is formed on the wafer W by the neutral layer forming device 31. The neutral layer is a layer having an intermediate affinity for the hydrophilic polymer and the hydrophobic polymer. The hydrophilic polymer and the hydrophobic polymer may be used. Random copolymers, graft copolymers, alternating copolymers. In this embodiment, the neutral layer uses, for example, a random copolymer of polymethyl methacrylate and polystyrene (PS-r-PMMA), a graft copolymer (PS-g-PMM A), or an alternating copolymer. . In the following, when referring to "neutral", it means that there is such an intermediate affinity for a hydrophilic polymer and a hydrophobic polymer.

For example, in the second block G2, as shown in FIG. 4, the ultraviolet irradiation device 40 that is modified by irradiating the wafer W with ultraviolet rays, and the heat treatment devices 41 and 42 that perform heat treatment on the wafer W are arranged in an up-down direction and a horizontal direction. The ultraviolet irradiation device 40 includes a mounting table on which the wafer W is placed, and an ultraviolet irradiation unit that irradiates the wafer W on the mounting table with ultraviolet rays.

The heat treatment devices 41 and 42 include a hot plate on which the wafer W is heated and a cooling plate on which the wafer W is cooled, and both heat treatment and cooling treatment can be performed. The heat treatment device 41 is used for heat treatment before and after the formation of the neutral layer. In addition, the heat treatment device 42 has a function of a polymer separation device that performs a heat treatment on the wafer W coated with the block copolymer by the block copolymer coating device 33 to separate the block copolymer phase. It becomes a hydrophilic polymer and a hydrophobic polymer. In addition, the number and arrangement of the ultraviolet irradiation device 40 and the heat treatment devices 41 and 42 can be arbitrarily selected, and it is desirable to arrange the wafer W in the processing station 11 with the shortest transfer time.

For example, in the third block G3, a plurality of transfer devices 50, 51, 52, 53, 54, 55, 56 are sequentially provided from below. In the fourth block G4, a plurality of transfer devices 60, 61, and 62 are provided in order from below.

As shown in FIG. 2, a wafer transfer area D is formed in a region surrounded by the first block G1 to the fourth block G4. The wafer transfer region D is provided with a plurality of wafer transfer devices 70 having a transfer arm that can move freely in, for example, the Y direction, the X direction, the θ direction, and the up-down direction. The wafer transfer device 70 can be moved in the wafer transfer area D to transfer the wafer W to a predetermined device in the surrounding first block G1, second block G2, third block G3, and fourth block G4. .

A wafer transfer area D is provided with a shuttle transfer device 80 that linearly transfers the wafer W between the third block G3 and the fourth block G4.

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

As shown in FIG. 2, a wafer transfer device 90 is provided beside the X-direction positive side of the third block G3. The wafer transfer device 90 includes a transfer arm that can move freely in the X direction, the θ direction, and the vertical direction, for example. The wafer transfer device 90 can move up and down while supporting the wafer W, and transfer the wafer W to each delivery device in the third block G3.

A wafer transfer device 91 and a transfer device 92 are provided at the interface station 13. The wafer transfer device 91 includes a transfer arm that can move freely in the Y direction, the θ direction, and the up-down direction, for example. The wafer transfer device 91 can support the wafer W by, for example, a transfer arm, and transfer the wafer W between each transfer device, the transfer device 92 and the exposure device 12 in the fourth block G4.

As shown in FIG. 5, the etching apparatus 3 includes a cassette station 100 that carries wafers W in and out of the etching processing apparatus 3, a common transfer unit 101 that carries wafers W, and is selected as an etching process for wafers W. Etching apparatuses 102 and 103 for removing a polymer of either a hydrophilic polymer or a hydrophobic polymer, and etching apparatuses 104 and 105 for etching a processed film on a wafer W into a predetermined pattern.

The cassette station 100 includes a transfer chamber 111 in which a wafer transfer mechanism 110 for transferring wafers W is provided. The wafer transfer mechanism 110 has a structure in which the two transfer arms 110a and 110b that hold the wafer W are approximately horizontal, and is configured to transfer the wafer W while holding the wafer W in either of the transfer arms 110a and 110b. A cassette mounting table 112 on which a cassette C capable of arranging a plurality of wafers W to be housed is arranged on the side of the transfer chamber 111. In the example shown in the figure, a plurality of, for example, three cassettes C can be mounted on the cassette mounting table 112.

The transfer chamber 111 and the common transfer unit 101 are connected to each other by two vacuum-loadable locking devices 113a and 113b.

The common transfer unit 101 includes a transfer chamber cavity 114 formed in a hermetically-sealed structure as viewed from above, forming a polygonal shape (hexagon in the example shown in the figure). A wafer transfer mechanism 115 for transferring a wafer W is provided in the transfer chamber cavity 114. The wafer transfer mechanism 115 has two transfer arms 115a and 115b that hold the wafer W approximately horizontally. The wafer transfer mechanism 115 is configured to be capable of transferring the wafer W while holding either of the transfer arms 115a and 115b.

On the outside of the transfer chamber cavity 114, the etching devices 102 to 105 and the lock devices 113 b and 113 a are arranged so as to surround the periphery of the transfer chamber cavity 114. The etching devices 102 to 105 and the locking devices 113b and 113a are arranged in a clockwise direction in order from the top, and are arranged to face the six side portions of the transfer chamber 114, respectively.

The etching devices 102 to 105 are, for example, RIE (Reactive Ion Etching) devices. That is, in the etching apparatuses 102 to 105, dry etching is performed on the hydrophobic polymer and the film to be treated with a reactive gas (etching gas), ions, and radicals.

As shown in FIG. 1, the above-mentioned substrate processing system 1 is provided with a control unit 300. The control unit 300 is, for example, a computer, and has a program storage unit (not shown). A program for controlling the processing of the wafer W of the substrate processing system 1 is stored in the program storage section. In addition, a program for controlling the operations of the driving systems such as the above-mentioned various processing devices and conveying devices to store the programs for realizing wafer processing of the substrate processing system 1 is also stored in the program storage section. In addition, the foregoing program may be recorded on a computer-readable recording medium such as a hard disk (HD), a flexible magnetic disk (FD), a compact disc (CD), a magneto-optical disk (MO), and a memory card, which are readable by a computer. , Or a program installed in the control unit 300 from the recording medium.

Next, the structure of the block copolymer coating device 33 will be described. As shown in FIG. 6, the block copolymer coating device 33 includes a processing container 120. A carry-in / out port (not shown) for the wafer W is formed on a side surface of the processing container 120.

The processing container 120 is provided with a spin chuck 121 as a substrate holding portion that holds the wafer W and rotates it about a vertical axis. The rotary chuck 121 can be rotated to a predetermined speed by a chuck drive section 122 such as a motor.

A cup body 123 is provided around the rotary chuck 121 to receive and collect the liquid scattered or dropped from the wafer W. Below the cup body 123, an exhaust pipe 124 for discharging the recovered liquid and an exhaust pipe 125 for exhausting the gaseous environment in the cup body 123 are connected.

As shown in FIG. 7, a track 126 extending in the Y direction (left-right direction in FIG. 7) is formed on the side of the negative direction (lower direction in FIG. 7) in the X direction of the cup body 123. The track 126 is formed, for example, from the outside of the Y-direction negative direction (left direction in FIG. 7) side to the outside of the Y-direction positive direction (right direction in FIG. 7) side. A nozzle arm 127 is attached to the rail 126.

The nozzle arm 127 can move freely on the rail 126 by the nozzle driving part 128 shown in FIG. 7. Thereby, the nozzle arm 127 can be moved from the standby portion 129 provided on the outer side in the positive direction of the Y direction of the cup body 123 to the center portion of the wafer W in the cup body 123, and further on the surface of the wafer W The wafer W moves in the radial direction. Moreover, the nozzle arm 127 can be raised and lowered freely by the nozzle driving part 128, and the height of the nozzle arm 127 can be adjusted.

As shown in FIG. 6, the nozzle arm 127 is provided with a first nozzle 130 for supplying a pre-wet liquid and a second nozzle 131 for supplying a BCP coating liquid.

The pre-wet liquid supply unit 133 is connected to the first nozzle 130 through, for example, a pipe 132. The pre-wet liquid supply unit 133 includes a pre-wet liquid supply source, a pump, a valve, and the like, and is configured to discharge the pre-wet liquid from the front end of the first nozzle 130. Similarly to the first nozzle 130, the second nozzle 131 is connected to the BCP coating liquid supply unit 135 via a pipe 134, and the BPC coating liquid can be discharged from the second nozzle 131. The pre-wet liquid of this embodiment is a liquid having good compatibility with the solvent of the BCP coating liquid, for example, a solvent containing the same component as the solvent of the BCP coating liquid. More specifically, as mentioned above, in this embodiment, a single solvent is used as the solvent of the BCP coating liquid, and when the block copolymer is PS-b-PMMA and the single solvent is PGMEA, the pre-wet liquid may use PGMEA and A mixed solution of propylene glycol methyl ether (PGM E) (for example, the mixing ratio is 7: 3).

Next, a coating method of the BCP coating liquid using the block copolymer coating apparatus 33 will be described with reference to FIGS. 8 to 10. FIG. 8 is a diagram illustrating the discharge positions of the pre-wet liquid and the BCP coating liquid in the block copolymer coating device 33. FIG. 9 and FIG. 10 are schematic views showing a state of a wafer center portion of a film formed by the block copolymer coating device 33.

As shown in FIG. 8 (A), the position where the pre-wet liquid L1 is discharged from the first nozzle 130 of the block copolymer coating device 33 is the center of the wafer W, and the pre-wet liquid L1 is discharged while being the same as other processing liquids While rotating the wafer W, a liquid film F1 of the pre-wet liquid L1 is formed on the entire surface of the wafer W as shown in FIG. 8 (B). After that, while the BCP coating liquid L2 is discharged from the second nozzle 131 of the block copolymer coating device 33 to the center of the wafer W, the wafer W is rotated to form the block copolymer (the coating solution). ) Film, and the film is dried to obtain a film F3 of a block copolymer as shown in FIG. 9 (A). The film thickness of the thin film F3 in FIG. 9 (A) is thin at the center portion C of the wafer W.

The inventors of the present case did not observe when using a BCP coating liquid containing a single solvent instead of a single solvent, and when using a pre-wetting liquid with poor compatibility with the single solvent for the BCP coating liquid of a single solvent As described above, the film of the block copolymer after drying is locally thinned at the center.

As described above, the reason why the film of the dried block copolymer is partially thinned at the center is as follows. That is, the compatibility between the pre-wet liquid and the solvent of the BCP coating liquid is good, and specifically, the solvent containing the same component as the solvent of the BCP coating liquid. Therefore, similar to the solvent of the BCP coating liquid, the pre-wet liquid has high solubility of the block copolymer. When the discharge position of this pre-wet liquid is the center of the wafer, the centrifugal force does not work on the pre-wet liquid at the center of the wafer, so as shown in Fig. 10 (A), the film of the block copolymer before drying is BCP. The liquid film F5 of the coating liquid (a mixed liquid with the pre-wet liquid) is partially at the center portion C of the wafer, and the amount of the pre-wet liquid is locally larger than that of the other portions. That is, the ratio of the solvent (component) with high solubility of the block copolymer is high in the wafer center portion C. Therefore, since the block copolymer in the center portion of the wafer dissolves faster in the drying process than in the other portions, the film thickness of the block copolymer in the center portion of the wafer after drying becomes thinner locally.

Therefore, in this embodiment, the block copolymer coating device 33 first forms a liquid film of the pre-wet liquid into a circular shape concentric with the wafer W. Specifically, as shown in FIG. 8 (C), the position where the pre-wet liquid L1 is discharged from the first nozzle 130 of the block copolymer coating device 33 is arranged at a predetermined position on the outer periphery of the wafer W, and In a state where the pre-wet liquid L1 is discharged from the first nozzle 130, the wafer W is rotated once, and the liquid film of the pre-wet liquid L1 is formed into a ring shape. Thereafter, the wafer W is rotated, and the liquid film F2 of the pre-wet liquid L1 is extended to the outer periphery of the wafer W as shown in FIG. 8 (D). Next, while the BCP coating liquid is discharged from the second nozzle 131 of the block copolymer coating device 33 to the center of the wafer W, the wafer W is rotated to form a thin film of the BCP coating liquid. At this time, since the pre-wet liquid does not exist in the center portion, as shown in FIG. 10 (B), there is no locally large portion of the solvent having a high solubility of the block copolymer in the center portion C of the wafer. Therefore, when the liquid film of the BCP coating liquid is dried, a film F4 of a block copolymer having a uniform film thickness as shown in FIG. 9 (B) can be obtained.

Next, wafer processing performed using the substrate processing system 1 will be described. FIG. 11 is a flowchart showing an example of a main process of the wafer processing.

First, the cassette C containing the plurality of wafers W is carried into a cassette station 10 of the substrate processing system 1 and placed on a predetermined cassette mounting plate 21. After that, each wafer W in the wafer cassette C is sequentially taken out by the wafer transfer device 23 and transferred to the transfer device 53 of the processing station 11. In addition, a resist film is formed on the wafer W to be processed in the substrate processing system 1 in advance, and an exposure process is performed on the resist film in a predetermined pattern.

Next, the wafer W is transferred to the developing device 30 by the wafer transfer device 70. In the developing device 30, a developing solution is supplied to the wafer W to develop a resist film into a predetermined pattern. After the development is completed, the wafer W is transferred to the heat treatment device 41 by the wafer transfer device 70 and subjected to a post-baking process. In this way, a predetermined resist pattern is formed on the wafer W (process S1 in FIG. 11). In this embodiment, the resist pattern has a linear line portion and a linear gap portion in a plan view, and is a so-called line and gap resist pattern. In addition, the width of the gap portion is set such that the hydrophilic polymer and the hydrophobic polymer are alternately arranged in the gap portion in the gap portion.

Then, the wafer W is transferred to the neutral layer forming device 31 by the wafer transfer device 70. In the neutral layer forming device 31, a neutral agent is coated on the wafer W to form a neutral layer (process S2 in FIG. 11). After that, the wafer W is transferred to the heat treatment apparatus 41, heated and adjusted in temperature, and then returned to the transfer apparatus 53.

Thereafter, the wafer W is transferred to the cleaning device 32 by the wafer transfer device 70. In the cleaning device 32, an organic solvent is supplied to the wafer W after the neutral layer is formed, and foreign matters on the resist pattern and the neutral layer are washed away.

Then, the wafer W is transferred to the block copolymer coating device 33 by the wafer transfer device 70. In the block copolymer coating device 33, a thin film of the block copolymer is formed on the neutral layer of the wafer W (process S3 in FIG. 11).

FIG. 12 is a flowchart showing an example of a block copolymer film forming process in the block copolymer coating apparatus 33. In addition, the wafer W is a wafer having a diameter of 300 mm.

First, the wafer W carried into the block copolymer coating apparatus 33 is held on the spin chuck 121. Next, the first nozzle 130 is moved above the position at a distance of 55 mm from the center of the wafer W by the nozzle arm 127. Then, while the pre-wet liquid is being discharged from the first nozzle 130, the chuck driving unit 122 is controlled to rotate the wafer W at 10 rpm for 6 seconds. Thereby, a ring-shaped pre-wet liquid film concentric with the wafer W is formed on the wafer W (process S11 in FIG. 12).

Thereafter, the discharge of the pre-wet liquid from the first nozzle 130 is stopped. The second nozzle 131 is moved above the center of the wafer by the nozzle arm 127. During this movement, the wafer W is rotated at a low speed of 30 rpm for 1 second, and then the wafer W is rotated at 1000 rpm for 0.1 second. Thereby, the liquid film of the pre-wet liquid can be extended to the outer peripheral portion of the wafer W (the process S12 in FIG. 12 and the pre-wet liquid diffusion process). In addition, the rotation at 30 rpm for 1 second is because the pre-wet liquid diffusion process is performed while the second nozzle 131 is moving. Do not expand the pre-wet liquid film toward the wafer center before the diffusion process starts. In addition, by applying a pre-wet liquid film to the outer periphery of the wafer W before applying the BCP coating liquid, dry spots can be prevented during the subsequent application of the BCP coating liquid (the BCP coating liquid is not supplied) Part).

After the movement of the second nozzle 131 and the pre-wet liquid diffusion process are completed, the BCP coating liquid is supplied from the second nozzle 131 located above the wafer center, and the wafer W is rotated at 2500 rpm for 1 second. Thereafter, in order to flatten the liquid film of the BCP coating liquid, the wafer W is rotated at 100 rpm while the supply of the BCP coating liquid is maintained. Next, after the supply of the BCP coating liquid is stopped, the wafer W is rotated at 1500 rpm for 15 seconds. Thereby, the BCP coating liquid is dried, and a desired block copolymer film with a uniform thickness is formed on the wafer (process S13 in FIG. 12). Here, "drying" does not mean that the solvent in the block copolymer film (the solvent in the BCP coating solution and the pre-wetting solution) is completely evaporated, but it means that the solvent in the block copolymer film is evaporated to the block copolymer film. The proportion of the internal solvent is suitable for the phase separation of the block copolymer.

In addition, the position of the first nozzle 130 for forming a liquid film of a ring-shaped pre-wet liquid is not limited to a position 55 mm apart from the center of the wafer W, as long as the pre-wet liquid discharged from the nozzle 130 does not expand. It is sufficient to reach the center of the wafer and obtain the effect of saving medicine. For example, when the wafer W has a diameter of 300 mm, the distance from the center of the wafer W to the horizontal direction of the first nozzle 130 may be 5 to 60 mm. When the wafer W has a diameter of 450 mm, the distance between the center of the wafer W and the first nozzle 130 in the horizontal direction may be 7.5 to 90 mm. That is, the distance from the center of the wafer W to the first nozzle when the pre-wet liquid is discharged should be greater than 3.3% of the radius of the wafer W and less than 40% of the radius.

In addition, considering the time required for phase separation of the block copolymer and the miniaturization of the pattern, the film thickness of the block copolymer film formed by the block copolymer coating device 33 should be thin, for example, about 20 to 60 nm. The film thickness is not limited to this, and may be 100 mm or less, and preferably 80 nm or less. The viscosity of the BCP coating liquid is, for example, about 1 to 2 cP (centipoise), and preferably 3 cP or less.

In the block copolymer film formation process, after the block copolymer film of process S13 is dried and the film thickness is adjusted, an EBR (Edge Bead Remover) nozzle is used to clean the wafer with a cleaning solution. W outer periphery. The cleaning may be performed on both the front surface and the back surface of the wafer W, and may be performed on either one.

Return to the description of FIG. 11. The wafer W on which the block copolymer film is formed is transferred to the heat treatment device 42 by the wafer transfer device 70. The heat treatment device 42 performs heat treatment on the wafer W at a predetermined temperature. At this time, in order to make the inside of the heat treatment device 42 into a low oxygen gas environment, for example, nitrogen gas is supplied, and the heat treatment is performed in this nitrogen gas environment. In this way, the block copolymer on the wafer W can be phase separated into a hydrophilic polymer and a hydrophobic polymer (process S4 in FIG. 11).

Here, as described above, in the block copolymer, the ratio of the molecular weight of the hydrophilic polymer is 40% to 60%, and the ratio of the molecular weight of the hydrophobic polymer is 60% to 40%. In this way, in the process S4, the hydrophilic polymer and the hydrophobic polymer are separated into a layered structure. In addition, since the width of the gap portion of the resist pattern is a predetermined width, the hydrophilic polymer and the hydrophobic polymer are alternately arranged in the gap portion of the resist pattern.

After that, the wafer W is transferred to the transfer 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.

When the wafer W is subjected to predetermined processing in the coating processing apparatus 2, the cassette C in which the wafer W is stored is carried out from the coating processing apparatus 2 and carried into the etching processing apparatus 3.

Next, the wafer W taken out from the cassette C is transferred to the etching apparatus 102. In the etching device 102, the hydrophilic polymer is selectively removed by an etching process to form a predetermined pattern of the hydrophobic polymer (process S5 in FIG. 11).

Thereafter, the wafer W is stored in the cassette C and carried out from the etching processing apparatus 3.

According to the above embodiment, since the pre-wet liquid is applied before the BCP coating liquid is applied, the consumption of the BCP coating liquid can be suppressed, and even if it is suppressed, dry spots of the BCP coating liquid will not be generated. Furthermore, by forming the liquid film of the pre-wet liquid into a ring shape concentric with the wafer W, the proportion of the solvent in the block copolymer film in the center of the wafer can be suppressed, so that a uniform film thickness can be obtained. Block copolymer film.

In the above embodiment, a pre-wetting solution is applied in advance when forming a block copolymer film, and a pre-wetting solution may be applied in advance to form a neutral layer. Annular liquid film. This is because when the solvent used for the coating solution for forming the neutral layer has good compatibility with the pre-wetting solution for the neutral layer, when the pre-wetting solution for the neutral layer is discharged to the center of the wafer, the Similarly, in the segmented copolymer film, the film thickness of the neutral layer in the center portion of the wafer becomes locally thin. For example, when a solution of PS-r-PMMA or PS-g-PMMA using PGMEA as a single solvent is used as the coating solution for the neutral layer, a solution containing PGMEA can be used as the pre-wetting solution for the neutral layer. The method for supplying and diffusing the pre-wetting solution for the neutral layer and the method for forming the neutral layer using the coating solution of the neutral layer after the pre-wetting solution is applied may be the same method as the method related to the above-mentioned block copolymer. . When an antireflection film is formed on the wafer W, the neutral layer may not be formed.

In the above embodiment, when the hydrophilic polymer is selectively removed, the so-called dry etching process is performed in the etching processing device 3, and the removal of the hydrophilic polymer may be performed by a wet etching process. At this time, in the process S5, it is first transferred to the ultraviolet irradiation apparatus 40 instead of the etching processing apparatus 3. Then, by irradiating the wafer W with a wavelength of 200 nm or less, for example, 172 nm, the hydrophilic polymer, that is, polyethyl methacrylate, can be cut off, and the hydrophobic polymer, that is, polystyrene, can be bridged . Thereafter, the wafer W is transferred to a solution supply device (not shown) provided in the coating processing device 2 or the like, and the solution W is supplied to the wafer W with, for example, isopropyl alcohol. Thereby, the hydrophilic polymer which cut | disconnected the connection chain by ultraviolet irradiation can be removed.

In the above embodiment, a resist film is formed on the wafer W in advance, and the resist film is subjected to exposure processing in a predetermined pattern. The substrate processing system 1 may be used to form a resist film and use an exposure device 12 Exposure processing. [Example]

In Examples 1 and 2, a thin film of a block copolymer was formed on a wafer having a flat surface on which a resist pattern or the like was not formed according to the procedure described in the flowchart of FIG. 12. In Comparative Examples 1 and 2, in the procedures of Examples 1 and 2, only pre-wetting conditions were changed, and a film of a block copolymer was formed on a wafer on which a resist pattern was not formed. In Examples 1 and 2, a pre-wetting liquid was supplied from a position spaced 55 mm from the center of the wafer to form a ring shape. In Comparative Examples 1 and 2, the wafer was pre-conditioned while the wafer rotation was stopped. The wet liquid is discharged to the center of the wafer for 2 seconds, and then the wafer is rotated at 1000 rpm for 0.1 second to expand the pre-wet liquid to the entire wafer.

In Example 1 and Comparative Example 1, PME-842 manufactured by Mercch was used as the coating solution of PS-b-PMMA using PGMEA as a single solvent. In Example 2 and Comparative Example 2, the coating liquid used was BP-D032C manufactured by Tokyo Yingka Kogyo Co., Ltd. In Examples 1 and 2 and Comparative Examples 1 and 2, OK73 (a mixed solution of 7: 3 of PGMEA and PGME) manufactured by Tokyo Yinghua Chemical Industry Co., Ltd. was used as the pre-wet liquid.

13 and 14 are graphs showing film thickness distributions of the block copolymers of Examples and Comparative Examples. In FIGS. 13 and 14, the distance between the horizontal axis and the center of the wafer is the thickness, and the vertical axis is the thickness. The film thickness was measured by the method ~.

As is clear from FIG. 13, in Comparative Example 1, the film thickness of the block copolymer is locally thinned at the center portion of the wafer. On the other hand, in Example 1, as shown in FIG. 13, the film thickness of the block copolymer was also uniform in the center portion of the wafer. In Comparative Example 1, the film thickness of the block copolymer was thin from the wafer center portion to the outer peripheral portion. In Example 1, the film thickness of the block copolymer was uniform throughout the wafer. In addition, even if the supply amount of the BCP coating liquid is the same, since the film thickness of the outer peripheral portion of the wafer in Example 1 is large, a chemical-saving liquid can be expected. Comparative Example 2 and Example 2 are also the same as Comparative Example 1 and Example 1. That is, the effects of the present invention can be obtained regardless of the type of the BCP coating liquid.

In the above embodiment, the block copolymer on the wafer W is phase-separated into a hydrophilic polymer and a hydrophobic polymer in a layered structure. The substrate processing system 1 of the present invention can also be applied to block copolymers. Phase separation into a hydrophilic polymer and a hydrophobic polymer with a cylindrical structure.

The preferred embodiments of the present invention have been described above with reference to the attached drawings, but the present invention is not limited to this example. It can be clearly understood that as long as it is the practitioner, various changes or amendments can be conceived within the scope of the idea described in the scope of patent application, and it is understood that these naturally belong to the technical scope of the present invention. The present invention is not limited to this example, and various aspects can be adopted. The present invention can also be applied to a case where the substrate is other substrates such as an FPD (Flat Panel Display) other than a wafer, a photomask for a photomask, and a reduction mask. [Industrial availability]

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

1‧‧‧ substrate processing system
2‧‧‧ coating treatment device
3‧‧‧ Etching device
10‧‧‧ Crystal Box Station
11‧‧‧processing station
12‧‧‧ exposure device
13‧‧‧Interface Station
20‧‧‧Crystal Mounting Stage
21‧‧‧Crystal plate mounting plate
22‧‧‧ transport route
23‧‧‧ Wafer Transfer Device
30‧‧‧Imaging device
31‧‧‧ neutral layer forming device
32‧‧‧cleaning device
33‧‧‧block copolymer coating device
40‧‧‧ultraviolet irradiation device
41‧‧‧Heat treatment equipment
42‧‧‧Heat treatment equipment
50‧‧‧ Transfer Device
51‧‧‧Transfer device
52‧‧‧Transfer device
53‧‧‧Transfer device
54‧‧‧Transfer device
55‧‧‧Transfer device
56‧‧‧ Transfer Device
60‧‧‧Transfer device
61‧‧‧Transfer device
62‧‧‧Transfer device
70‧‧‧ Wafer Transfer Device
80‧‧‧ Shuttle transfer device
90‧‧‧ Wafer Transfer Device
91‧‧‧ Wafer Transfer Device
92‧‧‧ Transfer Device
100‧‧‧ Crystal Box Station
101‧‧‧ Common Transportation Department
102‧‧‧Etching device
103‧‧‧Etching device
104‧‧‧etching device
105‧‧‧etching device
110‧‧‧wafer transfer mechanism
110a‧‧‧carrying arm
110b‧‧‧carrying arm
111‧‧‧ transfer room
112‧‧‧Crystal Mounting Stage
113a‧‧‧load lock device
113b‧‧‧load lock device
114‧‧‧ transfer chamber
115‧‧‧ Wafer Transfer Agency
115a‧‧‧carrying arm
115b‧‧‧carrying arm
120‧‧‧handling container
121‧‧‧Rotary suction cup
122‧‧‧ Suction drive unit
123‧‧‧ cup body
24‧‧‧ discharge pipe
125‧‧‧ exhaust pipe
126‧‧‧ track
127‧‧‧ Nozzle Arm
128‧‧‧ Nozzle driving unit
129‧‧‧Standby
130‧‧‧The first nozzle
131‧‧‧Nozzle 2
132‧‧‧Piping
133‧‧‧Pre-wet liquid supply department
134‧‧‧Piping
135‧‧‧BCP coating liquid supply department
300‧‧‧ Control Department
C‧‧‧Crystal Box (Figure 2-Figure 5)
C‧‧‧ Wafer center (Figure 9 (A), Figure 10 (A), Figure 10 (B)
F1‧‧‧ Pre-wet liquid film
F2‧‧‧ Pre-wet liquid film
F3‧‧‧ block copolymer film
F4‧‧‧ film of block copolymer
F5‧‧‧BCP coating liquid film
G1‧‧‧ Block 1
G2‧‧‧Block 2
G3‧‧‧ Block 3
G4‧‧‧ Block 4
L1‧‧‧Pre-wet liquid
L2‧‧‧BCP coating solution
S1‧‧‧Process
S2‧‧‧Process
S3‧‧‧Process
S4‧‧‧Process
S5‧‧‧Process
S11‧‧‧Process
S12‧‧‧Process
S13‧‧‧Process
W‧‧‧ Wafer
X‧‧‧ direction
Y‧‧‧direction θ‧‧‧direction

FIG. 1 is an explanatory plan view showing a schematic configuration of a substrate processing system according to this embodiment. FIG. 2 is an explanatory plan view showing the outline of the configuration of a coating processing apparatus. FIG. 3 is an explanatory front view showing the outline of the configuration of a coating processing apparatus. [Fig. 4] An explanatory view showing the back of the outline of the configuration of the coating processing device. 5 is an explanatory plan view showing an outline of a configuration of an etching apparatus. FIG. 6 is a longitudinal cross-sectional view showing a schematic configuration of a block copolymer coating device. [Fig. 7] A schematic cross-sectional view showing the structure of a block copolymer coating device. [Fig. 8] (A) to (D) are explanatory diagrams showing a state where a coating film of a block copolymer is formed on a wafer by a block copolymer coating apparatus. [FIG. 9] (A) and (B) are explanatory drawings which show typically the aspect of the film of a block copolymer. [Fig. 10] (A) and (B) are explanatory diagrams showing a state of a thin film of a block copolymer before drying at a center portion of a wafer. [FIG. 11] A flowchart explaining a main process of the wafer. FIG. 12 is a flowchart illustrating a block copolymer film forming process. FIG. 13 is a graph showing a film thickness distribution of the block copolymer films of Example 1 and Comparative Example 1. FIG. FIG. 14 is a graph showing film thickness distributions of the block copolymer films of Example 2 and Comparative Example 2. FIG.

127‧‧‧ Nozzle Arm

130‧‧‧The first nozzle

131‧‧‧Nozzle 2

F1‧‧‧ Pre-wet liquid film

F2‧‧‧ Pre-wet liquid film

L1‧‧‧Pre-wet liquid

L2‧‧‧BCP coating solution

W‧‧‧ Wafer

Claims (18)

A substrate processing method, which uses a block copolymer containing a hydrophilic polymer and a hydrophobic polymer to treat a substrate, and includes: a pre-wet liquid film forming process that uses a solvent of a coating solution containing the block copolymer A pre-wetting solution is supplied to the substrate to form a liquid film of the pre-wetting solution; and a block copolymer film forming process, after the pre-wetting liquid film forming process, the coating solution of the block copolymer is supplied To the substrate and rotating the substrate to form a thin film of the block copolymer; the pre-wet liquid film forming process includes forming the liquid film of the pre-wet liquid into a ring-shaped annular film concentric with the substrate Forming process. For example, in the substrate processing method of claim 1, the annular film forming process arranges a nozzle for supplying the pre-wetting liquid at a predetermined position on the outer periphery of the substrate, and supplies the pre-wetting from the nozzle. In the state of liquid, the substrate is rotated once, and the liquid film of the pre-wet liquid is formed into the ring shape. For example, the method for processing a substrate according to item 2 of the patent scope, wherein the distance from the center of the substrate to the nozzle is greater than 3.3% of the radius of the substrate and less than 40% of the radius. For example, the substrate processing method of item 2 or item 3 of the patent application scope, wherein the pre-wet liquid film formation process includes a pre-wet liquid film diffusion process, and the pre-wet liquid film diffusion process is The rotation speed of the substrate is fast, so that the substrate rotates, so that the liquid film of the pre-wet liquid formed in the shape of the ring is expanded toward the outer periphery of the substrate. For example, the method for processing a substrate according to any one of claims 1 to 3 of the patent application scope includes a drying process that dries the film of the block copolymer. For example, in the method for processing a substrate according to any one of claims 1 to 3, in the block copolymer film forming process, a coating solution of the block copolymer is supplied to a center portion of the substrate. . For example, the method for processing a substrate according to any one of claims 1 to 3, wherein the film thickness of the thin film of the block copolymer is 100 nm or less. For example, the method for processing a substrate according to any one of claims 1 to 3, wherein the viscosity of the coating solution of the block copolymer is 3 cP or less. A program that operates on a computer used to control a control unit of a substrate processing system to cause the substrate processing system to execute a substrate processing method according to any one of claims 1 to 8 of the scope of patent application. A readable computer recording medium storing a program such as the item 9 in the scope of patent application. A substrate processing system that uses a block copolymer containing a hydrophilic polymer and a hydrophobic polymer to process a substrate, and includes: a block copolymer coating device that supplies a coating solution for the block copolymer, And forming a thin film of the block copolymer; the block copolymer coating device has: a first nozzle for supplying a pre-wetting solution containing a solvent of the coating solution of the block copolymer to the substrate; and a second A nozzle, which supplies the coating solution of the block copolymer to the substrate; the block copolymer coating device supplies the pre-wet solution to the substrate from the first nozzle, and forms on the substrate the substrate and the substrate; A concentric annular liquid film of the pre-wet liquid, and supplying the coating solution of the block copolymer from the second nozzle to the substrate after forming the liquid film of the pre-wet liquid, and rotating the substrate, A film of the block copolymer is formed. For example, the substrate processing system according to claim 11 in which the block copolymer coating device arranges the first nozzle at a predetermined position on the outer periphery of the substrate, and supplies the pre-wet liquid from the first nozzle. In this state, the substrate is rotated once to form a liquid film of the annular pre-wet liquid. For example, the substrate processing system of claim 12 in which the distance from the center of the substrate to the first nozzle is greater than 3.3% of the radius of the substrate and less than 40% of the radius. For example, the substrate processing system of the 12th or 13th in the scope of patent application, wherein the block copolymer coating device has a "speed faster than the rotation speed of the substrate when the liquid film of the annular pre-wet liquid is formed. The "rotation speed" rotates the substrate, so that the liquid film of the annular pre-wetting liquid expands in the outer peripheral direction of the substrate. For example, the substrate processing system according to any one of claims 11 to 13, wherein the block copolymer coating device rotates the substrate and dries the film of the block copolymer. For example, the substrate processing system according to any one of claims 11 to 13, wherein the block copolymer coating device supplies the coating solution of the block copolymer to the substrate from the second nozzle. The center. For example, the substrate processing system according to any one of claims 11 to 13, wherein the film thickness of the thin film of the block copolymer is 100 nm or less. For example, the substrate processing system according to any one of claims 11 to 13, wherein the viscosity of the coating solution of the block copolymer is 3 cP or less.