TW202503038A - Development method and substrate processing system - Google Patents

Abstract

An object of the invention is to reduce the amount of residue produced on the surface of a substrate during development processing of a metal-containing coating film. A development method for performing development processing of a substrate, the method including a step of supplying a developing liquid containing an organic solvent to a substrate on which a metal-containing coating film has been exposed in a predetermined pattern, and a step of supplying a first cleaning liquid containing an organic solvent to the substrate to which the developing liquid has been supplied, wherein the first cleaning liquid has lower solubility of the metal-containing coating film than the developing liquid, and contains 0.25 to 50% by volume of pure water.

Description

Development method and substrate processing system

The present invention relates to a developing method and a substrate processing system.

Patent document 1 discloses a developing method, comprising: a developer supplying step, supplying a developer containing an organic solvent to a substrate having a metal-containing coating film exposed to a predetermined pattern; and a cleaning liquid supplying step, supplying a cleaning liquid containing an organic solvent to the substrate after the developer has been supplied. The cleaning liquid supplying step of the developing method uses a cleaning liquid in which the metal-containing coating film is more soluble than the developer. [Prior art document]

[Patent Document 1] Japanese Patent Application Publication No. 2022-096081

[Problems to be solved by the invention]

The technology of the present invention reduces: the amount of residue on the surface of the substrate generated during the development process of the metal-containing coating film. [Means for solving the problem]

One aspect of the present invention is a developing method for developing a substrate; it comprises: a developer supplying step, supplying a developer containing an organic solvent to the substrate having a metal-containing coating film exposed to a predetermined pattern; and a first cleaning liquid supplying step, supplying a first cleaning liquid containing an organic solvent to the substrate after the developer is supplied; the first cleaning liquid has a lower solubility in the metal-containing coating film than the developer, and the first cleaning liquid contains 0.25 to 50 volume % of pure water. [Effects of the invention]

According to the present invention, the amount of residue on the surface of the substrate generated during the development process of the metal-containing coating film can be reduced.

In the manufacturing process of semiconductor devices, there is a photolithography step, which is to coat a semiconductor wafer (hereinafter referred to as "wafer") with a photoresist to form a photoresist film, expose the photoresist film, and develop the exposed photoresist film to form a photoresist pattern. As is known to all, in this photolithography step, in order to form a finer photoresist pattern, a photoresist liquid containing metal is used to form a metal-containing photoresist film on the wafer.

When the metal-containing photoresist film is exposed, metal atoms and oxygen atoms undergo polymerization reaction in the exposed part, while no such polymerization reaction occurs in the unexposed part. Since the polymerized part is not easily dissolved in the developer, when the developer is supplied to the wafer after exposure, only the unexposed part is dissolved, forming a predetermined pattern on the wafer.

In other words, the unexposed area is basically an area where no polymerization reaction occurs, but in the area near the boundary between the unexposed area and the exposed area, an intermediate polymer that is not easily dissolved in the developer may be formed by slightly exposing the area. In the unexposed area where such an intermediate polymer is formed, when the developer is supplied during the development process, a part of the intermediate polymer is not dissolved by the developer, and residues such as photoresist residues remain on the wafer.

Since the residue on the wafer is the cause of pattern defects, people hope to reduce the amount of residue. In the developing method described in Patent Document 1, in terms of the solubility of the metal-containing photoresist film, a cleaning solution with a lower solubility than the developer is supplied to the wafer in an attempt to dissolve the residue instead of the pattern. However, from the perspective of reducing the amount of residue, there is still room for improvement.

The technology of the present invention reduces the amount of residue on the surface of the substrate generated during the development process of the metal-containing coating film.

Hereinafter, the developing method of this embodiment and the substrate processing system for performing the developing method will be described with reference to the drawings. In addition, in this specification and drawings, the elements having substantially the same functional structure are marked with the same symbols to omit repeated descriptions.

(Substrate processing system) First, a substrate processing system for performing the development method described below is described. FIG. 1 is a top view showing a schematic diagram of the internal structure of the substrate processing system of this embodiment. FIG. 2 and FIG. 3 are schematic diagrams showing the internal structure of the substrate processing system of FIG. 1 from the front side and the internal structure of the substrate processing system from the back side, respectively.

As shown in FIGS. 1 to 3 , the substrate processing system 1 comprises: a wafer cassette station 10, which is used to carry in and out a wafer cassette C containing a plurality of substrates, i.e., wafers W; and a processing station 11, which is equipped with a plurality of various processing devices, and performs predetermined processing on the wafers W. In addition, the substrate processing system 1 is integrally connected to: the wafer cassette station 10; the processing station 11; and an interface station 13, which is adjacent to the processing station 11 and transfers the wafers W between the exposure device 12.

The wafer cassette station 10 is provided with a wafer cassette placement table 20 . The wafer cassette placement table 20 is provided with a plurality of wafer cassette placement plates 21 , on which the wafer cassettes C are placed when the wafer cassettes C are carried in and out of the substrate processing system 1 .

The wafer cassette station 10 is provided with a wafer transfer device 23 that can move arbitrarily on a transfer path 22 extending along the X direction of FIG. 1 . The wafer transfer device 23 can also move arbitrarily in the up-down direction and around the lead straight axis (θ direction), and can transfer wafers W between the wafer cassettes C on each wafer cassette mounting plate 21 and the transfer device of the third block G3 of the processing station 11 described later.

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

2, the first block G1 is provided with a developer supply device 30, a photoresist coating device 31, and a cleaning liquid supply device 32 as liquid processing devices. The liquid processing devices 30-32 are arranged horizontally in parallel at different heights.

The developer supply device 30 supplies developer to the wafer W for development processing. The photoresist coating device 31 supplies a photoresist containing metal (such as Sn) as a metal-containing coating to the wafer, and forms a metal-containing photoresist film, i.e., a metal-containing coating film, on the wafer. The photoresist coating device 31 sprays the photoresist onto the wafer W from a nozzle, and rotates the wafer W to diffuse the photoresist on the surface of the wafer W. The cleaning liquid supply device 32 supplies a first cleaning liquid containing an organic solvent to the wafer to clean the wafer. The number or arrangement of these developer supply devices 30, photoresist coating devices 31, and cleaning liquid supply devices 32 can be selected arbitrarily.

The developer supply device 30, the photoresist coating device 31, and the cleaning liquid supply device 32 use, for example, a predetermined processing liquid or coating liquid to perform spin coating on the wafer W. In the spin coating process, for example, the processing liquid or coating liquid is sprayed onto the wafer W from a nozzle, and the wafer W is rotated to diffuse the processing liquid or coating liquid on the surface of the wafer W.

As shown in FIG3 , the second block G2 has a heat treatment device 40, a peripheral exposure device 41, and an ultraviolet irradiation device 42 arranged in parallel in the vertical direction and the horizontal direction. The heat treatment device 40 heats or cools the wafer W, that is, performs heat treatment. The peripheral exposure device 41 exposes the outer periphery of the wafer W. The ultraviolet irradiation device 42 irradiates ultraviolet rays to the wafer W. The number or arrangement of these heat treatment devices 40, peripheral exposure devices 41, and ultraviolet irradiation devices 42 can be selected arbitrarily.

The third block G3 is provided with a plurality of transmission devices in order from the bottom, namely, transmission devices 50, 51, 52, 53, 54, 55, 56. Moreover, the fourth block G4 is provided with a plurality of transmission devices in order from the bottom, namely, transmission devices 60, 61, 62.

As shown in FIG. 1 and FIG. 3 , the area surrounded by the first block G1 to the fourth block G4 forms a wafer transfer area T. The wafer transfer area T is provided with a wafer transfer device 70 .

Each wafer transport device 70 has a transport arm 70a, which can move arbitrarily in the X direction, Y direction, θ direction, and up and down direction, for example. The wafer transport device 70 has a plurality of stages arranged above and below, and each wafer transport device 70 moves in the wafer transport area T, for example, and can transport the wafer W to a predetermined device at approximately the same height of each block G1 to G4.

In addition, the wafer transfer area T is provided with a transfer shuttle transfer device 80 for linearly transferring the wafer W between the third block G3 and the fourth block G4.

The shuttle transport device 80 can move, for example, along any straight line in the Y direction of Fig. 3. The shuttle transport device 80 can transport wafers between the transfer device 52 in the third block G3 and the transfer device 62 in the fourth block G4 by moving along the Y direction while supporting the wafers.

As shown in FIG. 1 , a wafer transfer device 90 is provided on the positive side of the third block G3 in the X direction. The wafer transfer device 90 has a transfer arm 90a, which can move arbitrarily in the X direction, the θ direction, and the up and down direction, for example. The wafer transfer device 90 moves up and down while supporting the wafer W, and can transfer the wafer W to each transfer device 50 to 56 in the third block G3.

The interface station 13 is provided with a wafer transfer device 100 and a transfer device 101. The wafer transfer device 100 has a transfer arm 100a, which can be moved arbitrarily in the Y direction, the θ direction, and the up and down direction, for example. The wafer transfer device 100 supports the wafer W, for example, in the transfer arm 100a, and transfers the wafer W between the transfer devices 60-62 in the fourth block G4, the transfer device 101 of the interface station 13, and the exposure device 12.

As shown in FIG. 1 , the substrate processing system 1 described above is provided with a control unit 200. The control unit 200 is, for example, a computer equipped with a CPU or a memory, and has a program storage unit (not shown). The program storage unit stores a program, and the program includes instructions for controlling various processes performed by the substrate processing system 1. In addition, the program is stored in a storage medium H readable by a computer, or may be installed in the control unit 200 from the storage medium H. The storage medium H may be a temporary storage type or a non-temporary storage type.

The above is a brief description of the structure of the substrate processing system 1. Next, the structure of each of the developer supply device 30, the cleaning liquid supply device 32, the heat treatment device 40, and the ultraviolet irradiation device 42 provided in the substrate processing system 1 of this embodiment will be described in order.

<Developer supply device> Figure 4 is a longitudinal cross-sectional view showing the schematic structure of the developer supply device 30 of the present embodiment. The developer supply device 30 has a processing container 110, and a substrate, i.e., a wafer W feed-in and feed-out port (not shown) is formed on the side of the processing container 110. The processing container 110 has a substrate holding portion, i.e., a rotating chuck 111. The rotating chuck 111 holds the wafer W horizontally and is connected to a rotating portion 112 that can be raised and lowered at will. The rotating portion 112 is connected to a rotating drive portion 113 composed of a motor, etc., and the wafer W held by the rotating chuck 111 rotates by the drive of the rotating drive portion 113.

The top of the processing container 110 is provided with a filter device 114. The air purified by the filter device 114 is supplied to the processing container 110 through the air supply unit 115, and a downflow is formed in the processing container 110.

A cup body 116 is disposed around the rotary chuck 111 to receive and recover liquid scattered or dropped from the wafer W. A liquid drain pipe 117 and an exhaust pipe 118 are disposed at the bottom of the cup body 116. The exhaust pipe 118 is connected to an exhaust device 119 such as an exhaust pump.

The processing container 110 is provided with a developer nozzle 120 as a developer supply unit for spraying developer toward the surface of the wafer W. The developer nozzle 120 is provided, for example, on a nozzle support unit 121 of an arm or the like. The nozzle support unit 121 can be raised and lowered arbitrarily along the reciprocating arrow A indicated by the dashed line in the figure by a driving mechanism (not shown), and can be moved horizontally arbitrarily along the reciprocating arrow B indicated by the dashed line. The developer nozzle 120 is connected to a developer supply source 123 via a supply pipe 122.

Furthermore, the processing container 110 is provided with a first cleaning liquid nozzle 130 as a first cleaning liquid supply unit for spraying the first cleaning liquid toward the surface of the wafer W. The first cleaning liquid nozzle 130 is, for example, provided on a nozzle support unit 131 of an arm or the like. The nozzle support unit 131 can be raised and lowered arbitrarily along the reciprocating arrow S indicated by the dashed line in the figure by a driving mechanism (not shown), and can be moved horizontally arbitrarily along the reciprocating arrow D indicated by the dashed line. The first cleaning liquid nozzle 130 is connected to a supply source 133 of the first cleaning liquid via a supply pipe 132.

According to the developer supply device 30 of this embodiment, the developer or the first cleaning liquid is supplied to the center of the wafer W while rotating the wafer W, so that the developer or the first cleaning liquid is diffused throughout the wafer W.

Furthermore, the method of supplying the developer or the first cleaning liquid is not particularly limited as long as the developer or the first cleaning liquid can be supplied to the surface of the wafer W. That is, the device structure of the developer supply device 30 is appropriately changed according to the development method adopted, such as an immersion development method or a spraying development method. For another example, the cleaning liquid supply device 32 described below is provided with the first cleaning liquid nozzle 130, and after the development process, the wafer W is transported to the cleaning liquid supply device 32, and the first cleaning liquid is supplied to the wafer W.

<Cleaning liquid supply device> Figure 5 is a longitudinal cross-sectional view showing the schematic structure of the cleaning liquid supply device 32 of the present embodiment. The cleaning liquid supply device 32 has a housing 140, and the side surface of the housing 140 is formed with: a wafer W delivery port (not shown). The housing 140 has: a substrate holding portion, i.e., a rotating chuck 141. The rotating chuck 141 holds the wafer W horizontally and is connected to a rotating portion 142 that can be raised and lowered at will. The rotating portion 142 is connected to a rotating drive portion 143 composed of a motor, etc., and the wafer W held by the rotating chuck 141 rotates by the drive of the rotating drive portion 143.

The top of the housing 140 is provided with a filter device 144. The air purified by the filter device 144 is supplied to the housing 140 through the air supply unit 145, and a downflow is formed in the housing 140.

A cup body 146 is provided around the rotary chuck 141 to receive and recover liquid scattered or dropped from the wafer W. A liquid drain pipe 147 and an exhaust pipe 148 are provided at the bottom of the cup body 146. The exhaust pipe 148 is connected to an exhaust device 149 such as an exhaust pump.

The housing 140 is provided with a second cleaning liquid nozzle 150 as a second cleaning liquid supply unit for spraying the second cleaning liquid toward the surface of the wafer W. The second cleaning liquid nozzle 150 is, for example, provided on a nozzle support unit 151 of an arm or the like. The nozzle support unit 151 can be raised and lowered arbitrarily along the reciprocating arrow E indicated by the dotted line in the figure by a driving mechanism (not shown), and can be moved horizontally arbitrarily along the reciprocating arrow F indicated by the dotted line. The second cleaning liquid nozzle 150 is connected to a supply source 153 of the second cleaning liquid via a supply pipe 152.

According to the cleaning liquid supply device 32 of this embodiment, the second cleaning liquid is supplied to the center of the wafer W while rotating the wafer W, so that the second cleaning liquid is diffused throughout the wafer W. In addition, the method of supplying the cleaning liquid is not particularly limited as long as the second cleaning liquid can be supplied to the surface of the wafer W. That is, the structure of the cleaning liquid supply device 32 is not limited to the structure described in this embodiment.

<Heat treatment device> Figure 6 is a longitudinal cross-sectional view showing a schematic structure of the heat treatment device 40 of the present embodiment. The heat treatment device 40 has a processing container 160, and a wafer W delivery port (not shown) is formed on the side of the processing container 160. The processing container 160 is provided with a loading platform 161, which is a substrate holding part for loading the wafer W. The loading platform 161 is built with a heater 162, which is a heating part for heating the wafer W. In addition, the loading platform 161 has through holes 163 formed at multiple locations, and the lifting pins 164a that are raised and lowered in these through holes 163 are fixed to the lifting pin support part 164. The lifting pin support part 164 is lifted and lowered by the lifting mechanism 165.

In addition, the heat treatment device 40 is not limited to the structure described in this embodiment, as long as it can heat the wafer W.

<Ultraviolet irradiation device> Figure 7 is a longitudinal cross-sectional view showing the schematic structure of the ultraviolet irradiation device 42 of the present embodiment. The ultraviolet irradiation device 42 has a housing 170, and a wafer W delivery port (not shown) is formed on the side of the housing 170. In addition, a loading platform 171 is provided in the housing 170, which is a substrate holding portion for loading the wafer W. The loading platform 171 has through holes 172 formed at a plurality of locations, and the lifting pins 173a that are lifted and lowered in these through holes 172 are fixed to the lifting pin support portion 173. The lifting pin support portion 173 is lifted and lowered by the lifting mechanism 174.

Above the mounting table 171, there is disposed an ultraviolet lamp 175 as an ultraviolet irradiation unit for irradiating ultraviolet rays to the surface of the wafer W mounted on the mounting table 171. The ultraviolet lamp 175 radiates ultraviolet rays with a wavelength of 190 to 400 nm. The ultraviolet irradiation device 42 uses, for example, a KrF exposure device that irradiates ultraviolet rays with a wavelength of 248 nm, but the ultraviolet irradiation device 42 is not particularly limited as long as it can irradiate ultraviolet rays with a wavelength of 190 to 400 nm.

The above is a description of the substrate processing system 1 according to the present embodiment.

(Development method) Next, a development method for a wafer W using the substrate processing system 1 is described. FIG. 8 is an explanatory diagram showing the state of the photoresist film on the wafer in each step of the development method of this embodiment.

First, as shown in FIG. 8( a ), when developing the wafer W, a photoresist coating device is used to form a metal-containing photoresist film R on the surface of the wafer W.

Afterwards, the wafer W is subjected to peripheral exposure processing by the peripheral exposure device 41, exposure processing by the exposure device 12, and PEB processing by the heat treatment device 40. As shown in FIG8(b), the photoresist film formed on the surface of the wafer W is formed into a state where an unexposed photoresist film (hereinafter referred to as "unexposed photoresist film _R1 ") and a photoresist film after exposure (hereinafter referred to as "exposed photoresist film _R2 ") are mixed, and are exposed to a predetermined pattern. The predetermined pattern is appropriately set according to the specifications of the semiconductor product.

In other words, as shown in FIG9 , during the exposure process, the exposure is performed under a state where the exposure intensity changes periodically according to the characteristics of the exposure machine. Therefore, in the central area of the unexposed photoresist film _R1 that is sufficiently separated from the boundary of the exposed photoresist film _R2 , the exposure intensity is relatively small, which is equivalent to the degree that the polymerization reaction has not been carried out; however, compared with the central area of the unexposed photoresist film _R1 , the exposure intensity near the boundary between the unexposed photoresist film _R1 and the exposed photoresist film _R2 is relatively large.

Therefore, the central area of the unexposed photoresist film _R1 does not undergo polymerization, but only a slight polymerization reaction occurs near the boundary between the unexposed photoresist film _R1 and the exposed photoresist film _R2 to form an intermediate polymer. In the following description, the area of the unexposed photoresist film _R1 where the intermediate polymer is formed is referred to as "area _A1 ".

On the other hand, since the exposure intensity changes periodically as described above, the central region of the exposed photoresist film _R2 which is sufficiently separated from the boundary of the unexposed photoresist film _R1 is exposed at an exposure intensity at which the polymerization reaction is sufficiently carried out. However, near the boundary of the exposed photoresist film _R2 and the unexposed photoresist film _R1 , the exposure intensity is smaller than that of the central region of the exposed photoresist film _R2 .

Therefore, the central area of the exposed photoresist film _R2 undergoes sufficient polymerization reaction, but the polymerization reaction does not proceed sufficiently near the boundary between the exposed photoresist film _R2 and the unexposed photoresist film _R1 , and an intermediate polymer is formed. In the following description, the area of the exposed photoresist film _R2 where the intermediate polymer is formed is referred to as "area _A2 ".

Next, as shown in FIG8(c), the wafer W having a predetermined pattern exposed is transported to the developer supply device 30, and a developer containing an organic solvent is supplied to the surface of the wafer W. Thus, the unexposed photoresist film _R1 formed on the surface of the wafer W is dissolved.

Furthermore, the type of organic solvent contained in the developer is not particularly limited as long as it is an organic solvent that dissolves the unexposed photoresist film _R1 but does not dissolve the exposed photoresist film _R2 . Furthermore, the developer may be a mixture of two or more organic solvents, for example, a mixture of PGMEA (propylene glycol monomethyl ether acetate) and acetic acid may be used as the developer.

Furthermore, when the developer contains pure water, it is preferred that the pure water in the developer is less than 0.25%. When the pure water in the developer is less than 0.25%, the photoresist pattern can be suppressed from becoming thinner. When the pure water in the developer is more than 0.25%, the solubility of the exposed photoresist film _R2 in the developer increases, and the photoresist pattern may become thinner. In this regard, the exposure intensity of the exposure machine must be increased in the exposure process before development.

On the other hand, the unexposed photoresist film _R1 includes the region _A1 where the intermediate polymer is formed as described above. Compared with the central region of the unexposed photoresist film _R1 , the intermediate polymer included in this region _A1 is not easily dissolved in the developer. Therefore, in the step of supplying the developer to the wafer W shown in FIG8(c), a part of the intermediate polymer included in the region _A1 is not dissolved in the developer, and residues such as photoresist residues sometimes remain on the surface of the wafer W.

In order to remove the residue, in the next step, a first cleaning solution is supplied to the surface of the wafer W. The first cleaning solution supplied here includes an organic solvent and 0.25-50 volume % pure water. In order to avoid dissolving the photoresist pattern, the first cleaning solution is a processing solution containing a metal photoresist film whose solubility is lower than that of the developer.

The so-called "solubility of metal-containing photoresist film" is an indicator showing whether the metal-containing photoresist film is easily dissolved in a processing liquid such as a developer or a first cleaning liquid. For example, when evaluating the solubility of two processing liquids, the same amount of the two processing liquids is supplied to a metal-containing photoresist film of the same composition, and the dissolution amount (volume reduction) of the photoresist film per unit time is compared. In addition, the processing liquid with a smaller dissolution amount of the photoresist film per unit time of the two processing liquids is the processing liquid with a smaller solubility of the metal-containing photoresist film compared to the other processing liquid.

The developer has such solubility that the exposed photoresist film _R2 is not dissolved. However, if a treatment liquid having a solubility greater than that of the developer is used as the first cleaning liquid, the exposed photoresist film _R2 may be dissolved, resulting in the collapse of the pattern shape.

Moreover, compared with the central area of the exposed photoresist film R ₂ , the aforementioned area A ₂ of the exposed photoresist film R ₂ has not undergone polymerization reaction. Therefore, since the area A ₂ is more easily dissolved in the organic solvent than the central area of the exposed photoresist film R ₂ , when the solubility of the metal-containing photoresist film in the first cleaning solution is the same as that of the developer, the exposed photoresist film R ₂ in the area A ₂ is slightly dissolved, which may cause the pattern shape to collapse.

Therefore, in terms of the solubility of the metal photoresist film, by using the treatment liquid with a solubility lower than that of the developer as the first cleaning liquid, as shown in FIG8 (d), the exposed photoresist film _R2 can be dissolved without dissolving the residues left on the surface of the wafer W. In other words, the amount of residues on the surface of the wafer W can be reduced without causing pattern collapse.

The type of organic solvent contained in the first cleaning solution is not particularly limited as long as it is a processing solution that has a lower solubility in the metal-containing photoresist film than the developer. For example, when the organic solvent contained in the developer is 2-heptanone, the organic solvent contained in the first cleaning solution may be MIBC (4-methyl-2-pentanol) or PGMEA (propylene glycol monomethyl ether acetate), which have a lower solubility in the metal-containing photoresist film than 2-heptanone.

Furthermore, when the organic solvent contained in the developer is a mixture of PGMEA (propylene glycol monomethyl ether acetate) and acetic acid, the organic solvent contained in the first cleaning solution can be, for example, one selected from the group consisting of 2-heptanone, IPA (isopropyl alcohol), PGME (propylene glycol monomethyl ether), PGMEA (propylene glycol monomethyl ether acetate), nBA (n-butyl acetate), cyclohexanone, MIBC (4-methyl-2-pentanol), and ethyl lactate, or a mixture of two or more.

Since the pure water contained in the first cleaning solution is a highly polar solvent, it is easy to dissolve highly polar substances, i.e., residues. Therefore, by supplying the first cleaning solution containing 0.25 to 50 volume % of pure water to the wafer W, the amount of residues on the surface of the wafer W can be reduced compared to the case where a cleaning solution not containing pure water is supplied.

Furthermore, when the pure water in the first cleaning solution is less than 0.25 volume %, the residual material cannot be sufficiently dissolved.

On the other hand, when the pure water in the first cleaning liquid is above 50 volume %, the characteristics of the pure water have a major influence on the wettability of the first cleaning liquid, and the contact angle of the first cleaning liquid to the wafer W or the exposed photoresist film _R2 increases. Therefore, droplets are easily formed on the surface of the wafer W or the surface of the exposed photoresist film _R2 after being supplied with the first cleaning liquid, and liquid splashing is generated as the wafer W rotates, so the module is easily contaminated.

Furthermore, on the surface of the wafer W, there are areas with different wettability due to the presence of exposed areas or unexposed areas. However, if the contact angle of the first cleaning solution is increased by including more than 50 volume % of pure water in the first cleaning solution, the difference in contact angle increases in the areas with different wettability as described above. Since it is difficult for the liquid in the area with a smaller contact angle to flow to the area with a relatively larger contact angle, when the pure water in the first cleaning solution is more than 50 volume %, it is difficult to remove the first cleaning solution even if the wafer W is rotated.

Based on the above reasons, the pure water in the first cleaning solution is limited to 0.25-50 volume %.

In addition, among the organic solvents that can be used as the first cleaning solution, organic solvents such as IPA or PGME have a high hydrophilicity and are easily mixed with pure water. On the other hand, organic solvents such as 2-heptanone, PGMEA, and nBA have a lower hydrophilicity than the above-mentioned IPA or PGME and are easily separated from pure water.

Therefore, when the organic solvent contained in the first cleaning solution uses organic solvents with lower hydrophilicity such as 2-heptanone, PGMEA, and nBA, it is better to mix organic solvents with higher hydrophilicity such as IPA or PGME. In this way, organic solvents with higher hydrophilicity such as IPA or PGME promote the mixing of organic solvents with lower hydrophilicity such as 2-heptanone, PGMEA, and nBA with pure water. Even if organic solvents with lower hydrophilicity are used, the first cleaning solution can still be fully mixed with pure water.

The above is a description of the developing method of the present embodiment. According to the developing method, by supplying a developer to the wafer W and then supplying a first cleaning solution to the wafer W, a predetermined photoresist pattern can be formed while reducing the amount of "residues on the surface of the wafer W that are not dissolved in the developer and remain".

(Use the second cleaning solution for cleaning) In order to further reduce the amount of residues remaining on the surface of wafer W, after supplying the first cleaning solution to wafer W, perform the following steps as needed.

First, the wafer W cleaned by the cleaning solution is transported to the ultraviolet irradiation device 42, and the surface of the wafer W is irradiated with ultraviolet light of a wavelength of 190 to 400 nm. In this step, for example, KrF exposure with a wavelength of 248 nm is performed. When irradiating ultraviolet light, no mask is used, but the entire wafer W is uniformly irradiated with ultraviolet light. As shown in FIG8 (e), the exposure reaction of the entire exposure photoresist film _R2 is further performed, and the area _A2 of the photoresist film _R2 , which is relatively not subjected to the exposure reaction, is also subjected to the exposure reaction in the same manner as other areas.

Furthermore, when the wavelength of the ultraviolet light is less than 190 nm, after irradiation with the ultraviolet light, the C—O bond of the photoresist film R ₂ is broken, but no exposure reaction of the photoresist film R ₂ occurs. Furthermore, in the present embodiment, the ultraviolet light is irradiated by the ultraviolet light irradiation device 42, but it may also be irradiated by the exposure device 12, for example.

Next, the wafer W irradiated with ultraviolet rays is transported to a heat treatment device 40 for heating. As shown in FIG8(f), the polymerization reaction of the exposed photoresist film _R2 is further promoted, and the photoresist film _R2 is hardened and transformed into a strong photoresist film _R3 .

In this embodiment, the heat treatment device 40 is used to heat the wafer W after the ultraviolet irradiation. However, if the ultraviolet irradiation device 42 has a heating mechanism for the wafer W, the wafer W may be heated in the ultraviolet irradiation device. In addition, when the ultraviolet irradiation and the wafer W are heated in the same module, the wafer W may be heated during the ultraviolet irradiation or after the ultraviolet irradiation.

Next, the heated wafer W is transferred to the cleaning liquid supply device 32, and the second cleaning liquid is supplied to the surface of the wafer W. The second cleaning liquid contains an organic solvent, and as shown in FIG8(g), the second cleaning liquid contacts the residue on the surface of the wafer W, and the residue is dissolved.

Since the photoresist film _R3 hardened by ultraviolet irradiation and heat treatment is not easily dissolved in organic solvents, the second cleaning liquid can be a processing liquid with a higher solubility of the photoresist film than the first cleaning liquid. Therefore, in the step of cleaning the wafer W with the first cleaning liquid as shown in FIG8 (d), the residue that is not fully removed can be dissolved, and the amount of residue on the surface of the wafer W can be further reduced.

The organic solvent contained in the second cleaning solution is not particularly limited as long as it does not dissolve the hardened photoresist film _R3 , and may be a treatment solution formed by mixing two or more organic solvents. The organic solvent contained in the second cleaning solution is an alkaline treatment solution containing, for example, TMAH (tetramethylammonium hydroxide), or a treatment solution containing an organic acid such as acetic acid, formic acid, and citric acid.

In the present embodiment, the cleaning liquid supply device 32 supplies the second cleaning liquid to the wafer W. However, if the developer supply device 30 has a function of supplying the second cleaning liquid, the developer supply device 30 may also supply the second cleaning liquid.

Furthermore, the second cleaning liquid can be selected based on the difference in solubility caused by the difference in polarity between the second cleaning liquid and the first cleaning liquid. For example, when the concentration of pure water in the first cleaning liquid is low, a second cleaning liquid with a greater polarity than the first cleaning liquid can be used. As mentioned above, the solubility of the cleaning liquid can be changed, thereby suppressing the possibility of residues remaining on the surface of the wafer W.

After the wafer W is cleaned with the second cleaning solution as described above, the wafer W is then cleaned with pure water and dried, and a series of development steps are completed.

As described above, after the developer is supplied to the wafer W, the ultraviolet light with a wavelength of 190-400nm is irradiated, and then the wafer W is heated. Then, by supplying the second cleaning solution to the wafer W, the residue on the surface of the wafer can be dissolved, thereby further reducing the amount of residue.

For example, the device shown in FIG. 4 may also be implemented as described below: the supply source 133 is replaced by the supply source of the organic solvent, the supply pipe 132 is replaced by the supply pipe of the organic solvent, and the first cleaning liquid nozzle 130 is replaced by the organic solvent nozzle. At this time, the step of supplying the first cleaning liquid containing the organic solvent and pure water to the wafer W may be in the following two forms: adding and mixing pure water in the flow path of the organic solvent, that is, from the supply source of the organic solvent to the nozzle of the organic solvent nozzle; supplying the organic solvent to the surface of the wafer W, and supplying and mixing pure water to the organic solvent remaining on the surface of the wafer W.

In the flow path of the organic solvent, pure water is added and mixed, for example, a pure water supply pipe (not shown) is connected to a predetermined position of the organic solvent supply pipe, and pure water is supplied from the pure water supply pipe and mixed with the organic solvent. In addition, pure water is supplied and mixed with the organic solvent on the surface of the wafer W, for example, a nozzle (not shown) other than the organic solvent nozzle is set, and pure water is supplied from the separately set nozzle. The above-mentioned separately set nozzle can spray pure water toward the wafer W from a plurality of openings above the wafer W.

The pure water in the first cleaning solution is 0.25 to 50 volume %, but depending on the type of organic solvent, the higher the pure water concentration, the more likely it is to deteriorate due to the chemical reaction between the pure water and the organic solvent, which may cause degradation of process performance or defects. Taking this possibility into full consideration, the above-mentioned pure water concentration is preferably about 0.25 to 10 volume %. Compared to the situation where pure water is supplied in a liquid column state from the above-mentioned separately provided nozzle, when pure water is supplied in a spray state, the supply amount is quite small relative to the supply time, so it is easy to prepare the first cleaning solution with a pure water concentration of 0.25 to 10 volume % on the surface of the wafer W. Furthermore, since the first cleaning solution is supplied in a spray state, a first cleaning solution having a uniform pure water concentration distribution can be prepared in a short time on the surface of the wafer W. Moreover, the so-called "preparing the first cleaning solution on the surface of the wafer W" is equivalent to supplying the first cleaning solution containing an organic solvent and pure water to the wafer W, needless to say.

The step of supplying pure water to the organic solvent on the surface of wafer W may include: supplying developer to wafer W and after development is completed, supplying pure water only to a portion of the area including the center of wafer W. Regarding the timing of performing this step, the present invention accelerates the rotation speed of wafer W after the above-mentioned development process is completed, and uses centrifugal force to cause the liquid remaining on the surface of wafer W to begin to be discharged to the outside, and performs this step at the same time; or performs this step before accelerating the above-mentioned rotation speed. In addition, pure water may be supplied to the organic solvent on the surface of wafer W to prepare the first cleaning solution, and then pure water may be supplied to the above-mentioned portion of the area. In addition, the so-called above-mentioned portion of the area is: a portion of the inner area excluding the peripheral portion of the residual liquid on the surface of wafer W. In this way, since a region with a larger contact angle can be formed in the liquid remaining on the surface of the wafer W at a location closer to the inside than to its periphery, the liquid remaining on the surface of the wafer W can be pushed out by the inner liquid with the larger contact angle, thereby efficiently discharging the remaining liquid to the outside.

Furthermore, the substrate development method of the present invention can also be applied to processing target substrates other than semiconductor wafers, such as a method for developing an FPD (flat panel display) substrate.

The embodiments disclosed herein should be regarded as illustrative in all aspects, and not restrictive. The embodiments described above may be omitted, replaced, or changed in various ways without departing from the scope of the patent application in the appendix, the structural examples belonging to the technical scope of the present invention described later, and the main purpose thereof. For example, the constituent elements of the embodiments described above may be combined arbitrarily. From the arbitrary combination, the functions and effects of each constituent element of the combination may be obtained, and from the description of this specification, other functions and other effects that are clearly known to a person with ordinary knowledge in the relevant technical field may be obtained.

Furthermore, the effects described in this specification are still illustrative or exemplary in nature, not restrictive. That is, the technology of the present invention, in addition to the above effects, can also exert other effects that are clearly known to a person with ordinary knowledge in the relevant technical field from the description of this specification. Alternatively, it does not have the above effects, but can exert other effects that are clearly known to a person with ordinary knowledge in the relevant technical field from the description of this specification.

In addition, the following configuration examples also fall within the technical scope of the present invention. (1) A developing method for developing a substrate, comprising: a developer supplying step, supplying a developer containing an organic solvent to the substrate having a metal-containing coating film exposed to a predetermined pattern; and a first cleaning liquid supplying step, supplying a first cleaning liquid containing an organic solvent to the substrate after the developer has been supplied; the first cleaning liquid has a lower solubility in the metal-containing coating film than the developer, and the first cleaning liquid contains 0.25 to 50 volume % of pure water. (2) A developing method as in (1), wherein the organic solvent contained in the first cleaning solution is selected from the group consisting of 2-heptanone, isopropyl alcohol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, n-butyl acetate, cyclohexanone, 4-methyl-2-pentanol, and ethyl lactate, or a mixture of two or more. (3) A developing method as in (1) or (2), wherein the developer is a mixture of propylene glycol monomethyl ether acetate and acetic acid. (4) A developing method as in any one of (1) to (3), wherein the pure water contained in the developer is less than 0.25% by volume. (5) The developing method as described in any one of (1) to (4), further comprising: an ultraviolet irradiation step of irradiating the substrate with ultraviolet light having a wavelength of 190 to 400 nm after the substrate is supplied with the first cleaning solution; a substrate heating step of heating the substrate during or after the ultraviolet irradiation; and a second cleaning solution supplying step of supplying a second cleaning solution containing an organic solvent to the heated substrate. (6) The developing method as described in (5), wherein the second cleaning solution is an alkaline treatment solution or a treatment solution containing an organic acid. (7) A substrate processing system for developing a substrate; The substrate processing system comprises: A developer supply unit for supplying a developer containing an organic solvent to the substrate; A first cleaning liquid supply unit for supplying a first cleaning liquid containing an organic solvent to the substrate; and A control unit for controlling the operation of the developer supply unit and the first cleaning liquid supply unit; The control unit performs the following steps: A developer supply step for supplying the developer to the substrate having a metal-containing coating film exposed to a predetermined pattern; and A first cleaning liquid supply step for supplying the first cleaning liquid to the substrate after the developer is supplied; Compared with the developer, the first cleaning solution has a lower solubility in the metal-containing coating film, and the first cleaning solution contains 0.25-50 volume % of pure water. (8) A substrate processing system as in (7), wherein the organic solvent contained in the first cleaning solution is selected from one or a mixture of two or more selected from the group consisting of 2-heptanone, isopropyl alcohol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, n-butyl acetate, cyclohexanone, 4-methyl-2-pentanol, and ethyl lactate. (9) A substrate processing system as in (7) or (8), wherein the developer is a mixture of propylene glycol monomethyl ether acetate and acetic acid. (10) A substrate processing system as described in any one of (7) to (9), wherein the pure water contained in the developer is less than 0.25 volume %. (11) A substrate processing system as described in any one of (7) to (10), comprising: an ultraviolet irradiation unit for irradiating the substrate with ultraviolet rays having a wavelength of 190 to 400 nm; a heating unit for heating the substrate; and a second cleaning liquid supply unit for supplying a second cleaning liquid containing an organic solvent to the heated substrate; the control unit performs the following steps: an ultraviolet irradiation step for irradiating the substrate with ultraviolet rays having a wavelength of 190 to 400 nm after the first cleaning liquid is supplied; a substrate heating step for heating the substrate during or after the ultraviolet irradiation; and a second cleaning liquid supply step for supplying the second cleaning liquid to the heated substrate. (12) A substrate processing system as in (11), wherein the second cleaning solution is an alkaline processing solution or a processing solution containing an organic acid.

1: Substrate processing system 10: Wafer cassette station 11: Processing station 12: Exposure device 13: Interface station 20: Wafer cassette loading platform 21: Wafer cassette loading plate 22: Conveying path 23: Wafer conveying device 30: Developer supply device (liquid processing device) 31: Photoresist coating device (liquid processing device) 32: Cleaning liquid supply device (liquid processing device) 40: heat treatment device 41: peripheral exposure device 42: ultraviolet irradiation device 50~56: transfer device 60~62: transfer device 70: wafer transfer device 70a: transfer arm 80: shuttle transfer device 90: wafer transfer device 90a: transfer arm 100: wafer transfer device 100a: transfer arm 101: transfer device 110: treatment Container 111: Rotating chuck 112: Rotating part 113: Rotating driving part 114: Filter device 115: Air supply part 116: Cup body 117: Liquid discharge pipe 118: Air discharge pipe 119: Air discharge device 120: Developer nozzle 121: Nozzle support part 122: Supply pipe 123: Developer supply source 130: First cleaning liquid nozzle 131: Nozzle Nozzle support 132: supply pipe 133: supply source 140: housing 141: rotating chuck 142: rotating part 143: rotating drive part 144: filter device 145: air supply part 146: cup body 147: liquid discharge pipe 148: exhaust pipe 149: exhaust device 150: second cleaning liquid nozzle 151: nozzle support 152: supply pipe 153 : Supply source 160: Processing container 161: Mounting table 162: Heater 163: Through hole 164: Lifting pin support 164a: Lifting pin 165: Lifting mechanism 170: Housing 171: Mounting table 172: Through hole 173: Lifting pin support 173a: Lifting pin 174: Lifting mechanism 175: Ultraviolet lamp 200: Control unit A ₁ , A ₂ : Area A, B, S, D, E, F: Reciprocating arrows C: Wafer cassette G1: First block G2: Second block G3: Third block G4: Fourth block H: Storage medium R: Metal-containing photoresist film R ₁ : Unexposed photoresist film R ₂ : Exposed photoresist film R ₃ : Photoresist film T: Wafer transfer area W: Wafer X, Y, θ: Direction

[Figure 1] Figure 1 is a top view showing the schematic internal structure of a substrate processing system of an implementation. [Figure 2] Figure 2 is a front view showing the schematic internal structure of the substrate processing system of Figure 1. [Figure 3] Figure 3 is a back view showing the schematic internal structure of the substrate processing system of Figure 1. [Figure 4] Figure 4 is a longitudinal cross-sectional view showing the schematic structure of a developer supply device of an implementation. [Figure 5] Figure 5 is a longitudinal cross-sectional view showing the schematic structure of a cleaning liquid supply device of an implementation. [Figure 6] Figure 6 is a longitudinal cross-sectional view showing the schematic structure of a heat treatment device of an implementation. [Figure 7] Figure 7 is a longitudinal cross-sectional view showing the schematic structure of an ultraviolet irradiation device of an implementation. [Figure 8] Figure 8 (a) to (g) are explanatory diagrams showing the state of the photoresist film on the wafer in each step of the development method of the implementation. [Figure 9] Figure 9 is an explanatory diagram for explaining the exposed part and the unexposed part of the metal-containing photoresist film.

A ₁ ,A ₂ : Area

R: Metal-containing photoresist film

R ₁ : Unexposed photoresist film

R ₂ : Exposure photoresist film

R ₃ : Photoresist film

W: Wafer

Claims (12)

A developing method for developing a substrate comprises: a developer supplying step, supplying a developer containing an organic solvent to the substrate having a metal-containing coating film exposed to a predetermined pattern; and a first cleaning liquid supplying step, supplying a first cleaning liquid containing an organic solvent to the substrate after the developer is supplied; the first cleaning liquid has a lower solubility in the metal-containing coating film than the developer, and the first cleaning liquid contains 0.25 to 50 volume % of pure water. The developing method of claim 1, wherein the organic solvent contained in the first cleaning solution is selected from one or a mixture of two or more of the group consisting of 2-heptanone, isopropyl alcohol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, n-butyl acetate, cyclohexanone, 4-methyl-2-pentanol, and ethyl lactate. The developing method of claim 2, wherein the developing solution is a mixture of propylene glycol monomethyl ether acetate and acetic acid. A developing method as claimed in any one of items 1 to 3, wherein the pure water contained in the developer is less than 0.25% by volume. The developing method of any one of claims 1 to 3 further comprises: an ultraviolet irradiation step, irradiating the substrate with ultraviolet light having a wavelength of 190 to 400 nm after the substrate is supplied with the first cleaning solution; a substrate heating step, heating the substrate during or after the ultraviolet irradiation; and a second cleaning solution supplying step, supplying the heated substrate with a second cleaning solution containing an organic solvent. The developing method of claim 5, wherein the second cleaning solution is an alkaline treatment solution or a treatment solution containing an organic acid. A substrate processing system performs development processing on a substrate; The substrate processing system comprises: A developer supply unit supplies a developer containing an organic solvent to the substrate; A first cleaning liquid supply unit supplies a first cleaning liquid containing an organic solvent to the substrate; and A control unit controls the operation of the developer supply unit and the first cleaning liquid supply unit; The control unit performs the following steps: A developer supply step supplies the developer to the substrate having a metal-containing coating film exposed to a predetermined pattern; and A first cleaning liquid supply step supplies the first cleaning liquid to the substrate after the developer is supplied; Compared with the developer, the first cleaning solution has a lower solubility in the metal-containing coating film, and the first cleaning solution contains 0.25 to 50 volume % of pure water. The substrate processing system of claim 7, wherein the organic solvent contained in the first cleaning solution is selected from one or a mixture of two or more selected from the group consisting of 2-heptanone, isopropyl alcohol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, n-butyl acetate, cyclohexanone, 4-methyl-2-pentanol, and ethyl lactate. As in claim 8, the substrate processing system, wherein the developer is a mixture of propylene glycol monomethyl ether acetate and acetic acid. A substrate processing system as claimed in any one of claims 7 to 9, wherein the pure water contained in the developer is less than 0.25 volume %. The substrate processing system of any one of claims 7 to 9 further comprises: an ultraviolet irradiation unit for irradiating the substrate with ultraviolet rays having a wavelength of 190 to 400 nm; a heating unit for heating the substrate; and a second cleaning liquid supply unit for supplying a second cleaning liquid containing an organic solvent to the heated substrate; the control unit performs the following steps: an ultraviolet irradiation step for irradiating the substrate with ultraviolet rays having a wavelength of 190 to 400 nm after the first cleaning liquid is supplied; a substrate heating step for heating the substrate during or after the ultraviolet irradiation; and a second cleaning liquid supply step for supplying the second cleaning liquid to the heated substrate. A substrate processing system as claimed in claim 11, wherein the second cleaning solution is an alkaline processing solution or a processing solution containing an organic acid.

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