TWI867181B - Substrate processing method, substrate processing device, and storage medium - Google Patents

Abstract

An object of the invention is to form fine patterns more precisely. A substrate processing method includes: forming a resist film on the surface of a substrate, forming an interface control film by supplying a process liquid containing a water-soluble polymer onto the surface of the resist film on the substrate, heating the substrate on which the interface control film has been formed, and subjecting the resist film formed on the heated substrate to exposure.

Description

Substrate processing method, substrate processing device and recording medium

The present invention discloses a substrate processing method, a substrate processing device and a recording medium.

Patent document 1 discloses an exposure device that uses EUV light from an EUV light source. [Prior art document]

[Patent Document 1] Japanese Patent Application Publication No. 2009-43906

〔Problems to be solved〕

The present invention provides a technology that can form fine patterns with better precision. 〔Means for solving the problem〕

According to one aspect of the present invention, a substrate processing method comprises: forming a photoresist film on the surface of a substrate; supplying a processing liquid containing a water-soluble polymer to the surface of the photoresist film of the substrate to form an interface control film; heating the substrate on which the interface control film is formed; and exposing the photoresist film formed on the heated substrate. 〔Effects of the invention〕

According to the present invention, a technology capable of forming fine patterns with better precision can be provided.

Various exemplary implementations are described below.

An exemplary embodiment provides a substrate processing method. The substrate processing method includes the following steps: forming a photoresist film on the surface of a substrate; supplying a processing liquid containing a water-soluble polymer to the surface of the photoresist film of the substrate to form an interface control film; heating the substrate with the interface control film formed thereon; and exposing the photoresist film formed on the heated substrate.

According to the above substrate processing method, the substrate is heated while the interface control film is formed on the surface of the photoresist film, and then the photoresist film is exposed. As a result, since the components of the photoresist film are prevented from being unevenly distributed and separated due to heating, fine patterns using the photoresist film can be formed with good precision.

The heating may be performed in an ambient atmosphere of organic solvent vapor.

As described above, by heating the substrate in an ambient gas of organic solvent vapor, the uneven distribution and separation of the components of the photoresist film can be further suppressed.

The heating can be performed in any of the ambient gases of nitrogen, noble gas and carbon dioxide.

As described above, by heating the substrate in an ambient gas of any one of nitrogen, rare gas and carbon dioxide, the uneven distribution and separation of the components of the photoresist film can be further suppressed.

Furthermore, the method may further include the following step: removing the interface control film after the heating and before the exposure.

By removing the interface control film before exposure, the uneven distribution and separation of the components of the photoresist film during heating can be suppressed. In addition, since there is no need to adjust the light intensity in consideration of the interface control film during exposure, fine pattern formation with good precision can be achieved more easily.

The exposure may be set to a state where exposure is performed by EUV light.

When performing exposure using EUV light, the photoresist film must be thinned. In this case, the uneven distribution and separation of the components of the photoresist film have a greater impact on patterning. Therefore, the above-mentioned effect of preventing the uneven distribution and separation of the components of the photoresist film due to heating by forming an interface control film is particularly effective when performing exposure using EUV light.

An exemplary embodiment provides a substrate processing device. The substrate processing device includes: a photoresist liquid supply unit for supplying photoresist liquid on the surface of a substrate; a polymer supply unit for supplying a processing liquid containing a water-soluble polymer on the surface of the substrate; a heating processing unit for heating the substrate; and a control unit; the control unit performs the following processing: controlling the photoresist liquid supply unit to form a photoresist film on the surface of the substrate; controlling the polymer supply unit to form an interface control film on the surface of the photoresist film of the substrate; and controlling the heating processing unit to heat the substrate formed with the interface control film before exposure.

The substrate processing apparatus heats the substrate before exposure in a state where an interface control film is formed on the surface of the photoresist film, and then exposes the subsequent photoresist film. As a result, since the components of the photoresist film are prevented from being unevenly distributed and separated due to heating, fine patterns using the photoresist film can be formed with good precision.

In another exemplary embodiment, a computer-readable recording medium is provided, which stores a program for causing an apparatus to execute the above-mentioned substrate processing method.

Various exemplary embodiments are described in detail below with reference to the drawings. In each of the drawings, the same or corresponding parts are marked with the same symbols.

[Substrate processing system] The substrate processing system 1 shown in FIG. 1 is a system for forming a photosensitive coating on a substrate (workpiece W), exposing the photosensitive coating, and developing the photosensitive coating.

The workpiece W to be processed is, for example, a substrate for semiconductors. An example of a substrate is a silicon wafer. The workpiece W may be formed into a circular shape. Furthermore, the workpiece W to be processed may be a glass substrate, a mask substrate, an FPD (Flat Panel Display), etc. For example, the workpiece W may be selected from materials that can be applied to EUV lithography (Extreme ultraviolet lithography), which uses EUV light with a wavelength in the range of about 10nm to 100nm. For example, EUV light may use light with a wavelength of 13.5nm. Furthermore, as the photoresist film formed on the workpiece W, a photoresist film for EUV lithography may be used. Therefore, the photoresist liquid (chemical solution) used for the formation of the photoresist film is sensitive to EUV light. Furthermore, a known photoresist liquid that can be used for such a photoresist film for EUV lithography may be used.

The substrate processing system 1 includes a coating and developing device 2 and an exposure device 3. The exposure device 3 performs an exposure process on a photoresist film (photosensitive coating film) formed on a workpiece W (substrate). Specifically, an energy line is irradiated to an exposure target portion of the photoresist film by a method such as liquid immersion exposure. The coating and developing device 2 forms a photoresist film on the surface of the workpiece W (substrate) before performing an exposure process by the exposure device 3, and performs a development process on the photoresist film after the exposure process. Specifically, an energy line is selectively irradiated to an exposure target portion of the photoresist film by a method such as liquid immersion exposure. As energy lines, in addition to the above-mentioned EUV light, for example, argon fluoride (ArF) excimer laser, krypton fluoride (KrF) excimer laser, g-line, i-line, etc. can be cited. As mentioned above, the exposure process of the substrate processing system 1 is not limited to the process using EUV light.

The workpiece W may also be, for example, a substrate having a silicon-containing anti-reflective coating (SiARC) formed on its surface. In the case of lithography using UV light, there is a possibility that the UV light reflects off the substrate and generates a wave that affects the photoresist sidewalls. Therefore, a base film is sometimes formed to generally prevent reflection. However, since EUV light reflects less on the material of the substrate, the base film may be omitted. Alternatively, other base films may be formed to replace the silicon-containing anti-reflective coating (SiARC). Similarly, an upper film may be formed on the photoresist film.

[Substrate processing device] The following describes the structure of the coating and developing device 2 as an example of a substrate processing device. As shown in FIGS. 1 to 3 , the coating and developing device 2 includes a carrier block 4, a processing block 5, an interface block 6, and a control device 100 (control unit).

The carrier block 4 carries out: the introduction of the workpiece W into the coating and developing device 2, and the removal of the workpiece W from the coating and developing device 2. For example, the carrier block 4 can support a plurality of carriers C for the workpiece W, and has a built-in transfer arm A1. The carrier C stores a plurality of round workpieces W. The transfer arm A1 takes out the workpiece W from the carrier C and transfers it to the processing block 5, and receives the workpiece W from the processing block 5 and returns it to the carrier C.

The processing block 5 has a plurality of processing modules 11, 12, 13, and 14. The processing modules 11, 12, 13, and 14 have built-in coating units U1, heat treatment units U2, and conveying arms A3 for conveying workpieces W to these units. The coating unit U1 applies a processing liquid to the surface of the workpiece W. The heat treatment unit U2 has built-in, for example, a hot plate and a cooling plate, and heats the workpiece W with the hot plate and cools the heated workpiece W with the cooling plate to perform heat treatment.

The processing module 11 forms a base film on the surface of the workpiece W by means of the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the processing module 11 coats a treatment liquid for forming the base film on the workpiece W. The heat treatment unit U2 of the processing module 11 performs various heat treatments in conjunction with the formation of the base film.

The processing module 12 forms a photoresist film on the base film by means of the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the processing module 12 coats a treatment liquid for forming the photoresist film on the base film. Furthermore, the coating unit U1 forms an interface control film by supplying a water-soluble polymer to the coated treatment liquid. The heat treatment unit U2 of the processing module 12 performs various heat treatments in conjunction with the formation of the photoresist film. As a specific example of heat treatment, there can be cited a heat treatment (PAB: Pre Applied Bake) for hardening the coating film as a photoresist film.

The processing module 13 forms an upper film on the photoresist film by means of the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the processing module 13 coats the liquid for forming the upper film on the photoresist film. The heat treatment unit U2 of the processing module 13 performs various heat treatments in conjunction with the formation of the upper film.

The processing module 14 performs a developing process on the photoresist film after exposure by means of the coating unit U1 and the heat treatment unit U2. The coating unit U1 of the processing module 14 applies a developer on the surface of the workpiece W after exposure, and then washes off the developer with a rinser to perform a developing process on the photoresist film. The heat treatment unit U2 performs various heat treatments in conjunction with the developing process. Specific examples of heat treatment include heat treatment before developing process (PEB: Post Exposure Bake) and heat treatment after developing process (PB: Post Bake).

A shelf unit U10 is provided on the side of the carrier block 4 in the processing block 5. The shelf unit U10 is divided into a plurality of units arranged side by side in the vertical direction. A lifting arm A7 is provided near the shelf unit U10. The lifting arm A7 lifts the workpiece W between the units of the shelf unit U10.

A shelf unit U11 is provided on the interface block 6 side in the processing block 5. The shelf unit U11 is divided into a plurality of units arranged side by side in the vertical direction.

A film removal unit U13 is further provided on the shelf unit U11. The film removal unit U13 performs a process for removing the interface control film on the photoresist film after the process module 12 performs a process related to the formation of the photoresist film.

The interface block 6 transfers the workpiece W to the exposure device 3. For example, the interface block 6 has a transfer arm A8 built therein and is connected to the exposure device 3. The transfer arm A8 transfers the workpiece W disposed on the shelf unit U11 to the exposure device 3, and receives the workpiece W from the exposure device 3 and returns it to the shelf unit U11.

The control device 100 controls the coating and developing device 2 to perform coating and developing processing in the following order. First, the control device 100 controls the transfer arm A1 to transport the workpiece W in the carrier C to the shelf unit U10, and controls the lifting arm A7 to place the workpiece W in the unit for the processing module 11.

Next, the control device 100 controls the conveying arm A3 to convey the workpiece W in the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 in the processing module 11. Furthermore, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a base film on the surface of the workpiece W. Thereafter, the control device 100 controls the conveying arm A3 to return the workpiece W with the base film formed thereon to the shelf unit U10, and controls the lifting arm A7 to place the workpiece W in the unit for the processing module 12.

Next, the control device 100 controls the transport arm A3 to transport the workpiece W of the shelf unit U10 to the coating unit U1 and the heat treatment unit U2 in the processing module 12. In addition, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form a photoresist film on the surface of the workpiece W. At this time, an interface control film is formed on the surface of the workpiece W on the photoresist film. Thereafter, the control device 100 controls the transport arm A3 to return the workpiece W to the shelf unit U10, and controls the lifting arm A7 to place the workpiece W in the unit for the processing module 13.

Next, the control device 100 controls the transport arm A3 to transport the workpiece W of the shelf unit U10 to the film removal unit U13. Furthermore, the control device 100 controls the film removal unit U13 to remove the interface control film on the surface of the workpiece W. Thereafter, the control device 100 controls the transport arm A3 to return the workpiece W to the shelf unit U10, and controls the lifting arm A7 to place the workpiece W in the unit for the processing module 13.

Next, the control device 100 controls the transport arm A3 to transport the workpiece W of the shelf unit U10 to each unit in the processing module 13. Furthermore, the control device 100 controls the coating unit U1 and the heat treatment unit U2 to form an upper film on the photoresist film of the workpiece W. Thereafter, the control device 100 controls the transport arm A3 to transport the workpiece W to the shelf unit U11.

Next, the control device 100 controls the transfer arm A8 to deliver the workpiece W of the shelf unit U11 to the exposure device 3. Thereafter, the control device 100 controls the transfer arm A8 to receive the workpiece W subjected to the exposure process from the exposure device 3 and place it in the unit for the processing module 14 in the shelf unit U11.

Next, the control device 100 controls the transport arm A3 to transport the workpiece W in the shelf unit U11 to each unit in the processing module 14, and controls the coating unit U1 and the heat treatment unit U2 to perform a development process on the photoresist film of the workpiece W. Afterwards, the control device 100 controls the transport arm A3 to return the workpiece W to the shelf unit U10, and controls the lifting arm A7 and the transfer arm A1 to return the workpiece W to the carrier C. After the above procedures, the coating and development process is completed.

The specific configuration of the substrate processing apparatus is not limited to the configuration of the coating and developing apparatus 2 exemplified above. The substrate processing apparatus may be any apparatus as long as it includes a coating unit U1 , a heat treatment unit U2 , a film removal unit U13 , and a control device 100 capable of controlling these units.

In addition, depending on the condition of the workpiece W, the above-mentioned bottom film and top film may not be provided. In this case, each process in the processing module 11 and the processing module 13 may be omitted. For example, depending on the type of photoresist, the formation of the bottom film and top film may be omitted. In the following implementation, the case where the bottom film and top film are not formed is described.

(Coating unit) Referring to FIG. 4 , the coating unit U1 is described. The coating unit U1 shown in FIG. 4 is a coating unit U1 that is particularly applicable to the processing module 12 related to the photoresist film. As shown in FIG. 4 , the coating unit U1 has a rotating holding part 20, a liquid supply part 30 (photoresist liquid supply part), and a liquid supply part 40 (polymer supply part).

The rotating holding portion 20 has a rotating portion 21 and a holding portion 22. The rotating portion 21 has a shaft 23 protruding upward. The rotating portion 21 uses, for example, an electric motor as a power source to rotate the shaft 23. The holding portion 22 is provided at the front end of the shaft 23. The holding portion 22 is provided for people to place the workpiece W. The holding portion 22 is, for example, an adsorption chuck that holds the workpiece W in a roughly horizontal position by adsorption. The shape of the holding portion 22 (adsorption chuck) is not particularly limited and may be, for example, circular. The size of the holding portion 22 may be smaller than the workpiece W. In the case where the holding portion 22 is circular, the size of the holding portion 22 may be, for example, about 80 mm in diameter.

The rotating holding part 20 rotates the workpiece W around an axis (rotation axis) perpendicular to the surface Wa of the workpiece W when the workpiece W is in a substantially horizontal state. In the present embodiment, the rotation axis passes through the center of the circular workpiece W and is therefore also the central axis. In the present embodiment, as shown in FIG. 4 , the rotating holding part 20 rotates the workpiece W clockwise when viewed from above.

The liquid supply unit 30 is configured to supply the processing liquid L1 to the surface Wa of the workpiece W. In the processing module 12, the processing liquid L1 is a coating liquid composed of a photoresist material for forming a photoresist film. In this case, the liquid supply unit 30 functions as a photoresist liquid supply unit. In the processing modules 11, 13, and 14, the processing liquid L1 can be a material for forming a bottom layer film, a material for forming an upper layer film, or a developer.

In the processing module 12, the photoresist material used as the processing liquid L1 can be, as mentioned above, a photoresist for EUV lithography that is sensitive to EUV light, but is not limited thereto. In addition, as the photoresist material, any of negative type and positive type can be selected, and even a metal-based photoresist can be selected. As mentioned above, the type of photoresist material used for the processing liquid L1 is not particularly limited.

The liquid supply unit 30 has a liquid source 31, a pump 32, a valve 33, a nozzle 34, and a pipe 35. The liquid source 31 functions as a supply source for the processing liquid L1. The pump 32 draws the processing liquid L1 from the liquid source 31 and delivers it to the nozzle 34 through the pipe 35 and the valve 33. The nozzle 34 is arranged above the workpiece W in such a way that the nozzle faces the surface Wa of the workpiece W. The nozzle 34 can be moved in the horizontal direction and the vertical direction by a driving unit not shown. The nozzle 34 can spray the processing liquid L1 delivered from the pump 32 onto the surface Wa of the workpiece W. Starting from the upstream side, the pipe 35 sequentially connects the liquid source 31, the pump 32, the valve 33 and the nozzle 34.

The liquid supply unit 40 supplies the processing liquid L2 to the surface Wa of the workpiece W. In the processing module 12, the processing liquid L2 is a water-soluble polymer used to form an interface control film on the photoresist film. In this case, the liquid supply unit 40 functions as a polymer supply unit. In the processing modules 11 and 13, the processing liquid L2 may be set as various organic solvents for removing the bottom film or the upper film from the workpiece W. Moreover, in the processing module 14, the processing liquid L2 may be set as a rinse liquid. Moreover, depending on the condition of the processing module, it is not necessary to have the liquid supply unit 40.

As the water-soluble polymer used in the processing module 12 to form the interface control film, various materials can be selected. For example, polyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose, methyl vinyl ether, polyacrylamide, polyethylene oxide, sodium polyacrylate, water-soluble nylon, etc. can be selected. In the processing module 12, a processing liquid L2 in a state where these water-soluble polymers are dissolved in an aqueous solvent is prepared and supplied to the surface Wa of the workpiece W coated with the processing liquid L1 for the photoresist film.

The type of water-soluble polymer used to form the interface control film can be selected according to the type of the photoresist film formed thereunder. In other words, the water-soluble polymer can be selected according to the type of the processing liquid L1 as the material of the photoresist film.

The liquid supply unit 40 has a liquid source 41, a pump 42, a valve 43, a nozzle 44, and a pipe 45. The liquid source 41 functions as a supply source for the processing liquid L2. The pump 42 draws the processing liquid L2 from the liquid source 41 and delivers it to the nozzle 44 through the pipe 45 and the valve 43. The nozzle 44 is arranged above the workpiece W in such a way that the nozzle faces the surface Wa of the workpiece W. The nozzle 44 can move in the horizontal direction and the vertical direction by a driving unit not shown. The nozzle 44 can spray the processing liquid L2 delivered from the pump 42 onto the surface Wa of the workpiece W. Starting from the upstream side, the pipe 45 sequentially connects the liquid source 41, the pump 42, the valve 43, and the nozzle 44.

In the coating unit U1 of the processing module 12, a coating process is applied to the workpiece W to form a photoresist film R1 (a coating film formed by a photoresist liquid) on the surface Wa of the workpiece W, and further form an interface control film R2 on the top surface thereof.

(Heat treatment unit) The heat treatment unit U2 will be described in detail with reference to FIG5 . As shown in FIG5 , the heat treatment unit U2 includes a treatment chamber 50 , a solvent supply unit 70 , a gas supply unit 73 , and an exhaust unit 76 .

The processing chamber 50 accommodates the workpiece W to be heat-treated. The workpiece W is heat-treated in the processing chamber 50. The processing chamber 50 has a housing 51, a temperature adjustment mechanism 55, and a heating mechanism 60. FIG. 5 shows a part of the structure of the heat treatment unit U2, and does not show the entire structure of the heat treatment unit U2.

The housing 51 is a processing container that accommodates the temperature adjustment mechanism 55 and the heating mechanism 60. The housing 51 has an opening formed on the side wall thereof to form a carrying port 52 for carrying in the workpiece W.

The temperature adjustment mechanism 55 is a mechanism for adjusting the temperature of the workpiece W to a predetermined temperature in the processing chamber 50. The temperature adjustment of the workpiece W by the temperature adjustment mechanism 55 may be partially included in the heat treatment in the heat treatment unit U2. The temperature adjustment mechanism 55 transfers the workpiece W to the external conveying arm A3. The temperature adjustment mechanism 55 has a temperature adjustment plate 55a, a connecting bracket 55b, and a driving mechanism 55c.

The temperature adjustment plate 55a is a plate for adjusting the temperature of the workpiece W placed thereon. Specifically, the temperature adjustment plate 55a is a cooling plate for placing the workpiece W heated by the heating mechanism 60 and cooling the workpiece W to a predetermined temperature. For example, the temperature adjustment plate 55a may be formed in a substantially disk shape. The temperature adjustment plate 55a may be made of a metal such as aluminum, silver or copper with high thermal conductivity, or may be made of a single material from the viewpoint of preventing deformation due to heat. A cooling flow path (not shown) for circulating cooling water or cooling gas may be formed inside the temperature adjustment plate 55a.

The connecting bracket 55b is connected to the temperature adjustment plate 55a. The driving mechanism 55c is operated according to the instruction of the control device 100 to move the connecting bracket 55b. The connecting bracket 55b is moved in the housing 51 by the driving mechanism 55c. Specifically, the connecting bracket 55b moves along a guide rail (not shown) extending between the carrying-in port 52 of the housing 51 and the vicinity of the heating mechanism 60. By moving the connecting bracket 55b along the guide rail, the temperature adjustment plate 55a is moved between the carrying-in port 52 and the heating mechanism 60. In addition, the connecting bracket 55b may be made of a metal such as aluminum, silver or copper with high thermal conductivity.

The heating mechanism 60 is a mechanism for performing heat treatment on the workpiece W in the processing chamber 50. The heat treatment of the workpiece W performed by the heating mechanism 60 is included as a part of the heat treatment in the heat treatment unit U2. The heating mechanism 60 has a support table 61, a hot plate 62, a heater 63, a chamber 64 (cover), a lifting mechanism 65, a support pin 66, and a lifting mechanism 67.

The support table 61 is in the shape of a cylinder with a depression in the central portion. The support table 61 supports the hot plate 62. The hot plate 62 is formed, for example, in a roughly disc shape and is accommodated in the depression of the support table 61. The hot plate 62 has a mounting surface 62a. The workpiece W to be processed is mounted on the mounting surface 62a, and the workpiece W is supported by the hot plate 62. The hot plate 62 heats the mounted workpiece W. A heater 63 for heating the hot plate 62 is provided on the bottom surface of the hot plate 62 on the opposite side of the mounting surface 62a. For example, the heater 63 is composed of a resistance heating element. By causing an electric current to flow to the heater 63, the heater 63 generates heat. Then, the heat from the heater 63 spreads, and the temperature of the hot plate 62 rises. The heater 63 may be configured such that a current of a value indicated by the control device 100 flows therein, or a voltage of a value indicated by the control device 100 is applied thereto so that a current of a value of the voltage flows therein. The heater 63 may also be embedded in the heat plate 62. The heat plate 62 may be made of a metal such as aluminum, silver or copper with high thermal conductivity, but any shape and material may be used as long as the heat from the heater 63 can be conducted to heat the workpiece W.

The chamber 64 is configured to surround the mounting surface 62a of the workpiece W in the hot plate 62. The chamber 64 has a top cover 64a and a leg 64b. The top cover 64a is configured in the shape of a circular plate having a diameter approximately the same as that of the support table 61. The top cover 64a is arranged to be opposite to the mounting surface 62a of the hot plate 62 in the up-down direction. The leg 64b is configured to extend downward from the outer edge of the top cover 64a. The lifting mechanism 65 is a mechanism for lifting and lowering the chamber 64 according to the instruction of the control device 100. The chamber 64 is raised by the lifting mechanism 65, thereby opening the heating treatment space of the workpiece W, and the chamber 64 is lowered, thereby closing the heating treatment space of the workpiece W.

The support pin 66 is a pin that extends in the up-down direction in a manner that passes through the support table 61 and the hot plate 62, and supports the workpiece W from below. The support pin 66 is raised and lowered in the up-down direction to arrange the workpiece W at a predetermined position. The support pin 66 transfers the workpiece W to the temperature adjustment plate 55a that transports the workpiece W. The support pin 66 may be composed of three pins that are arranged at equal intervals along the circumferential direction, for example. The lifting mechanism 67 is a mechanism that lifts and lowers the support pin 66 according to the instructions of the control device 100. The lifting mechanism 67 is constructed in a manner that can lift and lower the workpiece W (in detail, the support pin 66 that supports the workpiece W) so that the workpiece W is close to the hot plate 62 and the workpiece W is placed on the hot plate 62.

The solvent supply unit 70 supplies solvent vapor from an organic solvent to the space where the workpiece W is subjected to a heat treatment. The solvent supply unit 70 includes a solvent supply source 71 and a vapor supply pipe 72. A valve V1 serving as an on-off valve is provided on the vapor supply pipe 72. By the on-off action of the valve V1, the solvent vapor from the solvent supply source 71 is supplied to the chamber 64, and the supply amount is adjusted.

As the solvent, an organic solvent having the property of dissolving the photoresist pattern can be used, for example, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, γ-butyrolactone, etc.

The gas supply unit 73 supplies rare gas or carbon dioxide to the space where the workpiece W is subjected to heat treatment. The gas supply unit 73 includes a gas supply source 74 and a gas supply pipe 75. A valve V2 serving as an on-off valve is provided on the gas supply pipe 75. By opening and closing the valve V2, the gas from the gas supply source 74 is supplied to the chamber 64, and the supply amount is adjusted.

In addition, as the gas supplied by the gas supply unit 73, for example, nitrogen ( _N2 ), argon (Ar), carbon dioxide, etc., can be cited. FIG5 shows a configuration for supplying, for example, _N2 , but in order to supply these gases, a plurality of gas supply units 73 may be provided. In addition, the supply amount of each gas supply unit 73 may be individually controlled by the valve V2.

The heating mechanism 60 may be provided with a mechanism for measuring the temperature of the hot plate and a mechanism for measuring the temperature in the chamber 64. These mechanisms may measure the temperature of the object to be measured according to the instructions from the control device 100. Furthermore, these mechanisms output the measurement results to the control device 100 respectively. These mechanisms may be thermistors respectively. The control device 100 may control the heating temperature according to the information from these mechanisms.

The exhaust section 76 exhausts gas from the processing chamber 50. For example, the exhaust section 76 exhausts gas from the processing chamber 50 to the outside of the heat treatment unit U2 (coating and developing device 2). The exhaust section 76 includes an exhaust duct 77 and an opening and closing section 78. The exhaust duct 77 connects the space in the processing chamber 50 (the space separated by the housing 51) and the exhaust destination. The opening and closing section 78 is provided on the flow path of the exhaust duct 77. The opening and closing section 78 switches the flow path of the exhaust duct 77 to an open state or a closed state according to the instruction of the control device 100. The opening and closing section 78 is, for example, an electromagnetic valve. By setting the opening and closing portion 78 to the open state, the flow path of the exhaust duct 77 is switched from the closed state to the open state. By setting the opening and closing portion 78 to the closed state, the flow path of the exhaust duct 77 is switched from the open state to the closed state.

Furthermore, in addition to the exhaust section 76, an exhaust section 79 may be provided. The exhaust section 79 exhausts gas from the space separated by the support table 61 and the chamber 64 (hereinafter referred to as the space in the chamber 64). When the exhaust section 79 is provided, for example, by operating in the same manner as the exhaust section 76, gas can be exhausted from the chamber 64 to the outside of the heat treatment unit U2 (coating and developing device 2).

(Film removal unit) Then, referring to FIG. 6 , the film removal unit U13 will be described. The film removal unit U13 shown in FIG. 6 removes the interface control film from the workpiece W after the photoresist film is formed and heat-treated. As shown in FIG. 6 , the film removal unit U13 includes a rotating holding portion 20 and a liquid supply portion 80 (removal liquid supply portion).

The rotating holding part 20 has the same structure as the rotating holding part 20 of the coating unit U1 (see FIG. 4 ). That is, the rotating holding part 20 of the film removal unit U13 also has a rotating part 21 and a holding part 22. The rotating part 21 has a shaft 23 protruding upward. The holding part 22 is provided at the front end of the shaft 23, and a workpiece W is placed on the holding part 22.

The rotating holding part 20 rotates the workpiece W around an axis (rotation axis) perpendicular to the surface Wa of the workpiece W when the workpiece W is in a substantially horizontal state. In the present embodiment, the rotation axis passes through the center of the circular workpiece W and is therefore also the central axis. In the present embodiment, as shown in FIG. 6 , the rotating holding part 20 rotates the workpiece W clockwise when viewed from above.

The liquid supply unit 80 supplies the processing liquid L3 to the surface Wa of the workpiece W. The processing liquid L3 is a processing liquid for removing the interface control film. For example, pure water can be used as the processing liquid L3.

The liquid supply unit 80 has a liquid source 81, a pump 82, a valve 83, a nozzle 84, and a pipe 85. The liquid source 81 functions as a supply source for the processing liquid L3. The pump 82 draws the processing liquid L3 from the liquid source 81 and delivers it to the nozzle 84 through the pipe 85 and the valve 83. The nozzle 84 is arranged above the workpiece W in such a way that the nozzle faces the surface Wa of the workpiece W. The nozzle 84 can be moved in the horizontal direction and the vertical direction by a driving unit not shown. The nozzle 84 can spray the processing liquid L3 delivered from the pump 82 onto the surface Wa of the workpiece W. Starting from the upstream side, the pipe 85 sequentially connects the liquid source 81, the pump 82, the valve 83 and the nozzle 84.

In the film removal unit U13, the workpiece W is processed to remove the interface control film formed on the surface Wa of the workpiece W, so that the photoresist film R1 is exposed on the surface.

(Control device) As shown in FIG. 7, the control device 100 includes a reading unit M1, a recording unit M2, a processing unit M3, and an indication unit M4 in terms of functional modules. These functional modules are merely obtained by dividing the functions of the control device 100 into a plurality of modules for convenience, and do not necessarily mean that the hardware constituting the control device 100 is divided into these modules. Each functional module is not limited to being implemented by executing a program, but can also be implemented by a dedicated circuit (such as a logic circuit). In addition, each functional module can also be implemented by an integrated circuit (ASIC: Application Specific Integrated Circuit) obtained by integrating this circuit.

The reading unit M1 reads a program from a computer-readable recording medium RM. The recording medium RM stores a program for operating each part of the substrate processing system 1. Examples of the recording medium RM include a semiconductor memory, a recording optical disk, a recording magnetic disk, and a recording magneto-optical disk.

The recording unit M2 stores various data. The recording unit M2 stores, for example, a program read from the recording medium RM by the reading unit M1, various data when processing the workpiece W (so-called processing recipes), setting data input from an operator via an external input device (not shown), and the like.

The processing unit M3 processes various data. For example, the processing unit M3 generates an operation signal for operating the coating unit U1, the heat treatment unit U2, and the film removal unit U13 according to various data stored in the recording unit M2.

The indicating unit M4 sends the action signal generated by the processing unit M3 to various devices. For example, the action signal sent to the heating mechanism 60 may include a signal indicating the current value sent to the heater 63. Alternatively, the indicating unit M4 may output the current having the current value set by the processing unit M3 to the heater 63 to the heater 63 through a digital-to-analog conversion circuit.

The hardware of the control device 100 is composed of, for example, one or more control computers. For example, the control device 100 has a circuit 120 as shown in FIG8 . The circuit 120 includes: one or more processors 121, a memory 122, a storage 123, an input/output port 124, and a timer 125. The storage 123 has a computer-readable recording medium such as a hard disk. The recording medium stores a program for the coating and developing device 2 to execute the substrate processing program described later. The recording medium may be a removable medium such as a non-volatile semiconductor memory, a recording disk, and an optical disk. The memory 122 temporarily stores: the program loaded from the recording medium of the storage 123 and the calculation results obtained by the processor 121. The processor 121 executes the above program in a coordinated manner with the memory 122, thereby constituting the above functional modules. The input/output port 124 inputs and outputs electrical signals with each part of the substrate processing system 1 according to the instructions from the processor 121. The timer 125 measures the elapsed time by calculating the reference pulse of a certain period, for example.

The control device 100 controls the coating unit U1, the heat treatment unit U2, and the film removal unit U13 included in the substrate processing system 1 by the above-mentioned structure. In addition, the control device 100 may also control other units not shown in FIG. 7. In addition, the structure of the control device 100 described above is an example and is not limited to the above-mentioned structure.

[Substrate processing method] An example of a substrate processing method is described with reference to FIGS. 9 and 10 . FIG. 9 illustrates a series of processes for forming a photoresist film on a workpiece W. Each step shown in FIG. 9 is executed by the control device 100 controlling each unit constituting the coating and developing device 2.

First, the control device 100 executes step S01. In step S01, the control device 100 sends the workpiece W into the coating unit U1 of the processing module 12, and supplies the processing liquid L1 to the surface Wa of the workpiece W to coat the photoresist liquid. In addition, before step S01, a base film may be formed on the surface Wa of the workpiece W in the processing module 11. In this way, as shown in FIG. 10 (a), a photoresist film R1 (corresponding to the coating film of the photoresist film R1) is formed on the workpiece W.

Next, the control device 100 executes step S02. In step S02, for the workpiece W in the state of being transported to the coating unit U1 of the processing module 12, the control device 100 supplies the processing liquid L2 to the top surface of the photoresist film R1 composed of the photoresist liquid coated on its surface Wa, thereby forming an interface control film R2. Thereby, as shown in FIG. 10 (b), the interface control film R2 is formed on the photoresist film R1 of the workpiece W (corresponding to the photoresist liquid layer of the photoresist film R1). The interface control film R2 can be formed in a manner covering the entire surface of the photoresist film R1. In this case, the effect to be achieved by providing the interface control film R2 can be enhanced. However, it is also possible to form the interface control film R2 in a state where a portion of the photoresist film R1 is exposed on the surface.

Next, the control device 100 executes step S03. In step S03, the control device 100 sends the workpiece W into the heat treatment unit U2 of the processing module 12, and performs heat treatment in the heating mechanism 60. At this time, gas is supplied from the solvent supply part 70 and the gas supply part 73, so that the chamber 64 becomes a gas environment for heat treatment. The air pressure in the chamber 64 can be adjusted to the atmospheric pressure. By the heating mechanism 60, for example, the temperature of the hot plate 62 is set to about 50°C to 150°C, and the temperature of the gas supplied to the chamber 64 is set to about 30°C to 60°C. In this state, the workpiece W is supported on the hot plate 62 and the workpiece W is subjected to heat treatment. The heating treatment time is set to, for example, several minutes to several tens of minutes. As a result of the heating treatment of the workpiece W, uneven distribution of components will occur at the interface between the workpiece W and the photoresist film R1, and between the photoresist film R1 and the interface control film R2. However, since the top surface of the workpiece W is covered by the interface control film R2, the uneven distribution of components is suppressed. In addition, FIG. 10 (c) schematically shows the uneven distribution of components that will occur at the interface between the workpiece W and the photoresist film R1.

Next, the control device 100 executes step S04. In step S04, the control device 100 feeds the workpiece W into the film removal unit U13, and supplies the processing liquid L3 to the surface Wa of the workpiece W, thereby removing the interface control film R2 provided on the surface Wa. As shown in FIG. 10(c), the interface control film R2 of the workpiece W is removed, and the photoresist film R1 is exposed.

Next, the control device 100 executes step S05. In step S05, the control device 100 sends the workpiece W to the exposure device 3 to perform exposure processing on the workpiece W. In addition, before step S05, the upper film forming processing can also be performed in the processing module 13 as needed. As a result of the exposure processing performed by the exposure device 3, a predetermined pattern is formed on the photoresist film R1.

Next, the control device 100 executes step S06. In step S06, the control device 100 sends the workpiece W into the processing module 14 to perform a developing process on the photoresist film R1 of the workpiece W. As a result, the unexposed portion of the photoresist film R1 is removed.

[Function] According to the substrate processing system 1 and the substrate processing method, the substrate is heated while the interface control film R2 is formed on the surface of the photoresist film R1, and then the photoresist film R1 is exposed. As a result, since the uneven distribution and separation of the photoresist film components caused by heating are prevented, fine patterns using the photoresist film can be formed with good precision.

In recent years, as patterns have become finer, photoresist films have been thinned to avoid problems such as pattern collapse. However, the applicant has found that thinned photoresist films are easily affected by heat treatment. In particular, if the photoresist film is less than 30nm thick, when heated, the components contained in the photoresist material are prone to uneven distribution and separation at the interface with the underlying substrate or near the surface, which may result in reduced performance as a photoresist. The uneven distribution and separation of components are caused by the difference in surface energy during heating, so the difference in surface energy at the interface during heating must be reduced.

In contrast, in the substrate processing system 1 and the substrate processing method, after the interface control film R2 is formed by supplying a processing liquid containing a water-soluble polymer onto the photoresist film R1, heating is performed in this state. Therefore, compared with the case where the photoresist film is exposed, the interface control film R2 formed by the processing liquid containing a water-soluble polymer can reduce the difference in surface energy with the photoresist material. Therefore, uneven distribution and separation of the components of the photoresist film on the surface of the photoresist film can be prevented, and fine pattern formation can be performed with good precision.

Furthermore, in the above-mentioned embodiment, heating is performed in an environment of organic solvent vapor supplied by the solvent supply unit 70. As described above, heating the substrate in an environment of organic solvent vapor can further suppress uneven distribution and separation of components of the photoresist film.

Furthermore, the heating may be performed in any of the ambient gases of nitrogen, rare gas, and carbon dioxide supplied by the gas supply unit 73. As described above, by heating the substrate in any of the ambient gases of nitrogen, rare gas, and carbon dioxide, the uneven distribution and separation of the components of the photoresist film can be further suppressed. When the heating treatment is performed in any of the ambient gases of nitrogen, rare gas, and carbon dioxide, for example, the temperature of the hot plate 62 is set to about 50°C to 150°C by the heating mechanism 60, and the temperature of the gas supplied to the chamber 64 is set to the level of room temperature.

In addition, the heating system is designed to be performed in the atmosphere without using the solvent supply unit 70 and the gas supply unit 73. Even in the case of heating in the atmosphere, the uneven distribution and separation of the components of the photoresist film can be suppressed. When the heating treatment is performed in the atmosphere, for example, the temperature of the hot plate 62 is set to about 50°C to 150°C by the heating mechanism 60, and the temperature of the gas supplied to the chamber 64 is set to the level of room temperature.

Furthermore, the use of an organic solvent vapor, or any one of nitrogen, rare gas, and carbon dioxide as the ambient gas during heating can suppress the uneven distribution and separation of the components of the photoresist film, rather than using the atmosphere. Since nitrogen, rare gas, and carbon dioxide are all less active gases, they can reduce the effect on the photoresist film during heating compared to the atmosphere. Furthermore, since the surface free energy of organic solvent vapor is close to the photoresist film, it can further reduce the effect on the photoresist film compared to nitrogen, rare gas, and carbon dioxide. In addition, organic solvent vapor can be mixed with nitrogen, rare gas, and carbon dioxide for use.

Furthermore, the interface control film may be removed in the film removal unit U13 after heating and before exposure. By removing the interface control film before exposure, since the uneven distribution and separation of the components of the photoresist film can be suppressed during heating, and there is no need to adjust the amount of light during exposure due to consideration of the interface control film, it is possible to more easily achieve the formation of fine patterns with good precision. When the interface control film is to be exposed on the photoresist film, the exposure amount must be adjusted in consideration of the influence of the interface control film, which may affect the formation of fine patterns. As described above, in the case of exposure after the interface control film is removed, there is no need to adjust the exposure amount in consideration of the interface control film.

In addition, the exposure is designed so that exposure processing can also be performed by EUV light. When using EUV light for exposure, the photoresist film must be thinned. In this case, the uneven distribution and separation of the components of the photoresist film have a greater impact on patterning. Therefore, the effect achieved by forming the interface control film, that is, the effect of preventing the uneven distribution and separation of the components of the photoresist film caused by heating, is particularly effective when exposure is performed by EUV light.

[Variations] The above description is based on various exemplary implementations, but the present invention is not limited to the above exemplary implementations, and various omissions, substitutions, and changes are possible. In addition, elements in different implementations can be combined to form other implementations.

For example, in the above-mentioned embodiment, the case where an interface control film is provided on the top surface of the photoresist film is described, but an interface control film may also be provided on the bottom surface of the photoresist film. As shown in FIG10 (c), uneven distribution of components may occur between the workpiece W and the photoresist film R1 due to heating. Therefore, in order to avoid this situation, an interface control film may be provided by applying a treatment liquid containing a water-soluble polymer. Furthermore, the material of the interface control film provided on the bottom surface of the photoresist film R1 may be changed. For example, from the perspective of preventing peeling, even in the case of providing a photoresist film for EUV lithography, a silicon-containing anti-reflective coating (SiARC) may be formed between the substrate and the photoresist film as an interface control film.

Furthermore, in the above-mentioned embodiment, the case where both the photoresist film R1 and the interface control film R2 are formed in the coating unit U1 is described, but these processes may be performed in separate units.

As can be seen from the above description, the various embodiments of the present invention are described in this specification for the purpose of explanation, and various changes can be made without departing from the scope and gist of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and gist are disclosed in the attached patent application scope.

1: Substrate processing system 2: Coating and developing device 3: Exposure device 4: Carrier block 5: Processing block 6: Interface block 11~14: Processing module 20: Rotating holding part 21: Rotating part 22: Holding part 23: Shaft 30,40,80: Liquid supply part 31,41,81: Liquid source 32,42,82: Pump 33,43,83: Valve 34,44,84: Nozzle 35, 45,85: Piping 50: Processing chamber 51: Casing 52: Loading port 55: Temperature adjustment mechanism 55a: Temperature adjustment plate 55b: Connecting bracket 55c: Driving mechanism 60: Heating mechanism 61: Support table 62: Hot plate 62a: Loading surface 63: Heater 64: Chamber (cover) 64a: Top cover 64b: Foot 65: Lifting mechanism 66: Support pin 67: Lifting mechanism 7 0: Solvent supply unit 71: Solvent supply source 72: Steam supply pipe 73: Gas supply unit 74: Gas supply source 75: Gas supply pipe 76: Exhaust unit 77: Exhaust duct 78: Opening and closing unit 79: Exhaust unit 100: Control device 120: Circuit 121: Processor 122: Memory 123: Storage 124: Input and output port 125: Timer A1, A8: Transfer arm A3: Conveyor arm A7: Lifting arm C: Carrier L1, L2, L3: Processing liquid M1: Reading unit M2: Recording unit M3: Processing unit M4: Indication unit R1: Photoresist film R2: Interface control film RM: Recording medium U1: Coating unit U2: Heat treatment unit U10, U11: Shelf unit U13: Film removal unit V1, V2: Valve W: Workpiece Wa: Surface of workpiece S01~S06: Steps

[Fig. 1] Fig. 1 is a schematic three-dimensional diagram showing an example of a substrate processing system. [Fig. 2] Fig. 2 is a schematic diagram showing an example of the internal structure of the substrate processing system shown in Fig. 1. [Fig. 3] Fig. 3 is a schematic diagram showing an example of the internal structure of the substrate processing system shown in Fig. 1. [Fig. 4] Fig. 4 is a schematic diagram showing an example of a processing module. [Fig. 5] Fig. 5 is a schematic diagram showing an example of a processing module. [Fig. 6] Fig. 6 is a schematic diagram showing an example of a processing module. [Fig. 7] Fig. 7 is a block diagram showing an example of the main part of the substrate processing system. [Fig. 8] Fig. 8 is a schematic diagram showing an example of the hardware structure of the control device. [Fig. 9] Fig. 9 is a flow chart showing an example of a substrate processing method. [Fig. 10] Fig. 10(a), Fig. 10(b), and Fig. 10(c) are diagrams showing an example of changes in the workpiece surface that occur as the substrate processing method proceeds.

S01~S06: Steps

Claims (6)

A substrate processing method comprises: forming a photoresist film for EUV light with a thickness of less than 30nm on the surface of a substrate; supplying a processing liquid containing a water-soluble polymer to the surface of the photoresist film of the substrate to form an interface control film; heating the substrate formed with the photoresist film and the interface control film in an ambient gas of organic solvent vapor to suppress the uneven distribution of components contained in the photoresist film on the surface of the photoresist film compared to a case where the interface control film is not formed; and exposing the photoresist film formed on the heated substrate by EUV light. A substrate processing method comprises: forming a photoresist film for EUV light with a thickness of less than 30nm on the surface of a substrate; supplying a processing liquid containing a water-soluble polymer to the surface of the photoresist film of the substrate to form an interface control film; heating the substrate formed with the photoresist film and the interface control film in an ambient gas of any one of nitrogen, rare gas and carbon dioxide to suppress the uneven distribution of components contained in the photoresist film on the surface of the photoresist film compared to a case where the interface control film is not formed; and exposing the photoresist film formed on the heated substrate by EUV light. The substrate processing method of claim 1 or 2 further comprises: removing the interface control film after the heating and before the exposure. A substrate processing device comprises: a photoresist liquid supply part configured to supply photoresist liquid for EUV light to the surface of a substrate; a polymer supply part configured to supply a processing liquid containing a water-soluble polymer to the surface of the substrate; a heating treatment part for heating the substrate; and a control part; the control part performs the following processing: controlling the photoresist liquid supply part to form a photoresist film with a thickness of less than 30 nm on the surface of the substrate; controlling the polymer supply part to form an interface control film on the surface of the photoresist film of the substrate; controlling the heating treatment part to heat the substrate formed with the photoresist film and the interface control film in an ambient gas of organic solvent vapor before exposure, so that the uneven distribution of the components contained in the photoresist film on the surface of the photoresist film is suppressed compared with the case where the interface control film is not formed. A substrate processing device comprises: a photoresist liquid supply part, which is configured to supply photoresist liquid for EUV light to the surface of a substrate; a polymer supply part, which is configured to supply a processing liquid containing a water-soluble polymer to the surface of the substrate; a heating treatment part, which heats the substrate; and a control part; the control part performs the following processing: controlling the photoresist liquid supply part to form a photoresist film with a thickness of less than 30nm on the surface of the substrate; controlling the polymer supply part to form an interface control film on the surface of the photoresist film of the substrate; controlling the heating treatment part to heat the substrate formed with the photoresist film and the interface control film in any one of nitrogen, rare gas and carbon dioxide ambient gas before exposure, so that the uneven distribution of the components contained in the photoresist film on the surface of the photoresist film is suppressed compared with the case where the interface control film is not formed. A computer-readable recording medium storing a program for causing a device to execute a substrate processing method as recited in any one of claims 1 to 3.

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