JP2011204774A - Pattern forming method, and dehydrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern forming method preventing an optical system from being damaged with EUV (Extreme Ultra-Violet) exposure to prevent a reduction in reflectivity, and to provide a method of manufacturing a semiconductor device, a dehydrator and an aligner.SOLUTION: The method includes the resist coating film forming step of forming a resist film on a substrate with a formed film to be dehydrated, the PAB (Post Applied Bake) step of heating the resist coating film to dry a solvent of the resist film, the EUV exposure step of exposing the dried resist film with EUV under a reduced pressure atmosphere, and the developing step of developing the EUV-exposed resist film to form a resist pattern. The dehydrating step of heating the film to be dehydrated to dehydrate the film to be dehydrated is included between the PAB step and the EUV exposure step to retain the substrate under a dried atmosphere between the dehydrating step and the EUV exposure step.

Description

  The present invention relates to a pattern forming method and a dehydrating apparatus.

  In EUV lithography using an EUV (Extreme Ultra-Violet) exposure apparatus, a reflective optical system comprising a multilayer film is used for an illumination optical system, a projection optical system, and a reflective exposure mask. These multilayer films are problematic in that they are damaged by being irradiated with EUV light in the presence of moisture in the atmosphere, resulting in a decrease in reflectance. For this reason, the vacuum chamber in which the projection optical system and the substrate on which the resist film to be exposed is formed in the EUV exposure apparatus is maintained at a vacuum of about 10 −5 Torr, and moisture is reduced.

  However, there is a possibility that moisture is brought into the vacuum chamber when the substrate to be exposed is taken in and out. In view of this, the inventor has proposed an invention in which a substrate coated with a resist is baked (heated after coating) and then held in a dry atmosphere until it is conveyed to an exposure apparatus (see Patent Document 1).

  On the other hand, a substrate for forming a resist film to be exposed may have a hygroscopic film such as a low-k film such as a silicon oxide film, a porous SiOC film, or a SiOCH film in a relatively upper layer. The hygroscopic film may absorb moisture to cause the substrate to have hygroscopicity. At least a resist film is formed on such a substrate. However, it is unlikely that the resist film becomes a barrier film with respect to the release of moisture from the hygroscopic film. Therefore, moisture in the hygroscopic film is released in a vacuum chamber or the like of the EUV exposure apparatus, and damages the optical system and mask of the exposure apparatus.

  The inventor has found that in a separately conducted study, when a film serving as a source of outgas during exposure is present in the lower layer of the resist film, the outgas from the film is likely to be released through the resist film. (For example, refer nonpatent literature 1). That is, since the size of water molecules is small, it is considered that there is a high possibility that moisture is released into the vacuum through the resist film and the lower layer film.

  By the way, in the EUV exposure apparatus, a load lock mechanism for reducing the substrate atmosphere to the same extent is provided in the front stage of the vacuum chamber in which exposure is performed in a vacuum atmosphere. Here, in order to apply the EUV exposure apparatus to mass production of semiconductor devices, a processing capacity of 100 or more per hour is required from the viewpoint of cost.

  For this reason, the decompression processing time in the load lock mechanism when decompressing in a single wafer type is about 30 seconds, and it is considered that the processing time is insufficient for removing water in the hygroscopic film. Therefore, there is a high possibility that moisture in the hygroscopic film is released in the vacuum chamber of the EUV exposure apparatus. Assuming that the decompression process in the load lock mechanism is a batch type of 25 lots per lot, and the vacuum standby time is 2 batches, the vacuum standby time is only 30 minutes. Therefore, it is considered that the processing time is insufficient for removing moisture in the hygroscopic film.

  Further, according to the investigation conducted separately by the inventor, in a short heating process (PAB: Post Applied Bake) of about 1 minute to 2 minutes performed by a normal baker after forming a resist film, a normal resist film is used. It is estimated that it is difficult to completely remove moisture in the hygroscopic film at the temperature applied in the forming process. Further, at the temperature applied in the PAB process, it is considered that the temperature is insufficient for dehydration of moisture in the hygroscopic film. And the glass transition temperature (Tg) of a resist film is only 150 to 200 degreeC. For this reason, when the heat treatment is performed at a higher temperature, there is a high possibility that the resolution performance of the resist is deteriorated. In addition, dehydration may be improved by increasing the heat treatment time. However, in this case, there is a problem that productivity decreases.

JP 2009-111186 A

“Pattern transfer process development for EUVL”, D. Kawamra et al, Proc. SPIE 7273-113, 2009

  An object of the present invention is to provide a pattern forming method and a dehydrating apparatus that can prevent damage to an optical system in EUV exposure and prevent a decrease in reflectance.

  According to one aspect of the present invention, a resist coating film forming process for forming a resist film on a substrate on which a film to be dehydrated is formed, and a PAB process for heating the resist coating film to dry the solvent of the resist film; An EUV exposure step of performing EUV exposure on the dried resist film under a reduced pressure atmosphere; and a developing step of developing the resist film after the EUV exposure to form a resist pattern, and the PAB step, A dehydration step of dehydrating the dehydrated film by heating the dehydrated film between the EUV exposure step and the substrate in a dry atmosphere between the dehydration step and the EUV exposure step; There is provided a pattern forming method characterized by being held below.

  Further, according to one aspect of the present invention, there is provided a dehydrating apparatus that performs a dehydration process on the film to be dehydrated on a substrate before exposure in which at least a film to be dehydrated and a resist film are sequentially formed on one surface, A dehydration processing unit that dehydrates the dehydrated film by housing the substrate and heating the dehydrated film, a dry gas supply unit that supplies a dry gas to the heat processing unit, and the heating A degassing unit for heating the dehydrating film by heating the dehydrating film in an atmosphere of the dry gas in the dehydrating unit. Are provided.

  According to the present invention, it is possible to prevent the optical system from being damaged in the EUV exposure and prevent the reflectance from being lowered.

FIG. 1 is a diagram showing a configuration of an EUV exposure system according to the first embodiment. FIG. 2 is a diagram illustrating a configuration of the dehydrating apparatus according to the first embodiment. FIG. 3 is a diagram showing the configuration of the EUV exposure apparatus according to the first embodiment. FIG. 4 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the first embodiment. FIG. 5 is a characteristic diagram showing the relationship between the substrate leaving time (evacuation time) and the pressure in the vacuum chamber. FIG. 6 is a diagram showing a configuration of an EUV exposure system according to the second embodiment. FIG. 7 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the second embodiment. FIG. 8 is a diagram showing a configuration of an EUV exposure system according to a first modification of the second embodiment. FIG. 9 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the first modification of the second embodiment. FIG. 10 is a flowchart for explaining the substrate exposure processing procedure using the EUV exposure system according to the second modification of the second embodiment. FIG. 11 is a flowchart for explaining a substrate exposure processing procedure according to the third embodiment. FIG. 12 is a flowchart for explaining a substrate exposure processing procedure using an EUV exposure system according to a modification of the third embodiment. FIG. 13 is a diagram showing a configuration of an EUV exposure system according to the fourth embodiment. FIG. 14 is a diagram showing a configuration of an EUV exposure system according to the fourth embodiment.

  Hereinafter, a resist pattern forming method and a dehydrating apparatus according to an embodiment will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an EUV exposure system according to the first embodiment. The EUV exposure system according to the first embodiment includes a coating and developing apparatus 1X, a dehydrating apparatus 10X, a substrate transport case 20X, an EUV exposure apparatus 30X, and a post-exposure heating (Post Exposure Bake: PEB) apparatus 40X. Prepare. The arrows in FIG. 1 indicate the flow of the substrate to be processed.

  Here, the coating and developing apparatus 1X and the dehydrating apparatus 10X and the EUV exposure apparatus 30X and the PEB apparatus 40X are connected, and the substrate is transported to the next process apparatus without being carried out of the apparatus. (Inline connection). That is, a coating and developing apparatus in a broad sense including the coating and developing apparatus 1X and the dehydrating apparatus 10X is configured. Further, an EUV exposure apparatus in a broad sense including the EUV exposure apparatus 30X and the PEB apparatus 40X is configured.

  On the other hand, there is no connection between the dehydrating apparatus 10X and the EUV exposure apparatus 30X, and between the PEB apparatus 40X and the coating and developing apparatus 1X, and the substrate is carried out into the substrate transfer case 20X, and the substrate transfer case It is put in and transported to the next process equipment (offline connection).

  The coating and developing apparatus 1X is an apparatus for applying various films used for processing to a substrate and applying and developing a resist sensitive to energy rays. The coating and developing apparatus 1X forms a coating film of various films used for processing on the substrate and performs a heating process (APB as a coating film drying process. The coating and developing apparatus 1X also forms a resist on the substrate. Is applied to form a resist film, and as a resist film drying process, post-application heat treatment (Post Applied Bake: PAB process) is performed on the resist film.

  Further, the coating and developing apparatus 1X has a development process for removing unnecessary portions from the resist film on which the latent image is formed after the PEB process is completed, and a rinse process for removing the developer and the resist solution used in the development process. To do. As a result, a desired resist pattern is formed. The coating and developing apparatus 1X may have a function of performing a PEB process on a substrate that has been exposed to the atmospheric pressure after the exposure process is completed by the EUV exposure apparatus 30X. Thereby, the coating and developing apparatus 1X forms a latent image in the resist film according to the EUV light pattern irradiated by the EUV exposure apparatus 30X. Further, the coating and developing apparatus 1X may be configured by being divided into a coating apparatus and a developing apparatus.

  FIG. 2 is a diagram illustrating a configuration of the dehydrating apparatus 10X. The dehydrating apparatus 10 </ b> X includes a transport unit 11, a dehydration processing unit 12, a dry gas supply unit 13, a gas discharge unit 14, a temperature adjustment unit 15, an atmospheric pressure adjustment unit 16, and a control unit 17.

  The transport unit 11 receives the substrate after the PAB process in the coating and developing apparatus 1X from the coating and developing apparatus 1X or the substrate transport case 20X, and transports it to the dehydration processing unit 12. Further, the transport unit 11 transports the substrate after the dehydration process from the dehydration processing unit 12 to the EUV exposure apparatus 30X or the substrate transport case 20X. The dehydration processing unit 12 stores the substrate and heats the predetermined hygroscopic film other than the resist on the substrate to dehydrate the hygroscopic film. In the dehydration processing unit 12, a substrate is held inside and can be sealed. For example, a chamber is used. The dehydration processing unit 12 includes, for example, an infrared irradiation unit (infrared lamp) as a heating unit, and selectively heats the hygroscopic film by irradiating the predetermined hygroscopic film with infrared rays. Moreover, it is also possible to use a normal baker as a heating means.

  The dry gas supply unit 13 supplies dry gas to the dehydration processing unit 12. The gas discharge unit 14 discharges the gas in the dehydration processing unit 12 and discharges the gas (water vapor) generated by heating the film on the substrate from the dehydration processing unit 12. The temperature adjustment unit 15 controls the temperature of the substrate to a predetermined temperature. When the dehydration process is performed under reduced pressure, the atmospheric pressure adjusting unit 16 depressurizes the ambient atmosphere of the substrate by the pressure adjustment function when the substrate is carried into the dehydration apparatus 10X. Then, the substrate is delivered to the dehydration processing unit 12 in a state where the substrate atmosphere is a reduced pressure atmosphere. The atmospheric pressure adjustment unit 16 includes a pressure reducing mechanism such as a load lock mechanism. The control unit 17 controls each component of the dehydrating apparatus 10X.

  The substrate transfer case 20X is a transfer means for storing a substrate that has been processed in each apparatus and transferring it to the next process apparatus connected offline. The atmosphere around the substrate in the substrate transfer case 20X is set to a dry atmosphere or an air atmosphere depending on the configuration of the EUV exposure system. Here, the dry atmosphere is an atmosphere having a very low water content, and examples thereof include a vacuum atmosphere, a dry nitrogen atmosphere, and a dry air atmosphere.

  The EUV exposure apparatus 30X is an exposure apparatus used in a lithography process when manufacturing a semiconductor device, and EUV pattern exposure (hereinafter referred to as EUV exposure) on a semiconductor substrate such as a wafer (process substrate W described later) in a vacuum atmosphere. To do. In the EUV exposure apparatus 30X according to the present embodiment, a substrate in which outgas generation is prevented in advance so as not to damage the optical system and the reflective mask due to outgas generated during EUV lithography is carried in. Specifically, the EUV exposure apparatus 30X carries a substrate on which a dehydration treatment of a hygroscopic film (dehydrated film) included in the substrate is performed immediately before exposure.

  FIG. 3 is a diagram showing a configuration of the EUV exposure apparatus 30X. The EUV exposure apparatus 30X includes an atmospheric pressure adjustment mechanism 31X, an EUV exposure mechanism 32X, and a control unit 33. The atmospheric pressure adjustment mechanism 31X includes a load lock chamber and the like, and carries in and out a substrate on which a semiconductor device is formed. The atmospheric pressure adjustment mechanism 31 </ b> X includes a conveyance unit 311 and an atmospheric pressure adjustment unit 312.

  The transport unit 311 carries the substrate into the EUV exposure apparatus 30X (atmospheric pressure adjustment mechanism 31X). When the substrate is carried into the atmospheric pressure adjustment mechanism 31X, the atmospheric pressure adjustment unit 312 depressurizes the ambient atmosphere around the substrate using the pressure adjustment function. The atmospheric pressure adjustment mechanism 31X is connected to the EUV exposure mechanism 32X, and the transport unit 311 transports the decompressed substrate to the EUV exposure mechanism 32X. The atmospheric pressure adjustment mechanism 31X and the EUV exposure mechanism 32X are disconnected during normal operation, and only when the substrate is transported between the atmospheric pressure adjustment mechanism 31X and the EUV exposure mechanism 32X, the atmospheric pressure adjustment mechanism 31X and the EUV exposure mechanism. 32X is released (load lock mechanism).

  The transport unit 311 stores the substrate transported from the EUV exposure mechanism 32X in the atmospheric pressure adjustment mechanism 31X. The atmospheric pressure adjustment unit 312 purges the ambient atmosphere of the substrate to atmospheric pressure by the pressure adjustment function when the substrate is carried out of the atmospheric pressure adjustment mechanism 31X. The transport unit 311 transports the substrate purged to atmospheric pressure to the PEB apparatus 40X connected to the EUV exposure apparatus 30X.

  The EUV exposure mechanism 32X performs EUV exposure on the substrate conveyed from the atmospheric pressure adjustment mechanism 31X. The EUV exposure mechanism 32X includes a transport unit 321, an exposure unit 322, and a temperature control unit 323. The transport unit 321 carries the substrate transported from the atmospheric pressure adjustment mechanism 31X into the EUV exposure mechanism 32X. The transport unit 321 transports the substrate to the temperature adjustment unit 323 and the exposure unit 322 and transports the exposed substrate to the atmospheric pressure adjustment mechanism 31X.

  The exposure unit 322 has a main chamber for performing EUV exposure and a reflective optical system and a mask. Using these optical system and a reflective mask, the substrate after temperature adjustment is irradiated with EUV light for exposure. Process. The main chamber includes a position measurement mechanism for the substrate, a mask transport mechanism, a mask drive mechanism, an accompanying diaphragm mechanism, a substrate drive mechanism, a projection optical system, and a movable mechanism for the associated optical system. Further, an EUV light source mechanism, an illumination optical system, and various measurement mechanisms and power mechanisms for operating them are attached, but since they are not directly related to the gist of the present invention, detailed description thereof is omitted.

  The temperature adjustment unit 323 performs substrate temperature adjustment (heating or cooling of the substrate) for ensuring overlay accuracy before the EUV exposure process for the substrate. It is necessary to suppress the deformation accompanying the thermal expansion of the substrate in order to obtain a high accuracy of alignment. In addition, the temperature control part 323 may be provided as a structure of multiple places and multiple stages.

  The control unit 33 controls the atmospheric pressure adjustment mechanism 31X and the EUV exposure mechanism 32X. The control unit 33 may be provided with an electronic processing system inside the coating and developing apparatus, but may be controlled by an electronic processing system provided outside the apparatus.

  The PEB apparatus 40X performs a post-exposure heating process (PEB process) on the substrate that has been exposed to the atmospheric pressure after the exposure process is completed by the EUV exposure apparatus 30X. Thereby, the coating and developing apparatus 1X forms a latent image in the resist film according to the EUV light pattern irradiated by the EUV exposure apparatus 30X.

  In the above description, the coating and developing apparatus 1X, the dehydrating apparatus 10X, the EUV exposure apparatus 30X, and the PEB apparatus 40X are described as separate apparatuses. However, an apparatus that combines the functions of the respective apparatuses may be configured. . For example, an integrated coating and developing apparatus 1X having functions of the coating and developing apparatus 1X and the dehydrating apparatus 10X may be configured. An integrated EUV exposure apparatus 30X having functions of the dehydrating apparatus 10X and the EUV exposure apparatus 30X may be configured.

  Next, a substrate exposure processing procedure using the EUV exposure system according to the first embodiment will be described with reference to FIG. FIG. 4 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the first embodiment. In the following, as one of the intermediate steps of the semiconductor device manufacturing process, after obtaining a resist pattern by the EUV lithography process on the process substrate W on which the hygroscopic film is formed, the process substrate W is processed using the resist pattern as a processing mask. An example of machining is shown.

  Examples of the hygroscopic film include a low-k film such as a porous silica film and a porous SiCO film, an additive-containing film, and a coating type silicon (Spin on Glass: SOG) film that is a coating type. It is a silicon oxide film in the meaning. It should be noted that the hygroscopic film is not limited to the uppermost layer when the EUV lithography process is performed, and even if a second film different from the hygroscopic film is formed on the hygroscopic film, In the case where moisture is released in vacuum, this embodiment can be applied and the effects of this embodiment can be obtained.

  First, a coating process is performed in the coating and developing apparatus 1X on the process substrate W on which a predetermined film including a hygroscopic film is formed. First, a coating type carbon (Spin on Carbon: SOC) film is formed on the process substrate W. As a typical method for forming the SOC film, after performing the SOC coating process (ST1) for forming the SOC coating film by spin coating, the SOC heating process (ST2) at a temperature of about 200 ° C. to 300 ° C. is performed. carry out. Next, an SOG film is formed on the process substrate W on which the SOC film is formed. As a typical method for forming an SOG film, an SOG coating process (ST3) for forming an SOG coating film by a spin coating method is performed, followed by an SOG heating process (ST4) at a temperature of about 180 ° C. to 300 ° C. To do.

  Next, an organic film is formed on the process substrate W on which the SOG film is formed. The organic film has improved adhesion between the SOG film, which is the uppermost layer of the process substrate W, and the resist film, a change in the surface state of the uppermost layer of the process substrate W in order to reduce development defects, and the bottom shape of the resist film. It is formed for the purpose of adjusting the exposure and improving the exposure sensitivity of the resist film. As a typical method for forming an organic film, an organic film heating step (ST6) at a temperature of about 150 ° C. to 250 ° C. is performed after an organic film coating step (ST5) for forming a coating film by a spin coating method. carry out.

  Next, a resist film is formed on the organic film. As a typical method for forming a resist film, after performing a resist coating step (ST7) for forming a coating film by a spin coating method, a resist PAB step (ST8) at a temperature of 80 ° C. to 150 ° C. is performed. The process substrate W that has completed the PAB process is transferred to the dehydrating apparatus 10X connected to the coating and developing apparatus 1X, and a predetermined dehydrating process (ST12) is performed in the dehydrating apparatus 10X.

  In the dehydrating apparatus 10X, the transport unit 11 receives the process substrate W that has completed the PAB process from the coating and developing apparatus 1X, and transports it to the dehydrating unit 12. When the process substrate W is held inside, the dehydration processing unit 12 is sealed. Then, the dry gas supply unit 13 supplies the dry gas to the dehydration processing unit 12, and the gas discharge unit exhausts. As a result, the atmosphere around the process substrate W is a dry atmosphere.

Next, in the dehydration processing unit 12, water in the hygroscopic film is selectively heated by irradiating the process substrate W with infrared rays by an infrared irradiation unit (infrared lamp), and the hygroscopic film is thus heated. Perform dehydration treatment. In the infrared irradiation process, it is desirable to irradiate the wavelength of the absorption band caused by the H ₂ O structure or OH bond. Thereby, the hygroscopic film on the process substrate W including the SOC film and the SOG film can be selectively heated to perform dehydration.

  In the dehydration process by infrared irradiation in the dehydration step (ST12), the far-infrared region near 3 μm or 6 μm, which is a selective absorption band of water molecules, is irradiated. The infrared light to be irradiated does not necessarily need to be an apparatus that irradiates only the wavelength in the vicinity of 3 μm to 6 μm. Further, as in the normal heating process, exhaust is required during heating. Since it is necessary to prevent the hygroscopic film from absorbing moisture again in the cooling step after heating, it is necessary to maintain a dry atmosphere at least from the cooling step after heating to the next exposure step.

  Therefore, the gas discharge unit 14 discharges the gas in the dehydration processing unit 12 together with the infrared irradiation, and the gas (water vapor) generated by heating the hygroscopic film is discharged from the dehydration processing unit 12. Thereby, the dehydration process can be performed on the hygroscopic film on the process substrate W while maintaining a dry atmosphere.

  And it is necessary to prevent the hygroscopic film subjected to the dehydration process from absorbing moisture again before the exposure process. For this reason, the process substrate W subjected to the dehydration step is held in a dry atmosphere during the EUV exposure step described later from the dehydration step. Therefore, in the present embodiment, the steps from the dehydration step (ST12) to the EUV exposure step (ST32) are performed in a dry atmosphere.

  Here, although the case where the dehydration process is performed by infrared irradiation with an infrared lamp has been described, the dehydration process may be performed by a heating process using a baker. In the case of a heating process by a baker, heating for about several minutes is required at 200 ° C. to 300 ° C. Further, as in the heating step by infrared irradiation, exhaust is required during heating. Further, since it is necessary to prevent the hygroscopic film from absorbing moisture again in the cooling step after heating, it is necessary to maintain a dry atmosphere at least from the cooling step after heating to the next exposure step.

  A predetermined temperature control process is performed on the process substrate W subjected to the dehydration process by the temperature control unit 15 of the dehydration apparatus 10X as necessary. In the temperature control step, process substrate W temperature adjustment (heating or cooling of the substrate) is performed to ensure overlay accuracy. It is necessary to suppress the deformation accompanying the thermal expansion of the substrate in order to obtain a high accuracy of alignment.

  Next, the process substrate W subjected to temperature control as necessary is transferred to the substrate transport case 20X while maintaining the dry atmosphere, and the atmosphere in the substrate transport case 20X is maintained in the dry atmosphere. Then, the process substrate W is transported to the EUV exposure apparatus 30X by the substrate transport case 20X in a state where the ambient atmosphere of the process substrate W is maintained in a dry atmosphere (substrate transport process, ST21). Then, the process substrate W is delivered from the substrate transport case 20X to the EUV exposure apparatus 30X in a state where the ambient atmosphere of the process substrate W is maintained in a dry atmosphere.

  In the EUV exposure apparatus 30X, the transport unit 311 carries the process substrate W into the EUV exposure apparatus 30X (atmospheric pressure adjustment mechanism 31X) while maintaining the atmosphere of the process substrate W in a dry atmosphere. When the process substrate W is carried into the atmospheric pressure adjusting mechanism 31X, the atmospheric pressure adjusting unit 312 performs a depressurization step (ST31) for reducing the drying atmosphere of the process substrate W.

  After the pressure inside the atmospheric pressure adjusting mechanism 31X is reduced to the same level as the main chamber of the exposure unit 322, the process substrate W is transferred into the main chamber of the EUV exposure mechanism 32X by the load lock mechanism of the atmospheric pressure adjusting mechanism 31X. In the EUV exposure mechanism 32X, the substrate temperature adjustment for ensuring the overlay accuracy is performed by the temperature adjustment unit 323 before the pattern exposure process on the process substrate W. Further, after a predetermined measurement process such as a substrate position and alignment is performed by the EUV exposure mechanism 32X, an EUV exposure process (ST32) is performed in a dry atmosphere and a reduced-pressure atmosphere.

  After the EUV exposure process is carried out, the process substrate W is transferred from the transport unit 321 of the EUV exposure mechanism 32X to the transport unit 311 of the atmospheric pressure adjustment mechanism 31X by the load lock mechanism of the atmospheric pressure adjustment mechanism 31X, and within the atmospheric pressure adjustment mechanism 31X. Stored in The atmospheric pressure adjustment unit 312 performs a purge step (ST33) of increasing the ambient atmosphere of the process substrate W to atmospheric pressure by the pressure adjustment function when the process substrate W is carried out of the atmospheric pressure adjustment mechanism 31X. The transport unit 311 transports the process substrate W after being purged to atmospheric pressure to the PEB apparatus 40X connected to the EUV exposure apparatus 30X. Note that after this purge step, the atmosphere of the process substrate W is a normal atmospheric atmosphere.

  The transport unit 311 transports the process substrate W after being purged to atmospheric pressure to the PEB apparatus 40X connected to the EUV exposure apparatus 30X. The PEB apparatus 40X performs a predetermined PEB process (ST41) on the process substrate W. When the resist film is a chemically amplified resist, a PEB process is generally performed between the EUV exposure process and the development process. In addition, when a resist film does not require a PEB process, it is not necessary to implement a PEB process. Therefore, the PEB apparatus 40X does not need to be connected to the EUV exposure apparatus 30X.

  Next, the process substrate W subjected to the PEB process (ST41) is accommodated in the substrate transport case 20X and transported to the coating and developing apparatus 1X (substrate transport process, ST51). The substrate transfer case 20X before and after transfer to the EUV exposure apparatus 30X is not necessarily the same. From the intention of the present invention, the atmosphere around the process substrate W needs to be a dry atmosphere when transported to the EUV exposure apparatus 30X. However, the atmosphere around the process substrate W does not need to be a dry atmosphere during transport after the exposure processing in the EUV exposure apparatus 30X is completed. Accordingly, the atmosphere around the process substrate W does not need to be a dry atmosphere when transported from the PEB apparatus 40X to the coating and developing apparatus 1X.

  Next, the process substrate W is transferred again from the substrate transport case 20X to the coating and developing apparatus 1X. In the coating and developing apparatus 1X, the developing step (ST61) and the rinsing step (ST62) for removing the resist film dissolved in the developing solution are performed on the resist film subjected to the EUV exposure step (ST32) and the PEB step (ST41). Is done. Thereby, a desired resist pattern is obtained on the process substrate W.

  Here, a typical developing solution for a resist film is a 2.38 wt% aqueous solution of TMAH (tetramethyl ammonium hydroxide). The TMAH concentration is not limited to 2.38% by weight. In addition, the TMAH aqueous solution may contain an additive such as a surfactant. The organic alkali component is not limited to TMAH, and may be TBAH (Tetrabuthyl Ammonium Hydroxide) or the like. Further, the developer may be an organic developer corresponding to the material of the resist film.

  Next, using the obtained resist pattern as a processing mask, the resist pattern pattern is transferred to the SOG film by etching to obtain an SOG film pattern. Next, using the SOG film pattern as a processing mask, the SOG film pattern is transferred to the SOC film by etching to obtain an SOC film pattern. Next, the pattern is transferred to a predetermined film on the process substrate W including the hygroscopic film by performing etching using the SOC film pattern as a processing mask. Then, after a series of etching steps, a removal step of the SOC film pattern and the like is performed. Thereafter, a predetermined process is performed on the process substrate W that has undergone the EUV lithography process to manufacture a desired semiconductor device.

  Here, a description will be given of the results of examination by the inventor regarding the release of moisture and re-absorption of moisture from a silicon substrate having a hygroscopic film in vacuum. A silicon substrate on which a hygroscopic film was formed (hereinafter referred to as a hygroscopic substrate) was placed in a FOUP (Front Open Unified Pod) and left in a clean room atmosphere for a predetermined time. The FOUP used in this study is not a special structure in which the lower part of the FOUP is sealed, but is an ordinary FOUP in which air moves between a clean room atmosphere. Then, the following measurements were performed using an outgas measuring device used in the pressure-rising method. An experiment was conducted in which the moisture-absorbing substrate was left in a vacuum chamber connected to a vacuum pump that continued to be evacuated with a constant capacity and evacuation was continued. Then, the standing time (evacuation time) and the pressure in the vacuum chamber were measured (first time). After the final vacuum was reached, the moisture absorbing substrate was taken out and left in the vacuum chamber again to continue evacuation (second time). Further, after the final vacuum level was reached (second time), the moisture absorbing substrate was taken out and left in the atmosphere in the FOUP for a whole day and then left again in the vacuum chamber to continue evacuation (third time). Similarly, an experiment was performed only once on a silicon substrate on which a hygroscopic film was not formed (hereinafter referred to as a silicon substrate).

  FIG. 5 is a characteristic diagram showing the relationship between the substrate leaving time (evacuation time) and the pressure in the vacuum chamber, and is a characteristic diagram showing the time dependence of the pressure in the vacuum chamber. FIG. 5 shows the first to third experimental results of the moisture-absorbing substrate and the experimental results of the silicon substrate.

  As can be seen from FIG. 5, with the silicon substrate, vacuuming to the final vacuum was completed in about 10 minutes. On the other hand, in the first moisture absorbing substrate, the final vacuum degree of the silicon substrate could not be reached even if 4 hours were required. In the second time of the moisture absorbing substrate, since the moisture was dehydrated from the moisture absorbing substrate in the first experiment, the vacuum reduction to the final vacuum degree was completed in about 10 minutes in the silicon substrate.

  Moreover, in the 3rd time of the moisture absorption board | substrate, the initial stage vacuum degree was equivalent to the vacuuming of the 1st time, and the pressure reduction behavior after that was also equivalent. According to analysis by Q-Mass (Quadrupole Mass spectroscopy) separately performed on the substrate having the same conditions as the first and third times, the amount of fragments estimated to be water in the vacuum chamber is larger than that of the silicon substrate. It was increasing. As a result, when the moisture-absorbing substrate contains moisture, the moisture is released in a vacuum, dehydration requires several hours for dehydration, and even if moisture is once released from the moisture-absorbing substrate, the moisture-absorbing substrate It shows that moisture is absorbed again from the substrate atmosphere.

  Therefore, when there is a waiting time between the dehydration process of the hygroscopic film on the process substrate W and the EUV exposure process and the process substrate W is held in the air atmosphere, the hygroscopic film It can be seen that moisture absorption occurs. In a conventional EUV exposure apparatus, a resist film coating process and an exposure process are continuously performed in one apparatus. However, since the throughput of the resist film coating process is high and the throughput of the EUV exposure process is low, there is a difference in throughput between the resist film coating process and the exposure process. For this reason, the coating process and the exposure process are separate apparatuses (offline), and after the coating process, the substrate is unloaded from the coating apparatus and held in a predetermined container, and then loaded into the exposure apparatus to carry out the exposure process. It is assumed that off-line processes will become mainstream. However, in this case, the substrate after the coating process has a waiting time before the exposure process, and moisture absorption in the hygroscopic film may occur.

  However, in the semiconductor device manufacturing method according to the first embodiment described above, the ambient atmosphere of the process substrate W is maintained in a dry atmosphere during the steps from the dehydration step to the EUV exposure step. For this reason, even in the case of off-line work, moisture absorption by the hygroscopic film on the process substrate W after the dehydration process is prevented.

  In the first embodiment described above, moisture in the hygroscopic film on the process substrate W is removed by a dehydration process performed before the EUV exposure process. During the steps from the dehydration step to the EUV exposure step, the atmosphere around the process substrate W is maintained in a dry atmosphere. For this reason, reabsorption of moisture by the hygroscopic film on the process substrate W after the dehydration step is prevented. Thereby, the moisture in the process substrate W brought into the EUV exposure process can be reduced, and the evaporation amount of the moisture from the process substrate W in the EUV exposure process can be reduced. Therefore, according to the first embodiment, it is possible to reduce damage to the optical system of the EUV exposure apparatus due to evaporation of moisture from the process substrate W in the EUV exposure process, and to prevent a decrease in reflectance. Become.

In the first embodiment, in the dehydration step, the process substrate W is irradiated with infrared rays having a wavelength of an absorption band caused by the H ₂ O structure or OH bond. Thereby, the moisture in the hygroscopic film can be selectively heated to perform the dehydration treatment, and the water in the hygroscopic film can be efficiently dehydrated.

  In the first embodiment, the dehydration process is performed after the PAB process. Thereby, the moisture absorbed by the hygroscopic film after the PAB process can be dehydrated before the EUV exposure process.

  Further, in the first embodiment, the period in which the ambient atmosphere of the process substrate W should be maintained in a dry atmosphere can be shortened as compared with the case where the dehydration process is performed, for example, before the formation of the SOC film. It is possible to reduce the amount of energy used for the supply and supply of the dry atmosphere used to maintain the ambient atmosphere of the process substrate W in the dry atmosphere.

  In addition, on some process substrates W or coating films, resist films, organic films, SOC films, etc. cause abnormalities such as pinholes in the coating film formation by spin coating in a dry atmosphere. There is a possibility. However, in the first embodiment, it is not always necessary to carry out the above-mentioned coating film formation in a dry atmosphere, so that an abnormal coating film formation can be avoided.

  In the first embodiment, the ambient atmosphere of the process substrate W is maintained in a dry atmosphere during the processes from the dehydration process to the EUV exposure process. For this reason, even in the case of off-line work in which the coating process and the exposure process are performed by separate apparatuses, even if a waiting time occurs between the coating process and the exposure process, the hygroscopic film on the process substrate W after the dehydration process is used. This prevents moisture from being absorbed again.

  As described above, according to the first embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, and the optical system of the EUV exposure apparatus is damaged due to the evaporation of moisture from the process substrate W. Can be reliably reduced, and a decrease in reflectance can be prevented.

(Second Embodiment)
FIG. 6 is a diagram showing a configuration of an EUV exposure system according to the second embodiment. The EUV exposure system according to the second embodiment includes a coating and developing apparatus 1X, a substrate transport case 20X, a dehydrating apparatus 10X, an EUV exposure apparatus 30X, and a PEB apparatus 40X. The arrows in FIG. 6 indicate the flow of the substrate to be processed.

  The dehydrator 10X and the EUV exposure apparatus 30X and the EUV exposure apparatus 30X and the PEB apparatus 40X are connected, and the substrate can be transferred to the next process apparatus without being carried out of the apparatus ( Inline connection). That is, an EUV exposure apparatus in a broad sense includes the dehydration apparatus 10X, the EUV exposure apparatus 30X, and the PEB apparatus 40X.

  On the other hand, the coating and developing apparatus 1X and the dehydrating apparatus 10X are not connected to each other and the PEB apparatus 40X and the coating and developing apparatus 1X are not connected. (Offline connection). The basic configuration of each device is the same as that of the first embodiment, and thus the same reference numerals as those in FIG. In the following, only the parts different from the case of the first embodiment will be described as appropriate.

  Next, a substrate exposure processing procedure using the EUV exposure system according to the second embodiment will be described with reference to FIG. FIG. 7 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the second embodiment. Hereinafter, as in the case of the first embodiment, as one of the intermediate steps of the semiconductor device manufacturing process, after obtaining a resist pattern by the EUV lithography process on the process substrate W on which the hygroscopic film is formed, An example of processing the process substrate W using the resist pattern as a processing mask will be described.

  First, a coating process is performed in the coating and developing apparatus 1X on the process substrate W on which a predetermined film including a hygroscopic film is formed in the same manner as in the first embodiment. That is, in the coating and developing apparatus 1X, the SOC coating process (ST1) to the PAB heating process (ST8) are performed on the process substrate W.

  Next, a predetermined temperature control step is performed by the temperature adjustment unit 15 of the dehydrating apparatus 10X as necessary on the process substrate W that has been subjected to the PAB heating step (ST8). Then, the temperature-controlled process substrate W is accommodated in the substrate transport case 20X and transported from the coating and developing apparatus 1X to the dehydrating apparatus 10X (substrate transport process, ST21). Note that the atmosphere around the process substrate W does not need to be a dry atmosphere during transport before the dehydration step. Therefore, in the substrate transfer step (ST21) in the present embodiment, the ambient atmosphere of the process substrate W may be an air atmosphere. However, when the resist film is a chemically amplified resist, the atmosphere around the process substrate W is preferably an atmosphere in which at least the base component is reduced. In the EUV exposure process, an acid component is generated in the exposed portion of the chemically amplified resist. However, if there is a base component around the substrate, the base component penetrates into the resist film, and the generated acid component reacts with the base component to reduce the acid component, making it impossible to form an accurate pattern.

Next, the process substrate W is subjected to a dehydration step (ST12) by infrared irradiation in the dehydration apparatus 10X in the same manner as in the first embodiment. That is, the hygroscopic film is heated by irradiating the process substrate W with infrared rays, and the dehydration process is performed on the hygroscopic film. As infrared rays, it is desirable to irradiate the wavelength of the absorption band caused by the H ₂ O structure or OH bond. Thereby, a dehydration process can be performed by selectively heating the hygroscopic film. Note that after the dehydration step (ST12), there may be a pressure-increasing step in a dehydration atmosphere or a substrate holding step at the same level as the dehydration step. Also in this embodiment mode, dehydration may be performed by a heating process using a baker.

  It is necessary to prevent the hygroscopic film subjected to the dehydration process from absorbing moisture again before the exposure process. For this reason, the process substrate W subjected to the dehydration step is held in a dry atmosphere during the EUV exposure step described later from the dehydration step. Therefore, in the present embodiment, the steps from the dehydration step (ST12) to the EUV exposure step (ST32) are performed in a dry atmosphere. Thereafter, a predetermined temperature control step is performed by the temperature control unit 15 of the dehydrating apparatus 10X as necessary on the process substrate W that has been subjected to the dehydrating step.

  Next, the process substrate W subjected to temperature control as necessary is transferred from the dehydrating apparatus 10X to the EUV exposure apparatus 30X in a state where the ambient atmosphere of the process substrate W is maintained in a dry atmosphere. Then, in the same manner as in the first embodiment, the EUV exposure apparatus 30X performs the decompression step (ST31) to the purge step (ST33) in a state where the ambient atmosphere of the process substrate W is maintained in a dry atmosphere. .

  In the subsequent steps, the PEB step (ST41) to the rinsing step (ST62) are performed on the process substrate W in the same manner as in the first embodiment. Thereby, a desired resist pattern is obtained on the process substrate W as in the case of the first embodiment.

  Then, using the obtained resist pattern as a processing mask, after performing a series of etching steps in the same manner as in the first embodiment, a removal step of the SOC film pattern and the like is performed. Thereafter, a predetermined process is performed on the process substrate W that has undergone the EUV lithography process to manufacture a desired semiconductor device.

  In the second embodiment described above, the moisture in the hygroscopic film on the process substrate W is removed by a dehydration process performed before the EUV exposure process, as in the case of the first embodiment. During the steps from the dehydration step to the EUV exposure step, the atmosphere around the process substrate W is maintained in a dry atmosphere. For this reason, reabsorption of moisture by the hygroscopic film on the process substrate W after the dehydration step is prevented. Thereby, the moisture in the process substrate W brought into the EUV exposure process can be reduced, and the evaporation amount of the moisture from the process substrate W in the EUV exposure process can be reduced. Therefore, according to the second embodiment, as in the case of the first embodiment, damage to the optical system of the EUV exposure apparatus due to evaporation of moisture from the process substrate W in the EUV exposure process is reduced, It is possible to prevent a decrease in reflectance.

In the second embodiment, in the dehydration step, the process substrate W is irradiated with infrared rays having a wavelength of an absorption band caused by an H ₂ O structure or an OH bond as in the case of the first embodiment. To do. Thereby, the moisture in the hygroscopic film can be selectively heated to perform the dehydration treatment, and the water in the hygroscopic film can be efficiently dehydrated.

  In the second embodiment, the dehydration process is performed after the PAB process and immediately before the EUV exposure process. Thereby, the moisture absorbed by the hygroscopic film after the PAB process can be dehydrated before the EUV exposure process.

  In the second embodiment, since the dehydration process is performed immediately before the EUV exposure process, the period in which the atmosphere around the process substrate W should be maintained in a dry atmosphere is shortened compared to the case of the first embodiment. Therefore, the amount of energy used for dehydration can be further reduced.

  In addition, on some process substrates W or coating films, resist films, organic films, SOC films, etc. cause abnormalities such as pinholes in the coating film formation by spin coating in a dry atmosphere. There is a possibility. However, in the second embodiment, since it is not always necessary to carry out the above-mentioned coating film formation in a dry atmosphere, abnormalities in coating film formation can be avoided as in the case of the first embodiment.

  In the second embodiment, the ambient atmosphere of the process substrate W is maintained in a dry atmosphere during the processes from the dehydration process to the EUV exposure process. For this reason, even in the case of off-line work in which the coating process and the exposure process are performed by separate apparatuses as in the case of the first embodiment, even if a waiting time occurs between the coating process and the exposure process, the dehydration process Subsequent moisture absorption by the hygroscopic film on the process substrate W is prevented.

  Furthermore, in the second embodiment, the dehydration process is performed immediately before the exposure process in the dehydration apparatus 10X connected inline with the EUV exposure apparatus 30X. For this reason, even in the case of off-line work in which the coating process and the exposure process are performed by separate apparatuses, unlike in the first embodiment, the inside of the substrate transport case 20X that transports the process substrate to the dehydrating apparatus 10X is not necessarily dry. There is no need to maintain. Therefore, the effect of the present embodiment can be obtained with a relatively simple mechanism even in an off-line structure.

  As described above, according to the second embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, and the optical system of the EUV exposure apparatus is damaged due to the evaporation of moisture from the process substrate W. Can be reliably reduced, and a decrease in reflectance can be prevented.

  Hereinafter, modifications of the second embodiment will be described. In the second embodiment described above, the EUV exposure system having an offline connection structure has been described. However, an EUV exposure system having an inline connection structure may be configured. In this case, the same effect as that of the EUV exposure system having the offline connection structure of the second embodiment can be obtained.

  FIG. 8 is a diagram showing a configuration of an EUV exposure system according to a first modification of the second embodiment. The EUV exposure system according to the first modification includes a coating and developing apparatus 1X, a dehydrating apparatus 10X, and an EUV exposure apparatus 30X. The function of the PEB device 40X is incorporated in the coating and developing device 1X. The function of the PEB apparatus 40X may be incorporated in the EUV exposure apparatus 30X. The arrows in FIG. 8 indicate the flow of the substrate to be processed.

  Here, the coating and developing apparatus 1X, the dehydrating apparatus 10X, and the EUV exposure apparatus 30X are connected, and the substrate can be transported to the next process apparatus without being carried out of the apparatus (in-line connection). The basic configuration of each device is the same as that of the first embodiment, and thus the same reference numerals as those in FIG.

  FIG. 9 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the first modification. The substrate exposure procedure is the same as that of the second embodiment described above except that the organic film forming step is omitted and the process substrate W is transferred between apparatuses without using the substrate transfer case 20X. Same as the case. That is, in the first modification, the process substrate W that has been subjected to a predetermined temperature control process as necessary after the resist PAB process (ST8) is transferred from the coating and developing apparatus 1X to the dehydrating apparatus 10X without using the substrate transfer case 20X. Is passed on. Further, after the purge process (ST33), the process substrate W is transferred from the EUV exposure apparatus 30X to the coating and developing apparatus 1X without using the substrate transport case 20X. Also in the first modified example, the steps from the dehydration step (ST12) to the EUV exposure step (ST32) are performed in a dry atmosphere.

  Also according to the first modified example as described above, as in the case of the second embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, resulting in evaporation of moisture from the process substrate W. It is possible to reliably reduce damage to the optical system of the EUV exposure apparatus and to prevent a decrease in reflectance.

  FIG. 10 is a flowchart for explaining the substrate exposure processing procedure using the EUV exposure system according to the second modification of the second embodiment. The EUV exposure system according to the second modification has a configuration in which the function of the dehydrating apparatus 10X is incorporated in the coating and developing apparatus 1X in the EUV exposure system according to the first modification. The substrate exposure procedure is such that, after the PAB step (ST8) is completed, a dehydration step (ST12) is performed in the coating and developing apparatus 1X on the process substrate W that has been subjected to a temperature control step as necessary. Except that the process substrate W is transferred from the coating and developing apparatus 1X to the EUV exposure apparatus 30X after the execution of (ST12), it is the same as in the case of the first modification described above. In the second modified example, the steps from the dehydration step (ST12) to the EUV exposure step (ST32) are performed in a dry atmosphere.

  Also in the second modification as described above, as in the case of the second embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, resulting in evaporation of moisture from the process substrate W. It is possible to reliably reduce damage to the optical system of the EUV exposure apparatus and to prevent a decrease in reflectance.

(Third embodiment)
In the third embodiment, an example in which the dehydration process is performed under reduced pressure in the configuration of the EUV exposure system according to the second embodiment will be described. FIG. 11 is a flowchart for explaining a substrate exposure processing procedure according to the third embodiment. Hereinafter, as in the case of the first embodiment, as one of the intermediate steps of the semiconductor device manufacturing process, after obtaining a resist pattern by the EUV lithography process on the process substrate W on which the hygroscopic film is formed, An example of processing the process substrate W using the resist pattern as a processing mask will be described. The substrate exposure procedure is the same as that in the second embodiment described above, except that the dehydration process is performed under reduced pressure. The dehydration process according to the third embodiment will be described below.

  A predetermined temperature control step is performed as necessary on the process substrate W that has been subjected to the PAB step (ST8). Then, the process substrate W subjected to temperature control as necessary is accommodated in the substrate transport case 20X and transported from the coating and developing apparatus 1X to the dehydrating apparatus 10X (substrate transport process, ST21). Note that the atmosphere around the process substrate W does not need to be a dry atmosphere during transport before the dehydration step. Therefore, in the substrate transfer step (ST21) in the present embodiment, the ambient atmosphere of the process substrate W may be an air atmosphere. However, the ambient atmosphere around the process substrate W is preferably an atmosphere in which at least the base component is reduced.

  The process substrate W transferred to the dehydrating apparatus 10X is subjected to the first depressurization step (ST11) in which the atmosphere around the substrate is depressurized to a predetermined pressure by the pressure adjustment function of the atmospheric pressure adjustment unit 16. In the dehydration process, since water is vaporized by the process, it is not efficient to make the degree of vacuum equal to that of the main chamber of the EUV exposure apparatus 30X, and it is efficient to be between the atmospheric pressure and the pressure of the main chamber. It is. Therefore, the pressure in the first decompression step (ST11) is an intermediate pressure between the pressure of the decompressed atmosphere and the atmospheric pressure in the EUV exposure step (ST32). In the present embodiment, the steps from the first decompression step (ST11) to the EUV exposure step (ST32) are performed in a dry atmosphere.

  Then, the process substrate W is delivered to the dehydration processing unit 12 by the load lock mechanism of the atmospheric pressure adjustment unit 16 in a state where the atmosphere around the substrate is a reduced pressure atmosphere and a dry atmosphere. In the dehydration processing unit 12, a dehydration step (ST12) by infrared irradiation is performed in the same manner as in the first embodiment in a state where the ambient atmosphere of the substrate is a reduced pressure atmosphere and a dry atmosphere. That is, the hygroscopic film is heated by irradiating the process substrate W with infrared rays, and dehydration is performed on the hygroscopic film.

As infrared rays, it is desirable to irradiate the wavelength of the absorption band caused by the H ₂ O structure or OH bond. Thereby, the moisture absorption film containing moisture can be dehydrated by selectively heating the SOC film and the SOG film. In addition, a certain increase in the dehydration rate is expected by heating under reduced pressure or infrared lamp irradiation. Note that after the dehydration step (ST12), there may be a pressure-increasing step in a dehydration atmosphere or a substrate holding step at the same level as the dehydration step. In this embodiment mode, dehydration may be performed by a heating process using a baker.

  It is necessary to prevent the hygroscopic film subjected to the dehydration process from absorbing moisture again before the exposure process. For this reason, the process substrate W subjected to the dehydration step is held in a dry atmosphere during the EUV exposure step described later from the dehydration step. Therefore, in the present embodiment, the processes from the dehydration process to the EUV exposure process are performed in a dry atmosphere.

  Then, the process substrate W subjected to the dehydration process is delivered to the EUV exposure apparatus 30X in a state where the ambient atmosphere of the process substrate W is maintained in a reduced pressure atmosphere and a dry atmosphere by the load lock mechanism of the dehydration processing unit 12. . By providing a load lock mechanism in the dehydration processing unit 12, water removed from the process substrate W by the dehydration apparatus 10X can be prevented from directly entering the EUV exposure apparatus 30X.

  In the EUV exposure apparatus 30X, the transport unit 311 carries the process substrate W into the EUV exposure apparatus 30X (atmospheric pressure adjustment mechanism 31X) while maintaining the atmosphere of the process substrate W in a reduced pressure atmosphere and a dry atmosphere. When the process substrate W is carried into the atmospheric pressure adjusting mechanism 31X, the atmospheric pressure adjusting unit 312 performs a second depressurization step (ST31-1) for further depressurizing the dry atmosphere of the process substrate W. Then, as in the case of the first embodiment, the EUV exposure process (ST32) is performed in the EUV exposure apparatus 30X in a state where the ambient atmosphere of the process substrate W is maintained in a dry atmosphere.

  In the subsequent steps, the purge step (ST33) to the rinsing step (ST62) are performed on the process substrate W in the same manner as in the first embodiment. Thereby, a desired resist pattern is obtained on the process substrate W as in the case of the first embodiment.

  Then, using the obtained resist pattern as a processing mask, after performing a series of etching steps in the same manner as in the first embodiment, a removal step of the SOC film pattern and the like is performed. Thereafter, a predetermined process is performed on the process substrate W that has undergone the EUV lithography process to manufacture a desired semiconductor device.

  In the third embodiment described above, the moisture in the hygroscopic film on the process substrate W is removed by the dehydration process performed before the EUV exposure process, as in the second embodiment. During the steps from the dehydration step to the EUV exposure step, the atmosphere around the process substrate W is maintained in a dry atmosphere. For this reason, reabsorption of moisture by the hygroscopic film on the process substrate W after the dehydration step is prevented. Thereby, the moisture in the process substrate W brought into the EUV exposure process can be reduced, and the evaporation amount of the moisture from the process substrate W in the EUV exposure process can be reduced. Therefore, according to the third embodiment, damage to the optical system of the EUV exposure apparatus due to the evaporation of moisture from the process substrate W in the EUV exposure process is reduced as in the second embodiment, It is possible to prevent a decrease in reflectance.

In the third embodiment, in the dehydration step, the process substrate W is irradiated with infrared rays having a wavelength of an absorption band caused by an H ₂ O structure or an OH bond as in the case of the second embodiment. . Thereby, the moisture in the hygroscopic film can be selectively heated to perform the dehydration treatment, and the water in the hygroscopic film can be efficiently dehydrated.

  In the third embodiment, the dehydration process is performed after the PAB process and immediately before the EUV exposure process. Thereby, as in the case of the second embodiment, the moisture absorbed by the hygroscopic film after the PAB process can be dehydrated before the EUV exposure process.

  In the third embodiment, since the dehydration process is performed immediately before the EUV exposure process, the period in which the atmosphere around the process substrate W should be maintained in a dry atmosphere is shortened compared to the case of the first embodiment. Therefore, the amount of energy used for dehydration can be further reduced.

  In addition, on some process substrates W or coating films, resist films, organic films, SOC films, etc. cause abnormalities such as pinholes in the coating film formation by spin coating in a dry atmosphere. There is a possibility. However, in the third embodiment, since it is not always necessary to perform the above-described coating film formation in a dry atmosphere, abnormalities in the coating film formation can be avoided as in the case of the second embodiment.

  In the third embodiment, the ambient atmosphere of the process substrate W is maintained in a dry atmosphere during the processes from the dehydration process to the EUV exposure process. For this reason, even in the case of off-line work in which the coating process and the exposure process are performed by separate apparatuses, even if a waiting time occurs between the coating process and the exposure process, the hygroscopic film on the process substrate W after the dehydration process is used. This prevents moisture from being absorbed again.

  Furthermore, in the method for manufacturing a semiconductor device according to the third embodiment, the dehydration process is performed immediately before the exposure process in the dehydration apparatus 10X connected inline with the EUV exposure apparatus 30X. For this reason, even in the case of off-line work in which the coating process and the exposure process are performed by separate apparatuses, unlike in the first embodiment, the inside of the substrate transport case 20X that transports the process substrate to the dehydrating apparatus 10X is not necessarily dry. There is no need to maintain. Therefore, the effect of the present embodiment can be obtained with a relatively simple mechanism even in an off-line structure.

  In the semiconductor device manufacturing method according to the third embodiment, the first decompression step is performed before the dehydration step, and the dehydration process is performed in a state where the ambient atmosphere of the process substrate W is decompressed. As a result, moisture in the ambient atmosphere of the process substrate W can be reduced in advance, so that an increase in dehydration rate is expected. Further, by providing a load lock mechanism between the dehydrating apparatus 10X and the EUV exposure apparatus 30X, water removed from the process substrate W by the dehydrating apparatus 10X can be prevented from directly entering the EUV exposure apparatus 30X.

  Thus, according to the third embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, and the optical system of the EUV exposure apparatus is damaged due to the evaporation of moisture from the process substrate W. Can be reliably reduced, and a decrease in reflectance can be prevented.

  Hereinafter, a modification of the third embodiment will be described. In the third embodiment described above, the EUV exposure system having an offline connection structure has been described. However, an EUV exposure system having an inline connection structure may be configured. In this case, the same effect as that of the EUV exposure system having the offline connection structure of the third embodiment can be obtained.

  The configuration of the EUV exposure system according to the modified example of the third embodiment is the same as that of the EUV exposure system according to the modified example of the second embodiment, and is the configuration shown in FIG. For this reason, detailed description is omitted.

  FIG. 12 is a flowchart for explaining a substrate exposure processing procedure using an EUV exposure system according to a modification of the third embodiment. The substrate exposure procedure is the same as that of the third embodiment described above except that the organic film forming step is omitted and the process substrate W is transferred between apparatuses without using the substrate transfer case 20X. Same as the case. That is, in this modification, the process substrate W that has been subjected to a predetermined temperature control process as necessary after the resist heating process (ST8, PAB process) is removed from the coating and developing apparatus 1X without using the substrate transport case 20X. Delivered to 10X. Further, after the purge process (ST33), the process substrate W is transferred from the EUV exposure apparatus 30X to the coating and developing apparatus 1X without using the substrate transport case 20X.

  Even in the modified example as described above, as in the case of the third embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, and the EUV resulting from the evaporation of moisture from the process substrate W is performed. It is possible to reliably reduce damage to the optical system of the exposure apparatus and prevent a decrease in reflectance.

(Fourth embodiment)
As another embodiment of the present invention, the following configuration is also conceivable. FIG. 13 is a diagram showing a configuration of an EUV exposure system according to the fourth embodiment. The EUV exposure system according to the fourth embodiment includes a dehydrating apparatus 10X, a coating and developing apparatus 1X, and an EUV exposure apparatus 30X. The function of the PEB device 40X is incorporated in the coating and developing device 1X. The arrows in FIG. 13 indicate the flow of the substrate to be processed.

  Here, the dehydrating apparatus 10X, the coating and developing apparatus 1X, and the EUV exposure apparatus 30X are connected, and the substrate can be transported to the next process apparatus without being carried out of the apparatus (in-line connection). The basic configuration of each device is the same as that of the first embodiment, and thus the same reference numerals as those in FIG.

  Next, a substrate exposure processing procedure using the EUV exposure system according to the fourth embodiment will be described with reference to FIG. FIG. 14 is a flowchart for explaining a substrate exposure processing procedure using the EUV exposure system according to the fourth embodiment. Hereinafter, as in the case of the first embodiment, as one of the intermediate steps of the semiconductor device manufacturing process, after obtaining a resist pattern by the EUV lithography process on the process substrate W on which the hygroscopic film is formed, An example of processing the process substrate W using the resist pattern as a processing mask will be described.

  First, with respect to the process substrate W on which a predetermined film including a hygroscopic film is formed, a dehydration process (ST12) by infrared irradiation is performed in the dehydration apparatus 10X in the same manner as in the first embodiment. . That is, the hygroscopic film is heated by irradiating the process substrate W with infrared rays, and the dehydration process is performed on the hygroscopic film.

  It is necessary to prevent the hygroscopic film subjected to the dehydration process from absorbing moisture again before the exposure process. For this reason, the process substrate W subjected to the dehydration step is held in a dry atmosphere during the EUV exposure step described later from the dehydration step. Therefore, in the present embodiment, the steps from the dehydration process (ST12) to the EUV exposure process (ST32) are performed in a dry atmosphere. In this embodiment mode, dehydration may be performed by a heating process using a baker.

  Next, the process substrate W subjected to the dehydration process is delivered from the dehydration apparatus 10X to the coating and developing apparatus 1X without using the substrate transfer case 20X in a state where the atmosphere around the process substrate W is maintained in a dry atmosphere. It is. Then, a coating process is performed in the coating and developing apparatus 1X in the same manner as in the first embodiment. That is, in the coating and developing apparatus 1X, the SOC coating process (ST1) to the resist heating process (ST8, PAB process) are performed on the process substrate W while the ambient atmosphere of the process substrate W is maintained in a dry atmosphere.

  Next, the process substrate W that has been subjected to the PAB step (ST8) is subjected to the coating and developing apparatus 1X to the EUV exposure apparatus 30X without using the substrate transfer case 20X in a state where the ambient atmosphere of the process substrate W is maintained in a dry atmosphere. Is passed on. Then, similarly to the case of the first embodiment, the depressurization step (ST31) to the purge step (ST33) are performed in the EUV exposure apparatus 30X. Note that the atmosphere around the process substrate W is maintained in a dry atmosphere until the pressure is increased in the purge step (ST33).

  In the subsequent steps, the PEB step (ST41) to the rinsing step (ST62) are performed on the process substrate W in the same manner as in the first embodiment. Thereby, a desired resist pattern is obtained on the process substrate W as in the case of the first embodiment.

  Then, using the obtained resist pattern as a processing mask, after performing a series of etching steps in the same manner as in the first embodiment, a removal step of the SOC film pattern and the like is performed. Thereafter, a predetermined process is performed on the process substrate W that has undergone the EUV lithography process to manufacture a desired semiconductor device.

  In the semiconductor device manufacturing method according to the fourth embodiment described above, the moisture in the hygroscopic film on the process substrate W is removed in the dehydration step before the EUV exposure step as in the case of the first embodiment. Is done. Then, the ambient atmosphere of the process substrate W is maintained in a dry atmosphere from the dehydration process to the EUV exposure process. For this reason, reabsorption of moisture by the hygroscopic film on the process substrate W after the dehydration step is prevented. Thereby, the moisture in the process substrate W brought into the EUV exposure process can be reduced, and the evaporation amount of the moisture from the process substrate W in the EUV exposure process can be reduced. Therefore, according to the method for manufacturing a semiconductor device according to the fourth embodiment, as in the case of the first embodiment, the optics of the EUV exposure apparatus resulting from the evaporation of moisture from the process substrate W in the EUV exposure process. It is possible to reduce the damage to the system and prevent the reflectance from decreasing.

Further, in the method of manufacturing a semiconductor device according to the fourth embodiment, in the dehydration step, the H ₂ O structure or the absorption due to the OH bond with respect to the process substrate W is performed as in the case of the first embodiment. Irradiate the band with infrared rays. Thereby, the moisture in the hygroscopic film can be selectively heated to perform the dehydration treatment, and the water in the hygroscopic film can be efficiently dehydrated.

  As described above, according to the fourth embodiment, the hygroscopic film on the process substrate W is efficiently dehydrated, and the optical system of the EUV exposure apparatus is damaged due to the evaporation of moisture from the process substrate W. Can be reliably reduced, and a decrease in reflectance can be prevented.

  1X coating and developing apparatus, 10X dehydrating apparatus, 11 transport section, 12 dehydration processing section, 13 dry gas supply section, 14 gas discharge section, 15 temperature control section, 16 atmospheric pressure adjustment section, 17 control section, 20X substrate transport case, 30X EUV Exposure device, 31X atmospheric pressure adjustment mechanism, 32X exposure mechanism, 33 control unit, 40X post-exposure heating (PEB) device, 311 conveyance unit, 312 atmospheric pressure adjustment unit, 321 conveyance unit, 322 exposure unit, 323 temperature adjustment unit, W process substrate .

Claims (5)

A resist coating film forming step of forming a resist film on the substrate on which the film to be dehydrated is formed;
A PAB step of heating the resist coating and drying the solvent of the resist film;
An EUV exposure step of performing EUV exposure in a reduced-pressure atmosphere on the dried resist film;
A development step of developing the resist film after the EUV exposure to form a resist pattern;
Including
A dehydration step of dehydrating the dehydrated film by heating the dehydrated film between the PAB step and the EUV exposure step;
Holding the substrate in a dry atmosphere between the dehydration step and the EUV exposure step;
A pattern forming method characterized by the above. In the dehydration step, heating the film to be dehydrated by irradiating the film to be dehydrated with infrared rays,
The pattern forming method according to claim 1. Selectively heating the film to be dehydrated by irradiating the film to be dehydrated with an infrared ray having a wavelength of an absorption band caused by an H ₂ O structure or an OH bond;
The pattern forming method according to claim 2. The dehydration step is performed under a reduced pressure atmosphere;
The pattern forming method according to claim 1. A dehydrating apparatus for performing a dehydration process on the film to be dehydrated on a substrate before exposure in which at least a film to be dehydrated and a resist film are sequentially formed on one surface,
A dehydration processing unit for dehydrating the film to be dehydrated by storing the substrate and heating the film to be dehydrated;
A drying gas supply unit for supplying a drying gas to the heat treatment unit;
A gas discharge unit for discharging the gas in the heat treatment unit;
With
Dehydrating the film to be dehydrated by heating the film to be dehydrated in the atmosphere of the dry gas in the dehydration processing unit;
A dehydrator characterized by.

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