JP2015015291A - Apparatus for processing substrate, system for processing substrate, method for processing substrate and recording medium for processing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for processing a substrate, which can form a fine pattern on a substrate while suppressing reduction in the throughput.SOLUTION: A coating and developing apparatus E2 includes: a developing unit for developing a resist film formed on a wafer W; a light irradiating unit U7 for irradiating the resist film with UV light having a longer wavelength compared to EUV light; and a control unit R1. The control unit R1 controls the developing unit to develop a resist film after the resist film is subjected to EUV exposure and controls the light irradiating unit U7 to irradiate the resist film with UV light in a region including the target part of the EUV exposure before the developing unit develops the resist film.

Description

  The present invention relates to a substrate processing apparatus, a substrate processing system, a substrate processing method, and a substrate processing recording medium.

  2. Description of the Related Art A technique for forming a pattern on a substrate by subjecting a photosensitive film formed on the substrate to exposure processing and development processing is widely used. For example, in a semiconductor manufacturing process, an etching resist pattern is formed by subjecting a photosensitive resist film (photosensitive coating) formed on the surface of a wafer (substrate) to exposure and development. With higher integration of semiconductors, there is a demand for finer resist patterns. In order to realize a finer resist pattern, an exposure process using a KrF excimer laser has been put into practical use, and an exposure process using an ArF excimer laser has also been put into practical use. In recent years, an exposure process using EUV (Extreme Ultraviolet) light has been proposed in order to realize further pattern miniaturization (see, for example, Patent Document 1).

JP 2006-78744 A

  However, EUV has less energy than ArF laser or the like. There is a limit to increasing the sensitivity of the resist film to compensate for this. For this reason, when EUV exposure is adopted, the time for exposing one irradiation region becomes longer, and as a result, the throughput is lowered and the productivity is lowered.

  Therefore, an object of the present invention is to provide a substrate processing apparatus, a substrate processing system, a substrate processing method, and a substrate processing recording medium capable of forming a fine pattern on a substrate while suppressing a decrease in throughput.

  A substrate processing apparatus according to the present invention includes a development processing unit for performing development processing on a photosensitive film formed on a substrate, and light irradiation for irradiating the photosensitive film with UV light having a wavelength longer than that of EUV light. A development control unit that controls the development processing unit to perform development processing on the photosensitive coating after the EUV exposure is performed on the photosensitive coating, and before the development processing unit performs development processing on the photosensitive coating. And a light irradiation control unit for controlling the light irradiation unit so as to irradiate the region of the photosensitive coating including the target portion of the EUV exposure with UV light.

  According to this substrate processing apparatus, both UV light irradiation (hereinafter referred to as “UV exposure”) and EUV exposure are performed prior to development processing. Thereby, both the EUV light and the UV light are irradiated to the target portion of the EUV exposure. By combining the irradiation of the UV light with the irradiation of the EUV light, the irradiation amount of the EUV light can be reduced, and the EUV exposure time can be shortened. Also, compared to EUV light, UV light tends to increase its energy. Further, in the UV exposure as an auxiliary to the EUV exposure, it is not necessary to selectively irradiate the target portion of the EUV exposure with the UV light, and the UV light can be simultaneously irradiated over a wide range. For these reasons, the exposure time can be shortened as compared with the case where exposure processing is performed by EUV exposure alone. Therefore, a fine pattern can be formed by employing EUV exposure while suppressing a decrease in throughput.

  In the UV exposure, the acid generator is decomposed by UV light irradiation to generate an acid. This acid serves as a catalyst for the reaction that changes the solubility of the photosensitive coating. In EUV exposure, atoms are ionized by the irradiation of EUV light to generate secondary electrons. Secondary electrons decompose the acid generator to generate an acid. This acid also serves as a catalyst for the reaction that changes the solubility of the photosensitive coating. Thus, although the reaction mechanism differs greatly between UV exposure and EUV exposure, they are common in that they generate acid as a catalyst. This common point makes it possible to assist EUV exposure with UV exposure.

  A heat treatment section for performing a heat treatment on the photosensitive film, and a heating control section for controlling the heat treatment section so as to perform the heat treatment on the photosensitive film between the EUV exposure and the development treatment for the photosensitive film. Further, the light irradiation control unit may control the light irradiation unit to irradiate the photosensitive film with UV light before the heat treatment unit performs the heat treatment on the photosensitive film. In this case, since both the reaction initiated by EUV exposure and the reaction initiated by UV exposure are promoted by heat treatment, the throughput can be improved.

  The light irradiation control unit may control the light irradiation unit so that the photosensitive film is irradiated with UV light before EUV exposure is performed on the photosensitive film. In this case, before the EUV exposure, the obstacle material for EUV exposure is reduced by the UV exposure, so that the pattern can be formed with higher accuracy.

  The light irradiation unit may irradiate UV light having a wavelength of 220 to 280 nm. In this case, it is possible to form a pattern with higher accuracy while more reliably suppressing a decrease in throughput.

  A substrate processing system according to the present invention includes the above substrate processing apparatus and an EUV exposure apparatus that performs EUV exposure on a photosensitive film on a substrate. According to this substrate processing system, a fine pattern can be formed while suppressing a decrease in throughput by using the substrate processing apparatus and the EUV exposure apparatus.

  In the substrate processing method according to the present invention, after the EUV exposure is performed on the photosensitive film formed on the substrate, the developing process is performed on the photosensitive film, and before the developing process is performed on the photosensitive film, The photosensitive film is irradiated with UV light having a wavelength longer than that of the above.

  According to this substrate processing method, both UV light irradiation (hereinafter referred to as “UV exposure”) and EUV exposure are performed prior to development processing. Thereby, both the EUV light and the UV light are irradiated to the target portion of the EUV exposure. By combining the irradiation of the UV light with the irradiation of the EUV light, the irradiation amount of the EUV light can be reduced, and the EUV exposure time can be shortened. Also, compared to EUV light, UV light tends to increase its energy. Further, in the UV exposure as an auxiliary to the EUV exposure, it is not necessary to selectively irradiate the target portion of the EUV exposure with the UV light, and the UV light can be simultaneously irradiated over a wide range. For these reasons, the exposure time can be shortened as compared with the case where exposure processing is performed by EUV exposure alone. Therefore, a fine pattern can be formed by employing EUV exposure while suppressing a decrease in throughput.

  Between the EUV exposure and the development process for the photosensitive film, the photosensitive film may be subjected to a heat treatment, and before the heat treatment for the photosensitive film, the photosensitive film may be irradiated with UV light. In this case, since both the reaction initiated by EUV exposure and the reaction initiated by UV exposure are promoted by heat treatment, the throughput can be improved.

  Before the EUV exposure is performed on the photosensitive coating, the photosensitive coating may be irradiated with UV light. In this case, before the EUV exposure, the obstacle material for EUV exposure is reduced by the UV exposure, so that the pattern can be formed with higher accuracy.

  You may irradiate UV light with a wavelength of 220-280 nm. In this case, it is possible to form a pattern with higher accuracy while more reliably suppressing a decrease in throughput.

  A substrate processing recording medium according to the present invention is a computer-readable recording medium on which a program for causing a substrate processing apparatus to execute the substrate processing method is recorded.

  According to the present invention, a fine pattern can be formed on a substrate while suppressing a decrease in throughput.

It is a perspective view of the substrate processing system concerning this embodiment. It is sectional drawing which follows the II-II line | wire in FIG. It is sectional drawing which follows the III-III line | wire in FIG. It is sectional drawing which follows the IV-IV line | wire in FIG. It is sectional drawing which follows the VV line in FIG. It is a schematic diagram of a light irradiation apparatus. It is sectional drawing which follows the VII-VII line in FIG. It is a flowchart which shows a resist pattern formation procedure. It is a figure which shows the evaluation result of the precision of a throughput and a resist pattern. It is a figure which shows the evaluation result of the precision of a throughput and a resist pattern. It is a graph which shows the relationship between the wavelength of UV light, and a light absorbency. It is a graph which shows the relationship between the wavelength of UV light, and the transmittance | permeability. It is a graph which shows the relationship between the dose amount of UV light, and the thickness of the resist film after a development process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements or elements having the same functions are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, the substrate processing system 1 includes an EUV exposure apparatus E1 and a coating / developing apparatus (substrate processing apparatus) E2. The EUV exposure apparatus E1 performs an exposure process on a resist film (photosensitive film) formed on the surface of a wafer (substrate). Specifically, EUV (Extreme Ultraviolet) light is selectively irradiated to the exposure target portion of the resist film by a method such as immersion exposure. The wavelength of EUV light is, for example, 13.5 nm.

  The coating / developing apparatus E2 performs a process of forming a resist film by applying a resist agent on the surface of the wafer before the exposure process by the EUV exposure apparatus E1, and after the exposure process by the EUV exposure apparatus E1, Perform development processing. As shown in FIGS. 1 and 2, the coating / developing apparatus E2 includes a carrier block S1, a processing block S2 adjacent to the carrier block S1, an interface block S3 adjacent to the processing block S2, and a control unit R1. . Hereinafter, “front / rear / left / right” in the description of the coating / developing apparatus E2 means a direction in which the interface block S3 side is the front side and the carrier block S1 side is the rear side.

  The carrier block S1 includes a carrier station 12 and a carry-in / carry-out unit 13. The carrier station 12 supports a plurality of carriers 11. The carrier 11 accommodates a plurality of wafers W in a sealed state, and has an open / close door (not shown) for taking in and out the wafers W on the side surface 11a side. The carrier 11 is detachably installed on the carrier station 12 so that the side surface 11a faces the loading / unloading unit 13 side.

  The carry-in / carry-out unit 13 has a plurality of opening / closing doors 13 a corresponding to the plurality of carriers 11 on the carrier station 12. By opening the open / close door and the open / close door 13a on the side surface 11a at the same time, the inside of the carrier 11 and the inside of the carry-in / out unit 13 are communicated. The carry-in / carry-out unit 13 includes a delivery arm A1. The transfer arm A1 takes out the wafer W from the carrier 11 and transfers it to the processing block S2. The transfer arm A1 receives the wafer W from the processing block S2 and returns it into the carrier 11.

  The processing block S2 includes a lower layer film formation (BCT) block 14, a resist film formation (COT) block 15, a protective film formation (TCT) block 16, and a development processing (DEV) block 17. These blocks are stacked in the order of the DEV block 17, the BCT block 14, the COT block 15, and the TCT block 16 from the floor side.

  As shown in FIG. 3, the BCT block 14 includes a coating unit U1, a heating / cooling unit U2, and a transfer arm A2 that transfers the wafer W to these units. The coating unit U1 applies a chemical solution for forming an antireflection film to the surface of the wafer W. For example, the heating / cooling unit U2 heats the wafer W with a hot plate to heat the chemical solution, and cools the heated wafer W with the cooling plate, thereby performing a heat treatment for curing the chemical solution.

  As shown in FIG. 4, the COT block 15 includes a coating unit U3, a heating / cooling unit U4, and a transfer arm A3 for transferring the wafer W to these units. The coating unit U3 applies a chemical solution (resist agent) for forming a resist film on the lower layer film. The heating / cooling unit U4 heats the resist W by heating the wafer W with a hot plate, for example, and cools the heated wafer W with the cooling plate, thereby performing heat treatment for curing the resist agent. The resist agent may be a positive type or a negative type.

  As shown in FIG. 5, the TCT block 16 includes a coating unit U5, a heating / cooling unit U6, a light irradiation unit U7, and a transfer arm A4 that transfers the wafer W to these units. The coating unit U5 applies a chemical solution for forming an antireflection film on the resist film. The heating / cooling unit U6 heats the wafer W by, for example, a hot plate to heat the chemical solution, and cools the heated wafer W by the cooling plate, thereby performing a heat treatment for curing the chemical solution.

  The light irradiation unit U7 includes a support base 21 and a light irradiation unit 22 (see FIG. 6). The support table 21 supports the wafer W arranged horizontally with the resist film Wa facing up. The light irradiation unit 22 is disposed to face the wafer W on the support base 21 with a gap. The light irradiation unit 22 has a plurality of light sources 23. The plurality of light sources 23 are arranged over the entire area on the lower side of the light irradiation unit 22 and each emits UV light downward. Thereby, the light irradiation part 22 irradiates UV light to the whole region of the resist film Wa. The wavelength of the UV light is preferably 220 to 280 nm, more preferably 222 nm, 248 nm, or 254 nm, and particularly preferably 248 nm. Note that the UV light irradiation region does not necessarily have to be the entire region of the resist film Wa, and may be any region including the target portion of the EUV exposure in the resist film Wa. When the light irradiation unit 22 irradiates the resist film Wa with UV light, air is interposed between the support base 21 and the light irradiation unit 22. Instead of air, an inert gas such as nitrogen gas may be interposed between the support base 21 and the light irradiation unit 22, or a vacuum may be applied between the support base 21 and the light irradiation unit 22. By irradiating UV light in an inert gas or in vacuum, it is possible to suppress the deactivation of the acid due to the amine component contained in a trace amount in the air.

  As shown in FIG. 7, the DEV block 17 includes a plurality of development processing units (development processing units) U8, a plurality of heating / cooling units (heat treatment units) U9, and a transfer arm A5 that transfers the wafer W to these units. And a direct transfer arm A6 that transfers the wafer W between before and after the processing block S2 without passing through these units.

  The development processing unit U8 performs development processing on the exposed resist film Wa. Specifically, for example, an alkaline developer is applied onto the resist film Wa to dissolve unnecessary portions of the resist film Wa, and the resist film Wa is washed away with a rinse liquid such as pure water.

  The heating / cooling unit U9 heats the resist film Wa by, for example, heating the wafer W with a hot plate, and cools the heated wafer W with the cooling plate. Accordingly, the heating / cooling unit U9 performs heat treatment such as post-exposure baking (PEB) and post-baking (PB). PEB is a process for heating the resist film Wa before the development process. PB is a process for heating the resist film Wa after the development process.

  A shelf unit U10 is provided on the rear side of the processing block S2. The shelf unit U10 is provided so as to extend from the floor surface to the TCT block 16, and is partitioned into a plurality of cells C30 to C38 arranged in the vertical direction. A lifting arm A7 is provided in the vicinity of the shelf unit U10. The lifting arm A7 transports the wafer W between the cells C30 to C38. A shelf unit U11 is provided on the front side of the processing block S2. The shelf unit U11 is provided so as to extend from the floor to the top of the DEV block 17, and is partitioned into a plurality of cells C40 to C42 arranged in the vertical direction.

  The interface block S3 is connected to the EUV exposure apparatus E1. The interface block S3 includes a delivery arm A8. The delivery arm A8 delivers the wafer W from the shelf unit U11 of the processing block S2 to the EUV exposure apparatus E1, and receives the wafer W from the EUV exposure apparatus E1 and returns it to the shelf unit U11.

  The control unit R1 is a control computer for causing the coating / developing apparatus E2 to execute the substrate processing method. The control unit R1 displays a program from a display unit (not shown) that displays a condition setting screen for each process in the substrate processing method, an input unit (not shown) that inputs conditions for each process, and a computer-readable recording medium. A reading unit (not shown). A program for causing the coating / developing apparatus E2 to execute the substrate processing method is recorded on the recording medium, and this program is read by the reading unit of the control unit R1. Examples of the recording medium include a hard disk, a compact disk, a flash memory, a flexible disk, and a memory card. The control unit R1 controls the coating / developing apparatus E2 in accordance with the processing conditions input to the input unit and the program read by the reading unit. The control procedure will be described below.

  As shown in FIG. 8, the controller R1 first controls the coating / developing apparatus E2 to perform a process of forming a lower layer film (S01). Specifically, the transfer arm A1 and the lift arm A7 are controlled so as to transport the wafer W in the carrier 11 to the cell C33 corresponding to the BCT block 14, and a coating unit is formed so as to form a lower layer film on the surface of the wafer W. U1, heating / cooling unit U2, and transfer arm A2 are controlled. The wafer W after the formation of the lower layer film is transferred to the cell C34 above the cell C33 by the transfer arm A2.

  Next, the control unit R1 controls the coating / developing apparatus E2 to perform a process of forming the resist film Wa on the lower layer film (S02). Specifically, the elevating arm A7 is controlled so as to transfer the wafer W of the cell C34 to the cell C35 corresponding to the COT block 15, and the coating unit U3, heating and heating so as to form a resist film Wa on the lower layer film. The cooling unit U4 and the transfer arm A3 are controlled. The wafer W after the formation of the resist film Wa is transferred to the cell C36 above the cell C35 by the transfer arm A3.

  Next, the controller R1 controls the coating / developing apparatus E2 to perform a process of forming a protective film on the resist film Wa (S03). Specifically, the elevating arm A7 is controlled so as to transfer the wafer W of the cell C36 to the cell C37 corresponding to the TCT block 16, and the coating unit U5, heating and heating so as to form a protective film on the resist film Wa. The cooling unit U6 and the transfer arm A4 are controlled.

Next, the controller R1 controls the coating / developing apparatus E2 to perform a process of irradiating the resist film Wa with UV light (S04). Specifically, the transfer arm A4 is controlled to transfer the wafer W to the light irradiation unit U7, and the light irradiation unit 22 is controlled to irradiate the entire region of the resist film Wa with UV light. That is, the control unit R1 functions as a light irradiation control unit. By irradiation with UV light, the acid generator in the resist film Wa is decomposed to generate an acid. The UV light irradiation amount (Dose amount) is preferably 8 mJ / cm ² or less. The controller R1 controls the transfer arm A4 so that the wafer W after irradiation with UV light is unloaded from the light irradiation unit U7 and transferred to the cell C38 above the cell C37.

  Next, the controller R1 controls the coating / developing apparatus E2 so as to send the wafer W to the EUV exposure apparatus E1 (S05). Specifically, the lifting arm A7 is controlled so that the wafer W of the cell C38 is directly transferred to the cell C32 corresponding to the transfer arm A6, and the wafer W of the cell C32 is directly transferred to the cell C42 of the shelf unit U11. The transfer arm A6 is controlled, and the transfer arm A8 is controlled so as to send the wafer W of the cell C42 to the EUV exposure apparatus E1. The EUV exposure is performed on the resist film Wa of the wafer W sent to the EUV exposure apparatus E1 (S06). In the EUV exposure, atoms in the resist film Wa are ionized by irradiation with EUV light to generate secondary electrons.

  Next, the control unit R1 controls the coating / developing apparatus E2 to receive the wafer W from the EUV exposure apparatus E1 (S07). Specifically, the transfer arm A8 is controlled so that the wafer W after EUV exposure is received from the EUV exposure apparatus E1 and transferred to the cells C40 and C41 below the cell C42.

  Next, the control unit R1 controls the coating / developing apparatus E2 to perform PEB (S08). Specifically, the transfer arm A5 is controlled so as to transfer the wafers W of the cells C40 and C41 to the heating / cooling unit U9 in the DEV block 17, and the wafer W is heated to heat the resist film Wa. The heating / cooling unit U9 is controlled. That is, the control unit R1 functions as a heating control unit.

  In PEB, an acid generator is decomposed by secondary electrons generated by irradiation with EUV light to generate an acid, and a reaction for changing the solubility of the resist film Wa proceeds using this acid as a catalyst. The acid generated by UV light irradiation also serves as a catalyst for the reaction that changes the solubility of the resist film Wa. When the resist agent is a positive type, an alkali-insoluble resin in the resist film Wa becomes alkali-soluble by the progress of a deprotection reaction using an acid as a catalyst. When the resist agent is a negative type, an acid-catalyzed crosslinking reaction proceeds, so that the alkali-soluble resin in the resist film Wa becomes alkali-insoluble.

  Next, the control unit R1 controls the coating / developing apparatus E2 to perform development processing (S09). Specifically, the transfer arm A5 is controlled to transfer the post-PEB wafer W to the development processing unit U8, and the development processing unit U8 is controlled to perform the development processing of the resist film Wa. That is, the control unit R1 functions as a development control unit. Thereby, a resist pattern is formed on the surface of the wafer W.

  Next, the control unit R1 controls the transfer arm A5 so as to transfer the wafer W to the cells C30, C31 below the cell C32, and moves the lifting arm A7 and the transfer arm A1 so as to return the wafer W into the carrier 11. Control.

  The substrate processing method is executed by the above procedure, and a resist pattern is formed on the wafer W. According to this substrate processing method, both UV light irradiation (hereinafter referred to as “UV exposure”) and EUV exposure are performed prior to the development processing. Thereby, both the EUV light and the UV light are irradiated to the target portion of the EUV exposure. By combining the irradiation of the UV light with the irradiation of the EUV light, the irradiation amount of the EUV light can be reduced, and the EUV exposure time can be shortened. Also, compared to EUV light, UV light tends to increase its energy. Further, in the UV exposure as an auxiliary to the EUV exposure, it is not necessary to selectively irradiate the target portion of the EUV exposure with the UV light, and the UV light can be simultaneously irradiated over a wide range. For these reasons, the exposure time can be shortened as compared with the case where exposure processing is performed by EUV exposure alone. Therefore, a fine pattern can be formed by employing EUV exposure while suppressing a decrease in throughput.

  As described above, in UV exposure, the acid generator is decomposed by irradiation with UV light to generate an acid. This acid serves as a catalyst for a reaction that changes the solubility of the resist film Wa. In EUV exposure, atoms are ionized by the irradiation of EUV light to generate secondary electrons. Secondary electrons decompose the acid generator to generate an acid. This acid also serves as a catalyst for the reaction that changes the solubility of the resist film Wa. Thus, although the reaction mechanism differs greatly between UV exposure and EUV exposure, they are common in that they generate acid as a catalyst. This common point makes it possible to assist EUV exposure with UV exposure.

  PEB is performed between EUV exposure and development processing, and UV exposure is performed before PEB. For this reason, since both the reaction initiated by EUV exposure and the reaction initiated by UV exposure are promoted by PEB, the throughput can be improved.

  The UV exposure is performed before the EUV exposure. Thereby, before performing EUV exposure, since the obstacle substance (quencher) of EUV exposure is reduced by UV exposure, a resist pattern can be formed with higher accuracy.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, the light irradiation unit U7 may not necessarily be provided in the TCT block 16, and the light irradiation unit U7 may be provided in the DEV block 17, for example. The UV exposure is not necessarily performed between the formation of the protective film and the EUV exposure, and the UV exposure may be performed between the formation of the resist film Wa and the formation of the protective film. In this case, the COT block 15 may be provided with the light irradiation unit U7. UV exposure may be performed between EUV exposure and PEB. In this case, it is preferable to provide the light irradiation unit U7 in the DEV block 17.

  Subsequently, examples and comparative examples will be described, but the present invention is not limited to the following examples and comparative examples.

[Confirmation of UV exposure effect]
The effects of UV exposure were confirmed by comparing the following Examples 1, 2, 3 and Comparative Example 1.

Example 1
A resist pattern was formed on the wafer by the substrate processing method according to the embodiment described above. The thickness of the lower layer film was 85 nm, the thickness of the resist film was 80 nm, and the thickness of the protective film was 90 nm. For the formation of the resist film, a positive resist agent adjusted for EUV exposure was used. In the UV exposure, the wavelength of UV light was 172 nm, and the irradiation amount (Dose amount) was 4 mJ / cm ² . The irradiation amount (Dose amount) of EUV light in EUV exposure was set so that the line width of the resist pattern after development processing was about 45 nm.

(Example 2)
A resist pattern was formed on the wafer under the same conditions as in Example 1 except that the wavelength of UV light in UV exposure was 193 nm, the dose amount was 1.5 mJ / cm ^2, and other conditions were the same as in Example 1.

Example 3
A resist pattern was formed on the wafer under the same conditions as in Example 1 except that the wavelength of UV light in UV exposure was 248 nm, the dose amount was 1.5 mJ / cm ^2, and other conditions were the same as in Example 1.

(Comparative Example 1)
A UV light exposure was not performed, and other conditions were the same as in Example 1, and a resist pattern was formed on the wafer. That is, a resist pattern was formed by performing an exposure process only with EUV light.

(Evaluation of throughput)
As described above, throughput is improved by reducing the irradiation amount of EUV light. Accordingly, a reduction rate of the dose amount of EUV light based on Comparative Example 1 (hereinafter referred to as “EUV light reduction rate”) is calculated for each of Examples 1 to 3, and based on the magnitude of the reduction rate. The degree of throughput improvement was evaluated. The dose amount of EUV light of Comparative Example 1 and Examples 1 to 3 and the EUV light reduction rate of Examples 1 to 3 are shown in FIG.

(Evaluation of resist pattern accuracy)
For each of Comparative Example 1 and Examples 1 to 3, the line width / height of the resist pattern formed after the development treatment was measured, and LWR (Line Width Roughness) was calculated. Furthermore, the LWR reduction rate based on Comparative Example 1 was calculated for each of Examples 1-3. Then, the accuracy of the resist pattern was evaluated based on the height of the resist pattern and the LWR reduction rate. The line width / height / LWR of the resist patterns of Comparative Example 1 and Examples 1 to 3 and the LWR reduction rate of Examples 1 to 3 are shown in FIG. In FIG. 9, the LWR reduction rate being a negative value means that the LWR has increased compared to Comparative Example 1.

(Comparison of throughput)
The reduction rates of EUV light in Examples 1, 2, and 3 were 39.3%, 40%, and 40%, respectively. That is, it was confirmed that the throughput was improved in any of Examples 1, 2, and 3 as compared with Comparative Example 1. Therefore, it was confirmed that by combining the UV exposure with the EUV exposure, a fine pattern can be formed on the wafer by adopting the EUV exposure while suppressing a decrease in throughput.

(Comparison of resist pattern accuracy)
The LWR reduction rates in Examples 1 and 2 were -118.3% and -45.2%, respectively. That is, the LWR in Examples 1 and 2 increased compared to Comparative Example 1. In Examples 1 and 2, the resist pattern height was 27 nm and 29 nm, respectively, which was lower than the resist pattern height (60 nm) in Comparative Example 1. That is, it was confirmed that the accuracy of the resist pattern was lowered in both Examples 1 and 2 as compared with Comparative Example 1.

  On the other hand, the LWR reduction rate in Example 3 was 14.1%. In Example 3, the height of the resist pattern was 60 nm, which was equivalent to the height of the resist pattern (60 nm) in Comparative Example 1. That is, according to Example 3, it was confirmed that the accuracy of the resist pattern was improved as compared with Comparative Example 1.

  From the above results, it was confirmed that the wavelength of UV light is preferably 248 nm compared to 172 nm and 193 nm. The main factor that determines the accuracy of the resist pattern is the absorbance and transmittance of UV light in the resist film. FIG. 11 is a graph showing the relationship between the wavelength of UV light and the absorbance. FIG. 12 is a graph showing the relationship between the wavelength of UV light and the transmittance. As shown in FIGS. 11 and 12, when the wavelength of the UV light is 220 to 250 nm, the absorbance and transmittance are equivalent to those when the wavelength of the UV light is 248 nm. For this reason, if the wavelength of the UV light is 220 to 250 nm, it is expected that the accuracy of the resist pattern can be improved as in the case where the wavelength of the UV light is 248 nm.

  When the wavelength of the UV light is less than 220 nm, the absorbance becomes larger and the transmittance becomes smaller than when the wavelength of the UV light is 248 nm. For this reason, reactions due to UV exposure are likely to concentrate on the surface layer of the resist film Wa, and it is predicted that the accuracy of the resist pattern will decrease.

  On the other hand, when the wavelength of the UV light exceeds 250 nm, the absorbance becomes smaller and the transmittance becomes the same as compared with the case where the wavelength of the UV light is 248 nm. In this case, since the reaction due to UV exposure does not easily concentrate on the surface layer of the resist film Wa, it is considered that the accuracy of the resist pattern is not significantly reduced. However, when the wavelength of the UV light exceeds 280 nm, the absorbance becomes substantially zero, so that the progress of the reaction by UV exposure becomes extremely slow, and it is predicted that the throughput cannot be sufficiently improved.

  From these things, it is estimated that it is preferable that the wavelength of UV light is 220-280 nm.

It was also confirmed that when the UV light wavelength was 248 nm and the dose amount of the UV light was 1.5 mJ / cm ² , the accuracy of the resist pattern compared to Comparative Example 1 did not decrease. FIG. 13 is a graph showing the thickness of the resist film remaining after the development processing when the resist film is subjected to UV exposure (wavelength 248 nm) alone. The horizontal axis indicates the dose amount of UV light, and the vertical axis indicates the thickness of the resist film. As shown in FIG. 13, if the dose amount is 8 mJ / cm ² or less, the decrease in the thickness of the resist film is negligibly small. Therefore, it is estimated that the dose amount of UV light is preferably 8 mJ / cm ² or less.

[Confirmation of the influence of UV exposure timing]
By comparing the following Examples 4 and 5 and Comparative Examples 2 and 3, the effect of the timing of performing UV exposure on the throughput and the accuracy of the resist pattern was confirmed.

Example 4
UV exposure was performed between the formation of the resist film and the formation of the protective film, and other conditions were the same as in Example 1 to form a resist pattern on the wafer.

(Example 5)
A UV exposure was performed between EUV exposure and PEB, and other conditions were the same as in Example 1 to form a resist pattern on the wafer.

(Comparative Example 2)
A UV light exposure was not performed, and other conditions were the same as in Example 1, and a resist pattern was formed on the wafer. That is, a resist pattern was formed by performing an exposure process only with EUV light.

(Comparative Example 3)
UV exposure was performed between the PEB and the development process, and other conditions were the same as in Example 1 to form a resist pattern on the wafer.

(Evaluation of throughput)
The reduction rate of the dose amount of EUV light based on Comparative Example 2 was calculated for each of Comparative Example 3 and Examples 4 and 5, and the degree of improvement in throughput was evaluated based on the magnitude of the reduction rate. The dose amount of EUV light in Comparative Examples 2 and 3 and Examples 4 and 5 and the EUV light reduction rate in Comparative Example 3 and Examples 4 and 5 are shown in FIG.

(Evaluation of resist pattern accuracy)
For each of Comparative Examples 2 and 3 and Examples 4 and 5, the line width / height of the resist pattern formed after the development processing was measured, and LWR (Line Width Roughness) was calculated. Furthermore, the LWR reduction rate based on Comparative Example 2 was calculated for each of Comparative Example 3 and Examples 4 and 5. Then, the accuracy of the resist pattern was evaluated based on the LWR reduction rate. FIG. 10 shows the LWR of the resist patterns of Comparative Examples 2 and 3 and Examples 4 and 5, and the LWR reduction rate of Comparative Example 3 and Examples 4 and 5.

(Comparison of throughput)
The reduction rates of EUV light in Examples 4 and 5 were 38.8% and 37.9%, respectively, and the reduction rate of EUV light in Comparative Example 3 was 0.3%. From these facts, it was confirmed that when the UV exposure timing was before PEB, the throughput was improved both before the protective film formation process and after the EUV exposure. On the other hand, it was confirmed that when the UV exposure timing was after PEB, the throughput was not substantially improved.

(Comparison of resist pattern accuracy)
The LWR reduction rates in Examples 4 and 5 were 6.4% and 1.8%, respectively. Further, as described above, the reduction rate of LWR in Example 3 was 14.1%. Since the LWR reduction rate in Examples 3 and 4 is larger than the LWR reduction rate in Example 5, the accuracy of the resist pattern is higher when performing UV exposure before EUV exposure than when performing EUV exposure. Has been confirmed to improve. In addition, since the LWR reduction rate in Example 4 is smaller than the LWR reduction rate in Example 3, the resist pattern of the UV exposure is performed after the protective film is formed, compared with the case where the UV exposure is performed before the protective film is formed. It was confirmed that the accuracy was improved.

  DESCRIPTION OF SYMBOLS 1 ... Substrate processing system, 22 ... Light irradiation part, E1 ... Exposure apparatus, E2 ... Coating / development apparatus, R1 ... Control part (development control part, heating control part, light irradiation control part), U8 ... Development processing unit (development) Processing section), U9 ... Heating / cooling unit (heat treatment section), W ... Wafer (substrate), Wa ... Resist film (photosensitive coating).

Claims (10)

A development processing unit for performing development processing on the photosensitive film formed on the substrate;
A light irradiation unit for irradiating the photosensitive film with UV light having a longer wavelength than EUV light;
A development control unit that controls the development processing unit to perform the development processing on the photosensitive film after the EUV exposure is performed on the photosensitive film;
Light irradiation for controlling the light irradiation unit to irradiate the UV light to a region including the target portion of the EUV exposure in the photosensitive film before the development processing unit performs the development processing on the photosensitive film. A substrate processing apparatus. A heat treatment part for performing a heat treatment on the photosensitive film;
A heating control unit that controls the heat treatment unit so as to perform a heat treatment on the photosensitive film between the EUV exposure and the development process on the photosensitive film;
The said light irradiation control part controls the said light irradiation part so that the said heat processing part may irradiate the said UV light to the said photosensitive film, before performing the said heat processing with respect to the said photosensitive film. Substrate processing equipment.   The substrate according to claim 1, wherein the light irradiation control unit controls the light irradiation unit to irradiate the photosensitive film with the UV light before the EUV exposure is performed on the photosensitive film. Processing equipment.   The substrate processing apparatus according to claim 1, wherein the light irradiation unit irradiates the UV light having a wavelength of 220 to 280 nm. A substrate processing apparatus according to any one of claims 1 to 4,
A substrate processing system comprising: an EUV exposure apparatus that performs the EUV exposure on the photosensitive coating on the substrate. After the EUV exposure is performed on the photosensitive film formed on the substrate, the developing process is performed on the photosensitive film.
A substrate processing method of irradiating the photosensitive coating with UV light having a wavelength longer than that of EUV light before performing the development processing on the photosensitive coating. Between the EUV exposure and the development process on the photosensitive film, a heat treatment is performed on the photosensitive film,
The substrate processing method according to claim 6, wherein the UV light is irradiated to the photosensitive film before the heat treatment is performed on the photosensitive film.   The substrate processing method of Claim 6 or 7 which irradiates the said UV light to the said photosensitive film before the said EUV exposure with respect to the said photosensitive film is performed.   The substrate processing method according to claim 6, wherein the UV light having a wavelength of 220 to 280 nm is irradiated.   A computer-readable recording medium for processing a substrate, in which a program for causing the substrate processing apparatus to execute the substrate processing method according to any one of claims 6 to 9 is recorded.

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