Patterning method and patterning apparatus

Abstract

To make it possible to develop a pattern exposed on a photoresist film by a dry process.SOLUTION: A patterning method includes an infiltration step and an etching step. The infiltration step is for infiltrating a material that expands a selectivity ratio between an exposed portion and an unexposed portion into a photoresist film of a substrate provided with the photoresist film on which the exposed portion and the unexposed portion are formed by exposure on the surface. In the etching step, the photoresist film that has undergone the infiltration step is dry etched.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The disclosed embodiments relate to a patterning method and a patterning apparatus. [Background technology]

[0002] Patent Document 1 discloses a technique for improving etching resistance after resist formation by exposing the formed resist to a metal-containing gas containing a metal, thereby causing the metal to infiltrate the resist. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-38929 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that enables a pattern exposed on a photoresist film to be developed by a dry process. [Means for solving the problem]

[0005] A patterning method according to one aspect of the present disclosure includes a wetting step and an etching step. The wetting step involves wetting a photoresist film on a substrate, the photoresist film having exposed and unexposed portions formed thereon, with a material that increases the selectivity between the exposed and unexposed portions. The etching step involves dry-etching the photoresist film that has been subjected to the wetting step. [Effects of the Invention]

[0006] According to the present disclosure, a pattern exposed on a photoresist film can be developed by a dry process. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of an overall flow of substrate processing according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a patterning apparatus according to this embodiment. [Figure 3] FIG. 3 is a diagram showing an example of a process flow of the patterning method according to the embodiment. [Figure 4] FIG. 4 is a conceptual diagram illustrating an example of a substrate according to an embodiment. [Figure 5] FIG. 5 is a diagram showing an example of a profile of silicon contained in a photoresist film according to an embodiment. [Figure 6] FIG. 6 is a diagram showing an example of a profile of dry etching of a photoresist film according to the embodiment. [Figure 7] FIG. 7 is a diagram conceptually showing an example of the result of etching the substrate according to the embodiment. [Figure 8] FIG. 8 is a diagram conceptually showing another example of the result of etching the substrate according to the embodiment. [Figure 9] FIG. 9 is a diagram schematically showing an example of the overall flow of substrate processing including a conventional lithography process. DETAILED DESCRIPTION OF THE INVENTION

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the patterning method and patterning apparatus disclosed in the present application will be described in detail with reference to the drawings. However, the disclosed patterning method and patterning apparatus are not limited to the embodiments.

[0009] In recent years, with the increasing integration and performance of semiconductor integrated circuits (LSIs), patterns formed on the surface of substrates have become finer. These patterns are formed on substrates through a lithography process. FIG. 9 is a diagram schematically illustrating an example of the overall flow of substrate processing including a conventional lithography process. In the substrate processing illustrated in FIG. 9, processes (1) to (8) are performed on a substrate W. The substrate W is, for example, a silicon substrate such as a silicon wafer. A film on which a pattern is to be formed is formed on the substrate W. (1) Surface processing involves performing predetermined preprocessing, such as cleaning the substrate W. (2) Spin coating involves applying a photoresist solution to the substrate W and rotating the substrate W to form a photoresist film PR on the substrate W. (3) Pre-baking involves heating the substrate W to evaporate the solvent contained in the photoresist film PR. (4) Exposure involves irradiating the substrate W with light such as ultraviolet light through a patterned photomask PM to form a latent image of the pattern in the photoresist film PR, consisting of exposed portions EP and unexposed portions UP. Here, the photoresist film PR can be either negative-type, in which exposed portions EP remain after development, or positive-type, in which unexposed portions UP remain after development. In the case of negative-type, exposure is performed using a photomask PM that allows the portions to remain in the photoresist film PR to be transparent. In the case of positive-type, exposure is performed using a photomask PM that allows the portions to remain in the photoresist film PR to be opaque. (5) PEB (Post Exposure Bake) promotes the reaction by heating. (6) Development + Rinse develops the latent image in the photoresist film PR using a solvent such as a developer, and then washes away the solvent used in development. Figure 9 shows the case of positive-type development, in which the unexposed portions UP remain and the exposed portions EP have dissolved away. These processes (1) to (6) correspond to the lithography process. A pattern is developed in the photoresist film PR through the lithography process. (7) Etching is performed using the photoresist film PR as a mask to process the substrate W. (8) Resist Stripping is performed, in which the photoresist film PR is stripped and removed. This forms a pattern on the substrate W.

[0010] However, as patterns become finer, if a pattern exposed on a photoresist film PR is developed using a wet process such as (6) development + rinse, there is a concern that pattern defects such as deterioration of roughness due to expansion of the photoresist film PR and pattern collapse due to surface tension may occur. On the other hand, if development is done using a dry process, these problems do not occur. However, with dry process development, the difference in etching rate between the exposed portion EP and the unexposed portion UP is small, making it difficult to develop the pattern exposed on the photoresist film PR. Therefore, a technology that enables development of a pattern exposed on a photoresist film PR using a dry process is desired.

[0011] (Embodiment) A patterning method according to an embodiment will be described. First, an example of the overall flow of substrate processing including a lithography process according to an embodiment will be described. FIG. 1 is a diagram schematically illustrating an example of the overall flow of substrate processing according to an embodiment. FIG. 1 illustrates substrate processing including processing of a patterning method according to an embodiment. In the substrate processing according to an embodiment, the (6) development + rinsing process of the conventional substrate processing shown in FIG. 9 is replaced with (6) infiltration and (7) etching processes. In the substrate processing shown in FIG. 1, processes (1) to (9) are performed. Processes (1) to (5), (8), and (9) in FIG. 1 are the same as processes (1) to (5), (7), and (8) in FIG. 9, and therefore will not be described.

[0012] By the exposure (4), a latent image of a pattern consisting of exposed portions EP and unexposed portions UP is formed in the photoresist film PR of the substrate W. The photoresist film PR is, for example, an organic film containing a photosensitive resin as a main component. Examples of such photoresist films PR include KrF photoresist and EUV photoresist.

[0013] In the (6) infiltration step, a material that increases the selectivity between the exposed and unexposed portions EP and UP is infiltrated into the photoresist film PR on the substrate W. Differences in infiltration depth, i.e., differences in the degree of modification of the photoresist film PR, result in differences in etching rate. For example, in the (6) infiltration step, the substrate W is exposed to a gas containing a material that increases the selectivity between the exposed and unexposed portions EP and UP, causing the material to infiltrate into the photoresist film PR. Because the infiltration depth differs between the exposed and unexposed portions EP and UP, differences in etching rate occur at the point where the difference in infiltration depth occurs, making it possible to develop a pattern. Furthermore, patterns can be developed even if the infiltration amount differs between the exposed and unexposed portions EP and UP. This includes cases where the material reacts only with one of the portions. If the infiltration amount differs, differences in etching rate occur from the start of etching, forming a pattern.

[0014] Materials that increase the selectivity between the exposed and unexposed portions EP and UP of the photoresist film PR include metal and semimetal elements. Metals include aluminum (Al), titanium (Ti), and germanium (Ge). Semimetals include silicon (Si). For example, when infiltrating silicon into the photoresist, N-(trimethylsilyl)dimethylamine (TMSDMA), bis(trimethylsilyl)amine (HMDS), and hexachlorosilane (HCD) are promising materials. When infiltrating aluminum into the photoresist, trimethylaluminum (TMA) and triethylaluminum (TEA) are suitable materials. When infiltrating titanium into the photoresist, TDMAT and TiCl4 are suitable materials. The infiltrating material is exposed to the photoresist film PR as a vapor by evaporation, bubbling, or skimming, allowing it to infiltrate into the photoresist film PR.

[0015] In the (7) etching process, the photoresist film PR that has been infiltrated with the material is dry-etched. The infiltration process (6) increases the selectivity between the exposed portions EP and the unexposed portions UP of the photoresist film PR, so that when etching is performed, the exposed portions EP are etched deeper than the unexposed portions UP. In the (7) etching process, by appropriately controlling the etching time, the exposed portions EP of the photoresist film PR can be removed by etching, leaving the unexposed portions UP. However, depending on the combination of the photoresist film PR and the materials used for infiltration, the portions that are removed and the portions that remain of the exposed portions EP and the unexposed portions UP may be reversed.

[0016] 1, the photoresist film PR is patterned by the infiltration and etching steps (6) and (7). The infiltration and etching steps (6) and (7) correspond to the processing of the patterning method of the present disclosure.

[0017] [Configuration of patterning device] Next, an example of a patterning apparatus that performs the processes of (6) infiltration and (7) etching steps will be described. Figure 2 is a block diagram showing an example of the configuration of a patterning apparatus 1 according to an embodiment. The patterning apparatus 1 according to this embodiment has an infiltration processing section 11 and an etching processing section 12.

[0018] The infiltration processing unit 11 is a unit that performs the infiltration process (6). The infiltration processing unit 11 can be configured using a reaction chamber in which a substrate W having an exposed portion EP and an unexposed portion UP formed in a photoresist film PR is placed, a heating device that heats the substrate W, a supply device that supplies a gas such as a metal-containing gas into the reaction chamber, an exhaust device that exhausts the inside of the reaction chamber, etc.

[0019] The etching processing unit 12 is a unit that performs the etching process (7). The etching processing unit 12 can be configured using, for example, a dry etching device. For example, the etching processing unit 12 performs reactive ion etching using an etching gas. The etching gas may be a hydrogen-containing gas, for example, hydrogen (H2) gas.

[0020] In addition, in the patterning apparatus 1, the infiltration processing section 11 and the etching processing section 12 do not necessarily have to be configured as one unit.

[0021] [Patterning method] Next, the process flow of the patterning method according to the embodiment will be described. Hereinafter, an example will be described in which a metal such as aluminum, titanium, or germanium, or a semimetal such as silicon, is infiltrated as a material for increasing the selectivity between the exposed portion EP and the unexposed portion UP of the photoresist film PR. FIG. 3 is a diagram showing an example of the process flow of the patterning method according to the embodiment. FIG. 3 shows details of the processes of the (6) infiltration and (7) etching steps. Before the process of the patterning method is performed, for example, a substrate W that has been subjected to the processes (1) to (5) in FIG. 1 is transported to the infiltration processing unit 11 and placed in a reaction chamber. The patterning apparatus 1 according to the embodiment performs the processes shown in FIG. 3.

[0022] The infiltration processing unit 11 reduces the pressure inside the reaction chamber to create a reduced pressure state inside the reaction chamber (step S10). The infiltration processing unit 11 also heats the substrate W placed inside the reaction chamber to raise the temperature of the substrate W to a predetermined temperature suitable for infiltration (step S11).

[0023] The immersion processing unit 11 exposes the photoresist film PR under predetermined conditions to a gas containing a material that increases the selectivity between the exposed portions EP and the unexposed portions UP. For example, the immersion processing unit 11 exposes the photoresist film PR under predetermined conditions to a gas containing a metal or a metalloid (step S12). Hereinafter, a gas containing a metal or a metalloid will be referred to as a "metal-containing gas."

[0024] Thereafter, the immersion processing unit 11 uses an inert gas such as N2 to purge the metal-containing gas from the reaction chamber (step S13). Thereafter, the immersion processing unit 11 exposes water vapor to the photoresist film PR under predetermined conditions (S14). Thereafter, the immersion processing unit 11 uses an inert gas such as N2 to purge the water vapor from the reaction chamber (step S15). The processes of steps S12 to S15 above may be repeated multiple times.

[0025] The patterning apparatus 1 removes the substrate W from the wetting processing section 11 and transports it to the etching processing section 12 (step S16). Note that if the wetting processing section 11 and the etching processing section 12 are configured as a single unit, step S16 is unnecessary.

[0026] The etching processing unit 12 etches the photoresist film PR on the substrate W (step S17). For example, the etching processing unit 12 dry-etches the photoresist film PR by reactive ion etching using H gas. By appropriately controlling the etching time, the exposed portions EP of the photoresist film PR can be removed, leaving the unexposed portions UP.

[0027] The "temperature of the substrate W" refers to the temperature of at least a portion of the substrate W including the photoresist film PR, and may be the surface temperature of the photoresist film PR. The "predetermined temperature" is preferably within the range of room temperature to 200°C. "Room temperature" refers to the temperature in a natural state without external heating or cooling, and is, for example, a temperature selected from the range of 1°C to 40°C (e.g., 25°C). If the temperature of the substrate W is lower than room temperature, it is often impossible to obtain sufficient energy to overcome the activation barrier for infiltrating the metal into the photoresist film PR (e.g., for causing a nucleophilic substitution reaction). 200°C, exemplified as the upper limit of the temperature of the substrate W, is a temperature sufficiently higher than the transition temperature of the photoresist film PR.

[0028] The "predetermined conditions" for exposing the metal-containing gas include the temperature of the substrate W, gas flow rate, exposure time, and pressure. The amount of infiltration of metals and metalloids into the photoresist film PR increases as the temperature of the substrate W increases and decreases as the temperature of the substrate W decreases. The infiltration amount also increases as the gas flow rate of the metal-containing gas increases and decreases as the gas flow rate decreases. The infiltration amount also increases as the exposure time of the metal-containing gas to the photoresist film PR increases and decreases as the exposure time decreases. The infiltration amount also increases as the pressure in the reaction chamber increases and decreases as the pressure decreases.

[0029] The processes of steps S14 and S15 are not essential. However, exposure to water vapor after exposure to a metal-containing gas can promote infiltration. The "predetermined conditions" for exposure to water vapor include the temperature of the substrate W, gas flow rate, exposure time, and pressure. The infiltration promotion effect of water vapor increases as the temperature of the substrate W increases and decreases as the temperature of the substrate W decreases. Furthermore, the infiltration promotion effect increases as the gas flow rate of water vapor increases and decreases as the gas flow rate decreases. Furthermore, the infiltration promotion effect increases as the exposure time of water vapor to the photoresist film PR increases and decreases as the exposure time decreases. Furthermore, the infiltration promotion effect increases as the pressure in the reaction chamber increases and decreases as the pressure decreases.

[0030] The conditions during exposure to water vapor (temperature of the substrate W, gas flow rate, exposure time, pressure, etc.) may be the same as the conditions during exposure to the metal-containing gas, or may be set to be different from the conditions during exposure to the metal-containing gas.

[0031] The amount of metal or metalloid infiltrated into the photoresist film PR is preferably within the range of 4 atomic % to 20 atomic %. If the amount of infiltration is less than 4 atomic %, the effect of increasing the etching resistance of the photoresist film PR is often not substantially observed. If the amount of infiltration is more than 20 atomic %, the organic properties inherent to the photoresist film PR (e.g., solubility in alkaline solutions) are impaired, the strippability of the photoresist film PR is reduced, and (9) it becomes difficult to strip the photoresist film PR from the film to be etched in the resist stripping process.

[0032] The infiltration amount can be controlled by adjusting the conditions during exposure to the metal-containing gas, the conditions during exposure to water vapor, and the number of times steps S12 to S15 are repeated. For example, the pressure during exposure to the metal-containing gas is preferably in the range of 0.05 Torr to 760 Torr. If the pressure is lower than 0.05 Torr, the infiltration amount may be less than 4 atomic %, and if the pressure is higher than 760 Torr, the infiltration amount may exceed 20 atomic %.

[0033] FIG. 4 is a conceptual diagram illustrating an example of a substrate W according to an embodiment. FIG. 4 illustrates a substrate W that has been exposed to TMSDMA and has had silicon infiltrated into a photoresist film PR. The substrate W has a photoresist film PR formed thereon. The photoresist film PR has exposed portions EP and unexposed portions UP alternately formed therein. FIG. 4 schematically illustrates the depth of silicon infiltration into the photoresist film PR with a line L1. As indicated by the line L1, silicon has infiltrated deeper into the unexposed portions UP than into the exposed portions EP.

[0034] 5 is a diagram showing an example of a profile of silicon contained in a photoresist film PR according to an embodiment. FIG. 5 shows the silicon content relative to the depth from the surface of the photoresist film PR, for the exposed portion EP and the unexposed portion UP. For example, at a depth of approximately 0 to 150 nm, the silicon content is slightly higher in the unexposed portion UP than in the exposed portion EP. Furthermore, at a depth of approximately 150 to 250 nm, the silicon content is clearly higher in the unexposed portion UP than in the exposed portion EP. This indicates that silicon has infiltrated deeper into the unexposed portion UP than into the exposed portion EP. Thus, the silicon infiltration depth differs between the unexposed portion UP and the exposed portion EP.

[0035] FIG. 6 is a diagram showing an example of a dry etching profile of a photoresist film PR according to an embodiment. FIG. 6 shows a profile of the remaining film thickness of the photoresist film PR versus the etching time when the photoresist film PR is dry etched. In FIG. 6, the profile of the exposed portion EP of the photoresist film PR infiltrated with silicon is shown by line L11, and the profile of the unexposed portion UP is shown by line L12. Also, in FIG. 6, as a comparative example, the profile of the exposed portion EP of the photoresist film PR in a state where silicon has not infiltrated is shown by line L13, and the profile of the unexposed portion UP is shown by line L14.

[0036] As shown by lines L13 and L14, the photoresist film PR that is not infiltrated with silicon is etched more deeply in a shorter etching time and has a higher etching rate than the photoresist film PR that is infiltrated with silicon, as shown by lines L11 and L12.

[0037] The etching resistance of the photoresist film PR increases as the silicon infiltrates. Therefore, as shown by lines L11 and L12, the etching rates of the exposed portion EP and the unexposed portion UP of the photoresist film PR infiltrated with silicon are lower than those of lines L13 and L14. Furthermore, as shown by line L11, the etching rate of the exposed portion EP increases along the way. This is because, as shown by line L1 in FIG. 4 and line L1 in FIG. 5, the infiltration range of the silicon in the exposed portion EP is shallower than that of the unexposed portion UP, and the etching rate is lower in the infiltrated range. However, as the infiltration range deepens, the etching rate changes to the same level as lines L13 and L14. On the other hand, as shown by line L12, the infiltration range of the silicon in the unexposed portion UP is deeper, and therefore the etching rate remains low.

[0038] As a result, in the photoresist film PR infiltrated with silicon, the exposed portions EP are etched deeper than the unexposed portions UP due to the difference in the infiltration range between the exposed portions EP and the unexposed portions UP.

[0039] FIG. 7 is a conceptual diagram illustrating an example of the results of etching a substrate W according to an embodiment. FIGS. 7A to 7C illustrate changes in the photoresist film PR when etching a substrate W that has been exposed to TMSDMA and infiltrated with silicon. FIG. 7A illustrates the photoresist film PR before etching. The photoresist film PR has alternating exposed portions EP and unexposed portions UP. FIGS. 7A to 7C illustrate the depth of silicon infiltration into the photoresist film PR, indicated by the line L1. FIG. 7B illustrates the photoresist film PR after etching for 7.5 minutes using an etching gas containing H2 gas. The unexposed portions UP are etched within the silicon infiltrated range. Meanwhile, the exposed portions EP are etched beyond the infiltrated range, resulting in a faster etching rate and deeper etching than the unexposed portions UP. FIG. 7C illustrates the photoresist film PR after etching for 9.5 minutes using an etching gas containing H2 gas. The unexposed portions UP are etched to approximately the infiltrated range. On the other hand, the exposed portions EP are etched much deeper than the unexposed portions UP. By appropriately controlling the etching time, the exposed portions EP of the photoresist film PR can be removed, leaving the unexposed portions UP. This allows the latent image pattern consisting of the exposed portions EP and the unexposed portions UP to be developed using a dry process. The photoresist film PR may leave scum, a residue of photoresist, at the interface with the underlying layer. The scum can be removed by reactive ion etching using O2 gas.

[0040] In the above embodiment, the substrate W, in which silicon has been infiltrated into the photoresist film PR, is developed by one-stage etching using H gas. However, this is not limiting. For example, the substrate W may be developed by two-stage etching. For example, a first etching and a second etching are performed on the substrate W. In the first etching, a first gas capable of etching the photoresist film PR infiltrated with a material is used to etch the exposed portions EP to a depth that is deeper than the depth to which the material has infiltrated into the unexposed portions UP, but shallower than the depth to which the material has infiltrated into the unexposed portions UP. For example, in the case of a photoresist film PR infiltrated with silicon, an etching gas containing a hydrogen-containing gas (e.g., H gas) is used to etch the exposed portions EP to a depth that is deeper than the depth to which the material has infiltrated into the unexposed portions UP. In the second etching, after the first etching, a second gas capable of etching the uninfiltrated photoresist film PR to a greater extent than the infiltrated photoresist film PR is used to etch the uninfiltrated photoresist film PR. For example, in the case of a photoresist film PR infiltrated with silicon, etching is performed using an etching gas containing an oxygen-containing gas (for example, O 2 gas).

[0041] FIG. 8 is a conceptual diagram illustrating another example of the results of etching a substrate W according to the embodiment. FIGS. 8A-8C illustrate the changes in the photoresist film PR when the substrate W, which has been exposed to TMSDMA and infiltrated with silicon, is etched in two stages. FIG. 8A illustrates the photoresist film PR before etching. The photoresist film PR has alternating exposed portions EP and unexposed portions UP. FIGS. 8A-8C illustrate the depth of silicon infiltration in the photoresist film PR, indicated by the line L1. FIG. 8B illustrates the state after etching the photoresist film PR for 7.5 minutes using an etching gas containing H gas. Both the exposed portions EP and the unexposed portions UP are etched. The unexposed portions UP are etched within the silicon-infiltrated range. Meanwhile, the exposed portions EP are etched beyond the infiltration range, resulting in a faster etching rate and a deeper etching depth than the unexposed portions UP. At the stage shown in FIG. 8B, the photoresist film PR is then etched using an etching gas containing O gas. Figure 8(C) shows the state after etching the photoresist film PR for 50 seconds using an etching gas containing O2 gas. In the unexposed portions UP, where the amount of silicon infiltration is large, a silicon oxide film forms on the surface and functions as an etch stop layer. In the exposed portions EP, where the amount of silicon infiltration is small (or there is no silicon infiltration), a silicon oxide film cannot be formed, so they are etched. As a result, a high selectivity is achieved between the exposed portions EP and the unexposed portions UP. By appropriately controlling the etching time, the exposed portions EP of the photoresist film PR can be removed, leaving the unexposed portions UP. This allows the latent image pattern consisting of the exposed portions EP and the unexposed portions UP to be developed using a dry process.

[0042] In this way, the patterning method according to the embodiment can increase the etching selectivity between the exposed portions EP and the unexposed portions UP, and therefore the pattern exposed on the photoresist film PR can be developed by a dry process. As a result, the patterning method according to the embodiment can suppress pattern defects such as increased roughness and pattern collapse in the developed photoresist film PR, even when the pattern is miniaturized.

[0043] [effect] As described above, the patterning method according to the embodiment includes a wetting step (steps S12 to S15) and an etching step (step S17). In the wetting step, a material that increases the selectivity between the exposed portions EP and the unexposed portions UP is wetting the photoresist film PR of the substrate W, on the surface of which the photoresist film PR has been formed, with exposed portions EP and unexposed portions UP. In the etching step, the photoresist film PR that has been subjected to the wetting step is dry-etched. In this way, the patterning method can develop the pattern exposed on the photoresist film PR by a dry process.

[0044] Furthermore, the infiltration step exposes the substrate W to a gas containing the material, thereby allowing the patterning method to infiltrate the material into the photoresist film PR.

[0045] The material is a metal or semi-metal element. The metal is aluminum, titanium, or germanium. The semi-metal is silicon. The infiltration process infiltrates the material deeper into the unexposed portions UP than into the exposed portions EP. This allows the patterning method to increase the selectivity between the exposed portions EP and the unexposed portions UP.

[0046] The amount of the metal or metalloid infiltrated into the photoresist film PR is set to a range of 4 atomic % to 20 atomic %, which enables the patterning method to increase the etching resistance of the photoresist film PR while suppressing a decrease in the strippability of the photoresist film PR.

[0047] Furthermore, in the etching step, the exposed portions EP are etched deeper than the unexposed portions UP, so that the patterning method can develop the pattern exposed on the photoresist film PR by a dry process.

[0048] The etching process includes a first etching step using a first gas capable of etching the photoresist film PR infiltrated with the material to a depth deeper than the depth to which the material has infiltrated the exposed portions EP and shallower than the depth to which the material has infiltrated the unexposed portions UP, followed by a second etching step using a second gas capable of etching the photoresist film PR not infiltrated with the material to a greater extent than the photoresist film PR infiltrated with the material. The first gas is a hydrogen-containing gas (e.g., H2 gas). The second gas is an oxygen-containing gas (e.g., O2 gas). This allows the patterning method to etch with a higher selectivity between the exposed portions EP and the unexposed portions UP.

[0049] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0050] For example, in the above embodiment, the substrate W is a silicon substrate, but is not limited thereto. Examples of the substrate W include a silicon substrate, a glass substrate, a transparent electrode such as ITO, a metal substrate such as gold, silver, copper, palladium, nickel, titanium, aluminum, or tungsten, a plastic substrate, and a substrate made of a composite material thereof. [Explanation of symbols]

[0051] 1. Patterning device 11 Infiltration treatment section 12 Etching processing section EP exposure area PM Photomask PR photoresist film UP Unexposed area W substrate

Claims

1. an infiltration step of infiltrating a material into the entire surface of a photoresist film of a substrate on whose surface an exposed portion and an unexposed portion have been formed by exposure, the material being deeper in the unexposed portion than in the exposed portion, and increasing the selectivity between the exposed portion and the unexposed portion, thereby forming a difference in infiltration depth between the exposed portion and the unexposed portion; an etching step of dry-etching the photoresist film after the infiltration step, the etching step is performed such that the exposed portion is etched deeper than the unexposed portion due to the difference in penetration depth. Patterning method.

2. The infiltration step involves exposing the substrate to a gas containing the material. The patterning method according to claim 1 .

3. The material is a metal or semi-metal element 3. The patterning method according to claim 1 or 2.

4. The metal is aluminum, titanium, or germanium. The patterning method according to claim 3 .

5. The metalloid is silicon The patterning method according to claim 3 .

6. The amount of the metal or metalloid infiltrated into the photoresist film is in the range of 4 atomic % to 20 atomic %.

6. The patterning method according to claim 3.

7. The etching step includes performing a first etching using a first gas capable of etching the photoresist film infiltrated with the material to a depth deeper than the depth to which the material has infiltrated in the exposed portion and shallower than the depth to which the material has infiltrated in the unexposed portion, and then performing a second etching using a second gas capable of etching a greater portion of the photoresist film not infiltrated with the material than the photoresist film infiltrated with the material. The patterning method according to any one of claims 1 to 6.

8. the first gas is a hydrogen-containing gas; The second gas is an oxygen-containing gas. The patterning method according to claim 7 .

9. The first gas is H ２ It is a gas, The second gas is O ２ It is a gas 9. The patterning method according to claim 7 or 8.

10. a permeation treatment section that permeates an entire surface of a photoresist film of a substrate, the photoresist film having exposed and unexposed portions formed thereon by exposure, with a material that permeates the entire surface of the photoresist film deeper into the unexposed portions than into the exposed portions, thereby increasing the selectivity between the exposed and unexposed portions, and thereby forming a difference in permeation depth between the exposed and unexposed portions; an etching processing unit that dry-etches the photoresist film that has been infiltrated with a material by the infiltration processing unit; and the etching processing unit etches the exposed portion deeper than the unexposed portion due to the difference in infiltration depth; Patterning equipment.

11. a permeation step of permeating a photoresist film, on a surface of which an exposed portion and an unexposed portion are formed by exposure, with a material that increases the selectivity between the exposed portion and the unexposed portion; an etching step of dry etching the photoresist film that has been subjected to the infiltration step; Including, The etching step includes performing a first etching using a first gas capable of etching the photoresist film infiltrated with the material to a depth deeper than the depth to which the material has infiltrated in the exposed portion and shallower than the depth to which the material has infiltrated in the unexposed portion, and then performing a second etching using a second gas capable of etching a greater portion of the photoresist film not infiltrated with the material than the photoresist film infiltrated with the material. Patterning method.

12. a permeation processing unit that permeates a photoresist film of a substrate, the photoresist film having exposed and unexposed portions formed thereon by exposure, with a material that increases a selectivity between the exposed and unexposed portions; an etching processing unit that dry-etches the photoresist film that has been infiltrated with a material by the infiltration processing unit; and The etching processing unit performs a first etching using a first gas capable of etching the photoresist film infiltrated with the material to a depth deeper than the depth to which the material has infiltrated in the exposed portion and shallower than the depth to which the material has infiltrated in the unexposed portion, and then performs a second etching using a second gas capable of etching a greater portion of the photoresist film not infiltrated with the material than the photoresist film infiltrated with the material. Patterning equipment.

Images