Patterning method and patterning device
Patent Information
- Authority / Receiving Office
- TW · TW
- Patent Type
- Patents
- Current Assignee / Owner
- TOKYO ELECTRON LTD
- Filing Date
- 2023-03-14
- Publication Date
- 2026-08-01
AI Technical Summary
Existing patterning methods face challenges in developing finer patterns on substrates due to roughness deterioration and pattern collapse during wet development, while dry development struggles with insufficient etching rate differences between exposed and unexposed parts.
A patterning method involving a wetting step to infiltrate a material like metals or semi-metals into the photoresist film, followed by dry etching, to enhance the selectivity ratio between exposed and unexposed parts, allowing for pattern development through a dry process.
The method effectively develops patterns on substrates by increasing the etching selectivity ratio, preventing roughness deterioration and pattern collapse, even with miniaturized features.
Smart Images
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Abstract
Description
Technical Field
[0001] The disclosed embodiments relate to a patterning method and a patterning device. Prior Art
[0002] Patent document 1 discloses a technology that improves the etching resistance of the formed photoresist by exposing the formed photoresist to a metal-containing gas containing metal to wet the photoresist with metal. [Conventional technical literature] [Patent Document]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2020-38929 Summary of the Invention
[0004] [Problems to be solved by the invention]
[0005] The present invention provides a technology that can develop a pattern exposed on a photoresist film through a dry process. [Technical means to solve the problem]
[0006] A patterning method according to one aspect of the present invention includes a wetting step and an etching step. In the wetting step, a material is impregnated into a photoresist film on a substrate having a photoresist film formed thereon. The photoresist film is exposed to light to form exposed and unexposed portions. The material increases the selectivity between the exposed and unexposed portions. In the etching step, the photoresist film subjected to the wetting step is dry-etched. [Effects of the Invention]
[0007] According to the present invention, the pattern exposed on the photoresist film can be developed through a dry process. Simple diagram description
[0008] [Figure 1] Figures 1 (1) to (9) are diagrams schematically showing an example of the overall process of substrate processing in an embodiment. [Fig. 2] Fig. 2 is a block diagram showing an example of the structure of a patterning device according to an embodiment. [Fig. 3] Fig. 3 is a diagram showing an example of a processing flow of a patterning method according to an embodiment. [Fig. 4] Fig. 4 is a diagram conceptually showing an example of a substrate according to an embodiment. [Fig. 5] Fig. 5 is a diagram showing an example of the outline of silicon contained in the photoresist film of the embodiment. [Fig. 6] Fig. 6 is a diagram showing an example of an overview of dry etching of a photoresist film according to an embodiment. [Fig. 7] Fig. 7 (A) to (C) are diagrams conceptually showing an example of the results of etching the substrate of the embodiment. [Fig. 8] Fig. 8 (A) to (C) are diagrams conceptually showing another example of the results of etching the substrate of the embodiment. [Figure 9] Figures 9 (1) to (8) are diagrams schematically showing an example of the overall process of substrate processing including conventional lithography steps. Implementation Method
[0009] The following will describe in detail the embodiments of the patterning method and patterning device disclosed in this case with reference to the drawings. Furthermore, the disclosed patterning method and patterning device are not limited to the embodiments.
[0010] In recent years, the patterns formed on the surface of a substrate have become increasingly miniaturized as semiconductor integrated circuits (LSI) have become increasingly more integrated and performant. On a substrate, a pattern is formed by a lithography step. FIG9 is a diagram schematically showing an example of an overall process of substrate processing including a conventional lithography step. In the substrate processing shown in FIG9 , the processes (1) to (8) are performed on a substrate W. The substrate W is a silicon substrate such as a silicon wafer. A film to be patterned is formed on the substrate W. In (1) surface treatment, predetermined pre-treatments such as cleaning of the substrate W are performed. In (2) spin coating, a photoresist liquid is applied to the substrate W and the substrate W is rotated to form a photoresist film PR on the substrate W. In (3) pre-baking, the substrate W is heated to evaporate the solvent contained in the photoresist film PR. In (4) exposure, ultraviolet light or the like is irradiated through a photomask PM having a pattern formed thereon, so as to form a latent image of a pattern consisting of an exposed portion EP and an unexposed portion UP on the photoresist film PR. The photoresist film PR mentioned here has a negative type and a positive type. The negative type retains the exposed portion EP by development, and the positive type retains the unexposed portion UP by development. In the case of a negative type, exposure is performed using a photomask PM that sets the portion to be retained on the photoresist film PR as a transparent portion. In the case of a positive type, exposure is performed using a photomask PM that sets the portion to be retained on the photoresist film PR as a non-transparent portion. In (5) PEB (Post Exposure Bake), heating is used to promote the reaction. In (6) development + washing, the latent image of the photoresist film PR is developed with a solvent such as a developer, and the solvent used for development is then washed away. FIG9 shows the case of positive type development, where the unexposed portion UP remains and the exposed portion EP dissolves and disappears. The processes (1) to (6) correspond to the lithography step. Through the lithography step, a pattern is developed on the photoresist film PR. In (7) etching, etching is performed using the photoresist film PR as a mask to process the substrate W. In (8) photoresist stripping, the photoresist film PR is stripped and removed. In this way, a pattern is formed on the substrate W.
[0011] However, if the pattern is miniaturized, when developing the pattern exposed on the photoresist film PR using a wet process such as (6) development + rinsing, there is a concern that pattern defects may occur, such as worsening of the roughness due to expansion of the photoresist film PR or pattern collapse due to surface tension. On the other hand, if a dry process is used for development, the above problems will not occur. However, in the past, when using a dry process for development, the difference in etching rate between the exposed part EP and the unexposed part UP was small, making it difficult to develop the pattern exposed on the photoresist film PR. In view of this, it is expected that there will be a technology that can develop the pattern exposed on the photoresist film PR using a dry process.
[0012] (Implementation form) The patterning method of the embodiment is described. First, an example of the overall process of substrate processing including the lithography step of the embodiment is described. FIG1 is a diagram schematically showing an example of the overall process of substrate processing of the embodiment. FIG1 shows: substrate processing including the processing of the patterning method of the embodiment. The substrate processing of the embodiment is to change the (6) development + washing step of the conventional substrate processing shown in FIG9 to the (6) immersion and (7) etching steps. In the substrate processing shown in FIG1, the processing of (1) to (9) is performed. Since the processing of (1) to (5), (8), and (9) in FIG1 is the same as the processing of (1) to (5), (7), and (8) in FIG9, the description is omitted.
[0013] On the photoresist film PR of the substrate W, a latent image of a pattern consisting of exposed portions EP and unexposed portions UP is formed by exposure (4). The photoresist film PR is, for example, an organic film mainly composed of a photosensitive resin. Such a photoresist film PR may be, for example, a KrF photoresist or an EUV photoresist.
[0014] In (6) wetting, a material that increases the selectivity between the exposed portion EP and the unexposed portion UP is infiltrated into the photoresist film PR of the substrate W. Due to the difference in the infiltration depth, that is, the difference in the degree of modification of the photoresist film PR, a difference in etching rate is generated. For example, in (6) wetting, the substrate W is exposed to a gas containing a material that increases the selectivity between the exposed portion EP and the unexposed portion UP, and the material is infiltrated into the photoresist film PR. Since the infiltration depths are different between the exposed portion EP and the unexposed portion UP, a difference in etching rate will occur starting from the portion where the difference in infiltration depth occurs, allowing the pattern to be developed. Furthermore, the pattern can also be developed when the infiltration amount is different between the exposed portion EP and the unexposed portion UP. This includes the case where the material reacts to only one of the parts. If the infiltration amount is different, a difference in etching rate will occur from the time when etching starts, forming a pattern.
[0015] Materials that increase the selectivity between the exposed portion EP and the unexposed portion UP of the photoresist film PR can be metals or semimetallic elements. Examples of metals include aluminum (Al), titanium (Ti), and germanium (Ge). Semimetals include silicon (Si). For example, when wetting silicon into the photoresist, excellent wetting materials include N-(trimethylsilyl)dimethylamine (TMSDMA), bis(trimethylsilyl)amine (HMDS), hexachlorosilane (HCD), and the like. Furthermore, when wetting aluminum into the photoresist, wetting materials include trimethylaluminum (TMA) and triethylaluminum (TEA). Furthermore, when wetting titanium into the photoresist, wetting materials include TDMAT (tetramethylammoniumtitanium) and TiCl₄ (titanium tetrachloride). The material to be wetted is converted into vapor by vaporization, bubbling, or skimming, and is exposed to the photoresist film PR, thereby gradually wetting the photoresist film PR.
[0016] In the (7) etching step, the photoresist film PR soaked with the material is dry-etched. Since the photoresist film PR has been soaked in (6), the selectivity ratio of the exposed portion EP to the unexposed portion UP has been increased. Therefore, when etching, the exposed portion EP is etched deeper than the unexposed portion UP. In the (7) etching step, by properly controlling the etching time, the exposed portion EP of the photoresist film PR can be etched away while the unexposed portion UP is retained. However, depending on the combination of the material used for the photoresist film PR or the soaking, the portion to be removed and the portion to be retained in the exposed portion EP and the unexposed portion UP may also be opposite.
[0017] In the substrate processing shown in FIG1 , the photoresist film PR is patterned by the steps (6) wetting and (7) etching. The steps (6) wetting and (7) etching correspond to the processing of the patterning method of the present invention.
[0018] [Structure of Patterning Device] Next, an example of a patterning apparatus for performing the processes of (6) wetting and (7) etching will be described. FIG2 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 comprises: a wetting treatment section 11 and an etching treatment section 12.
[0019] The immersion treatment unit 11 is a unit that performs the immersion treatment (6). The immersion treatment unit 11 can be composed of the following components: a reaction chamber for mounting a substrate W, wherein the substrate W has an exposed portion EP and an unexposed portion UP formed on a photoresist film PR; a heating device for heating the substrate W; a supply device for supplying a gas containing a metal gas or the like into the reaction chamber; and an exhaust device for exhausting the reaction chamber.
[0020] The etching processing unit 12 is a unit that performs the etching step (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 can be a hydrogen-containing gas, for example, hydrogen (H2) gas.
[0021] Furthermore, the immersion processing section 11 and the etching processing section 12 of the patterning apparatus 1 may not be configured as a single unit.
[0022] [Patterning method] Next, the processing flow of the patterning method of the embodiment will be described. In the following, as a material for increasing the selectivity ratio between the exposed portion EP and the unexposed portion UP of the photoresist film PR, the case of infiltration of a metal such as aluminum, titanium, germanium, or a semi-metal such as silicon will be described as an example. FIG3 is a diagram showing an example of the processing flow of the patterning method of the embodiment. FIG3 shows the details of the processing of the (6) infiltration and (7) etching steps. The substrate W that has been processed, for example, as shown in (1) to (5) of FIG1 before the patterning method is implemented is transported to the infiltration processing section 11 and placed in the reaction chamber. The patterning device 1 of the embodiment will implement the processing shown in FIG3.
[0023] The immersion treatment unit 11 depressurizes the reaction chamber to achieve a decompressed state (step S10). The immersion treatment unit 11 then heats the substrate W placed in the reaction chamber to a predetermined temperature suitable for immersion (step S11).
[0024] Under predetermined conditions, the immersion treatment section 11 exposes the photoresist film PR to a gas containing a material that increases the selectivity between the exposed portions EP and the unexposed portions UP. For example, the immersion treatment section 11 exposes the photoresist film PR to a gas containing a metal or a semi-metal under predetermined conditions (step S12). Hereinafter, the gas containing a metal or a semi-metal is referred to as a "metal-containing gas."
[0025] Next, the immersion treatment section 11 uses an inert gas such as N₂ to purge the metal-containing gas from the reaction chamber (step S13). Next, the immersion treatment section 11 exposes the photoresist film PR to water vapor under predetermined conditions (step S14). Next, the immersion treatment section 11 uses an inert gas such as N₂ to purge the water vapor from the reaction chamber (step S15). Steps S12 through S15 can be repeated multiple times.
[0026] The patterning apparatus 1 removes the substrate W from the immersion treatment section 11 and transports it to the etching treatment section 12 (step S16). If the immersion treatment section 11 and the etching treatment section 12 are configured as a single unit, step S16 is unnecessary.
[0027] The etching unit 12 etches the photoresist film PR on the substrate W (step S17). For example, the etching unit 12 dry-etches the photoresist film PR using reactive ion etching (RIE) using H₂ gas. By properly controlling the etching time, the exposed portion EP of the photoresist film PR is removed while the unexposed portion UP remains.
[0028] 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 also refer to the surface temperature of the photoresist film PR. The "predetermined temperature" is preferably within a range of room temperature to 200°C. "Room temperature" refers to a temperature in a natural state without external heating or cooling, for example, a temperature within the range of 1°C to 40°C (e.g., 25°C). If the temperature of the substrate W is below room temperature, sufficient energy to penetrate the activation barrier for metal wetting into the photoresist film PR (e.g., to induce a nucleophilic substitution reaction) is often insufficient. The upper limit of the substrate W temperature, 200°C, is sufficiently higher than the transfer temperature of the photoresist film PR.
[0029] The "given conditions" for exposure to the metal-containing gas include substrate W temperature, gas flow rate, exposure time, and pressure. The amount of metal or semi-metal wetting into the photoresist film PR increases with higher substrate W temperature and decreases with lower substrate W temperature. Furthermore, the wetting amount increases with higher metal-containing gas flow rates and decreases with lower gas flow rates. Furthermore, the wetting amount increases with longer exposure times to the metal-containing gas and decreases with shorter exposure times. Furthermore, the wetting amount increases with higher chamber pressure and decreases with lower pressures.
[0030] Processing in steps S14 and S15 is not essential. However, wetting can be promoted by exposing the film to water vapor after exposure to the metal-containing gas. The "given conditions" for water vapor exposure include substrate W temperature, gas flow rate, exposure time, and pressure. The wetting-promoting effect of water vapor increases with higher substrate W temperatures and decreases with lower substrate W temperatures. Furthermore, the wetting-promoting effect increases with higher water vapor flow rates and decreases with lower flow rates. Furthermore, the wetting-promoting effect increases with longer water vapor exposure times and decreases with shorter exposure times. Furthermore, the wetting-promoting effect increases with higher chamber pressures and decreases with lower pressures.
[0031] The conditions for exposure to water vapor (substrate W temperature, gas flow rate, exposure time, pressure, etc.) can be the same as those for exposure to metal-containing gas, or can be set to be different from those for exposure to metal-containing gas.
[0032] The amount of metal or semi-metal infiltration into the photoresist film PR is preferably in the range of 4 atomic % to 20 atomic %. If the infiltration amount is less than 4 atomic %, the effect of increasing the etching resistance of the photoresist film PR is often not substantially seen. If the infiltration amount is higher than 20 atomic %, the original organic properties of the photoresist film PR (for example, solubility in alkaline solution, etc.) are damaged, resulting in a decrease in the stripping property of the photoresist film PR. In the photoresist stripping process (9), it is difficult to strip the photoresist film PR from the etched film.
[0033] The wetting amount can be controlled by adjusting the conditions for exposure to the metal-containing gas, the conditions for exposure to water vapor, and the number of times steps S12 through S15 are repeated. For example, the pressure during exposure to the metal-containing gas is preferably within the range of 0.05 Torr to 760 Torr. If the pressure is lower than 0.05 Torr, the wetting amount may be less than 4 atomic %. If the pressure is higher than 760 Torr, the wetting amount may exceed 20 atomic %.
[0034] FIG4 conceptually illustrates an example of a substrate W according to an embodiment. FIG4 shows a substrate W exposed to TMSDMA to wet silicon into a photoresist film PR. The substrate W is formed with a photoresist film PR. The photoresist film PR alternates between exposed portions EP and unexposed portions UP. FIG4 schematically illustrates the depth of silicon wetting in the photoresist film PR, as indicated by line L1. As shown by line L1, silicon wetting in the unexposed portions UP is deeper than in the exposed portions EP.
[0035] FIG5 is a diagram showing an example of the silicon content in the photoresist film PR according to an embodiment. FIG5 shows the silicon content ratio relative to the depth from the surface of the photoresist film PR, distinguishing between the exposed portion EP and the unexposed portion UP. For example, at a depth of approximately 0-150 nm, the unexposed portion UP has a slightly higher silicon content than the exposed portion EP. Furthermore, at a depth of approximately 150-250 nm, the unexposed portion UP has a significantly higher silicon content than the exposed portion EP. This indicates that silicon penetrates deeper into the unexposed portion UP than into the exposed portion EP. Thus, the silicon penetration depths differ between the unexposed portion UP and the exposed portion EP.
[0036] FIG6 is a diagram illustrating an example of dry etching of a photoresist film PR according to an embodiment. FIG6 schematically illustrates the residual film thickness of the photoresist film PR relative to etching time after dry etching. FIG6 shows the profile of the exposed portion EP of the photoresist film PR wetted with silicon as shown by line L11, while the profile of the unexposed portion UP is shown by line L12. Furthermore, FIG6 shows the profile of the exposed portion EP of the photoresist film PR not wetted with silicon as a comparative example as shown by line L13, while the profile of the unexposed portion UP is shown by line L14.
[0037] As shown by lines L13 and L14, the photoresist film PR that is not wetted with silicon is deeply etched in a short etching time compared to the photoresist film PR that is wetted with silicon as shown by lines L11 and L12, and has a high etching rate.
[0038] The photoresist film PR increases its etching resistance by being wetted with silicon. Therefore, as shown by lines L11 and L12, the exposed portion EP and unexposed portion UP of the photoresist film PR, wetted with silicon, exhibit lower etching rates compared to lines L13 and L14. Furthermore, the etching rate of the exposed portion EP, as shown by line L11, increases midway. This is because the exposed portion EP, as shown by lines L1 in Figures 4 and 5, has a shallower wetting range with silicon than the unexposed portion UP. Therefore, while the etching rate is low within the wetting range, it shifts to approximately the same rate as lines L13 and L14 once it reaches deeper into the wetting range. On the other hand, the unexposed portion UP, as shown by line L12, exhibits a consistently low etching rate due to its deep wetting range with silicon.
[0039] As a result, in the photoresist film PR wetted with silicon, due to the difference in the wetting range between the exposed portion EP and the unexposed portion UP, the exposed portion EP is etched deeper than the unexposed portion UP.
[0040] FIG7 conceptually illustrates an example of the results of etching a substrate W according to an embodiment. FIG7(A) through (C) illustrate changes in the photoresist film PR during etching of a substrate W exposed to TMSDMA, where silicon is wetted into the photoresist film PR. FIG7(A) shows the photoresist film PR before etching. The photoresist film PR alternates between exposed portions EP and unexposed portions UP. FIG7(A) through (C) schematically illustrate the depth of silicon wetted into the photoresist film PR as indicated by line L1. FIG7(B) shows the photoresist film PR etched for 7.5 minutes using an etching gas containing H₂. The unexposed portions UP, which are the wetting range of silicon, are etched. Meanwhile, the exposed portions EP, due to exceeding the wetting range, exhibit a faster etching rate and are etched deeper than the unexposed portions UP. FIG7(C) shows the photoresist film PR etched for 9.5 minutes using an etching gas containing H₂. The unexposed portions UP are etched to approximately the wetting range. Meanwhile, the exposed portions EP are etched more thoroughly and deeply than the unexposed portions UP. By properly controlling the etching time, the exposed portions EP of the photoresist film PR can be removed while preserving the unexposed portions UP. This allows the latent image formed by the exposed and unexposed portions EP to be developed through a dry process. The photoresist film PR sometimes has residual photoresist, or scum, at the interface with the underlying layer. This scum can be removed by reactive ion etching using O2 gas (oxygen).
[0041] Furthermore, in the above embodiment, a case where a silicon-wetted photoresist film PR is developed by a single-stage etching process using H₂ gas is used as an example. However, this is not limiting. For example, the substrate W may be developed using a two-stage etching process. For example, a first etching process and a second etching process are performed on the substrate W. In the first etching process, a first gas capable of etching the material-wetted photoresist film PR is used to etch the substrate to a depth deeper than the material wetting depth in the exposed portion EP and shallower than the material wetting depth in the unexposed portion UP. For example, in the case of a silicon-wetted photoresist film PR, an etching gas containing a hydrogen-containing gas (e.g., H₂ gas) is used to etch the substrate to a depth deeper than the material wetting depth in the exposed portion EP and shallower than the material wetting depth in the unexposed portion UP. In the second etching process, after the first etching process, a second gas capable of etching a greater portion of the photoresist film PR not wetted by the material than the material-wetted photoresist film PR is used. For example, in the case of a photoresist film PR wetted with silicon, etching is performed using an etching gas containing an oxygen-containing gas (eg, O 2 gas).
[0042] FIG8 is a diagram conceptually illustrating another example of the results of etching a substrate W according to an embodiment. FIG8(A)-(C) show the changes in the photoresist film PR during a two-step etching process for a substrate W exposed to TMSDMA to wet the photoresist film PR with silicon. FIG8(A) shows the photoresist film PR before etching. The photoresist film PR alternates between exposed portions EP and unexposed portions UP. FIG8(A)-(C) schematically shows the depth of silicon wetting in the photoresist film PR as indicated by line L1. FIG8(B) shows the photoresist film PR after etching for 7.5 minutes using an etching gas containing H₂. Both the exposed portions EP and the unexposed portions UP are etched. The unexposed portions UP are etched within the wetting range of silicon. Meanwhile, the exposed portions EP, exceeding the wetting range, etch at a faster rate, resulting in a deeper etching depth than the unexposed portions UP. At this stage (Figure 8(B)), the photoresist film PR is then etched using an etching gas containing O2. Figure 8(C) shows the photoresist film PR after being etched for 50 seconds using an etching gas containing O2. In the unexposed portions (UP), where silicon infiltration is high, a silicon oxide film forms on the surface, acting as an etch stop. The exposed portions EP, where silicon infiltration is low (or silicon is not wetted), do not form a silicon oxide film and are therefore etched. This results in a high selectivity between the exposed portions EP and the unexposed portions UP. By properly controlling the etching time, the exposed portions EP of the photoresist film PR can be removed while the unexposed portions UP remain. This allows the latent image pattern formed by the exposed and unexposed portions EP to be developed through a dry process.
[0043] In this manner, the patterning method of the embodiment increases the etching selectivity between the exposed portion EP and the unexposed portion UP, thereby enabling the pattern exposed on the photoresist film PR to be developed through a dry process. Consequently, the patterning method of the embodiment can suppress pattern defects such as deterioration in roughness and pattern collapse in the developed photoresist film PR, even when the pattern is miniaturized.
[0044] [Effect] Thus, the patterning method of the embodiment includes a wetting step (steps S12-S15) and an etching step (step S17). In the wetting step, a material is impregnated into the photoresist film PR on a substrate W having the photoresist film PR formed on its surface. The photoresist film PR is exposed to light to form exposed portions EP and unexposed portions UP. The material is selected to increase the selectivity between the exposed portions EP and the unexposed portions UP. In the etching step, the photoresist film PR that has undergone the wetting step is dry-etched. Thus, the patterning method enables the pattern exposed on the photoresist film PR to be developed through a dry process.
[0045] Furthermore, in the wetting step, the substrate W is exposed to a gas containing the material. In this way, the patterning method can wet the photoresist film PR with the material.
[0046] Furthermore, the material is a metal or semimetal element. The metal is any of aluminum, titanium, and germanium. The semimetal is silicon. The wetting step allows the material to penetrate deeper into the unexposed portion UP than into the exposed portion EP. This allows the patterning method to increase the selectivity between the exposed portion EP and the unexposed portion UP.
[0047] Furthermore, the metal or semi-metal wetting ratio of the photoresist film PR is within the range of 4 atomic % to 20 atomic %. Thus, the patterning method can increase the etching resistance of the photoresist film PR while suppressing the degradation of the photoresist film PR's peeling properties.
[0048] Furthermore, the etching step etches the exposed portion EP more deeply than the unexposed portion UP. In this way, the patterning method can develop the pattern exposed on the photoresist film PR through a dry process.
[0049] Furthermore, in the etching step, after the first etching step is performed using a first gas capable of etching the photoresist film PR wetted with the material to a depth deeper than the depth of material wetting in the exposed portion EP and shallower than the depth of material wetting in the unexposed portion UP, a second etching step is performed using a second gas capable of etching a greater portion of the photoresist film PR unwetted with the material than the photoresist film PR wetted with the material. The first gas is a hydrogen-containing gas (e.g., H₂ gas), and the second gas is an oxygen-containing gas (e.g., O₂ gas). This patterning method can further enhance the selectivity between the exposed portion EP and the unexposed portion UP, thereby performing etching.
[0050] The above descriptions are based on various exemplary embodiments, but the present invention is not limited to the exemplary embodiments described above. Various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different exemplary embodiments may be combined to form other exemplary embodiments.
[0051] For example, the above embodiment describes a case where the substrate W is a silicon substrate, but the present invention is not limited thereto. The substrate W may be, for example, 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; or a substrate composed of a composite material thereof.
[0052] 1: Patterning device 11: Infiltration treatment unit 12: Etching treatment unit EP:Exposure part PM: Photomask PR: Photoresist film UP: Unexposed part W: substrate L1, L11~L14: Line S10~S17: Procedure
Claims
1. A patterning method comprising the following steps: an immersion step, wherein a material is immersed in the entire surface of a photoresist film having an exposed portion and an unexposed portion formed on the surface of a substrate, and the material is immersed deeper into the unexposed portion than into the exposed portion, thereby creating a difference in immersion depth between the exposed portion and the unexposed portion, wherein the photoresist film is formed by exposure of the exposed portion and the unexposed portion, and the material is a material that increases the selectivity ratio of the exposed portion and the unexposed portion; and an etching step, wherein the photoresist film having undergone the immersion step is dry etched; wherein, due to the difference in immersion depth, the exposed portion is etched deeper than the unexposed portion in the etching step.
2. As in the patterning method of request item 1, wherein, This wetting step involves exposing the substrate to a gas containing the material.
3. The patterning method as described in request item 1 or 2, wherein, This material is a metallic or semi-metallic element.
4. As in the patterning method of request item 3, wherein, The metal is any one of aluminum, titanium, or germanium.
5. The patterning method as described in request item 3, wherein, This semi-metal is silicon.
6. The patterning method as described in request item 3, wherein, The amount of the metal or the half-metal wetting the photoresist film is in the range of 4 atomic% to 20 atomic%.
7. The patterning method as described in request item 1 or 2, wherein, In this etching step, after first etching is performed using a first gas that can etch the photoresist film wetted with the material to a depth that is deeper than the depth to which the material wets the exposed portion and shallower than the depth to which the material wets the unexposed portion, a second etching is performed using a second gas that can etch more of the unwetted photoresist film compared to the photoresist film wetted with the material.
8. The patterning method as described in request item 7, wherein, The first gas is a hydrogen gas; the second gas is an oxygen gas.
9. The patterning method as described in request item 7 or 8, wherein, The first gas is hydrogen; the second gas is oxygen.
10. A patterning device, comprising: The immersion processing section immerses material on the entire surface of a photoresist film on a substrate having exposed and unexposed portions, and further immerses the material into the unexposed portions than the exposed portions, creating a difference in immersion depth between the exposed and unexposed portions. The photoresist film forms the exposed and unexposed portions through exposure, and the material is a material that increases the selectivity ratio between the exposed and unexposed portions. The etching processing section performs dry etching on the photoresist film that has been immersed in material by the immersion processing section. Through the etching processing section, due to the difference in immersion depth, the exposed portions are etched more deeply than the unexposed portions.
11. A patterning method comprising the following steps: an immersion step, wherein a material is immersed in a photoresist film on a substrate having a photoresist film on its surface, the photoresist film being exposed to form exposed portions and unexposed portions, the material being a material that increases the selectivity ratio of the exposed portions to the unexposed portions; and an etching step, wherein the photoresist film having undergone the immersion step is dry etched; the etching step, wherein after a first etching using a first gas capable of etching the photoresist film immersed in the material to a depth greater than the depth to which the material is immersed in the exposed portions and shallower than the depth to which the material is immersed in the unexposed portions, a second etching is performed using a second gas capable of etching more of the un-immersed photoresist film than the photoresist film immersed in the material.
12. A patterning device, comprising: The immersion processing section immerses the material in the photoresist film on the substrate with a photoresist film on its surface. The photoresist film forms exposed and unexposed portions by exposure. The material is a material that increases the selectivity ratio between the exposed and unexposed portions. The etching process unit performs dry etching on the photoresist film that has been wetted by the immersion process unit. After the etching process unit performs a first etching to a depth that is deeper than the depth to which the material wets the exposed portion and shallower than the depth to which the material wets the unexposed portion using a first gas that can etch the photoresist film wetted by the material, it performs a second etching using a second gas that can etch more of the unwetted photoresist film than the photoresist film wetted by the material.