Diluent composition and method for treating the surface of a semiconductor substrate

Abstract

This application discloses a diluent composition and a method for treating the surface of a semiconductor substrate. This disclosure relates to a diluent composition for removing photoresist and a method for treating a semiconductor substrate using the diluent composition. Specifically, the diluent composition comprises (a) propylene glycol monoalkyl ether, (b) propylene glycol monoalkyl ether acetate, (c) cyclohexanone, and (d) cyclopentanone. Furthermore, the method for treating the semiconductor substrate includes applying a photoresist composition onto the semiconductor substrate; and removing the applied photoresist composition using the diluent composition of the present invention.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0012724, filed with the Korean Intellectual Property Office on January 29, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a thinner composition for improving edge bead removal (EBR) and a method for treating the surface of a semiconductor substrate using the thinner composition. Background Technology

[0004] Photoresist, comprising photoresist compounds and solvents, is applied to a conductive metal or oxide layer to form tiny circuit patterns, such as those found in semiconductor integrated circuits. The photoresist is formed on a substrate using spin coating or spin-coating methods, followed by subsequent exposure, development, etching, and stripping processes.

[0005] After the photoresist is applied, subsequent exposure processes use light with short wavelengths (e.g., ultraviolet light) to expose the desired tiny patterns on the coating. The exposure process is highly sensitive to both internal and external contamination. Excess photoresist residue and other contaminants remaining at the substrate edges or back layers can become fatal during the exposure process. Therefore, it has been recommended to perform an EBR (External Back Rinse) process or a back rinse process before exposure to remove unwanted photoresist residue and contaminants from the substrate edges or back layers.

[0006] The EBR process or wash-back process can be performed using a diluent composition for removing photoresist.

[0007] Examples of compositions used in the removal of photoresist in related technologies include single solvents such as ethyl cellosolve acetate (ECA), methyl methoxypropionate (MMP), and ethyl lactate (EL). Such compositions can be used to remove photoresist used in KrF and ArF (including ArF immersion) lithography.

[0008] Recently, the demand for increased integration in semiconductor devices has necessitated the use of photoresists suitable for extreme ultraviolet (EUV) lithography. EUV is suitable for forming tiny patterns in semiconductor devices with high integration. However, when diluent compositions that remove the single solvent used in KrF and ArF photoresists are applied to EUV, residual photoresist may remain or result in poor EBR cross-sectional characteristics. Therefore, there is a need to develop diluent compositions for use with EUV to prevent or reduce defects during the formation of tiny patterns, thereby enabling satisfactory next-generation semiconductor devices.

[0009] To improve the stability of the EBR process, it is necessary to develop a diluent composition that can easily remove photoresist used for EUV as well as photoresist used for KrF and ArF. Summary of the Invention

[0010] One aspect of this disclosure relates to providing a diluent composition that can be used to improve the effect of EBR.

[0011] In another aspect of this disclosure, a method for treating the surface of a semiconductor substrate using the diluent composition is provided.

[0012] Various embodiments of this disclosure relate to diluent compositions for removing resists, including (a) propylene glycol monoalkyl ether, (b) propylene glycol monoalkyl ether acetate, (c) cyclohexanone, and (d) cyclopentanone.

[0013] Various other embodiments of this disclosure relate to methods for treating the surface of a semiconductor substrate by applying photoresist onto the substrate and performing an EBR process for removing photoresist formed on the edge and / or back surface of the substrate by spraying a diluent composition comprising propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, cyclohexanone, and cyclopentanone.

[0014] By providing a diluent composition having at least four components and a specific composition according to the concept of this disclosure, unwanted or excess resist adhering to the edge or back portion of a substrate during the fabrication of semiconductor devices and thin-film transistors can be effectively and rapidly removed, and the EBR cross-sectional profile can be improved. Furthermore, because the substrate surface is treated with the diluent composition before photoresist application, a smaller or reduced amount of photoresist can be used to uniformly coat the entire surface of the substrate. As a result, the photoresist application rate can be significantly improved, photoresist usage can be reduced, and manufacturing process efficiency and productivity can be achieved simultaneously. For example, semiconductor manufacturing processes that generate unwanted particles leading to defects can be improved to reduce defect rates, process efficiency can be increased, and semiconductor manufacturing yield can be further increased by using the disclosed diluent composition. Attached Figure Description

[0015] The above and other features and advantages of the disclosed technology will become apparent when considered in conjunction with the accompanying drawings and with reference to the following detailed description.

[0016] The accompanying drawings in this disclosure are included to illustrate embodiments of the invention and, together with the detailed description, to provide a further understanding of the inventive concept. Therefore, the scope of the disclosed concept should not be construed as a limitation on the matters described in these drawings or the detailed description.

[0017] Figure 1 This is an electron microscope image of the resist layer after an EBR process using the diluent composition of Example 2.

[0018] Figure 2 This is an electron microscope image of the resist layer after an EBR process using the diluent composition of Comparative Example 3. Detailed Implementation

[0019] The diluent composition for removing resist according to the embodiments includes (a) propylene glycol monoalkyl ether, (b) propylene glycol monoalkyl ether acetate, (c) cyclohexanone and (d) cyclopentanone. Each component is discussed below.

[0020] (a) Propylene glycol monoalkyl ether

[0021] (a) Propylene glycol monoalkyl ethers are substances with excellent solubility (i.e., high solubility) for various types of photoresists, such as methacrylate-based photoresists for ArF, for example. Using (a) propylene glycol monoalkyl ethers as a component of a diluent composition for removing photoresists can increase the solubility of the photoresist. For example, because propylene glycol monoalkyl ethers are highly volatile, increasing the amount of propylene glycol monoalkyl ethers in the composition will increase the solubility of the photoresist. However, excessive solubility may lead to variations or inconsistencies in the thickness of the photoresist, or even lifting.

[0022] In propylene glycol monoalkyl ethers, the term "alkyl" preferably refers to a group having 1 to 10 carbon atoms. Specifically, (a) a propylene glycol monoalkyl ether can be one or more selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether. In particular, a propylene glycol monoalkyl ether can be propylene glycol monomethyl ether.

[0023] Based on the total weight of the diluent composition, (a) propylene glycol monoalkyl ethers may be included by weight percentage (wt%). For example, the range of (a) propylene glycol monoalkyl ethers may be 1 wt% to 35 wt%, 1 wt% to 30 wt%, or 1 wt% to 25 wt% of the diluent composition.

[0024] If the amount of (a) propylene glycol monoalkyl ether meets one of the above ranges, the properties of the edge bead region and the EBR cross-sectional profile can be improved. However, if the amount of (a) propylene glycol monoalkyl ether is less than 1 wt%, the solubility of the diluent composition for the resist may be reduced. Therefore, any improvement to the EBR cross-sectional profile may be negligible, and removal of the photoresist layer during reprocessing may be more difficult due to increased defect generation. If the amount of (a) propylene glycol monoalkyl ether is greater than 30 wt%, the volatility of the diluent composition may increase, and the resist formed after pre-wetting may be uneven and may exhibit large thickness deviations.

[0025] (b) Propylene glycol monoalkyl ether acetate

[0026] (b) Propylene glycol monoalkyl ether acetate is a material with relatively low polarity and excellent solubility compared to all photoresists. Furthermore, the (b) propylene glycol monoalkyl ether acetate in the composition helps to achieve uniform application of the photoresist surface tension characteristics. Therefore, EBR process characteristics and reduced resist consumption (RRC) process effects can be significantly improved.

[0027] In propylene glycol monoalkyl ether acetate, the term "alkyl" preferably refers to a group having 1 to 10 carbon atoms. Specifically, (b) propylene glycol monoalkyl ether acetate may be one or more selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and propylene glycol monobutyl ether acetate.

[0028] Based on the total weight of the diluent composition, (b) propylene glycol monoalkyl ether acetate may be included by weight percentage. For example, (b) propylene glycol monoalkyl ether acetate may be included in the range of 40 wt% to 70 wt%, 40 wt% to 60 wt%, or 45 wt% to 55 wt% of the diluent composition for use in removing resist.

[0029] If the amount of propylene glycol monoalkyl ether acetate (b) meets any of the above ranges, a suitable surface tension can be achieved, resulting in excellent uniformity of photoresist coating, while tailing may not occur in the EBR process at the edge, thus allowing for efficient removal processes.

[0030] If the amount of (b) propylene glycol monoalkyl ether acetate is less than 40 wt%, the hump at the edge may be exacerbated, or residues may form at the edge. If the amount of (b) propylene glycol monoalkyl ether acetate is greater than 70 wt%, the surface tension may increase. As a result, when the photoresist is applied, it may not spread uniformly, and thus may not be able to overcome the micro-pattern steps (uniform thickness) on the wafer, thus potentially causing splitting at the edge.

[0031] (c) Cyclohexanone and (d) Cyclopentanone

[0032] (c) Cyclohexanone and (d) cyclopentanone are both substances with excellent solubility for all photoresists. (c) Cyclohexanone and (d) cyclopentanone are used as components in compositions for removing photoresist and are used to mitigate the increase in photoresist solubility, thereby achieving suitable surface tension and excellent EBR performance.

[0033] Based on the total weight of the diluent composition, (c) cyclohexanone and (d) cyclopentanone may be included by weight percentage. For example, (c) cyclohexanone and (d) cyclopentanone may be included together in the range of 25 wt% to 59 wt%, 25 wt% to 50 wt%, or 25 wt% to 45 wt% of the diluent composition. Furthermore, preferably, the content of (c) cyclohexanone in the diluent composition is 40 wt% to 60 wt% or 45 wt% to 55 wt% relative to the total amount of (c) cyclohexanone and (d) cyclopentanone. Preferably, the content of (d) cyclopentanone in the diluent composition is 60 wt% to 40 wt% or 55 wt% to 45 wt% relative to the total amount of (d) cyclopentanone and (c) cyclohexanone.

[0034] When the total amount of (c)cyclohexanone and (d)cyclopentanone is included within the above range, a diluent composition with improved solubility in photoresist and reduced surface tension can be prepared. Using this diluent composition, a stable EBR process can be performed even when process conditions change. Conversely, if the total amount of (c)cyclohexanone and (d)cyclopentanone deviates from the stated range, defects such as tailing may occur during the EBR process, and discoloration and other defects may occur due to uneven film thickness during photoresist application.

[0035] According to some embodiments, the weight ratio of (c) cyclohexanone to (d) cyclopentanone can be in the range of 1:0.1 to 1:10, such as, for example, in the range of 1:0.2 to 1:8, preferably in the range of 1:0.8 to 1:1.2. In other embodiments, the ratio of (c) cyclohexanone to (d) cyclopentanone can exceed these ranges and can be, for example, 3:1.

[0036] If the weight ratio of (c) cyclohexanone to (d) cyclopentanone meets the above range, excellent solubility and appropriate surface tension for photoresist can be ensured.

[0037] If the weight ratio of (c) cyclohexanone to (d) cyclopentanone deviates from the above range, the residue at the edge may increase.

[0038] The beneficial effects of the diluent composition can be further enhanced with common additives such as surfactants. Surfactants can be fluorinated, nonionic, or ionic, but are not limited to these examples. Additives can be included, by weight, in amounts from about 10 to 500 ppm relative to the diluent composition to improve EBR results.

[0039] As described above, embodiments of this disclosure include diluent compositions that are non-toxic to humans, do not exhibit odor-related discomfort, and possess high operational stability and low corrosivity. Furthermore, unwanted photoresist at the edges or back portions of the substrate, resulting from an increase in the diameter of the substrate used to manufacture semiconductor devices, can be uniformly and efficiently removed within a short time. Moreover, because the diluent composition exhibits excellent dissolving power for various photoresists and bottom anti-reflective coatings (BARC), EBR performance, reprocessing performance, and photoresist application processes can be improved. Therefore, the diluent composition can be used in pretreatment processes of the wafer surface prior to photoresist application, such as EBR processes, reprocessing processes, and wafer bottom cleaning processes.

[0040] With the increasing substrate (wafer) caliber used in integrated circuit manufacturing, Reactive Coating (RRC) processes have been researched and developed to reduce photoresist usage and thus lower costs. In the RRC process, by treating the substrate surface with a pretreatment composition before applying the photoresist, a small amount of photoresist can be used to uniformly coat the entire surface of the substrate. If the diluent composition disclosed herein is used in such an RRC process, the amount of unwanted particles that may be generated during semiconductor manufacturing can be minimized, significantly reducing the defect rate and improving the efficiency of the RRC process.

[0041] The diluent compositions disclosed herein are preferably applied to photoresist resins using high-energy light or high-energy light, such as light with a wavelength of 500 nanometers (nm) or shorter, X-rays, electron beams, etc. In particular, the diluent compositions disclosed herein are preferably applied to photoresists used for EUV, i-line, KrF, or ArF photoresists.

[0042] Typically, photoresists used for i-line, KrF, ArF, or EUV each comprise photoresist resins with different basic structures. Therefore, the composition of the diluent composition disclosed herein can be tailored to the type of photoresist used to improve solubility and coatability. However, the diluent composition disclosed herein exhibits excellent solubility for most photoresists and meets the solubility requirements for the main components of highly polar photoresists and antireflective layers. Therefore, by using the diluent composition disclosed herein, contamination of the production equipment (e.g., contamination of the coating machine's cup holders or blockage of the outlet) can be prevented even after completing EBR processes using KrF or ArF photoresists other than those used for EUV, cleaning processes performed on the wafer bottom, and pretreatment processes performed on the wafer top before applying the photoresist, which can improve productivity.

[0043] Methods for treating semiconductor substrate surfaces

[0044] In another aspect of this disclosure, a method for treating the surface of a semiconductor substrate using the diluent composition of this disclosure is provided.

[0045] In one embodiment, a method may include spraying a diluent composition onto edge and back portions of a substrate on which a photoresist composition is coated, to remove any unwanted portions of the photoresist layer during a semiconductor device or thin-film transistor manufacturing process.

[0046] In one embodiment, the method may include the steps of applying photoresist to a substrate and performing an EBR process for removing the photoresist formed on the edges and / or back surface of the substrate, which includes spraying the diluent composition disclosed herein.

[0047] The photoresist can be a KrF or ArF photoresist, or a EUV photoresist.

[0048] During the EBR process, the diluent composition can be sprayed onto the edges and back surface of the substrate at a rate of 5 to 50 cc / min while the substrate is rotating. The disclosed EBR method effectively prevents unwanted photoresist contamination of the substrate.

[0049] In addition to the surface treatment of the semiconductor substrate, in additional embodiments of this disclosure, subsequent processes known in the art of manufacturing semiconductor devices and thin-film transistors may be performed after the EBR process.

[0050] For example, after removing moisture or water from the photoresist layer by performing a soft baking process in a temperature range of about 100°C to 150°C or in a range of about 100°C to 120°C, an exposure step can be performed to selectively expose a portion of the photoresist layer using an exposure mask.

[0051] The photoresist layer can then be developed using a developer such as tetramethylammonium hydroxide (TMAH) and n-butyl acetate (n-BA) to complete the photoresist pattern. In the example, if a positive photoresist is used, the exposed photoresist layer can be partially removed, while if a negative photoresist is used, the exposed photoresist layer can be retained.

[0052] The photoresist pattern created by the above process can be used to form various tiny patterns in semiconductor devices. However, if there are defects in the completed photoresist pattern, it is economically advantageous to remove the defective photoresist pattern and reuse the substrate.

[0053] In other words, if defects exist in the photoresist pattern formed on the substrate, a reprocessing step for removing the photoresist pattern may also be included, using the diluent composition disclosed herein. Then, after removing the photoresist pattern using the diluent composition, a drying process can be performed on the remaining diluent composition on the substrate. Therefore, after removing the photoresist using the disclosed method, the substrate can be reused.

[0054] In a further embodiment, the method for processing the surface of a semiconductor substrate may further include: applying a hard mask layer or an anti-reflective layer to the substrate; spraying a diluent composition; and applying a photoresist.

[0055] The step of spraying the thinner composition can be performed by conventional methods such as spin coating. Examples include: methods of applying a thinner composition to a substrate and then rotating the substrate to coat the back surface and / or front surface of the substrate with the thinner composition, and methods of applying a thinner composition to a rotating substrate by spraying and then coating the back surface and / or front surface of the substrate with the thinner composition.

[0056] If the thinner composition is sprayed before applying the photoresist using the method described above, the removal process for unwanted photoresist at the edge portions of the substrate can be performed efficiently without tailing, and coating uniformity can be maintained extremely well. Furthermore, by spraying the thinner composition before applying the photoresist, the wettability of the substrate can be improved before photoresist application, and a small amount of photoresist can be used to form a thin and uniformly thick photoresist layer. In addition, coating defects in the photoresist layer at the edge portions of the substrate can be minimized, any uneven thickness that may exist on the substrate can be easily overcome, and thickness deviations in the photoresist layer can be reduced.

[0057] The specific structural or functional descriptions of examples of embodiments of the concepts disclosed in this specification are merely illustrative of examples of embodiments of the concepts. Examples of embodiments of the concepts may be implemented in various forms; however, the description is not limited to the examples of the embodiments described below.

[0058] Various modifications and changes can be made to the examples of the embodiments based on the described concept, and therefore examples of embodiments will be shown in the accompanying drawings and described in the specification. However, embodiments based on the concept of this disclosure are not to be construed as limited to the specific disclosure, but rather include all variations, equivalents, or substitutions without departing from the spirit and technical scope of this disclosure. In describing those embodiments, descriptions of techniques well-known in the art to which this disclosure pertains and not directly related to this disclosure will be omitted. This is intended to make the gist of the disclosure clearer by omitting unnecessary descriptions.

[0059] Example

[0060] Example 1.

[0061] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 15 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, 15 wt% cyclohexanone, and 15 wt% cyclopentanone.

[0062] Example 2.

[0063] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 5 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, 20 wt% cyclohexanone, and 20 wt% cyclopentanone.

[0064] Example 3.

[0065] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 5 wt% propylene glycol monomethyl ether, 45 wt% propylene glycol monomethyl ether acetate, 25 wt% cyclohexanone, and 25 wt% cyclopentanone.

[0066] Example 4.

[0067] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 37 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, 4 wt% cyclohexanone, and 4 wt% cyclopentanone.

[0068] Example 5.

[0069] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 9 wt% propylene glycol monomethyl ether, 75 wt% propylene glycol monomethyl ether acetate, 8 wt% cyclohexanone, and 8 wt% cyclopentanone.

[0070] Example 6.

[0071] Individual compounds were injected into a container to prepare a diluent composition for removing resists (see Table 1 below): 1 wt% propylene glycol monomethyl ether, 39 wt% propylene glycol monomethyl ether acetate, 30 wt% cyclohexanone, and 30 wt% cyclopentanone.

[0072] Example 7.

[0073] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 10 wt% propylene glycol monomethyl ether, 70 wt% propylene glycol monomethyl ether acetate, 10 wt% cyclohexanone, and 10 wt% cyclopentanone.

[0074] Example 8.

[0075] Individual compounds were injected into a container to prepare a diluent composition for removing resists (see Table 1 below): 5 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, 2 wt% cyclohexanone, and 38 wt% cyclopentanone.

[0076] Example 9.

[0077] Individual compounds were injected into a container to prepare a diluent composition for removing resist (see Table 1 below): 15 wt% propylene glycol monomethyl ether, 65 wt% propylene glycol monomethyl ether acetate, 15 wt% cyclohexanone, and 5 wt% cyclopentanone.

[0078] Compare with Example 1.

[0079] Individual compounds were injected into a container to prepare a diluent composition for removing resists, comprising: 15 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, and 30 wt% cyclohexanone. (See Table 1 below)

[0080] Compare with Example 2.

[0081] Individual compounds were injected into a container to prepare a diluent composition for removing resists, comprising: 5 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, and 40 wt% cyclohexanone. (See Table 1 below)

[0082] Compare with Example 3.

[0083] Individual compounds were injected into a container to prepare a diluent composition for removing resists, comprising: 25 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, and 20 wt% cyclohexanone. (See Table 1 below)

[0084] Compare with Example 4.

[0085] Individual compounds were injected into a container to prepare a diluent composition for removing resists, comprising: 15 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, and 30 wt% cyclopentanone. (See Table 1 below)

[0086] Compare with Example 5.

[0087] Individual compounds were injected into a container to prepare a diluent composition for removing resists, consisting of 5 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, and 40 wt% cyclopentanone (see Table 1 below).

[0088] Compare with Example 6.

[0089] Individual compounds were injected into a container to prepare a diluent composition for removing resists, comprising: 25 wt% propylene glycol monomethyl ether, 55 wt% propylene glycol monomethyl ether acetate, and 20 wt% cyclopentanone. (See Table 1 below)

[0090] [Table 1]

[0091]

[0092] Experimental Example 1: Evaluation of EBR performance.

[0093] On a silicon wafer with a diameter of 300 nm, a resist for EUV (manufacturer: TOKYO OHKA KOGYO Co., Ltd. (TOK), product name: TOEL-0140) is applied to a layer thickness of 40 nm.

[0094] Then, while rotating the resist-coated silicon wafer, approximately 7 ml of the diluent composition of Example 1 was discharged onto the edge of the wafer, and an EBR process was performed (discharge rate: 20 ml / min, discharge time: 20 seconds). The diluent compositions of Examples 2 to 9 and the diluent compositions of Comparative Examples 1 to 6 were used on additional silicon wafers in the same manner.

[0095] Next, the wafer was dried by performing a soft bake (110°C), and any bulges, edge residues, and dicing position misalignments in the resist layer of the silicon wafer were evaluated using an electron microscope (750x magnification). The results are shown in Table 2 below. Figure 1 and Figure 2 Electron micrographs of the resist layers of silicon wafers to which the diluent composition of Example 2 and the diluent composition of Comparative Example 3 were applied are shown respectively.

[0096] Evaluation criteria for bulges and residues at the edges (bulges / edge residues):

[0097] A: The case where the EBR line uniformity on the resist remains constant after EBR.

[0098] B: Cases where the uniformity of the EBR lines on the resist after EBR is 75% or greater.

[0099] C: Uneven EBR lines on the resist after EBR.

[0100] D: After EBR, the shape of the edge portion of the resist is deformed due to the dissolution effect of the diluent composition, or a tailing phenomenon occurs at the edge portion due to resist dissolution defects.

[0101] Evaluation criteria for cutting position offset:

[0102] O: The EBR linewidth of the resist cross section is less than 2.0 mm (±0.3 mm).

[0103] X: The EBR linewidth of the resist cross section is 2.0 mm (±0.3 mm) or greater.

[0104] [Table 2]

[0105]

[0106]

[0107] Referring to Table 2, the diluent compositions of Examples 1 to 3 exhibit better EBR performance against the resist compared to the diluent compositions of Comparative Examples 1 to 6. In contrast, the diluent compositions of Comparative Examples 1 to 6 show significantly reduced performance in resist removal.

[0108] refer to Figure 1 When using the diluent composition of Example 2, the uniformity of the EBR lines on the resist after EBR is regular and constant. Conversely, refer to... Figure 2 When using the diluent composition of Comparative Example 3, the uniformity of the EBR line on the resist after EBR is not uniform, and tailing occurs on the layer around the edge portion due to dissolution defects.

[0109] Regarding the diluent compositions of Examples 4 to 9, compared to the diluent compositions of Examples 1 to 3, changing the amount of the components among the four constituent substances of the diluent compositions in Table 1 reduces the resist removal performance. Compared to Comparative Examples 1 to 6, including both cyclohexanone and cyclopentanone in Examples 4 to 9 can result in improved resist removal.

[0110] Experimental Example 2: EBR Evaluation (2).

[0111] On a silicon wafer with a diameter of 300 nm, a resist for ArF (manufacturer: TOK, product name: ATONH-8390) is applied to a layer thickness of 90 nm.

[0112] Then, while rotating the resist-coated silicon wafer, approximately 7 ml of the diluent composition of Example 1 was dispensed onto the edge portion of the wafer, and an EBR process was performed (dispensing rate: 20 ml / min, dispensing time: 20 seconds). The diluent compositions of Examples 2 to 3 and the diluent compositions of Comparative Examples 1 to 6 were applied to other silicon wafers in the same manner.

[0113] The wafer was then dried by performing a soft bake (110°C), and any bulges, edge residues, and dicing position offsets in the resist layer of the silicon wafer were evaluated using an electron microscope (750x magnification). The results are shown in Table 3 below.

[0114] Evaluation criteria for bulges and residues at the edges (bulges / edge residues):

[0115] A: The uniformity of the EBR lines on the resist remains constant after EBR.

[0116] B: Cases where the uniformity of the EBR lines on the resist after EBR is 75% or greater.

[0117] C: Uneven EBR lines on the resist after EBR.

[0118] D: After EBR, the shape of the edge portion of the resist is deformed due to the dissolution effect of the diluent composition, or a tailing phenomenon occurs at the edge portion due to resist dissolution defects.

[0119] Evaluation criteria for cutting position offset:

[0120] O: The EBR linewidth of the resist cross section is less than 2.0 mm (±0.3 mm).

[0121] X: The EBR linewidth of the resist cross section is 2.0 mm (±0.3 mm) or greater.

[0122] [Table 3]

[0123] Raised / edge residue Cutting position Example 1 A O Example 2 A O Example 3 A O Comparison Example 1 C O Comparison Example 2 C O Comparison Example 3 D O Comparison Example 4 C O Comparison Example 5 C O Comparison Example 6 D O

[0124] Referring to Table 3, the diluent compositions of Examples 1 to 3 exhibit better EBR performance for the resist used in ArF compared to the diluent compositions of Comparative Examples 1 to 6. In contrast, the performance of the diluent compositions of Comparative Examples 1 to 6 is reduced in terms of resist removal.

[0125] The embodiments of the inventive concept have been disclosed above for illustrative purposes. Those skilled in the art will understand that various modifications, additions, and substitutions are possible without departing from the scope and spirit of the inventive concept disclosed in the appended claims.

Claims

1. A diluent composition for removing resist comprising propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, cyclohexanone, and cyclopentanone, wherein, The total amount of the combination of the cyclohexanone and the cyclopentanone is 25 wt% to 59 wt% of the diluent composition, based on the total weight of the diluent composition, the weight ratio of the cyclohexanone to the cyclopentanone being between 1 :0.1 and 1 :

10.

2. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether is one or more selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monopropyl ether, and propylene glycol monobutyl ether.

3. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether is 1 wt% to 35 wt% of the diluent composition, based on the total weight of the diluent composition.

4. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether acetate is one or more selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and propylene glycol monobutyl ether acetate.

5. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether acetate is 40 wt% to 70 wt% of the diluent composition, based on the total weight of the diluent composition.

6. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether is 15 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate is 55 wt% of the diluent composition, the cyclohexanone is 15 wt% of the diluent composition, and the cyclopentanone is 15 wt% of the diluent composition, based on the total weight of the diluent composition.

7. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether is 5 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate is 55 wt% of the diluent composition, the cyclohexanone is 20 wt% of the diluent composition, and the cyclopentanone is 20 wt% of the diluent composition, based on the total weight of the diluent composition.

8. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether is 5 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate is 45 wt% of the diluent composition, the cyclohexanone is 25 wt% of the diluent composition, and the cyclopentanone is 25 wt% of the diluent composition, based on the total weight of the diluent composition.

9. The diluent composition for removing resist according to claim 1, wherein, The propylene glycol monoalkyl ether is 2 wt% to 30 wt% of the diluent composition, based on the total weight of the diluent composition.

10. The diluent composition for removing a resist according to claim 1, wherein, The propylene glycol monoalkyl ether acetate is 45 wt% to 55 wt% of the diluent composition, based on the total weight of the diluent composition.

11. The diluent composition for removing a resist according to claim 1, wherein, The total amount of the combination of the cyclohexanone and the cyclopentanone is 25 wt% to 45 wt% of the diluent composition, based on the total weight of the diluent composition.

12. A method of processing a surface of a semiconductor substrate, the method comprising: applying a photoresist on the semiconductor substrate; and performing an EBR process for removing the photoresist formed on the edge and / or back surface of the substrate by spraying a diluent composition comprising a propylene glycol monoalkyl ether, a propylene glycol monoalkyl ether acetate, a cyclohexanone, and a cyclopentanone; wherein the total amount of the combination of the cyclohexanone and the cyclopentanone is 25 wt% to 59 wt% of the diluent composition, the weight ratio of the cyclohexanone to the cyclopentanone being between 1 :0.1 and 1 :

10.

13. The method of claim 12, wherein the method is performed in a single processing chamber. The photoresist is a photoresist for EUV, a photoresist for KrF, or a photoresist for ArF.

14. The method of claim 12, wherein the method is performed in a single processing chamber. The propylene glycol monoalkyl ether comprises 1 wt% to 35 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate comprises 40 wt% to 70 wt% of the diluent composition, based on the total weight of the diluent composition.

15. The method of claim 12, wherein the method is performed in a single wafer processing system. The propylene glycol monoalkyl ether comprises 15 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate comprises 55 wt% of the diluent composition, the cyclohexanone comprises 15 wt% of the diluent composition, and the cyclopentanone comprises 15 wt% of the diluent composition, based on the total weight of the diluent composition.

16. The method of claim 12, wherein the method is performed in a single processing chamber. The propylene glycol monoalkyl ether comprises 5 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate comprises 55 wt% of the diluent composition, the cyclohexanone comprises 20 wt% of the diluent composition, and the cyclopentanone comprises 20 wt% of the diluent composition, based on the total weight of the diluent composition.

17. The method of claim 12, wherein the method is performed in a single wafer processing system. The propylene glycol monoalkyl ether comprises 5 wt% of the diluent composition, the propylene glycol monoalkyl ether acetate comprises 45 wt% of the diluent composition, the cyclohexanone comprises 25 wt% of the diluent composition, and the cyclopentanone comprises 25 wt% of the diluent composition, based on the total weight of the diluent composition.

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