Substrate processing method and substrate processing apparatus

Abstract

Provided are a substrate processing method and a substrate processing apparatus for improving the pattern of a photoresist film. A substrate processing method includes: a step of preparing a substrate having a photoresist film containing a metal oxide containing a first metal element; a step for forming an opening pattern in the photoresist film by subjecting the substrate to an exposure process and a development process; and a step of supplying a metal-containing gas containing a second metal element different from the first metal element to the substrate, and forming a metal oxide film containing the second metal element on the side wall of the photoresist film.

Description

Technical Field

[0001] This invention relates to a substrate processing method and a substrate processing apparatus. Background Technology

[0002] Patent document 1 discloses a substrate processing method, which includes: a deposition stage in which a deposition layer is deposited on an exposed surface of an etch mask feature (etch mask feature) containing vertical sidewalls; and an etching stage in which the deposition layer is selectively etched back onto the vertical sidewalls to leave residual deposition.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2008-524851. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In one aspect, the present invention provides a substrate processing method and a substrate processing apparatus for improving the patterning of photoresist films.

[0008] Technical means for solving problems

[0009] To address the aforementioned problems, a substrate processing method is provided, comprising: preparing a substrate having a photoresist film, the photoresist film comprising a metal oxide containing a first metal element; performing exposure and development processing on the substrate to form an opening pattern in the photoresist film; and supplying a metal-containing gas containing a second metal element different from the first metal element to the substrate to form a metal oxide film containing the second metal element on the sidewall of the photoresist film.

[0010] Invention Effects

[0011] According to one aspect, a substrate processing method and a substrate processing apparatus for improving the pattern of a photoresist film can be provided. Attached Figure Description

[0012] Figure 1 This is a flowchart illustrating an example of the substrate processing method of this embodiment.

[0013] Figure 2A This is an example of a cross-sectional schematic diagram of the substrate in each step.

[0014] Figure 2B This is an example of a cross-sectional schematic diagram of the substrate in each step.

[0015] Figure 2C This is an example of a cross-sectional schematic diagram of the substrate in each step.

[0016] Figure 2D This is an example of a cross-sectional schematic diagram of the substrate in each step.

[0017] Figure 3 This is a schematic diagram illustrating an example of a substrate processing apparatus.

[0018] Figure 4 This is a flowchart illustrating an example of film formation processing in a substrate processing apparatus.

[0019] Figure 5A This is an example of a cross-sectional schematic diagram of a photoresist film.

[0020] Figure 5B This is an example of a cross-sectional schematic diagram of a photoresist film.

[0021] Figure 5C This is an example of a cross-sectional schematic diagram of a photoresist film. Detailed Implementation

[0022] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals are used to label the same components, and sometimes repeated descriptions are omitted.

[0023] use Figure 1 and Figures 2A to 2D An example of the substrate processing method of this embodiment will be described. Figure 1 This is a flowchart illustrating an example of the substrate processing method of this embodiment. Figures 2A to 2D This is an example of a cross-sectional schematic diagram of the substrate in each step.

[0024] In step S101, a substrate is prepared. Here, the prepared substrate includes a base film 310 (see reference). Figure 2A The base film 310 is disposed on the photoresist film 320 described later (see reference). Figure 2A The substrate 310 is a film on which the opening pattern of the photoresist film 320 is transferred during the etching process described later (see S107). The substrate 310 can be, for example, a silicon-containing film (e.g., SOG (Spin On Glass) film), a carbon-containing film (e.g., SOC (Spin On Carbon) film), etc. Alternatively, the substrate 310 can be a laminated film containing multiple films such as silicon-containing films and carbon-containing films. Furthermore, the substrate 310, as a laminated film, can also have a bottom anti-reflective coating (BARC). The substrate 310 can, for example, be a film used as a hard mask.

[0025] In step S102, a process is performed to form a photoresist film 320 on the substrate. Figure 2A This is an example of a cross-sectional schematic diagram of a substrate after the formation of the photoresist film 320.

[0026] Here, a photoresist film 320 is formed on the base film 310. The photoresist film 320 is a film containing a metal oxide comprising a first metal element. Alternatively, the photoresist film 320 can be a metal oxide resist containing a first metal element, or a resin resist (chemically amplified resist (CAR)) using a metal oxide containing a first metal element as a sensitizer; there is no limitation on this. Here, the first metal element includes any one or more of Sn, W, Te, Zn, Zr, Sb, In, etc. The metal oxide can be, for example, SnO. x (x is any number), WO x (x is any number), TeO x (x is any number), ZnO x (x is any number), ZrO x (x is any number), SbO x (x is any number), InO x (x is any number) etc. Furthermore, in the exposure process described later (refer to S103), the valence of the first metal element changes due to exposure to EUV (Extreme Ultraviolet). Additionally, the photoresist film 320 is a negative photoresist film.

[0027] In step S103, the substrate is exposed. Figure 2B This is an example of a cross-sectional schematic diagram of a substrate after exposure processing.

[0028] Here, under a nitrogen atmosphere, EUV is applied to the photoresist film 320 of the substrate through a photomask (not shown) with a prescribed pattern. Thus, as... Figure 2B As shown, an exposed portion 321 that has been irradiated with EUV and an unexposed portion 322 that has not been irradiated with EUV are formed on the photoresist film 320.

[0029] In step S104, the substrate is subjected to a development process. Figure 2C This is an example of a cross-sectional schematic diagram of a substrate after development.

[0030] Here, the unexposed portions 322 of the photoresist film 320 are selectively removed by a developing process. The developing process can be at least one of wet or dry processing. Thus, as... Figure 2C As shown, photoresist film 320 (reference) Figure 2AThis forms a photoresist film 320A with an opening pattern 325. Here, the width of the photoresist film 320A is greater than the width of the exposure portion 321 (see...). Figure 2C (The dotted line in the middle) is small.

[0031] In step S105, the substrate is annealed. Here, the annealing process removes impurities such as those adhering to the sidewalls of the photoresist film 320. Furthermore, the annealing temperature is set at the temperature of the modified layer 321b1 (see reference 1). Figure 5C The annealing process is carried out within a temperature range that does not change the function of the catalyst. In other words, the annealing temperature is within the range of the modified layer 321b1 described later (see reference). Figure 5C The annealing process involves heating within a temperature range where the valence of the first metallic element in the metal remains unchanged. The annealing temperature is, for example, in the range of 60°C to 250°C. However, annealing is not mandatory and can be omitted.

[0032] In step S106, a process is performed to selectively form a metal oxide film 330 on the sidewall of the photoresist film 320. Figure 2D This is an example of a cross-sectional schematic diagram of a substrate after the metal oxide film 330 has been formed. Furthermore, regarding the selective formation of the metal oxide film 330, the following method is used... Figure 3 , Figure 4 and Figures 5A to 5C This will be described later. Therefore, it is possible to make the width of the photoresist film 320A close to the desired width (e.g., Figure 2B The width of the EUV-irradiated exposure section 321 shown.

[0033] In step S107, an etching process is performed on the substrate. Here, the photoresist film 320 is used as a mask, and an etching gas is used to etch the base film 310. For example, if the base film 310 is an SOG film, a CF-based gas or the like is used as the etching gas. As a result, the pattern 325 of the openings in the photoresist film 320 is transferred to the base film 310, forming the pattern of openings on the base film 310.

[0034] Next, use Figure 3 , Figure 4 and Figures 5A to 5C The process shown in step S106 will be explained.

[0035] First, use Figure 3 This describes an example of a substrate processing apparatus that performs the processing shown in step S106 on substrate W. Figure 3 This is a schematic diagram illustrating an example of a substrate processing apparatus.

[0036] The substrate processing apparatus has a processing container 1, a stage 2, a nozzle 3, an exhaust unit 4, a gas supply unit 5, and a control unit 6.

[0037] The processing container 1 is made of a metal such as aluminum and has a generally cylindrical shape. The processing container 1 houses the substrate W. An inlet / outlet 11 for feeding or discharging the substrate W is formed on the side wall of the processing container 1. The inlet / outlet 11 is opened and closed by a gate valve 12. An annular exhaust pipe 13 with a rectangular cross-section is provided on the main body of the processing container 1. A slit 13a is formed along the inner circumferential surface of the exhaust pipe 13. An exhaust port 13b is formed on the outer wall of the exhaust pipe 13. A top wall 14 is provided on the upper surface of the exhaust pipe 13 to close the upper opening of the processing container 1. The exhaust pipe 13 and the top wall 14 are airtightly sealed by a sealing ring 15.

[0038] The mounting stage 2 horizontally supports the substrate W within the processing container 1. The mounting stage 2 is a circular plate larger than the substrate W and is constructed from ceramic materials such as aluminum nitride (AlN) or metallic materials such as aluminum and nickel alloys. A heater 21 for heating the substrate W is embedded inside the mounting stage 2. The heater 21 is powered by a heater power supply (not shown) and generates heat. Furthermore, the output of the heater 21 is controlled by the temperature signal from a thermocouple (not shown) located near the upper surface of the mounting stage 2, thereby controlling the substrate W to a predetermined temperature. A cover member 22 made of ceramic such as alumina is provided on the mounting stage 2 to cover the outer periphery and sides of the upper surface.

[0039] The platform 2 is supported by a support member 23. The support member 23 extends downwards from a hole formed in the bottom wall of the processing container 1 through the center of the bottom surface of the platform 2, and its lower end is connected to a lifting mechanism 24. The platform 2 is lifted by the lifting mechanism 24. Figure 3 The processing position, indicated by the solid line, moves up and down between the transport position (indicated by the double-dotted line below it) and the transport position (indicated by the double-dotted line below it) for transporting the substrate W. A flange 25 is mounted below the processing container 1 of the support member 23. A bellows 26 is provided between the bottom surface of the processing container 1 and the flange 25. The bellows 26 separates the atmosphere inside the processing container 1 from the external gas and extends and retracts as the stage 2 moves up and down.

[0040] Near the bottom surface of the processing container 1, three (two shown only) wafer support pins 27 are provided, protruding upwards from the lifting plate 27a. The wafer support pins 27 are raised and lowered via the lifting plate 27a using a lifting mechanism 28 located below the processing container 1. The wafer support pins 27 pass through a through hole 2a provided in the transport stage 2, allowing them to protrude and embed relative to the upper surface of the transport stage 2. By raising and lowering the wafer support pins 27, the substrate W is transferred between the transport robot (not shown) and the transport stage 2.

[0041] The nozzle 3 supplies processing gas into the processing container 1 in a spray pattern. The nozzle 3 is made of, for example, metal and is disposed opposite to the mounting platform 2. The nozzle 3 has a diameter approximately the same as that of the mounting platform 2. The nozzle 3 includes a main body 31 and a spray plate 32. The main body 31 is fixed to the lower surface of the top wall 14. The spray plate 32 is connected to the lower part of the main body 31. A gas diffusion space 33 is formed between the main body 31 and the spray plate 32. A gas inlet hole 36 is provided in the gas diffusion space 33, penetrating the center of the top wall 14 and the main body 31. A downwardly protruding annular protrusion 34 is formed on the periphery of the spray plate 32. A plurality of gas outlet holes 35 are formed on the flat surface inside the annular protrusion 34 of the spray plate 32.

[0042] With the platform 2 in the processing position, a processing space 38 is formed between the platform 2 and the spray plate 32, and the upper surface of the cover member 22 approaches the annular protrusion 34 to form an annular gap 39.

[0043] The exhaust unit 4 exhausts gas from the interior of the processing container 1. The exhaust unit 4 includes an exhaust pipe 41 and an exhaust mechanism 42. The exhaust pipe 41 is connected to the exhaust port 13b. The exhaust mechanism 42 is connected to the exhaust pipe 41 and includes a vacuum pump, a pressure control valve, etc. The exhaust mechanism 42 discharges the gas inside the processing container 1 through the exhaust pipe 13 and the exhaust pipe 41.

[0044] The gas supply unit 5 supplies various gases to the nozzle 3. The gas supply unit 5 has a gas supply source 51. The gas supply source 51 supplies various processing gases to the processing space 38 through the gas inlet 36 and the gas diffusion space 33 from the gas outlet 35.

[0045] The control unit 6 is, for example, a computer, equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and auxiliary storage devices. The CPU operates based on a program stored in the ROM or auxiliary storage devices, controlling the operation of the substrate processing device. The control unit 6 can be located inside or outside the substrate processing device. When the control unit 6 is located outside the substrate processing device, it can control the substrate processing device via a wired or wireless communication network.

[0046] Next, use Figure 4 An example of film formation processing using a substrate processing apparatus will be described. Figure 4 This is a flowchart illustrating an example of film formation processing in a substrate processing apparatus.

[0047] In step S201, the substrate is prepared. Here, as... Figure 2CAs shown, the prepared substrate has a base film 310 and a photoresist film 320A formed on the base film 310 and having an opening pattern 325.

[0048] Here, refer to Figure 1 And use Figure 2 Figures 5A to 5C The prepared substrate will be described. Figures 5A to 5C This is an example of a cross-sectional schematic diagram of the photoresist film 320.

[0049] Figure 5A This is an example of a cross-sectional schematic diagram of the photoresist film 320A formed in step S102.

[0050] Figure 5B This is an example of a cross-sectional schematic diagram of the photoresist film 320 after exposure treatment (S103). Here, in the exposure treatment of step S103, the dose of EUV photons is less than the dose of photons that would cause the entire exposure section 321 to react. Therefore, in the exposure section 321, a reaction layer 321a is formed on the central side of the exposure section 321, and a modification layer 321b is formed on the outer periphery side of the exposure section 321. The reaction layer 321a is the region where EUV exposure is sufficient and the valence of the first metal element changes due to EUV. The modification layer 321b is the region where EUV exposure is insufficient and some of the first metal element whose valence does not change remains.

[0051] Figure 5C This is an example of a cross-sectional schematic diagram of the photoresist film 320A after development treatment (S104). Through the development treatment, the unexposed portion 322 and a portion of the modified layer 321b are removed. Thus, a photoresist film 320A with a modified layer 321b1 on the sidewall is formed. Here, the modified layer 321b1 retains a first metal element whose valence remains unchanged.

[0052] return Figure 4In step S202, a metal-containing gas containing a second metal element different from the first metal element is supplied to the substrate as a precursor gas (film-forming gas). Here, the control unit 6 controls the gas supply unit 5 to supply the metal-containing gas containing the second metal element into the processing container 1. The second metal element includes at least one of Sn, W, Te, Zn, Zr, Sb, In, etc., when Al, Ti, Ga, Ru, Hf, and the first metal element are not used. In other words, when any one of "Sn, W, Te, Zn, Zr, Sb, In" is selected as the first metal element, the second metal element can be any element other than the element selected as the first metal element from "Al, Ti, Ga, Ru, Hf" and "Sn, W, Te, Zn, Zr, Sb, In". For example, the metal-containing gas containing the second metal element includes TMA (trimethylaluminum), TDMAT (tetra(dimethylamino)titanium), TEGa (triethylgallium), Ru3CO. 12 One or more of the following. In addition, by setting a temperature lower than the temperature at which the metal-containing gas forms a film due to thermal decomposition, the formation of the metal oxide film 330 can be suppressed on the upper surface of the photoresist film 320 and at the bottom of the opening of the photoresist film 320.

[0053] In contrast, in the modified layer 321b of the sidewall of the photoresist film 320A, the first metal element whose valence remains unchanged in the modified layer 321b1 acts as a catalyst and reacts with the metal-containing gas containing the second metal element. As a result, the precursor of the metal-containing gas is decomposed, and a metal oxide film (metal-containing film) 330 is selectively formed on the sidewall of the photoresist film 320A.

[0054] In step S203, an inactive gas is supplied to the substrate. The control unit 6 controls the gas supply unit 5 to supply the inactive gas into the processing container 1. The inactive gas is a metal-containing gas that is inactive relative to the sidewall of the photoresist film 320A. The inactive gas includes any one or more of nitrogen (N2) gas, Ar gas, and He gas. Here, the inactive gas is used to purge the metal-containing gas physically adsorbed on the upper surface of the photoresist film 320 and the bottom of the opening of the photoresist film 320 (the part exposed from the opening of the base film 310).

[0055] In step S204, the control unit 6 determines whether the processes of steps S202 and S203 have been repeated a predetermined number of times. If the predetermined number of times has not been repeated (S204, "No"), the control unit 6 returns to step S202. Here, when the thickness of the metal oxide film 330 reaches a predetermined thickness (e.g., about 1 nm), the catalytic effect of the modified layer 321b1 disappears, and the growth of the metal oxide film 330 stops. Thus, the thickness of the metal oxide film 330 can be appropriately controlled. Then, if the predetermined number of times has been repeated (S204, "Yes"), the process of the control unit 6 ends.

[0056] Furthermore, in step S202, the case where a metal-containing gas containing a second metal element is supplied as a precursor gas (film-forming gas) to form a metal oxide film 330 containing a second metal element on the sidewall of the photoresist film 320A is described, but it is not limited to this. The precursor gas (film-forming gas) can also be structured as follows: a semiconductor gas containing any one or more semiconductor materials (semiconductor elements) such as Si, B, Ge, and Se is supplied to the processing container 1 instead of the metal-containing gas, forming a semiconductor film (not shown) containing a semiconductor material (semiconductor element) different from the first metal element on the sidewall of the photoresist film 320A. That is, in step S202, either a metal-containing gas containing a second metal element or a semiconductor gas containing semiconductor materials can be supplied. Thus, a structure in which a semiconductor film (not shown) containing semiconductor materials (semiconductor elements) is selectively formed on the sidewall of the photoresist film 320A can also be formed. Furthermore, it is not limited to this; in step S202, both a metal-containing gas containing a second metal element and a semiconductor gas containing semiconductor materials can be supplied.

[0057] As described above, during the exposure process, when exposure is performed at a dose less than the desired dose of photons that would cause the exposure section 321 to react overall, the pattern formed on the photoresist film 320A becomes a width narrower than the desired width (see reference). Figure 2C and Figure 5C In contrast, according to Figure 1 and Figure 4 The substrate processing method shown allows for the formation of a photoresist film 320A with a desired width by selectively forming a metal oxide film 330 on the sidewalls of the photoresist film 320A. This improves the shape of the pattern of the openings transferred to the substrate film 310 during the etching process.

[0058] In other words, it can reduce the dose of photons in the exposure process, and improve production efficiency by reducing power consumption and exposure time.

[0059] Alternatively, the thickness of the metal oxide film 330 can be adjusted by regulating the thickness of the modified layer 321b1 and the amount of the first metal element with an unchanged valence remaining in the modified layer 321b1. Specifically, the thickness of the modified layer 321b1 and the amount of the first metal element with an unchanged valence remaining in the modified layer 321b1 can be adjusted by regulating the photon dose, exposure time, and development time in the development process.

[0060] In addition, it was explained Figure 3 The substrate processing apparatus shown is an apparatus for performing selective film formation processing (S106), but it is not limited to this. It can also be configured to utilize, in addition to selective film formation processing (S106), [other processes]. Figure 3 The substrate processing apparatus shown performs one or more of the following processes: development (S104), annealing (S105), and etching (S107).

[0061] In addition, the apparatus for developing (S104), the apparatus for annealing (S105), the apparatus for selective film formation (S106), and the apparatus for etching (S107) are each composed of different devices, or they can be substrate processing apparatuses that connect these devices using the same transport device.

[0062] The substrate processing method of this embodiment has been described above, but the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the spirit of the present invention described in the technical solution.

[0063] Furthermore, this application claims priority based on Japanese Patent Application No. 2023-141102, filed on August 31, 2023, the entire contents of which are incorporated herein by reference.

[0064] Explanation of reference numerals in the attached figures

[0065] 310 Basement membrane

[0066] 320 and 320A photoresist films

[0067] 321 Exposure Department

[0068] 321a Reaction Layer

[0069] 321b, 321b1 Modified Layer

[0070] 322 Unexposed Department

[0071] 330 Metal oxide film.

Claims

1. A substrate processing method, characterized in that, have: The step of preparing a substrate having a photoresist film, wherein the photoresist film comprises a metal oxide containing a first metal element; The step of performing exposure and development treatment on the substrate to form an opening pattern in the photoresist film; and The step of supplying a metal-containing gas containing a second metal element different from the first metal element to the substrate, and forming a metal oxide film containing the second metal element on the sidewall of the photoresist film.

2. The substrate processing method as described in claim 1, characterized in that: The exposure process utilizes extreme ultraviolet light to form exposed and unexposed areas on the photoresist film. The exposure unit includes: The reaction layer is the region where the valence of the first metallic element changes due to the extreme ultraviolet radiation; and The modified layer is the region of the first metal element whose valence remains unchanged.

3. The substrate processing method as described in claim 2, characterized in that: The developing process removes the unexposed portion and a portion of the modified layer.

4. The substrate processing method as described in claim 3, characterized in that: In the step of forming the metal oxide film Using the first metal element, whose valence remains unchanged in the modified layer, as a catalyst, a metal oxide film containing the second metal element is formed on the sidewall of the photoresist film.

5. The substrate processing method as described in claim 4, characterized in that: The thickness of the metal oxide film is adjusted based on the thickness of the modified layer and the amount of the first metal element in the modified layer whose valence remains unchanged.

6. The substrate processing method as described in claim 1, characterized in that: It also includes a step of annealing the substrate within a temperature range in which the valence of the first metal element will not change, after the step of forming the pattern of the opening in the photoresist film and before the step of forming the metal oxide film.

7. The substrate processing method as described in claim 1, characterized in that: It also includes a step of supplying an inactive gas to the substrate after the step of forming the metal oxide film.

8. The substrate processing method as described in claim 1, characterized in that: The first metallic element includes any one of Sn, W, Te, Zn, Zr, Sb, and In.

9. The substrate processing method as described in claim 1, characterized in that: The second metallic element comprises any one of the following elements: Al, Ti, Ga, Ru, Hf, and Sn, W, Te, Zn, Zr, Sb, and In, which are not used as the first metallic element.

10. The substrate processing method as described in claim 1, characterized in that: Instead of forming a metal oxide film containing the second metal element, the method involves supplying a semiconductor gas containing a semiconductor material to the substrate, and forming a semiconductor film containing the semiconductor material, which is different from the first metal element, on the sidewall of the photoresist film.

11. The substrate processing method as described in claim 10, characterized in that: The semiconductor material includes any one of Si, B, Ge, and Se.

12. A substrate processing apparatus, characterized in that, include: A stage that supports a substrate having a photoresist film, the photoresist film being patterned with openings and containing a metal oxide containing a first metal element; A processing container for housing the mounting platform; A gas supply unit that supplies gas into the processing container; and Control Department The control unit is configured to perform the following steps: supplying a metal-containing gas containing a second metal element different from the first metal element into the processing container, and forming a metal oxide film containing the second metal element on the sidewall of the photoresist film.

13. The substrate processing apparatus as described in claim 12, characterized in that: The control unit is configured to perform the step of supplying inactive gas into the processing container.

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