Substrate processing method

Abstract

The present invention provides a substrate processing method for forming a mask of a positive pattern.　The substrate processing method includes: a step for preparing a substrate which has a photoresist film that contains a metal oxide containing a first metal element; a step for performing light exposure processing on the substrate so as to form an exposed part and an unexposed part in the photoresist film; a step for supplying a metal-containing gas which contains a second metal element that is different from the first metal element to the substrate so as to form a metal oxide film that contains the second metal element on the exposed surface of the unexposed part; and a step for removing the exposed part of the photoresist film using the metal oxide film as a mask.

Description

Substrate processing method

[0001] The present disclosure relates to a substrate processing method.

[0002] Patent Document 1 discloses a method for manufacturing a semiconductor device, which comprises the steps of depositing an organic insulating film on a semiconductor substrate, selectively forming a silylated layer on the organic insulating film, and etching the organic insulating film using the silylated layer as a mask to form recesses in the organic insulating film that will become connection holes or wiring grooves.

[0003] Japanese Patent Application Laid-Open No. 2001-168192

[0004] In one aspect, the present disclosure provides a substrate processing method for forming a positive patterned mask.

[0005] In order to solve the above problem, there is provided a substrate processing method comprising the steps of: preparing a substrate having a photoresist film containing a metal oxide containing a first metal element; subjecting the substrate to an exposure process to form exposed and unexposed portions in the photoresist film; 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 exposed surface of the unexposed portion; and removing the exposed portion of the photoresist film using the metal oxide film as a mask.

[0006] According to one aspect, a substrate processing method for forming a positive pattern mask can be provided.

[0007] 1. A flowchart showing an example of a substrate processing method according to a first embodiment. 2. An example of a schematic view of a substrate in each process. 3. An example of a schematic view of a substrate in each process. 4. An example of a schematic view of a substrate in each process. 5. An example of a schematic view of a substrate in each process. 6. An example of a schematic view of a substrate in each process. 7. An example of a schematic view of a substrate in each process. 8. An example of a schematic view of a substrate in each process. 9. An example of a schematic view of a substrate in each process. 10. An example of a schematic view of a substrate in each process. 11. A schematic view of a substrate in each process. 12. An example of a schematic view of a substrate in each process. 13. An example of a schematic view of a substrate in each process. 14. An example of a schematic view of a substrate in each process. 15. An example of a schematic view of a substrate in each process.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] First Embodiment An example of a substrate processing method according to a first embodiment will be described with reference to FIGS. 1 to 6B. FIG. 1 is a flowchart showing an example of a substrate processing method according to the first embodiment. FIGS. 2 to 6B are exemplary schematic diagrams of a substrate in each process. FIG. 2 is a schematic cross-sectional view of the substrate. In addition, in FIGS. 3A and 3B, FIG. 3B is a schematic view of the substrate viewed from above. FIG. 3A is a schematic cross-sectional view taken along line A-A in FIG. 3B. Similarly, in FIGS. 4A and 4B, FIG. 4B is a schematic view of the substrate viewed from above. FIG. 4A is a schematic cross-sectional view taken along line A-A in FIG. 4B. In FIGS. 5A and 5B, FIG. 5B is a schematic view of the substrate viewed from above. FIG. 5A is a schematic cross-sectional view taken along line A-A in FIG. 5B. In FIGS. 6A and 6B, FIG. 6B is a schematic view of the substrate viewed from above. FIG. 6A is a schematic cross-sectional view taken along line A-A in FIG. 6B. Although FIGS. 3B, 4B, 5B, and 6B are views seen from above, each configuration is illustrated with hatching similar to that of the cross sections of FIGS. 3A, 4A, 5A, and 6A.

[0010] In step S101, a substrate is prepared. Here, the prepared substrate includes an underlayer film 310 (see FIG. 2). The underlayer film 310 is a film disposed under a photoresist film 320 (see FIG. 2), which will be described later. The underlayer film 310 is a film onto which an opening pattern of a mask 320A (see FIGS. 6A and 6B), which will be described later and on which a pattern of openings 325 has been formed, is transferred by etching. The underlayer film 310 may be, for example, a silicon-containing film (e.g., a spin-on-glass (SOG) film) or a carbon-containing film (e.g., a spin-on-carbon (SOC) film). The underlayer film 310 may also be a laminated film in which multiple films, such as silicon-containing films and carbon-containing films, are stacked. The laminated underlayer film 310 may also include a film such as a bottom anti-reflective coating (BARC). The underlayer film 310 may also be a film used as, for example, a hard mask.

[0011] In step S102, the substrate is subjected to a process of forming a photoresist film 320. Fig. 2 is a schematic diagram of an example of the substrate after the photoresist film 320 has been formed.

[0012] Here, a photoresist film 320 is formed on an underlayer film 310. The photoresist film 320 is a film containing a metal oxide containing a first metal element. The photoresist film 320 may be a metal oxide resist containing the first metal element, or a resin resist (chemically amplified resist (CAR)) using a metal oxide containing the first metal element as a sensitizer, but is not limited thereto. Here, the first metal element includes one or more of Sn, W, Te, Zn, Zr, Sb, In, etc. The metal oxide may be, for example, SnO ｘ (x is any number), WO ｘ (x is an arbitrary number), TeO ｘ (x is an arbitrary number), ZnO ｘ (x is an arbitrary number), ZrO ｘ (x is an arbitrary number), SbO ｘ (x is an arbitrary number), InO ｘ(x is any number), etc. Furthermore, the valence or oxidation number of the first metal element in the photoresist film 320 is changed by exposure to EUV (Extreme Ultraviolet) in an exposure process (see S103) described below. Furthermore, the photoresist film 320 is a negative photoresist film.

[0013] In step S103, the substrate is subjected to an exposure process. Figures 3A and 3B are schematic diagrams showing an example of the substrate after the exposure process.

[0014] Here, EUV light is irradiated onto a photoresist film 320 on the substrate through a photomask (not shown) having a predetermined pattern in a nitrogen atmosphere. As a result, as shown in FIGS. 3A and 3B , an exposed portion 321 irradiated with EUV light and an unexposed portion 322 not irradiated with EUV light are formed in the photoresist film 320. As shown in FIGS. 10A and 10B (described later), the photoresist film 320 may have a reaction layer 321 a (fully exposed portion) formed at the center of the exposed portion 321 and an unreacted material-containing layer 321 b (intermediately exposed portion) formed at the outer periphery of the exposed portion 321. The reaction layer 321 a is a region that has been sufficiently exposed to EUV light and in which the valence or oxidation number of the first metal element has changed due to EUV light. The unreacted material-containing layer 321 b is a region that has not been sufficiently exposed to EUV light and in which the first metal element remains partially unchanged in valence or oxidation number. In the unexposed portion 322, the first metal element has not been exposed to EUV and the valence or oxidation number has not changed, so it remains.

[0015] In step S104, a process for selectively depositing a metal oxide film 330 is performed on the upper surface (exposed surface) of the unexposed portion 322 of the photoresist film 320. FIGS. 4A and 4B are exemplary schematic diagrams of the substrate after the selective deposition process for the metal oxide film 330. The process for selectively depositing the metal oxide film 330 will be described later with reference to FIGS. 7 and 8 . As a result, the metal oxide film 330 is deposited on the upper surface of the unexposed portion 322. In addition, when the exposed portion 321 has a reaction layer 321a (fully exposed portion) and an unreacted substance-containing layer 321b (intermediately exposed portion), the metal oxide film 330 is deposited on the upper surfaces of the unexposed portion 322 and the unreacted substance-containing layer 321b (intermediately exposed portion).

[0016] In step S105, a resist etching process is performed. Figures 5A and 5B are schematic diagrams of an example of the substrate after the resist etching process.

[0017] Here, the photoresist film 320 is etched using the metal oxide film 330 as a mask. As a result, the exposed portion 321 is etched to form a mask 320A having an opening 325. Note that, when the exposed portion 321 has a reaction layer 321a (completely exposed portion) and an unreacted substance-containing layer 321b (intermediately exposed portion), the reaction layer 321a (completely exposed portion) is etched to form the mask 320A having the opening 325.

[0018] In step S106, a metal oxide film etching process is performed. Figures 6A and 6B are schematic diagrams of an example of the substrate after the metal oxide film etching process. Here, the metal oxide film 330 is removed by the etching process. Note that if the metal oxide film 330 does not affect other processes, the process of step S106 may be omitted.

[0019] 2, a mask 320A can be formed on the substrate, with the exposed portion in the exposure process (S103) being the opening 325. That is, a positive pattern mask 320A can be formed on the substrate.

[0020] Next, the process shown in step S104 will be described with reference to FIGS.

[0021] First, an example of a substrate processing apparatus that performs the processing shown in step S104 on a substrate W will be described with reference to Fig. 7. Fig. 7 is a schematic view showing an example of the substrate processing apparatus.

[0022] The substrate processing apparatus includes a processing chamber 1 , a mounting table 2 , a shower head 3 , an exhaust unit 4 , a gas supply unit 5 , and a control unit 6 .

[0023] The processing vessel 1 is made of a metal such as aluminum and has a generally cylindrical shape. The processing vessel 1 accommodates a substrate W. A loading / unloading port 11 is formed in a sidewall of the processing vessel 1 for loading and unloading the substrate W. The loading / unloading port 11 is opened and closed by a gate valve 12. An annular exhaust duct 13 having a rectangular cross section is provided on the main body of the processing vessel 1. A slit 13a is formed along the inner peripheral surface of the exhaust duct 13. An exhaust port 13b is formed in the outer wall of the exhaust duct 13. A ceiling wall 14 is provided on the upper surface of the exhaust duct 13 to close the upper opening of the processing vessel 1. A seal ring 15 hermetically seals the space between the exhaust duct 13 and the ceiling wall 14.

[0024] The mounting table 2 horizontally supports the substrate W within the processing chamber 1. The mounting table 2 has a disk shape larger than the substrate W and is made of a ceramic material such as aluminum nitride (AlN) or a metal material such as an aluminum or nickel alloy. A heater 21 for heating the substrate W is embedded inside the mounting table 2. The heater 21 generates heat when power is supplied from a heater power supply (not shown). The output of the heater 21 is controlled by a temperature signal from a thermocouple (not shown) provided near the top surface of the mounting table 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 table 2 to cover the outer periphery of the top surface and the side surfaces.

[0025] The mounting table 2 is supported by a support member 23. The support member 23 extends from the center of the bottom surface of the mounting table 2 to below the processing vessel 1, passing through a hole formed in the bottom wall of the processing vessel 1, and its lower end is connected to a lifting mechanism 24. The lifting mechanism 24 moves the mounting table 2 up and down between a processing position indicated by a solid line in FIG. 7 and a transfer position indicated by a two-dot chain line below that where a substrate W can be transferred. A flange 25 is attached to the support member 23 below the processing vessel 1. A bellows 26 is provided between the bottom surface of the processing vessel 1 and the flange 25. The bellows 26 separates the atmosphere inside the processing vessel 1 from the outside air and expands and contracts as the mounting table 2 is raised and lowered.

[0026] Three wafer support pins 27 (only two are shown) are provided near the bottom of the processing vessel 1 so as to protrude upward from a lift plate 27a. The wafer support pins 27 are raised and lowered via the lift plate 27a by a lift mechanism 28 provided below the processing vessel 1. The wafer support pins 27 are inserted into through holes 2a provided in the mounting table 2 at the transfer position, and are capable of protruding and retracting from the upper surface of the mounting table 2. By raising and lowering the wafer support pins 27, the substrate W is transferred between a transfer robot (not shown) and the mounting table 2.

[0027] The showerhead 3 supplies a processing gas into the processing chamber 1 in a shower-like manner. The showerhead 3 is made of, for example, a metal material and is disposed facing the mounting table 2. The showerhead 3 has approximately the same diameter as the mounting table 2. The showerhead 3 includes a main body 31 and a shower plate 32. The main body 31 is fixed to the lower surface of the ceiling wall 14. The shower plate 32 is connected below the main body 31. A gas diffusion space 33 is formed between the main body 31 and the shower plate 32. A gas introduction hole 36 is provided in the gas diffusion space 33 so as to penetrate through the center of the ceiling wall 14 and the main body 31. A downwardly protruding annular protrusion 34 is formed on the periphery of the shower plate 32. A number of gas discharge holes 35 are formed on the flat surface of the shower plate 32 on the inner side of the annular protrusion 34.

[0028] When the mounting table 2 is in the processing position, a processing space 38 is formed between the mounting table 2 and the shower plate 32, and the upper surface of the cover member 22 and the annular protrusion 34 are close to each other to form an annular gap 39.

[0029] The exhaust unit 4 exhausts the inside of the processing vessel 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 exhausts gases inside the processing vessel 1 via the exhaust duct 13 and the exhaust pipe 41.

[0030] The gas supply unit 5 supplies various gases to the shower head 3. The gas supply unit 5 has a gas supply source 51. The gas supply source 51 supplies various processing gases from the gas outlet holes 35 through the gas introduction holes 36 and the gas diffusion space 33 to the processing space 38.

[0031] The control unit 6 is, for example, a computer, and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls the operation of the substrate processing apparatus. The control unit 6 may be provided inside or outside the substrate processing apparatus. When the control unit 6 is provided outside the substrate processing apparatus, the control unit 6 can control the substrate processing apparatus via a communication network, such as a wired or wireless communication network.

[0032] Next, an example of a film formation process in the substrate processing apparatus will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of a film formation process in the substrate processing apparatus.

[0033] In step S201, a substrate is prepared. Here, the substrate to be prepared has a photoresist film 320 having an exposed portion 321 and an unexposed portion 322, as shown in FIGS. 3A and 3B.

[0034] In 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 chamber 1. The second metal element includes one or more of Al, Ti, Ga, Ru, Hf, and, only if not used as the first metal element, Sn, W, Te, Zn, Zr, Sb, In, etc. In other words, when any of "Sn, W, Te, Zn, Zr, Sb, In" is selected as the first metal element, the second metal element may be selected from "Al, Ti, Ga, Ru, Hf" and "Sn, W, Te, Zn, Zr, Sb, In" excluding the element selected as the first metal element. Examples of the metal-containing gas containing the second metal element include TMA (trimethylaluminum), TDMAT (tetrakis(dimethylamino)titanium), TEGa (triethylgallium), and Ru. ３ CO １２ The temperature is set to be lower than the temperature at which the metal-containing gas forms a film by thermal decomposition, thereby suppressing the formation of the metal oxide film 330 on the upper surface of the exposed portion 321 .

[0035] Meanwhile, on the upper surface of the unexposed portion 322, the first metal element remaining in the unexposed portion 322, whose valence or oxidation number has not changed, acts as a catalyst to react with a metal-containing gas containing a second metal element, decomposing the precursor of the metal-containing gas, and selectively forming a metal oxide film (metal-containing film) 330 on the upper surface of the unexposed portion 322.

[0036] In step S203, an inert gas is supplied to the substrate. The control unit 6 controls the gas supply unit 5 to supply the inert gas into the processing chamber 1. The inert gas is a gas that is inert to the photoresist film 320 and the metal-containing gas. The inert gas is nitrogen (N ２ The gas includes at least one of Ar gas, Ar gas, He gas, etc. Here, the metal-containing gas physically adsorbed on the upper surface of the exposed portion 321, etc. is purged with an inert gas.

[0037] 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 processes have not been repeated the predetermined number of times (S204: NO), the control unit 6 returns to step S202 and repeats the process. Here, when the thickness of the metal oxide film 330 reaches a predetermined thickness (e.g., approximately 1 nm), the catalytic effect of the unexposed portion 322 disappears, and the growth of the metal oxide film 330 stops. This allows the thickness of the metal oxide film 330 to be suitably controlled. Then, if the processes have been repeated the predetermined number of times (S204: YES), the control unit 6 ends the process.

[0038] 8, the metal oxide film 330 can be selectively formed on the upper surface of the unexposed portion 322 relative to the upper surface of the exposed portion 321. When the exposed portion 321 has a reaction layer 321a (completely exposed portion) and an unreacted substance-containing layer 321b (intermediately exposed portion), the metal oxide film 330 can be selectively formed on the upper surfaces of the unexposed portion 322 and the unreacted substance-containing layer 321b (intermediately exposed portion) relative to the upper surface of the reaction layer 321a (completely exposed portion).

[0039] In step S202, 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 the second metal element on the upper surfaces of the unexposed portion 322 and the unreacted material-containing layer 321b. However, this is not limited to this. Instead of a metal-containing gas, a semiconductor gas containing one or more semiconductor raw materials (semiconductor elements) of Si, B, Ge, Se, etc. may be supplied into the processing chamber 1 as a precursor gas (film-forming gas) to form a semiconductor film (not shown) containing a semiconductor raw material (semiconductor element) different from the first metal element on the upper surfaces of the unexposed portion 322 and the unreacted material-containing layer 321b. That is, in step S202, either a metal-containing gas containing the second metal element or a semiconductor gas containing a semiconductor raw material may be supplied. This may result in selective deposition of a semiconductor film (not shown) containing a semiconductor raw material (semiconductor element) on the upper surfaces of the unexposed portion 322 and the unreacted material-containing layer 321b. Furthermore, the present invention is not limited to this, and in step S202, both a metal-containing gas containing the second metal element and a semiconductor gas containing a semiconductor raw material may be supplied.

[0040] Second Embodiment An example of a substrate processing method according to a second embodiment will be described with reference to FIGS. 9 to 14B . FIG. 9 is a flowchart illustrating an example of a substrate processing method according to the second embodiment. FIGS. 10A to 14B are exemplary schematic diagrams of a substrate in each process. In FIGS. 10A and 10B , FIG. 10B is a schematic diagram of the substrate viewed from above. FIG. 10A is a schematic cross-sectional view taken along line A-A in FIG. 10B . Similarly, in FIGS. 11A and 11B , FIG. 11B is a schematic diagram of the substrate viewed from above. FIG. 11A is a schematic cross-sectional view taken along line A-A in FIG. 11B . In FIGS. 12A and 12B , FIG. 12B is a schematic diagram of the substrate viewed from above. FIG. 12A is a schematic cross-sectional view taken along line A-A in FIG. 12B . In FIGS. 13A and 13B , FIG. 13B is a schematic diagram of the substrate viewed from above. Fig. 13A is a schematic cross-sectional view taken along line A-A in Fig. 13B. In Figs. 14A and 14B, Fig. 14B is a schematic view of the substrate viewed from above. Fig. 14A is a schematic cross-sectional view taken along line A-A in Fig. 14B. Although Figs. 10B, 11B, 12B, 13B, and 14B are views viewed from above, each configuration is illustrated with hatching similar to that in the cross sections of Figs. 10A, 11A, 12A, 13A, and 14A.

[0041] In step S301, a substrate is prepared. Here, the prepared substrate includes an underlayer film 310 (see FIG. 2). The underlayer film 310 is a film disposed under a photoresist film 320 (see FIG. 2), which will be described later. The underlayer film 310 is a film onto which an opening pattern of a mask is transferred by etching using a metal oxide film 330 (see FIGS. 14A and 14B), on which a pattern of openings 335, which will be described later, is formed, as a mask. The underlayer film 310 may be, for example, a silicon-containing film (e.g., a spin-on-glass (SOG) film) or a carbon-containing film (e.g., a spin-on-carbon (SOC) film). The underlayer film 310 may also be a laminated film in which multiple films, such as silicon-containing films and carbon-containing films, are stacked. The laminated underlayer film 310 may also include a film such as a bottom anti-reflective coating (BARC). The underlayer film 310 may also be a film used as, for example, a hard mask.

[0042] In step S302, the substrate is subjected to a process of forming a photoresist film 320. Fig. 2 is a schematic diagram of an example of the substrate after the photoresist film 320 has been formed.

[0043] Here, a photoresist film 320 is formed on an underlayer film 310. The photoresist film 320 is a film containing a metal oxide containing a first metal element. The photoresist film 320 may be a metal oxide resist containing the first metal element, or a resin resist (chemically amplified resist (CAR)) using a metal oxide containing the first metal element as a sensitizer, but is not limited thereto. Here, the first metal element includes one or more of Sn, W, Te, Zn, Zr, Sb, In, etc. The metal oxide may be, for example, SnO ｘ (x is any number), WO ｘ (x is an arbitrary number), TeO ｘ (x is an arbitrary number), ZnO ｘ (x is an arbitrary number), ZrO ｘ (x is an arbitrary number), SbO ｘ (x is an arbitrary number), InO ｘ (x is any number), etc. Furthermore, the valence or oxidation number of the first metal element in the photoresist film 320 is changed by exposure to EUV (Extreme Ultraviolet) in an exposure process (see S103) described below. Furthermore, the photoresist film 320 is a negative photoresist film.

[0044] In step S303, the substrate is subjected to an exposure process. Figures 10A and 10B are schematic diagrams showing an example of the substrate after the exposure process.

[0045] Here, in a nitrogen atmosphere, EUV is irradiated onto a photoresist film 320 on the substrate through a photomask (not shown) having a predetermined pattern. As a result, as shown in FIGS. 10A and 10B , an exposed portion 321 irradiated with EUV and an unexposed portion 322 not irradiated with EUV are formed in the photoresist film 320. Here, as shown in FIGS. 10A and 10B , the photoresist film 320 is formed with a reaction layer 321 a (fully exposed portion) at the center of the exposed portion 321 and an unreacted material-containing layer 321 b (intermediately exposed portion) at the outer periphery of the exposed portion 321. The reaction layer 321 a is a region that has been sufficiently exposed to EUV and in which the valence or oxidation number of the first metal element has changed due to EUV. The unreacted material-containing layer 321 b is a region that has not been sufficiently exposed to EUV, in which the first metal element remains partially unchanged in valence or oxidation number. In the unexposed portion 322, the first metal element has not been exposed to EUV and the valence or oxidation number has not changed, so it remains.

[0046] In step S304, the substrate is subjected to a development process. Figures 11A and 11B are schematic diagrams of an example of the substrate after the development process.

[0047] Here, the unexposed portion 322 of the photoresist film 320 and a portion of the unreacted substance-containing layer 322b are selectively removed by a development process. The development process can be performed using at least one of a wet process and a dry process. As a result, as shown in FIGS. 11A and 11B, the photoresist film 320 (see FIG. 2) becomes a photoresist film 320B having a pattern of openings 325. Note that the sidewalls of the openings 325 in the photoresist film 320B are formed by the remaining portions of the unreacted substance-containing layer 322b.

[0048] In step S305, a process is performed to selectively form a metal oxide film 330 on the sidewall of the opening 325 of the photoresist film 320B.

[0049] First, a process is performed to selectively form a metal oxide film 330 on the sidewall of the opening 325 in the photoresist film 320B. Figures 12A and 12B are schematic diagrams of an example of the substrate after selectively forming the metal oxide film 330. Here, by the process shown in Figure 8, the metal oxide film 330 can be selectively formed on the exposed surface (sidewall of the opening 325) of the unreacted-substance-containing layer 321b (intermediately exposed portion) relative to the exposed surface (top surface) of the reaction layer 321a (fully exposed portion).

[0050] Next, a process for growing a metal oxide film 330 formed on the sidewall of the opening 325 in the photoresist film 320B is performed. FIGS. 13A and 13B are schematic diagrams of an example of the substrate after the growth of the metal oxide film 330. Here, a metal-containing gas and a reactive gas (oxidizing gas) are alternately supplied to the substrate to grow the metal oxide film 330 by atomic layer deposition (ALD), thereby filling the opening 325 in the photoresist film 320B. Alternatively, the metal oxide film 330 may be selectively grown laterally starting from the metal oxide film 330 formed on the sidewall of the opening 325 in step S305. The method for filling the opening 325 in the photoresist film 320B with the metal oxide film 330 is not limited to this. For example, a flowable film may be used to fill the opening 325 from the bottom.

[0051] The metal-containing gas may be the same as the gas supplied in step S202. The metal contained in the metal-containing gas may be any of B, Al, Si, Ti, V, Mn, Fe, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Pd, In, Sb, Te, Hf, Ta, W, Pt, and Bi. The oxidizing gas may be water vapor, oxygen, or ozone.

[0052] In step S306, a resist etching process is performed. Figures 14A and 14B are schematic diagrams of an example of the substrate after the resist etching process.

[0053] Here, the photoresist film 320B is removed by etching, thereby forming the metal oxide film 330 having the opening 335. The etching gas is H ２, HF, HCl, HBr, HI, F ２ , Cl ２ ,Br ２ , I ２ , BCl ３ , CH4, C ｘ -Hy, C ｘ -Cly, C ｘ -Br, organic acids (carboxylic acid gas, etc.), halosilane (Si-Cl ｘ , Si—H ｘ -Cly) (where x and y are arbitrary numbers).

[0054] 9, the metal oxide film 330 can be formed on the substrate as a mask, with the exposed portion of the metal oxide film 330 having the opening 335 in the exposure process (S303). That is, a positive pattern mask (metal oxide film 330 having the opening 335) can be formed on the substrate.

[0055] 7 has been described as an apparatus that performs the selective film formation process (S104, S305), but is not limited to this. The substrate processing apparatus shown in FIG. 7 may be configured to perform one or more of the development process (S304) and the etching process (S105, S106, S306) in addition to the selective film formation process (S104, S305).

[0056] In addition, the apparatus for performing the selective film formation process (S104, S305), the apparatus for performing the development process (S304), and the apparatus for performing the etching process (S105, S106, S306) may each be configured as separate apparatuses, and the substrate processing apparatus may be configured such that these apparatuses are connected by the same transport apparatus.

[0057] The substrate processing method according to the present embodiment has been described above, but the present disclosure is not limited to the above embodiment, and various modifications and improvements are possible within the scope of the gist of the present disclosure as set forth in the claims.

[0058] This application claims priority based on Japanese Patent Application No. 2024-002841, filed on January 11, 2024, the entire contents of which are incorporated herein by reference.

[0059] 310 Undercoat film 320, 320B Photoresist film 320A Mask 321 Exposed portion 321a Reacted layer 321b Unreacted substance-containing layer 322 Unexposed portion 325 Opening 330 Metal oxide film 335 Opening

Claims

1. A substrate processing method, comprising: preparing a substrate having a photoresist film containing a metal oxide containing a first metal element; performing an exposure process on the substrate to form an exposed portion and an unexposed portion on the photoresist film; 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 exposed surface of the unexposed portion; and removing the exposed portion of the photoresist film using the metal oxide film as a mask.

2. The substrate processing method according to claim 1, wherein the exposure process is performed by exposing with extreme ultraviolet light to form the exposed portion and the unexposed portion on the photoresist film, and the exposed portion includes a reaction layer which is a region where the valence or oxidation number of the first metal element is changed by the extreme ultraviolet light, and an unreacted substance-containing layer which is a region where the first metal element whose valence or oxidation number has not changed remains.

3. The substrate processing method according to claim 2, wherein the step of forming the metal oxide film forms the metal oxide film containing the second metal element on the exposed surfaces of the unexposed portion and the unreacted substance-containing layer using the first metal element whose valence or oxidation number has not changed in the unexposed portion and the unreacted substance-containing layer as a catalyst.

4. A substrate processing method, comprising: preparing a substrate having a photoresist film containing a metal oxide containing a first metal element; performing an exposure process and a development process on the substrate to form an opening pattern on the photoresist film; 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 from the sidewall of the opening of the photoresist film; and removing the photoresist film.

5. The substrate processing method according to claim 4, wherein the exposure process is performed by exposing with extreme ultraviolet light to form an exposed portion and an unexposed portion on the photoresist film, and the exposed portion includes a reaction layer which is a region where the valence or oxidation number of the first metal element is changed by the extreme ultraviolet light, and an unreacted substance-containing layer which is a region where the first metal element whose valence or oxidation number has not changed remains.

6. The substrate processing method according to claim 5, wherein the development process removes a part of the unexposed portion and the unreacted substance-containing layer.

7. The method for substrate processing according to claim 6, wherein the step of forming the metal oxide film forms the metal oxide film containing the second metal element on the exposed surface of the unreacted material-containing layer, using the first metal element whose valence or oxidation number has not changed in the unreacted material-containing layer as a catalyst.

8. The method for substrate processing according to claim 3 or 7, further comprising a step of supplying an inert gas to the substrate after the step of forming the metal oxide film.

9. The method for substrate processing according to claim 7, wherein the step of forming the metal oxide film includes a step of supplying a metal-containing gas containing the second metal element to form the metal oxide film containing the second metal element on the exposed surface of the unreacted material-containing layer, and a step of alternately supplying the metal-containing gas containing the second metal element and an oxidation gas to grow the metal oxide film.

10. The method for substrate processing according to claim 1 or 4, wherein the first metal element includes any one of Sn, W, Te, Zn, Zr, Sb, and In.

11. The method for substrate processing according to claim 1 or 4, wherein the second metal element includes any one of Al, Ti, Ga, Ru, Hf, and Sn, W, Te, Zn, Zr, Sb, and In only when not used as the first metal element.

12. The method for substrate processing according to claim 1, having a step of supplying a semiconductor gas containing a semiconductor raw material to the substrate to form a semiconductor film containing the semiconductor raw material different from the first metal element on the sidewall of the photoresist film, instead of the step of forming the metal oxide film containing the second metal element.

13. The method for substrate processing according to claim 12, wherein the semiconductor raw material includes any one of Si, B, Ge, and Se.

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