Substrate processing method and substrate processing system

Abstract

Provided are a substrate processing method and a substrate processing system that improve line edge roughness of a pattern formed on a base film when etching the base film using a metal oxide resist film as a mask. A substrate processing method includes a step of forming a metal oxide resist film on a substrate having a base film, a step of forming a pattern on the metal oxide resist film, a step of modifying the metal oxide resist film on which the pattern is formed, and a step of forming a pattern on the metal oxide resist film by using the modified metal oxide resist film as a mask. And a step for etching the base film.

Description

Technical Field

[0001] The invention relates to a substrate processing method and a substrate processing system. Background Art

[0002] Patent Documents 1 and 2 disclose substrate processing methods for performing patterning using a resist composed of a metal oxide in EUV lithography.

[0003] [Prior art literature]

[0004] [Patent Literature]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 305048

[0006] [Patent Document 2] U.S. Patent Application Publication No. 2020 / 326627 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] In one embodiment, the present invention provides a substrate processing method and a substrate processing system for improving the line edge roughness of a pattern formed on a base film when etching the base film using a metal oxide resist film as a mask.

[0009]

Methods to solve the problem

[0010] In order to solve the above-mentioned problems, according to one embodiment, a substrate processing method can be provided, which includes: a process of forming a metal oxide resist film on a substrate having a base film, a process of forming a pattern on the metal oxide resist film, a process of modifying the metal oxide resist film having the pattern formed thereon, and a process of etching the base film using the modified metal oxide resist film as a mask.

[0011] [Effects of the invention]

[0012] According to one aspect, a substrate processing method and a substrate processing system can be provided, wherein when a base film is etched using a metal oxide resist film as a mask, line edge roughness of a pattern formed on a base film is improved. BRIEF DESCRIPTION OF THE DRAWINGS

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[0032] Hereinafter, various exemplary embodiments will be described in detail with reference to the drawings. In addition, in each drawing, the same or corresponding parts are given the same reference numerals.

[0033] <First embodiment>

[0034] Regarding an example of a substrate processing method according to the first embodiment, Figures 1 to 5 Provide explanation.

[0035] Figure 1 This is an example of a flowchart showing the substrate processing method according to the first embodiment.

[0036] In step S101, the following process (MOR film formation process) is performed to form a metal oxide resist film 640 (hereinafter also referred to as MOR (Metal Oxide Resist) film) made of metal oxide on the substrate having the base film.

[0037] Figure 2 This is an example of a schematic cross-sectional view of a substrate after the MOR film formation process.

[0038] Here, the substrate before the MOR film formation process includes a substrate 610 and a base film (an organic film 620 and a film containing silicon 630). The substrate 610 is composed of, for example, Si, SiO2, SiN, TiN, etc. The base film is formed on the substrate 610. Figure 2 In the example shown, as the base film, a stacked structure of an organic film 620 and a silicon-containing film 630 is formed. The organic film 620 is formed on a substrate 610. The organic film 620 is, for example, a carbon film. The silicon-containing film 630 is formed on the organic film 620. The silicon-containing film 630 is, for example, an SOG (spin-on-glass) film. The silicon-containing film 630 is, for example, composed of SiOC, SiOCN, SiC, TiO2, SnO2, carbon, etc. In addition, the structure of the base film is not limited to this. The base film may be only any one of the organic film 620 and the silicon-containing film 630.

[0039] In the MOR film forming process, the MOR film 640 is formed on the base film of the substrate. Figure 2In the example shown, the MOR film 640 is formed on the silicon-containing film 630. The MOR film 640 is composed of a metal oxide containing at least metal atoms and oxygen atoms (O). In addition, the MOR film 640 may be a metal oxide containing an alkyl group. The metal atoms contained in the MOR film 640 include, for example, at least any one of Sn, Sb, In, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, Lu, etc.

[0040] The formation method of the MOR film 640 can be, for example, by forming a film using plasma CVD (chemical vapor deposition) using a gas containing an organic metal and an oxidizing gas. The gas containing the organic metal contains an alkyl group and a metal atom. The gas containing the organic metal can use, for example, at least any one of trimethyltin chloride (Me3SnCl), dimethyltin dichloride (Me2SnCl2), methyltin trichloride (MeSnCl3), tri(dimethylamino)methyltin (IV) ((Me2N)3SnMe), (dimethylamino)trimethyltin (IV) ((Me2N)SnMe3), etc. In addition, the oxidizing gas contains oxygen atoms (O). The oxidizing gas can use, for example, at least any one of O2, O3, H2O2, H2O, etc. In addition, the formation method of the MOR film 640 is not limited to a dry process, but can also be a wet process without limitation.

[0041] Next, a process of forming a pattern on the MOR film 640 is performed. First, in step S102, an exposure process is performed on the substrate having the MOR film 640. Next, in step S103, a development process is performed on the substrate having the MOR film 640. In addition, the MOR film 640 may be a positive resist film whose exposed portion in the exposure process is removed by the development process, or a negative resist film whose unexposed portion in the exposure process is removed by the development process.

[0042] Figure 3 1 is an example of a schematic cross-sectional view of a substrate after development processing. A pattern of openings 661 is formed in the MOR film 640 through the exposure processing and the development processing.

[0043] In step S104, a modification treatment is performed on the substrate having the MOR film 640 with a pattern formed with the opening portion 661. Here, the modification treatment is to modify the MOR film 640 with a pattern formed. In addition, the modification treatment is an oxidation treatment. Specifically, the modification treatment exposes the substrate to an oxygen-containing gas atmosphere. The oxygen-containing gas is, for example, hydrogen peroxide (H2O2) gas and / or ozone (O3) gas. For example, the temperature of the modification treatment is 100 to 350°C, the pressure is 1.2 to 120 Torr, and the treatment time is 100 to 1200 seconds. Thus, the MOR film 640 is further oxidized to form a modified MOR film 645. For example, when the MOR film 640 is composed of a metal oxide containing an alkyl group, the alkyl group is detached and the oxygen atom (O) is combined through the oxidation treatment.

[0044] Figure 4 1 is an example of a schematic cross-sectional view of a substrate after the modification process. The MOR film 640 is modified by the modification process to form a modified MOR film 645.

[0045] In step S105, etching is performed on the substrate having the modified MOR film 645 having the pattern of the opening 661. Here, the base film (silicon-containing film 630, organic film 620) is etched using the patterned modified MOR film 645 as a mask to form a pattern on the base film.

[0046] Figure 5 1 is an example of a schematic cross-sectional view of a substrate after etching. A pattern of recessed portions 662 is formed on the silicon-containing film 630 by etching.

[0047] Here, regarding the linearity of the edge (side wall) of the groove-shaped pattern formed on the base film, Figure 6 illustrate. Figure 6 This is an example of a graph showing the line edge roughness (LER: Line Edge Roughness) of a pattern formed on a base film.

[0048] Here, in step S102 and step S103, a groove-shaped pattern is formed on the MOR film 640. Then, in step S105, the MOR film 640 or the modified MOR film 645 having the groove-shaped pattern is used as a mask to perform an etching process on the silicon-containing film 630 as a base film, thereby forming a groove-shaped pattern on the silicon-containing film 630. The line edge roughness (LER) in the groove-shaped pattern formed on the silicon-containing film 630 is measured.

[0049] (a) shows the line edge roughness (LER) when step S104 is omitted and the base film is etched using the unmodified MOR film 640. Figure 6In FIG. 1 , the range of line edge roughness (LER) ±5% in (a) is indicated by a dotted line.

[0050] (b) shows the line edge roughness (LER) when the substrate is modified with hydrogen peroxide (H 2 O 2 ) gas in step S104 and the base film is etched with the modified MOR film 645 .

[0051] (c) shows the line edge roughness (LER) when the substrate is modified with ozone (O 3 ) gas in step S104 and the base film is etched with the modified MOR film 645 .

[0052] like Figure 6 As shown in FIG. 1 , a groove-shaped pattern is formed on a base film using a modified MOR film 645 modified with hydrogen peroxide (H2O2) gas and / or ozone (O3) gas as shown in (b) and (c), thereby reducing the line edge roughness compared to the case where a groove-shaped pattern is formed on a base film using the MOR film 640 not subjected to the modification treatment as shown in (a) (refer to FIG. 1 ). Figure 6 ).

[0053] Thus, the line edge roughness of the pattern formed on the base film can be improved. In addition, when the organic film 620 is etched using the silicon-containing film 630 having the pattern of the recess 662 as a mask, and a pattern is formed on the organic film 620, the line edge roughness of the pattern formed on the organic film 620 can also be improved. In addition, when the substrate 610 is etched using the base film having the pattern as a mask, and a pattern is formed on the substrate 610, the line edge roughness of the pattern formed on the substrate 610 can also be improved. In addition, by modifying the MOR film 640, the etching resistance can also be improved. In addition, along with the improvement of the line edge roughness, the line width roughness (LWR: Line Width Roughness) can also be improved.

[0054] <Second embodiment>

[0055] Next, regarding an example of a substrate processing method according to the second embodiment, Figures 7 to 9 Provide explanation.

[0056] Figure 7 This is an example of a flowchart showing the substrate processing method according to the second embodiment.

[0057] In step S201, a process of forming a MOR film 640 composed of a metal oxide is performed on a substrate having a base film (MOR film forming process). Next, a process of forming a pattern on the MOR film 640 is performed. First, in step S202, an exposure process is performed on the substrate. Next, in step S203, a development process is performed on the substrate. In addition, the process from step S201 to step S203 is similar to the process from step S101 to step S103 (refer to Figure 1 ) are the same, and repeated description is omitted.

[0058] Figure 8 661 is an example of a cross-sectional schematic diagram of a substrate before annealing. Through exposure and development, a pattern of an opening 661 is formed on the MOR film 640. Here, a protrusion 641 is formed that overflows from the upper part of the side wall of the MOR film 640 toward the opening 661. In other words, the cross-sectional shape of the MOR film 640 is a substantially T-shaped shape that expands in the width direction at the top. In addition, the upper surface of the silicon-containing film 630 of the opening 661 has a residue portion 642 caused by the development process.

[0059] In step S204, the substrate is subjected to annealing treatment. Here, the substrate is subjected to annealing treatment under the following treatment conditions: substrate temperature 150°C to 400°C, pressure 1 to 500 Torr, and treatment time 30 to 60 minutes, using an inert gas atmosphere. As the inert gas, N2 gas, Ar gas, or a mixed gas of N2 gas and Ar gas can be used.

[0060] Fig. 9 FIG. 6 is an example of a schematic cross-sectional view of a substrate after annealing. The sidewall 643 of the MOR film 640 is improved in shape by annealing. In addition, the residue portion 642 (see FIG. 643 ) of the upper surface 644 of the silicon-containing film 630 of the opening 661 is Figure 8 ) are removed or reduced.

[0061] In step S205, the substrate is subjected to a modification process. Next, in step S206, the substrate is subjected to an etching process. In addition, the process from step S205 to step S206 is similar to the process from step S104 to step S105 (refer to Figure 1 ) are the same, and repeated description is omitted. Thus, a pattern of recessed portions 662 is formed on the silicon-containing film 630 (refer to Figure 5 ).

[0062] Here, the shapes of the MOR film 640 before and after annealing are shown in FIG. Fig.10 and Fig.11 Provide explanation.

[0063] Fig.10 is an example of a cross-sectional view of a substrate before annealing. Fig.10As shown, a protrusion 641 is formed that overflows from the upper sidewall of the MOR film 640 toward the opening 661. In other words, the cross-sectional shape of the MOR film 640 is a T-shape that expands upward in the width direction. In addition, the upper surface of the silicon-containing film 630 in the opening 661 has a residual portion 642.

[0064] Fig.11 is an example of a cross-sectional view of a substrate after annealing. Fig.11 As shown in FIG. 1 , the sidewall 643 of the MOR film 640 is formed by the annealing process. In addition, the residue portion 642 (see FIG. 1 ) is removed from the upper surface 644 of the silicon-containing film 630 in the opening 661. Figure 8 ).

[0065] By annealing, the line edge roughness (LER) of the sidewall 643 of the MOR film 640 can be improved. Thus, the line edge roughness (LER) of the concave portion 662 of the silicon-containing film 630 formed by etching using the modified MOR film 645 as a mask can also be improved. In addition, when the organic film 620 is etched using the silicon-containing film 630 with the pattern of the concave portion 662 as a mask and a pattern is formed on the organic film 620, the line edge roughness of the pattern formed on the organic film 620 can also be improved. In addition, when the substrate 610 is etched using the base film with the pattern as a mask and a pattern is formed on the substrate 610, the line edge roughness of the pattern formed on the substrate 610 can also be improved. In addition, along with the improvement of the line edge roughness, the line width roughness (LWR) is also improved.

[0066] <Third embodiment>

[0067] Next, regarding an example of a substrate processing method according to a third embodiment, Figure 12 to Figure 15 Provide explanation.

[0068] Fig.12 This is an example of a flowchart showing a substrate processing method according to the third embodiment.

[0069] In step S301, a process of forming a MOR film 640 composed of a metal oxide is performed on a substrate having a base film (MOR film forming process). Next, a process of forming a pattern on the MOR film 640 is performed. First, in step S302, an exposure process is performed on the substrate. Next, in step S303, a development process is performed on the substrate. Next, in step S304, an annealing process is performed on the substrate. In addition, the process from step S301 to step S304 is the same as the process from step S201 to step S204 (refer to Figure 7 ) are the same, and repeated description is omitted. In addition, the annealing treatment of step S304 can also be omitted.

[0070] In step S305 , a process (protective film forming process) of forming the protective film 650 on the upper part of the MOR film 640 is performed. In addition, the protective film forming process of step S305 also includes a modification process of the MOR film 640 .

[0071] Here, regarding an example of the protective film forming process of step S305, Fig.13 illustrate. Fig.13 This is an example of a flowchart showing a protective film forming process.

[0072] In step S311, a substrate is placed on a mounting portion of a substrate processing apparatus.

[0073] Fig.14 1 is an example of a schematic cross-sectional view of a substrate before a protective film forming process. Here, a MOR film 640 having a pattern formed on a base film (organic film 620, film 630 containing silicon) is provided.

[0074] In step S312, a metal-containing precursor is supplied as a raw material gas to the substrate. As a result, the metal-containing precursor is adsorbed on the substrate surface. Here, the metal-containing precursor is selectively adsorbed on the non-depressed shape forming area (upper part of the MOR film 640) of the MOR film 640 compared to the depressed shape forming area (lower part in the opening 661) of the MOR film 640.

[0075] In step S313, an oxidizing gas is supplied to the substrate as a reaction gas. Here, the oxidizing gas may be hydrogen peroxide (H2O2) gas and / or ozone (O3) gas. As a result, the metal-containing precursor adsorbed on the surface of the substrate is oxidized to form a protective film 650. In addition, the MOR film 640 is subjected to an oxidation treatment (equivalent to the modification treatment of step S104) by the oxidizing gas, so that the MOR film 640 is further oxidized to form a modified MOR film 645.

[0076] In step S314, it is determined whether the process from step S312 to step S313 is repeated a specified number of times. If it is not repeated a specified number of times (S314·NO), the process from step S312 to step S313 is repeated. If it is repeated a specified number of times (S314·YES), the process proceeds to step S315.

[0077] In step S315, the substrate is unloaded from the substrate processing apparatus.

[0078] Fig.15 FIG. 6 is an example of a cross-sectional schematic diagram of a substrate after the protective film forming process. The protective film forming process of step S305 also includes a modification process of the MOR film 640. Therefore, the MOR film 640 (see Fig.14) is modified by an oxygen-containing gas to become a modified MOR film 645. In addition, a protective film 650 is formed on the non-concave shape forming area of ​​the modified MOR film 645. In other words, the protective film 650 is formed on the upper part of the modified MOR film 645. The protective film 650 is, for example, any one of a titanium oxide film, a titanium oxynitride film, an aluminum oxide film, and a silicon oxide film. In addition, the protective film 650 has a higher etching resistance than the silicon-containing film 630 under the conditions of the etching process of step S307 described later.

[0079] In step S306, a protective film forming process is performed on the substrate. Here, for example, the protective film 650 formed on the upper surface 644 of the silicon-containing film 630 is removed. For example, in step S305, a protective film 650 thicker than the concave shape forming region (the lower part in the opening 661) is formed on the non-concave shape forming region (the upper part of the modified MOR film 645). In step S306, the protective film 650 of the concave shape forming region is removed by etching while leaving the protective film 650 of the non-concave shape forming region.

[0080] In step S307, etching is performed on the substrate. Figure 1 ) are the same, and repeated description is omitted. Thus, a pattern of recessed portions 662 is formed on the silicon-containing film 630 (refer to Figure 5 ). In addition, the protective film 650 has a higher etching resistance than the silicon-containing film 630. Thus, the selectivity of the etching process is improved. In addition, by performing the modification process and the protective film forming process together, the number of steps can be reduced.

[0081] Here, regarding an example of a substrate processing apparatus used for the protective film forming process in step S305, Figure 16 to Figure 18 Provide explanation. Fig.16 FIG. 6 is a schematic cross-sectional view showing an example of a film forming apparatus for forming the protective film 650 . Fig.17 This is a schematic perspective view showing the structure inside the vacuum container of the film forming apparatus. Fig.18 It is a schematic plan view showing the structure inside the vacuum container of the film forming apparatus.

[0082] Reference Figure 16 to Figure 18 The film forming device comprises a flat vacuum container 1 having a substantially circular planar shape, and a rotating table 2 which is arranged in the vacuum container 1 and has a rotation center at the center of the vacuum container 1. The vacuum container 1 is a processing chamber for performing film forming processing on the surface of a wafer accommodated inside. The vacuum container 1 comprises: a container body 12 having a cylindrical shape with a bottom, and a sealing member 13 (such as an O-ring) which is sealed to the upper surface of the container body 12. Fig.16 ) is configured as a top plate 11 that can be loaded and unloaded in an airtight manner.

[0083] The rotating table 2 is fixed to a cylindrical core 21 through its center, and the core 21 is fixed to the upper end of a rotating shaft 22 extending in the vertical direction. The rotating shaft 22 passes through the bottom 14 of the vacuum container 1, and the lower end is mounted on a Fig.16 ) on a driving unit 23 that rotates around a vertical axis. The rotating shaft 22 and the driving unit 23 are housed in a cylindrical housing 20 with an upper surface opening. In the housing 20, a flange portion provided on its upper surface is airtightly mounted on the lower surface of the bottom 14 of the vacuum container 1 to maintain an airtight state between the internal atmosphere of the housing 20 and the external atmosphere.

[0084] In the protective film forming process, when the protective film 650 is grown upward, the turntable 2 is rotated at a specified speed of more than 120 rpm, for example, in the range of 120 rpm to 300 rpm. Therefore, the driving unit 23 is configured so that the turntable 2 can be rotated at a high speed in a range of at least 120 rpm to 300 rpm. By rotating the turntable 2 at a high speed, the protective film 650 can be selectively formed on the upper part of the MOR film 640. In addition, in a general film forming process, the rotation speed of the turntable 2 is mostly set to about 20 to 30 rpm. In addition, the turntable 2 is configured so that it can also rotate at a low speed.

[0085] On the surface of the rotating table 2, along Fig.17 and Fig.18 In the rotation direction (circumferential direction) shown, a circular recess 24 is provided for mounting a plurality (five in the example shown) of semiconductor wafers (hereinafter referred to as "wafers") W as substrates. Fig.18 For convenience, the wafer W is placed on only one recess 24. The recess 24 has an inner diameter that is only 4 mm larger than the diameter of the wafer W and a depth that is substantially equal to the thickness of the wafer W. Therefore, when the wafer W is accommodated in the recess 24, the surface of the wafer W and the surface of the turntable 2 (the area where the wafer W is not placed) are at the same height. The bottom surface of the recess 24 is formed with through holes (not shown) through which, for example, three lifting pins are passed for supporting the back side of the wafer W and raising and lowering the wafer W.

[0086] Fig.17 and Fig.18 1 is a diagram for explaining the structure inside the vacuum container 1. For convenience, the top plate 11 is omitted. Fig.17 and Fig.18 As shown, above the turntable 2, the reaction gas nozzles 31, 32, 33 and the separation gas nozzles 41, 42, each made of, for example, quartz, are arranged in the circumferential direction of the vacuum container 1 (the rotation direction of the turntable 2 ( Fig.18In the example shown in the figure, the separation gas nozzle 41, the reaction gas nozzle 31, the separation gas nozzle 42, the reaction gas nozzle 32 and the reaction gas nozzle 33 are arranged in sequence clockwise (the direction of rotation of the turntable 2). These nozzles 31, 32, 33, 41, 42 are connected by gas introduction ports 31a, 32a, 33a, 41a, 42a ( Fig.18 ) is fixed to the outer peripheral wall of the container body 12, and is installed to be introduced into the vacuum container 1 from the outer peripheral wall of the vacuum container 1, and extends horizontally relative to the turntable 2 along the radial direction of the container body 12.

[0087] In this embodiment, if Fig.18 As shown, the reaction gas nozzle 31 is connected to the supply source 130 of the raw material gas (metal-containing precursor) through the piping 110 and the flow controller 120. The reaction gas nozzle 32 is connected to the supply source 131 of the oxidizing gas (H2O2 and / or O3) through the piping 111 and the flow controller 121. Further, the reaction gas nozzle 33 is connected to the etching gas supply source 132 through the piping 112 and the flow controller 122. As the etching gas, halogen gases including fluorine-based gases such as CF4, C2F6, CH3F, CHF3, Cl2, ClF3, BCl3, NF3, etc. can be used. If it is an etchable gas, there is no particular limitation. The separation gas nozzles 41 and 42 are connected to the supply source (not shown) of the separation gas through piping and flow control valves, etc., which are not shown in the figure. As the separation gas, rare gases such as helium (He) and argon (Ar), and inactive gases such as nitrogen (N2) gas can be used. In this embodiment, an example in which N 2 gas is used as the separation gas is described.

[0088] As the raw material gas supplied from the reaction gas nozzle 31 , various organic metal gases or organic semi-metal gases can be used according to the application, from among organic metal gases or organic semi-metal gases.

[0089] On the reaction gas nozzles 31, 32, and 33, a plurality of gas exhaust holes are opened toward the turntable 2 and are arranged along the length direction of the reaction gas nozzles 31, 32, and 33, for example, at intervals of 10 mm. The area below the reaction gas nozzle 31 is the first processing area P1 for adsorbing the raw material gas onto the wafer W. The area below the reaction gas nozzle 32 is the second processing area P2 where an oxidizing gas is supplied to oxidize the raw material gas adsorbed onto the wafer W in the first processing area P1, and a molecular layer of an organic metal or organic semimetal oxide contained in the raw material gas is generated as a reaction product. In addition, the molecular layer of the organic metal oxide or organic semimetal oxide constitutes a protective film 650 formed. The area below the reaction gas nozzle 33 is the third processing area P3 where, after the organic metal oxide or organic semimetal oxide (protective film 650) generated by oxidation in the second processing area P2 is grown upward, the unnecessary protective film 650 grown laterally is removed by etching. As shown in FIG. Fig.18 As conceptually shown, in the third processing area P3, a plasma generator 80 ( Fig.18 In the figure, the position where the plasma generator 80 is set is shown by a dotted line. In addition, activated oxygen gas can be supplied to the second processing area P2, for example, activated oxygen gas can be supplied by thermal oxidation or activated oxygen gas can be supplied by plasma. When the oxidizing gas is activated by plasma, the second processing area P2 can also be provided with a plasma generator.

[0090] Here, the first processing region P1 is a region where the raw material gas is adsorbed onto the wafer W, and thus may also be referred to as the raw material gas adsorption region P1. The second processing region P2 is a region where the raw material gas adsorbed onto the surface of the wafer W is oxidized, and thus may also be referred to as the oxidation region P2. In addition, the third processing region P3 is a region on the side of the etching protection film 650, and thus may also be referred to as the etching region P3.

[0091] The plasma generator 80 is not necessarily provided above the third processing area P3. For example, when a gas with a sufficiently strong etching force, such as ClF3 or HF, is used as an etching gas, etching can be performed without using the plasma generator 80. Therefore, the plasma generator 80 can be provided as needed.

[0092] As mentioned above, the raw material gas supplied from the reaction gas nozzle 31 is an organic metal gas or an organic semi-metal gas. The raw material gas can use various organic metal gases or organic semi-metal gases, which are selected according to the type of the protective film to be formed. The organic metal gas can be a gas containing various organic metals. For example, when forming the TiO2 protective film 650, a gas containing organic amino titanium such as TDMAT (tetrakis dimethylamino titanium) is selected. In addition, the organic semi-metal gas can use an organic silane gas, such as an organic amino silane gas such as 3DMASi. When supplying these organic metal gases or organic semi-metal gases, the following structure can be used as needed, using a vaporizer or the like to gasify the organic metal or organic semi-metal to generate the organic metal gas or organic semi-metal gas, and the organic metal gas or organic semi-metal gas generated using a carrier gas is supplied into the vacuum container 1.

[0093] In addition, various oxidizing gases can be used as the oxidizing gas supplied from the reaction gas nozzle 32, as long as they react with the supplied organic metal gas or organic semi-metal gas to generate organic metal oxides. For example, when the organic metal gas is oxidized by thermal oxidation and the MOR film 640 is also oxidized, H2O2 and / or O3 are selected.

[0094] As the etching gas supplied from the reaction gas nozzle 33, various etching gases can be selected as long as they can etch the protective film composed of the organic metal oxide film or the organic semi-metal oxide film. For example, a fluorine-containing gas can be used. As the fluorine-containing gas, CF4, ClF3, etc. can be cited. Whether to set the plasma generator 80 can be determined according to the selected etching gas, as described above.

[0095] Reference Fig.17 and Fig.18 , two convex portions 4 are provided in the vacuum container 1. The convex portion 4 together with the separation gas nozzles 41 and 42 constitute the separation area D, and thus, as described later, is mounted on the back of the top plate 11 in a manner protruding toward the turntable 2. In addition, the convex portion 4 has a fan-shaped planar shape with the top cut in an arc shape, and in this embodiment, it is configured such that the inner arc is connected to the protrusion 5 (described later), and the outer arc is along the inner circumferential surface of the container body 12 of the vacuum container 1.

[0096] A convex portion 4 is mounted on the back of the top plate 11. In the vacuum container 1, there is a flat low top surface 44 (first top surface) as the lower surface of the convex portion 4, and a top surface 45 (second top surface) located on both sides of the top surface 44 in the circumferential direction and higher than the top surface 44. The top surface 44 has a fan-shaped plane shape with the top cut in an arc shape. In addition, as shown in the figure, in the convex portion 4, a groove portion 43 extending in the radial direction is formed in the circumferential center, and the separation gas nozzle 42 is accommodated in the groove portion 43. The other convex portion 4 also forms a groove portion 43, where the separation gas nozzle 41 is accommodated. In addition, the space below the high top surface 45 is provided with reaction gas nozzles 31 and 32 respectively. These reaction gas nozzles 31 and 32 are away from the top surface 45 and are arranged near the wafer W. In addition, the reaction gas nozzle 31 is provided in the right space below the high top surface 45, and the reaction gas nozzle 32 is provided in the left space below the high top surface 45.

[0097] In addition, the separation gas nozzles 41 and 42 accommodated in the grooves 43 of the convex portion 4 have a plurality of gas discharge holes opened toward the turntable 2 arranged at intervals of, for example, 10 mm along the length direction of the separation gas nozzles 41 and 42 .

[0098] The top surface 44 forms a separation space as a narrow space relative to the turntable 2. When N2 gas is supplied from the discharge hole of the separation gas nozzle 42, the N2 gas flows through the separation space to the space including the processing area P1 and the space including the processing areas P2 and P3. At this time, the volume of the separation space is smaller than the volume of the space including the processing area P1 and the space including the processing areas P2 and P3, so the pressure of the separation space can be higher than the pressure of the space including the processing area P1 and the space including the processing areas P2 and P3 due to the N2 gas. That is, a separation space with high pressure is formed between the space including the processing area P1 and the space including the processing areas P2 and P3. In addition, the N2 gas flowing out from the separation space to the space including the processing area P1 and the space including the processing areas P2 and P3 moves as a countercurrent relative to the raw material gas from the first processing area P1 and the reaction gas from the second processing area P2. Therefore, the raw material gas from the first processing area P1 and the second reaction gas from the second processing area P2 are separated through the separation space. Therefore, in the vacuum container 1 , mixing and reaction of the source gas and the reaction gas are suppressed.

[0099] In addition, the height of the top surface 44 relative to the upper surface of the turntable 2 is preferably set to an appropriate height so that the pressure of the separation space is higher than the pressure of the space including the processing area P1 and the pressure of the space including the processing areas P2 and P3, taking into account the pressure in the vacuum container 1 during film formation, the rotation speed of the turntable 2, the supply amount of the separation gas (N2 gas), etc.

[0100] On the other hand, the lower surface of the top plate 11 is provided with a protrusion 5 surrounding the outer periphery of the core 21 of the fixed turntable 2. The protrusion 5 is continuous with the rotation center side of the convex portion 4 in this embodiment, and its lower surface is formed at the same height as the top surface 44.

[0101] On the peripheral edge of the fan-shaped convex portion 4 (the portion on the outer edge side of the vacuum container 1), a curved portion 46 curved in an L shape is formed opposite to the outer end surface of the turntable 2. The curved portion 46, like the convex portion 4, suppresses the intrusion of the reaction gas from both sides of the separation area D and suppresses the mixing of the two reaction gases. The fan-shaped convex portion 4 is provided on the top plate 11, and the top plate 11 can be removed from the container body 12, so that there is a small gap between the outer peripheral surface of the curved portion 46 and the container body 12. The gap between the inner peripheral surface of the curved portion 46 and the outer end surface of the turntable 2, and the gap between the outer peripheral surface of the curved portion 46 and the container body 12 are set to the same size as, for example, the height of the top surface 44 relative to the upper surface of the turntable 2.

[0102] The inner peripheral wall of the container body 12 is formed as a vertical surface close to the outer peripheral surface of the curved portion 46 in the separation area D, and in the parts other than the separation area D, such as Fig.16 As shown, for example, from the portion facing the outer end surface of the turntable 2 to the bottom 14, it is sunken toward the outside. In the following, for the convenience of explanation, the sunken portion with a roughly rectangular cross-sectional shape is referred to as the exhaust area. Specifically, the exhaust area connected to the first processing area P1 is referred to as the first exhaust area E1, and the area connected to the second and third processing areas P2 and P3 is referred to as the second exhaust area E2. On the bottom of these first exhaust area E1 and second exhaust area E2, as shown in FIG. Fig.16 To Fig.18 As shown in FIG. 1 , a first exhaust port 61 and a second exhaust port 62 are formed respectively. Fig.16 As shown, each exhaust pipe 63 is connected to a vacuum pump 64 as a vacuum exhaust means. In addition, between the vacuum pump 64 and the exhaust pipe 63, a pressure controller 65 is provided.

[0103] In the space between the rotating table 2 and the bottom 14 of the vacuum container 1, as shown in FIG. Fig.16As shown, a heating unit 7 is provided as a heating means, and the wafer W on the turntable 2 is heated to a temperature determined by the process plan (for example, 150° C.) by the turntable 2. On the lower side near the periphery of the turntable 2, an annular covering member 71 is provided to separate the atmosphere from the upper space of the turntable 2 to the exhaust areas E1 and E2 and the atmosphere where the heating unit 7 is placed, and to suppress the intrusion of gas toward the lower area of ​​the turntable 2. The covering member 71 includes an inner member 71a provided from the lower side to the outer edge of the turntable 2 and the outer peripheral side of the outer edge, and an outer member (not shown) provided between the inner member 71a and the inner wall surface of the vacuum container 1. The outer member (not shown) is provided below the curved portion 46 formed on the outer edge of the convex portion 4 in the separation area D, and is close to the curved portion 46. The inner member 71a surrounds the entire circumference of the heating unit 7 below the outer edge of the turntable 2 (and below the portion slightly outside the outer edge).

[0104] The bottom 14 at a position closer to the center of rotation than the space where the heating unit 7 is arranged protrudes upward as a protrusion 12a so as to be close to the core 21 in the vicinity of the center of the lower surface of the turntable 2. There is a narrow space between the protrusion 12a and the core 21. In addition, the gap between the inner circumferential surface of the through hole of the rotating shaft 22 that penetrates the bottom 14 and the rotating shaft 22 is narrow, and these narrow spaces are connected to the housing 20. In addition, a cleaning gas supply pipe 72 for supplying N2 gas as a cleaning gas into the narrow space for cleaning is provided on the housing 20. In addition, a plurality of cleaning gas supply pipes 73 for cleaning the arrangement space of the heating unit 7 are provided on the bottom 14 of the vacuum container 1 at a predetermined angular interval in the circumferential direction below the heating unit 7. In addition, between the heating unit 7 and the turntable 2, a cover member 7a is provided to cover the area from the inner peripheral wall of the outer member (not shown) (the upper surface of the inner member 71a) to the upper end of the protrusion 12a in the circumferential direction in order to suppress the intrusion of gas into the area where the heating unit 7 is installed. The cover member 7a can be made of quartz, for example.

[0105] In addition, the vacuum container 1 is configured as follows: a separation gas supply pipe 51 is connected to the center of the top plate 11 of the vacuum container 1, and N2 gas as a separation gas is supplied to the space between the top plate 11 and the core portion 21. The separation gas supplied to the space including the central region C is discharged toward the periphery along the surface of the wafer mounting region side of the turntable 2 through the narrow gap between the protrusion 5 and the turntable 2. The space including the central region C can be maintained at a higher pressure than the space including the processing region P1 and the space including the processing regions P2 and P3 by the separation gas. Therefore, through the space including the central region C, the mixing of the organic metal gas supplied to the first processing region P1 and the oxidizing gas supplied to the second processing region P2 through the central region C is suppressed. That is, the space including the central region C (or the central region C) can play the same role as the separation space (or the separation region D).

[0106] Furthermore, on the side wall of the vacuum container 1, as Fig.17 ,like Fig.18 As shown, a transfer port 15 is formed between the external transfer arm 10 and the turntable 2 for transferring the wafer W as a substrate. The transfer port 15 is opened and closed by a gate valve not shown. In addition, a concave portion 24 as a wafer loading area in the turntable 2 is used to transfer the wafer W with the transfer arm 10 at a position opposite to the transfer port 15. Therefore, a through concave portion 24, a lifting pin for lifting the wafer W from the back and a lifting mechanism thereof (all not shown) are provided at the lower side of the turntable 2 at a position corresponding to the transfer position.

[0107] In addition, in the film forming apparatus of this embodiment, if Fig.16 As shown, a control unit 100 composed of a computer for controlling the operation of the entire device is provided, and a program for implementing the protective film forming method described later on the film forming device under the control of the control unit 100 is stored in the memory of the control unit 100. The program combines a step group in a manner to execute the protective film forming method described later, is stored in a medium 102 such as a hard disk, an optical disk, a magneto-optical disk, a memory card, or a floppy disk, is read into the storage unit 101 by a designated reading device, and is installed in the control unit 100.

[0108] Furthermore, the control unit 100 can also control the rotation speed of the turntable 2. Thus, the rotation speed of the turntable 2 can be set to a high speed rotation of 120 rpm or more or 120 rpm to 300 rpm as described above, or a low speed rotation of 60 rpm.

[0109] Furthermore, the control unit 100 may also control the flow rate controllers 120 to 122. Thus, the flow rate of each gas supplied from the reaction gas nozzles 31 to 33 may be controlled.

[0110] With such a structure, in the protective film forming process of step S305, the raw material gas (metal-containing precursor) is supplied from the supply source 130 to the first processing area P1, and the oxidizing gas is supplied from the supply source 131 to the second processing area P2. In addition, the separation gas is supplied to the separation area D. The wafer W as a substrate arranged on the recess 24 of the turntable 2 passes through the first processing area P1 (raw material gas adsorption area P1), the separation area D, the second processing area P2 (oxidation area P2), and the separation area D every time the turntable 2 rotates. That is, the processes of steps S312 and S313 are repeated every time the turntable 2 rotates. Thus, the protective film 650 is formed. In addition, by the high-speed rotation of the turntable 2, the upper part of the MOR film 640 selectively adsorbs the raw material gas, and the protective film 650 is selectively formed on the upper part of the MOR film 640.

[0111] In the protective film forming process of step S306, etching gas is supplied to the third processing area P3 from the supply source 132. In addition, separation gas is supplied to the separation area D. Thus, a part of the protective film 650 is removed, and the protective film 650 is formed.

[0112] Next, regarding the linearity of the edge (side wall) of the groove-shaped pattern, Fig.19 Further explanation. Fig.19 This is an example of a graph showing line edge roughness (LER).

[0113] Here, a groove-shaped pattern is formed on the MOR film 640. Then, the modified MOR film 645 having the groove-shaped pattern is used as a mask to perform an etching process on the silicon-containing film 630 as a base film, thereby forming a groove-shaped pattern on the silicon-containing film 630. The line edge roughness in the groove-shaped pattern formed on the silicon-containing film 630 is measured.

[0114] (a) shows the line edge roughness (LER) when the base film is etched using the unmodified MOR film 640.

[0115] (b1) and (b2) show the line edge roughness (LER) when the base film is etched with the modified MOR film 645 without forming the protective film 650. In addition, the average value of (b1) and (b2) is shown in the dashed line.

[0116] (c) shows the line edge roughness (LER) when the base film is etched using the modified MOR film 645 formed with the protective film 650.

[0117] (d1) and (d2) show the line edge roughness (LER) when the protective film forming process shown in step S306 is performed and the base film is etched using the modified MOR film 645 formed with the protective film 350. The average value of (d1) and (d2) is shown by the dotted line.

[0118] As shown in comparison between (a) and (b1) and (b2), it is shown that the line edge roughness (LER) is improved by forming a pattern of recessed portions 662 on the silicon-containing film 630.

[0119] Furthermore, as shown by comparison between ( b1 ), ( b2 ), and ( c ), it is shown that by forming the protective film 650 , the line edge roughness (LER) is further improved.

[0120] As shown in the comparison between (c) and (d1) and (d2), it is shown that the line edge roughness (LER) is further improved by performing the protective film forming process (refer to step S306). Therefore, compared with the case where the groove-shaped pattern is formed on the base film using the MOR film 640 that has not been subjected to the modification process shown in (a), the line edge roughness can be reduced (refer to Fig.19 ).

[0121] Fig. 20 This is a diagram showing the result of the groove shape when the annealing process in step S304 is omitted and the protective film 650 is formed. Fig.21 2 is a diagram showing the result of the groove shape when the annealing process of step S304 is performed to form the protection film 650.

[0122] When the protective film 650 is formed by omitting the annealing treatment, the protrusion 641 (see Figure 8 ) is also formed on the protective film 650, thereby forming an overhang on the protective film 650 in a manner covering the opening 661. Fig. 20 As shown, a protrusion extending from one side wall of the opening 661 to the other side wall of the opening 661 is shown.

[0123] In this regard, annealing treatment is performed to suppress overhang of the protective film 650 when the protective film 650 is formed.

[0124] <Fourth embodiment>

[0125] Next, regarding an example of a substrate processing method according to a fourth embodiment, Fig. 22 Provide explanation.

[0126] Fig. 22 This is an example of a flowchart showing a substrate processing method according to the fourth embodiment.

[0127] In step S401, a process of forming a MOR film 640 composed of a metal oxide is performed on a substrate having a base film (MOR film forming process). Next, a process of forming a pattern on the MOR film 640 is performed. First, in step S402, an exposure process is performed on the substrate. Next, in step S403, a development process is performed on the substrate. Next, in step S404, an annealing process is performed on the substrate. Next, in step S405, a modification process is performed on the substrate. In addition, the process from step S401 to step S405 is the same as the process from step S201 to step S205 (refer to Figure 7 ) are the same, and repeated description is omitted. In addition, the annealing treatment of step S404 can be omitted.

[0128] In step S406, a process of forming a protective film 650 on the upper portion of the modified MOR film 645 (protective film forming process) is performed. In addition, the process of step S406 is similar to the process of step S305 (see Fig.12 ) are the same, and repeated description is omitted. Fig.13 In the flowchart shown, the case where the reaction gas reacting with the metal-containing precursor is an oxidizing gas (refer to step S313) is described, but it is not limited to this. As the reaction gas, a nitriding gas can be used instead of the oxidizing gas. In addition, the protective film 650 is, for example, any one of a titanium oxide film, a titanium oxynitride film, an aluminum oxide film, a silicon oxide film, a titanium nitride film, and a silicon nitride film. In addition, the protective film 650 has a higher etching resistance than the silicon-containing film 630 under the conditions of the etching process of step S408 described later.

[0129] In step S407, a protective film forming process is performed on the substrate. In step S408, an etching process is performed on the substrate. In addition, the process from step S407 to step S408 is the same as the process from step S306 to step S307 (refer to Fig.12 ) are the same, and repeated description is omitted. Thus, a pattern of recessed portions 662 is formed on the silicon-containing film 630 (refer to Figure 5 ). In addition, the protective film 650 has a higher etching resistance than the silicon-containing film 630. Thus, the selectivity of the etching process is improved. In addition, according to the substrate processing method involved in the fourth embodiment, the reaction gas for forming the protective film 650 and the oxidizing gas for modifying the MOR film 640 may be the same gas or different gases.

[0130] <Substrate processing system>

[0131] Next, regarding an example of a substrate processing system 500, Fig.23 Provide explanation. Fig.23 1 is a block diagram showing an example of a substrate processing system 500 .

[0132] The substrate processing system 500 includes a substrate processing device 510 and an exposure device 520. The substrate processing device 510 includes one or more processing chambers for performing one or more processes selected from a MOR film forming process 511, a developing process 512, a thermal annealing process 513, a modification process 514, a protective film forming process 515, and an etching process 516. The exposure device 520 includes a processing chamber for performing an exposure process 521.

[0133] The substrate processing device 510 and the exposure device 520 may be connected in series. The MOR film forming process 511, the developing process 512, the thermal annealing process 513, the modifying process 514, the protective film forming process 515, and the etching process 516 may be performed in different processing chambers, respectively. In addition, a plurality of processes selected from the MOR film forming process 511, the developing process 512, the thermal annealing process 513, the modifying process 514, the protective film forming process 515, and the etching process 516 may be performed in the same processing chamber.

[0134] Although the embodiments of the plasma processing system have been described above, the present invention is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the gist of the present invention described in the claims.

[0135] In addition, the present application claims priority based on U.S. Patent Provisional Application No. 63 / 366,346 filed on June 14, 2022, and the entire contents of these U.S. Patent Provisional Applications are incorporated by reference into the present application.

[0136] [Description of Reference Numerals]

[0137] 610 base material

[0138] 620 organic film

[0139] 630 Silicone-containing membrane

[0140] 640MOR film (metal oxide resist film)

[0141] 645 modified MOR film (metal oxide resist film)

[0142] 641 Protrusion

[0143] 642 Residue Department

[0144] 643 side wall

[0145] 644 upper surface

[0146] 650 protective film

[0147] 661 opening

[0148] 662 concave part

Claims

1. A substrate processing method, comprising: forming a metal oxide resist film on a substrate having a base film, a step of forming a pattern on the metal oxide resist film, a step of modifying the metal oxide resist film having the pattern formed thereon, and A step of etching the base film using the modified metal oxide resist film as a mask. 2 . The substrate processing method according to claim 1 , wherein the step of modifying the metal oxide resist film is a process of oxidizing the metal oxide resist film. 3 . The substrate processing method according to claim 2 , wherein the step of modifying the metal oxide resist film is a process of exposing the substrate to hydrogen peroxide and / or ozone.

4. The substrate processing method according to claim 1, wherein after the step of forming a pattern on the metal oxide resist film and before the step of modifying the metal oxide resist film, The method further includes performing an annealing process on the substrate.

5. The substrate processing method according to claim 1, after the step of forming a pattern on the metal oxide resist film, The method further comprises forming a protective film on the non-depressed shape forming area of ​​the metal oxide resist film, The step of forming the protective film includes the step of supplying a metal-containing precursor, and The step of supplying an oxidizing gas also serves as a step of modifying the metal oxide resist film. 6 . The substrate processing method according to claim 5 , wherein the protective film is any one of a titanium oxide film, a titanium oxynitride film, an aluminum oxide film, and a silicon oxide film.

7. The substrate processing method according to claim 1, wherein after the step of modifying the metal oxide resist film, The method further comprises the step of forming a protective film on the non-depressed shape forming area of ​​the metal oxide resist film, The step of forming the protective film includes a step of supplying a metal-containing precursor and a step of supplying a reaction gas. 8 . The substrate processing method according to claim 7 , wherein the protective film is any one of a titanium oxide film, a titanium oxynitride film, an aluminum oxide film, a silicon oxide film, a titanium nitride film, and a silicon nitride film.

9. The substrate processing method according to any one of claims 5 to 8, wherein after the step of forming the protective film and before the step of etching the base film, The method further includes performing a process of forming the protective film.

10. A substrate processing system, comprising: A film forming apparatus for forming a metal oxide resist film on a substrate having a base film. an exposure device for performing an exposure process on the substrate on which the metal oxide resist film is formed, a developing device for performing a developing process on the substrate subjected to the exposure process, a modifying device for modifying the metal oxide resist film of the substrate subjected to the development process, and An etching device etches the base film using the modified metal oxide resist film as a mask.

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