Substrate proessing method and substrate processing apparatus

Abstract

A technology is provided that can efficiently etch atomic layers of a metal film containing ruthenium. A substrate treatment method according to one aspect of the present disclosure comprises a process of treating the surface of a metal film containing ruthenium with a first treatment solution to form a metal chloride on the surface of the metal film, and a process of removing the metal chloride with a second treatment solution.

Description

Technology Field

[0001] An embodiment of the disclosure relates to a substrate processing method and a substrate processing apparatus. Background Technology

[0002] Recently, the demand for miniaturization in semiconductor device manufacturing processes has been increasing. To meet this demand, the development of Atomic Layer Etching (ALE) technology, which etches target materials on an atomic layer order, is underway. For example, a technology for atomic layer etching of a metal film containing cobalt or copper using a wet process has been disclosed (see Patent Document 1). Prior art literature

[0003] Japanese Patent Publication No. 2018-181984 The problem to be solved

[0004] The present disclosure provides a technique for efficiently etching atomic layers of a metal film containing ruthenium. means of solving the problem

[0005] A substrate treatment method according to one aspect of the present disclosure includes a process of treating the surface of a metal film containing ruthenium with a first treatment solution to form a metal chloride on the surface of the metal film, and a process of removing the metal chloride with a second treatment solution. Effects of the invention

[0006] According to the present disclosure, a metal film containing ruthenium can be efficiently etched atomic layer. In addition, the effects described herein are not necessarily limited and may be any one of the effects described in the present disclosure. Brief explanation of the drawing

[0007] Figure 1 is a schematic diagram showing the schematic configuration of a substrate processing system according to an embodiment. FIG. 2 is a schematic diagram showing an example of the specific configuration of a processing unit according to an embodiment. FIG. 3 is a flowchart showing an example of the sequence of substrate processing according to an embodiment. FIG. 4 is an enlarged cross-sectional view showing an example of the state of the wafer surface after preparation treatment according to an embodiment. FIG. 5 is an enlarged cross-sectional view showing an example of the state of the wafer surface after chloride formation treatment according to an embodiment. FIG. 6 is an enlarged cross-sectional view showing an example of the state of the wafer surface after chloride removal treatment according to an embodiment. Figure 7 is a figure showing the relationship between the number of substrate processing steps according to an embodiment and the etching thickness of various materials. Specific details for implementing the invention

[0008] Hereinafter, embodiments of the substrate processing method and substrate processing apparatus disclosed herein will be described in detail with reference to the attached drawings. Furthermore, the present disclosure is not limited by the embodiments shown below. Additionally, it should be noted that the drawings are schematic and that the relationships between the dimensions of each element, the ratios of each element, etc., may differ from reality. Furthermore, there may be parts in which the relationships between dimensions or ratios differ from one another.

[0009] Recently, the demand for miniaturization in semiconductor device manufacturing processes has been increasing. To meet this demand, the development of atomic layer etching technology, which etches target materials on an atomic layer order, is underway. For example, a technology for atomic layer etching of metal films containing cobalt or copper using a wet process has been disclosed.

[0010] Meanwhile, in the aforementioned conventional technology, there was room for further improvement in that it efficiently etched atomic layers of a metal film containing ruthenium, which is being considered for application to semiconductor devices.

[0011] Accordingly, the realization of a technology that can efficiently etch atomic layers of metal films containing ruthenium by overcoming the aforementioned problems is expected.

[0012] <Overview of Substrate Processing System>

[0013] First, with reference to FIG. 1, the schematic configuration of a substrate processing system (1) according to an embodiment will be described. FIG. 1 is a schematic diagram showing the schematic configuration of a substrate processing system (1) according to an embodiment. In the following, to clarify the positional relationship, the X-axis, Y-axis, and Z-axis are defined as mutually orthogonal, and the Z-axis forward direction is defined as the vertical upward direction.

[0014] A substrate processing system (1) is an example of a substrate processing device. As shown in FIG. 1, the substrate processing system (1) is equipped with an incoming / outgoing station (2) and a processing station (3). The incoming / outgoing station (2) and the processing station (3) are provided adjacent to each other.

[0015] The incoming / outgoing station (2) is equipped with a carrier placement section (11) and a return section (12). In the carrier placement section (11), a plurality of carriers (C) are arranged to receive a plurality of substrates, and in an embodiment, a semiconductor wafer (W) (hereinafter referred to as wafer (W)) in a horizontal state.

[0016] The transport unit (12) is provided adjacent to the carrier placement unit (11) and is equipped with a substrate transport device (13) and a delivery unit (14) inside. The substrate transport device (13) is equipped with a wafer holding mechanism for holding a wafer (W). Additionally, the substrate transport device (13) is capable of movement in the horizontal and vertical directions and rotation around a vertical axis, and transports the wafer (W) between the carrier (C) and the delivery unit (14) using the wafer holding mechanism.

[0017] A processing station (3) is provided adjacent to a return section (12). The processing station (3) is equipped with a return section (15) and a plurality of processing units (16). The plurality of processing units (16) are arranged on both sides of the return section (15).

[0018] The transport unit (15) is equipped with a substrate transport device (17) inside. The substrate transport device (17) is equipped with a wafer holding mechanism for holding a wafer (W). Additionally, the substrate transport device (17) is capable of moving in the horizontal and vertical directions and rotating around a vertical axis, and transports the wafer (W) between the transport unit (14) and the processing unit (16) using the wafer holding mechanism.

[0019] The processing unit (16) performs a predetermined substrate processing on a wafer (W) that is transported by a substrate transport device (17).

[0020] Additionally, the substrate processing system (1) is equipped with a control device (4). The control device (4) is, for example, a computer and is equipped with a control unit (18) and a memory unit (19). A program for controlling various processes executed in the substrate processing system (1) is stored in the memory unit (19). The control unit (18) controls the operation of the substrate processing system (1) by reading and executing the program stored in the memory unit (19).

[0021] In addition, such a program may be recorded on a computer-readable storage medium and installed from the storage medium into the memory unit (19) of the control device (4). Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), a memory card, etc.

[0022] In the substrate processing system (1) configured as described above, first, the substrate transport device (13) of the incoming / outgoing station (2) extracts a wafer (W) from a carrier (C) placed in the carrier placement section (11) and places the extracted wafer (W) in the transfer section (14). The wafer (W) placed in the transfer section (14) is extracted from the transfer section (14) by the substrate transport device (17) of the processing station (3) and brought into the processing unit (16).

[0023] A wafer (W) brought into the processing unit (16) is processed by the processing unit (16), then removed from the processing unit (16) by the substrate transport device (17) and placed in the transfer unit (14). Then, the processed wafer (W) placed in the transfer unit (14) is returned to the carrier (C) of the carrier placement unit (11) by the substrate transport device (13).

[0024] <Composition of Processing Unit>

[0025] Next, the configuration of the processing unit (16) will be described with reference to FIG. 2. FIG. 2 is a schematic diagram showing an example of the specific configuration of the processing unit (16) according to an embodiment. As shown in FIG. 2, the processing unit (16) is equipped with a chamber (20), a substrate processing unit (30), a liquid supply unit (40), and a recovery cup (50).

[0026] The chamber (20) accommodates a substrate processing unit (30), a liquid supply unit (40), and a recovery cup (50). A Fan Filter Unit (FFU) (21) is provided in the ceiling of the chamber (20). The FFU (21) forms a downflow within the chamber (20).

[0027] The substrate processing unit (30) is equipped with a holding unit (31), a support unit (32), and a driving unit (33), and performs liquid treatment on a placed wafer (W). The holding unit (31) holds the wafer (W) horizontally. The support unit (32) is a member extending in a vertical direction, and its base end is rotatably supported by the driving unit (33), and its tip end supports the holding unit (31) horizontally. The driving unit (33) rotates the support unit (32) around a vertical axis.

[0028] This substrate processing unit (30) rotates the holding unit (31) supported by the holding unit (32) by using the driving unit (33) to rotate the holding unit (32), and thereby rotates the wafer (W) held by the holding unit (31).

[0029] On the upper surface of the holding member (31) provided by the substrate processing unit (30), a holding member (31a) is provided to hold the wafer (W) from the side. The wafer (W) is held horizontally by this holding member (31a) in a state slightly separated from the upper surface of the holding member (31). Additionally, the wafer (W) is held in the holding member (31) with the surface on which substrate processing is performed facing upward.

[0030] The liquid supply unit (40) supplies a processing fluid to the wafer (W). The liquid supply unit (40) is equipped with nozzles (41a, 41b), an arm (42a) that horizontally supports the nozzles (41a, 41b), and a pivot lifting mechanism (43a) that pivots and raises the arm (42a). Additionally, the liquid supply unit (40) is equipped with nozzles (41c, 41d), an arm (42b) that horizontally supports the nozzles (41c, 41d), and a pivot lifting mechanism (43b) that pivots and raises the arm (42b).

[0031] The nozzle (41a) is connected to the first supply unit (46a) via a valve (44a) and a flow regulator (45a). The first treatment liquid supplied from the first supply unit (46a) is composed of, for example, ethyl acetate, acetone, or acetonitrile as a solvent, and also trichloroisocyanuric acid (TCCA) as a solute. The concentration of trichloroisocyanuric acid in the first treatment liquid is, for example, 0.01 wt% to 1.0 wt%.

[0032] The nozzle (41b) is connected to the second supply unit (46b) via a valve (44b) and a flow regulator (45b). The second treatment liquid supplied from the second supply unit (46b) is, for example, TMAH (tetramethylammonium hydroxide) or an aqueous choline solution.

[0033] The nozzle (41c) is connected to the third supply unit (46c) via a valve (44c) and a flow regulator (45c). The third treatment liquid supplied from the third supply unit (46c) is, for example, ethyl acetate, acetone, or acetonitrile.

[0034] The nozzle (41d) is connected to the fourth supply unit (46d) via a valve (44d) and a flow regulator (45d). The rinse liquid supplied from the fourth supply unit (46d) is, for example, DIW (Deionized Water).

[0035] From the nozzle (41a), a first treatment liquid supplied from the first supply unit (46a) is discharged. From the nozzle (41b), a second treatment liquid supplied from the second supply unit (46b) is discharged. From the nozzle (41c), a third treatment liquid supplied from the third supply unit (46c) is discharged. From the nozzle (41d), a rinse liquid supplied from the fourth supply unit (46d) is discharged.

[0036] The recovery cup (50) is positioned to surround the holding portion (31) and collects the processing liquid scattered from the wafer (W) by the rotation of the holding portion (31). A drain port (51) is formed at the bottom of the recovery cup (50), and the processing liquid collected by the recovery cup (50) is discharged to the outside of the processing unit (16) through this drain port (51). Additionally, an exhaust port (52) is formed at the bottom of the recovery cup (50) to discharge the gas supplied from the FFU (21) to the outside of the processing unit (16).

[0037] Substrate Processing

[0038] Next, details of the substrate processing according to the embodiment will be explained with reference to FIGS. 3 to 7. FIG. 3 is a flowchart showing an example of the sequence of substrate processing according to the embodiment.

[0039] As shown in FIG. 3, in the substrate processing according to the embodiment, a preparatory process is first performed (step (S101)). In this preparatory process, for example, a wafer (W) is prepared in a state where the surface is in the state shown in FIG. 4. FIG. 4 is an enlarged cross-sectional view showing an example of the state of the wafer (W) surface after the preparatory process according to the embodiment.

[0040] The state shown in FIG. 4 is, first, by using a known film deposition method, on the surface of a wafer (W) SiO x (Silicon oxide) film, SiCN (silicon carbonitride) film, TiN (titanium nitride) film, Ru (ruthenium) film, SiCN film, SiO x Thin films are formed in the order of the membranes.

[0041] A Ru film is an example of a metal film. Furthermore, in the present disclosure, the Ru film is not limited to being composed solely of ruthenium, but only needs to contain at least ruthenium.

[0042] Next, using a known etching method, one or more (multiple in the drawing) indentations (T) are formed on the surface of the wafer (W). These indentations (T) are formed on the uppermost layer of SiOx It is formed to penetrate from the film to the TiN film. By doing so, the preparation process according to the embodiment is completed.

[0043] And, in the wafer (W) after the preparation process is completed, as shown in FIG. 4, a plurality of residues (A) are attached to the side of the Ru film exposed in the concave portion (T). These residues (A) are, for example, generated during the etching process that forms the concave portion (T), and are Ru oxide and Ru chloride, etc. The substrate treatment described later is performed primarily for the purpose of removing these plurality of residues (A).

[0044] Returning to the description of FIG. 3. Following the preparation process described so far, the control unit (18) (see FIG. 1) sets a counter (n) for counting the number of substrate processing steps to 1 (step (S102)).

[0045] In the substrate processing according to the embodiment, a chloride formation process is subsequently performed (step (S103)). In this chloride formation process, the control unit (18) holds the wafer (W) with the holding unit (31) (see FIG. 2), and then controls the liquid supply unit (40) (see FIG. 2) to supply a first processing liquid to the rotating wafer (W) from the nozzle (41a) (see FIG. 2).

[0046] Accordingly, as shown in FIG. 5, a film of Ru chloride (RuCl3) is formed on the surface of the Ru film exposed in the concave portion (T). FIG. 5 is an enlarged cross-sectional view showing an example of the state of the wafer (W) surface after chloride formation treatment according to an embodiment.

[0047] Ru chloride (RuCl3) is an example of a metal chloride. The film of this Ru chloride (RuCl3) has a thickness on the order of atomic layers, for example, a thickness of 1 nm or less.

[0048] In this way, in the embodiment, trichloroisocyanuric acid included in the first treatment solution reacts with ruthenium in the Ru film, thereby forming a film of Ru chloride (RuCl3) of atomic layer order on the surface of the Ru film.

[0049] In addition, in the embodiment, the first treatment solution may contain 0.01 to 1.0 wt% of trichloroisocyanuric acid. By doing so, a film of Ru chloride (RuCl3) of atomic layer order can be efficiently formed on the surface of the Ru film.

[0050] In addition, in the embodiment, ethyl acetate, acetone, or acetonitrile, which are organic solvents, may be used as the solvent of the first treatment solution. In this way, by using an organic solvent other than water as the solvent of the first treatment solution, the surface of the Ru film on which the Ru chloride (RuCl3) film is formed can be suppressed from being unexpectedly etched by water.

[0051] Returning to the description of FIG. 3. In the substrate processing according to the embodiment, a rinse treatment is subsequently performed (step (S104)).

[0052] In this rinsing process, the control unit (18) controls the liquid supply unit (40), etc., and supplies a third treatment liquid, such as ethyl acetate, acetone, or acetonitrile, from the nozzle (41c) (see FIG. 2) to the wafer (W) that is rotated and wet with the first treatment liquid. By doing so, the first treatment liquid is removed from the surface of the wafer (W), and the reaction between the Ru film and the first treatment liquid is stopped.

[0053] In addition, in the embodiment, ethyl acetate, acetone, or acetonitrile, which are organic solvents, may be used as the third treatment solution used for the rinsing treatment. In this way, by using an organic solvent instead of water for the rinsing treatment, the surface of the Ru film on which the Ru chloride (RuCl3) film is formed can be suppressed from being unexpectedly etched by water.

[0054] In addition, in the embodiment, it is preferable to use ethyl acetate as the third treatment solution. By doing so, the drying treatment described later can be performed at a suitable drying speed.

[0055] In the substrate processing according to the embodiment, a drying process is subsequently performed (step (S105)). In this drying process, the control unit (18) controls the substrate processing unit (30) and the liquid supply unit (40), etc., to stop the supply of the third processing liquid from the nozzle (41c), and also rotates the wafer (W) at high speed to shake off the third processing liquid. By doing so, a drying process is performed on the wafer (W).

[0056] In the substrate processing according to the embodiment, a chloride removal process is subsequently performed (step (S106)). In this chloride removal process, the control unit (18) controls the substrate processing unit (30) and the liquid supply unit (40), etc., and supplies a second processing liquid, such as TMAH or a choline aqueous solution, from the nozzle (41b) (see FIG. 2) to the rotating wafer (W).

[0057] Accordingly, as shown in FIG. 6, a film of Ru chloride (RuCl3) (see FIG. 5) formed on the surface of the Ru film is removed. FIG. 6 is an enlarged cross-sectional view showing an example of the state of the wafer (W) surface after chloride removal treatment according to an embodiment. Also, as shown in FIG. 6, in the third treatment solution, the Ru film itself is not etched.

[0058] As explained so far, in the substrate treatment according to the embodiment, the Ru film can be efficiently etched atomic layer by using the first treatment solution and the third treatment solution.

[0059] In addition, in an embodiment, a plurality of residues (A) (see FIG. 5) attached to a film of Ru chloride (RuCl3) are removed from the Ru film together with the film of Ru chloride (RuCl3). By doing so, a plurality of residues (A) can be efficiently removed.

[0060] In addition, in the embodiment, since the film thickness of Ru chloride (RuCl3) is on the order of atomic layers, damage to the Ru film can be minimized, and the increase in surface roughness of the Ru film due to etching treatment can also be suppressed.

[0061] In addition, in the embodiment, TMAH or an aqueous choline solution may be used as the third treatment solution. Thus, by using TMAH or an aqueous choline solution that does not contain metal elements as the third treatment solution for removing the Ru chloride (RuCl3) film, contamination of the wafer (W), etc. with metal elements can be suppressed.

[0062] Returning to the description of FIG. 3. In the substrate treatment according to the embodiment, following the chloride removal treatment described so far, a rinsing treatment is performed (step (S107)).

[0063] In this rinsing process, the control unit (18) controls the liquid supply unit (40), etc., and supplies DIW, which is the rinsing liquid, from the nozzle (41d) (see FIG. 2) to the wafer (W) that is rotated and also wet with the second treatment liquid. By doing so, the second treatment liquid is removed from the surface of the wafer (W).

[0064] In the substrate processing according to the embodiment, a drying process is subsequently performed (step (S108)). In this drying process, the control unit (18) controls the substrate processing unit (30) and the liquid supply unit (40), etc., to stop the supply of rinse liquid from the nozzle (41d), and also rotates the wafer (W) at high speed to shake off the rinse liquid. By doing so, a drying process is performed on the wafer (W).

[0065] In the substrate processing according to the embodiment, the control unit (18) then determines whether the counter (n) indicating the number of substrate processing operations is greater than or equal to the given number (N) (step (S109)).

[0066] Then, if the counter (n) is greater than or equal to the number of times the substrate is processed (N) (step (S109), Yes), the series of substrate processing is terminated. Meanwhile, if the counter (n) is not greater than or equal to the number of times the substrate is processed (N) (step (S109), No), the control unit (18) increments the counter (n) indicating the number of times the substrate is processed (step (S110)), and returns to the processing of step (S103).

[0067] In this way, in the embodiment, the processing of steps (S103 to S108) may be performed sequentially. By doing so, the surface of the Ru film can be etched with high precision to a desired thickness.

[0068] In addition, in an embodiment, the Ru film is SiO x It is preferable that it be located on a film of at least one type selected from SiCN, SiN (silicon nitride), SiOC (silicon oxycarbide), and TiN. Accordingly, by substrate treatment according to the embodiment, SiO x At least one type of film among , SiCN, SiN, SiOC and TiN can suppress etching together with the Ru film.

[0069] FIG. 7 is a figure showing the relationship between the number of substrate treatment steps according to an embodiment and the etching thickness of various materials. In addition, in the example of FIG. 7, a treatment solution in which 1.0 wt% of trichloroisocyanuric acid is added to ethyl acetate is used as the first treatment solution, ethyl acetate is used as the second treatment solution, and 1 mol / L of TMAH is used as the third treatment solution. In addition, in the example of FIG. 7, the temperature of each treatment solution is room temperature.

[0070] As shown in FIG. 7, in the substrate treatment according to the embodiment, the amount of Ru etched increases linearly as the number of treatment cycles increases. Meanwhile, SiO x It can be seen that in , SiCN, SiN, SiOC, and TiN, the amount of etching hardly increases even when the number of processing cycles is increased.

[0071] That is, in the substrate treatment according to the embodiment, Ru, SiO x Among SiCN, SiN, SiOC, and TiN, only Ru can be selectively etched. Therefore, according to the embodiment, in a device structure as shown in FIG. 4, the device structure can be maintained well in that only the Ru film can be selectively etched.

[0072] A substrate processing method according to an embodiment includes a forming process (step (S103)) and a removing process (step (S106)). The forming process (step (S103)) involves treating the surface of a metal film (Ru film) containing ruthenium with a first treatment solution to form a metal chloride (Ru chloride (RuCl3)) on the surface of the metal film (Ru film). The removing process (step (S106)) involves removing the metal chloride (Ru chloride (RuCl3)) with a second treatment solution. By doing so, the Ru film can be efficiently etched atomic layers.

[0073] In addition, in the substrate treatment method according to the embodiment, the first treatment solution contains 0.01 to 1.0 wt% of trichloroisocyanuric acid. By doing so, a film of Ru chloride (RuCl3) of atomic layer order can be efficiently formed on the surface of the Ru film.

[0074] In addition, in the substrate treatment method according to the embodiment, the solvent of the first treatment solution is ethyl acetate, acetone, or acetonitrile. By doing so, the surface of the Ru film on which the Ru chloride (RuCl3) film is formed can be suppressed from being unexpectedly etched by water.

[0075] In addition, in the substrate processing method according to the embodiment, the metal film (Ru film) is SiO x It is located on at least one film among SiCN, SiN, SiOC, and TiN. By doing so, the device structure on the wafer (W) can be maintained well.

[0076] In addition, in the substrate treatment method according to the embodiment, the second treatment solution is TMAH or a choline aqueous solution. By doing so, contamination of the wafer (W), etc. with metal elements can be suppressed.

[0077] In addition, the substrate treatment method according to the embodiment further includes a rinsing process (step (S104)) and a drying process (step (S105)). The rinsing process (step (S104)) is performed after the forming process (step (S103)) and rinses the surface of the metal chloride (Ru chloride (RuCl3)) with a third treatment solution. The drying process (step (S105)) is performed after the rinsing process (step (S104)) and dries the surface of the metal chloride (Ru chloride (RuCl3)). By doing so, the formation of Ru chloride (RuCl3) with an excessive film thickness on the surface of the Ru film can be suppressed.

[0078] In addition, in the substrate treatment method according to the embodiment, the third treatment solution is ethyl acetate, acetone, or acetonitrile. By doing so, the surface of the Ru film on which the Ru chloride (RuCl3) film is formed can be prevented from being unexpectedly etched by water.

[0079] In addition, in the substrate processing method according to the embodiment, the forming process (step (S103)) and the removing process (step (S106)) are performed sequentially. By doing so, the surface of the Ru film can be etched with high precision to a desired thickness.

[0080] In addition, in the substrate treatment method according to the embodiment, the film thickness of the metal chloride (Ru chloride (RuCl3)) is 1 nm or less. By doing so, damage to the Ru film can be minimized, and the increase in surface roughness of the Ru film can also be suppressed.

[0081] Additionally, the substrate processing device according to the embodiment comprises a holding unit (31), a liquid supply unit (40), and a control unit (18). The holding unit (31) holds and rotates a substrate (wafer (W)) on which a metal film (Ru film) containing ruthenium is formed. The liquid supply unit (40) supplies a processing liquid to the substrate (wafer (W)) held by the holding unit (31). The control unit (18) controls each unit. Additionally, the control unit (18) treats the surface of the metal film (Ru film) with a first processing liquid to form a metal chloride (Ru chloride (RuCl3)) on the surface of the metal film (Ru film), and removes the metal chloride (Ru chloride (RuCl3)) with a second processing liquid. By doing so, the Ru film can be efficiently etched atomic layers.

[0082] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and various modifications are possible as long as they do not deviate from the spirit thereof. For example, in the above embodiments, an example in which the technology of the present disclosure is applied to a wafer (W) with a surface structure shown in FIG. 4 has been shown, but the present disclosure is not limited to such an example.

[0083] For example, the technology of the present disclosure may be applied to a Ru film that is embedded in a concave portion formed on a wafer (W) and has an exposed upper surface. By doing so, the Ru film can also be efficiently etched atomic layers.

[0084] The embodiments disclosed herein should be assumed not to be limited to examples in all respects. Indeed, the above embodiments may be implemented in various forms. Furthermore, the above embodiments may be omitted, substituted, or modified in various forms without departing from the scope and intent of the appended claims.

Claims

Claim 1 A substrate treatment method comprising: a process of treating the surface of a metal film containing ruthenium with a first treatment solution to form a metal chloride on the surface of the metal film; and a process of removing the metal chloride with a second treatment solution. Claim 2 A substrate treatment method according to claim 1, wherein the first treatment solution contains 0.01 to 1.0 wt% of trichloroisocyanuric acid. Claim 3 In claim 2, the solvent of the first treatment solution is ethyl acetate, acetone, or acetonitrile, in the substrate treatment method. Claim 4 In any one of claims 1 to 3, the metal film is SiO x A substrate processing method positioned on a film of at least one type among , SiCN, SiN, SiOC, and TiN. Claim 5 A method for treating a substrate in which the second treatment solution is TMAH or a choline aqueous solution, in any one of claims 1 to 3. Claim 6 A substrate treatment method according to any one of claims 1 to 3, further comprising a process of rinsing the surface of the metal chloride with a third treatment solution after the forming process, and a process of drying the surface of the metal chloride after the rinsing process. Claim 7 In claim 6, the third treatment solution is a substrate treatment method in which ethyl acetate, acetone, or acetonitrile is used. Claim 8 A substrate processing method according to any one of claims 1 to 3, wherein the forming process and the removing process are performed sequentially. Claim 9 A substrate processing method according to any one of claims 1 to 3, wherein the thickness of the metal chloride film is 1 nm or less. Claim 10 A substrate processing apparatus comprising a holding unit for holding and rotating a substrate having a metal film containing ruthenium formed thereon, a liquid supply unit for supplying a processing liquid to the substrate held in the holding unit, and a control unit for controlling each unit, wherein the control unit processes the surface of the metal film with a first processing liquid to form a metal chloride on the surface of the metal film and removes the metal chloride with a second processing liquid.

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