Substrate processing method, substrate processing device, method for producing semiconductor device, and semiconductor production device

Abstract

The present invention provides: a substrate processing method that makes it possible to efficiently form a self-assembled monolayer film on a substrate surface in a short time, the self-assembled monolayer film having excellent density and protection performance due to suppression or reduction in the occurrence of film defects; a substrate processing device; a method for producing a semiconductor device; and a semiconductor production device. The substrate processing method according to the present invention for forming a SAM on a surface Wf of a substrate W includes: a surface modification step S102 for performing surface modification that enables formation of a SAM on the surface Wf of the substrate W; a first contact step S104 for forming a SAM by bringing a first processing liquid containing a first molecule 5 capable of forming a SAM into contact with the surface Wf of the substrate W after the surface modification step S102; and a second contact step S106 for bringing a second processing liquid containing a second molecule 8 of the same kind as or different kind from the first molecule 5 into contact with the surface Wf of the substrate W after the first contact step S104 to chemisorb the second molecule 8 in a region where the SAM is not formed. The second contact step S106 is performed at least once until the area ratio (%) of a film defect of the SAM formed on the surface Wf of the substrate W becomes equal to or less than an arbitrarily set threshold.

Description

Substrate processing method, substrate processing apparatus, semiconductor device manufacturing method, and semiconductor manufacturing apparatus

[0001] The present invention relates to a substrate processing method and apparatus capable of efficiently forming a self-assembled monolayer having excellent density and protective performance in a short time, as well as a semiconductor device manufacturing method and semiconductor manufacturing apparatus.

[0002] In the manufacture of semiconductor devices, photolithography is widely used as a technique for selectively forming a film on a specific surface region of a substrate. For example, after forming a lower layer wiring, an insulating film is formed, and then a dual damascene structure having trenches and via holes is formed by photolithography and etching, and a conductive film such as Cu is filled in the trenches and via holes to form wiring.

[0003] However, in recent years, as semiconductor devices have become increasingly miniaturized, the alignment accuracy of photolithography has become insufficient, and therefore there is a demand for an alternative method to photolithography that can selectively form films in specific regions on the substrate surface with high precision.

[0004] For example, Patent Document 1 discloses a method for manufacturing a silicon nitride (SiN) film and a silicon oxide (SiO ２ In a substrate having a silicon nitride film and a silicon dioxide film formed in the surface thereof, a method is disclosed in which a hot phosphoric acid resistant material is formed as a SAM in advance on the surface of the silicon dioxide film in order to selectively etch the silicon nitride film.

[0005] In order to adequately protect the silicon oxide film from the etching solution, it is necessary to form a highly dense SAM. However, with conventional SAM formation methods, it is difficult to form such a highly dense SAM in a short time, resulting in poor production efficiency.

[0006] Japanese Patent No. 5490071

[0007] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a substrate processing method and substrate processing apparatus, as well as a semiconductor device manufacturing method and semiconductor manufacturing apparatus, that are capable of efficiently depositing a self-assembled monolayer having excellent density and protective performance on a substrate surface in a short time by suppressing or reducing the occurrence of film defects.

[0008] In order to solve the above-mentioned problems, the present invention provides a substrate processing method for forming a self-assembled monolayer on a surface of a substrate, the method comprising: a surface modification step of modifying the surface of the substrate to enable the formation of the self-assembled monolayer; a first contact step of contacting the surface of the substrate after the surface modification step with a first treatment liquid containing first molecules capable of forming the self-assembled monolayer, thereby forming the self-assembled monolayer; and a second contact step of contacting the surface of the substrate after the first contact step with a second treatment liquid containing second molecules of the same or different species as the first molecules, thereby chemically adsorbing the second molecules to areas where the self-assembled monolayer is not formed, wherein the second contact step is performed at least once until the area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the substrate becomes equal to or less than an arbitrarily set threshold value.

[0009] According to the above-described configuration, first, in the surface modification step, a surface modification that enables the formation of a self-assembled monolayer (hereinafter, sometimes referred to as "SAM") is performed on the substrate surface. Subsequently, in the first contact step, a first treatment liquid containing first molecules capable of forming a SAM is contacted with the surface-modified substrate surface. This causes the first molecules to chemisorb to the substrate surface and self-assemble to form a SAM. Here, in the SAM formed in the first contact step, film defects may occur due to the first molecules being unable to chemisorb to the substrate surface locally. In particular, if the contact time of the first molecules with the substrate surface is short, the frequency of film defects within the surface increases or the area of ​​the film defects increases. However, in the above-described configuration, in the second contact step, a second treatment liquid containing second molecules of the same or different species as the first molecules is contacted with the substrate surface after the first contact step. This causes the second molecules to chemisorb to areas where no SAM has been formed, thereby reducing or repairing film defects in the SAM. Furthermore, this second contact step is performed at least once until the area ratio (%) of film defects in the SAM falls below an arbitrarily set threshold value. Therefore, with the above configuration, unlike conventional substrate processing methods, the occurrence of film defects can be suppressed without requiring the SAM molecules to be in contact with the substrate surface for a long period of time in order to form a dense SAM, and a SAM with excellent denseness and protective performance can be efficiently formed in a short period of time.

[0010] In the above configuration, it is preferable that the second molecules have a molecular chain length equal to or shorter than that of the first molecules. This prevents or reduces the possibility that the second molecules will be unable to chemisorb to the substrate surface due to steric hindrance between the second molecules and the first molecules already chemisorbed to the substrate surface. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0011] Furthermore, in the above-described configuration, when the second contact step is performed multiple times, it is preferable that the second molecule used in the earlier step has a molecular chain length equal to or longer than that of the second molecule used in the later step. This prevents or reduces the inability of the second molecule to be chemisorbed in the later step to chemisorb due to steric hindrance between the second molecule and the first molecule or second molecule already chemisorbed on the substrate surface, even when the second contact step is performed multiple times. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0012] Furthermore, in the above-described configuration, it is preferable that the first molecule and the second molecule have functional groups capable of undergoing a dehydration condensation reaction with hydroxyl groups, the surface modification step is a step of adding the hydroxyl groups to the surface of the substrate, and the first contact step and the second contact step are steps of chemically adsorbing the first molecule or the second molecule to the surface of the substrate by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the substrate.

[0013] Furthermore, in the above-described configuration, the surface modification step can be a step of providing the hydroxyl groups to the surface of the substrate by contacting the surface of the substrate with a surface modification liquid consisting of an alkaline solution or by irradiating the surface of the substrate with ultraviolet light in an atmosphere containing oxygen atoms. This allows for the introduction of hydroxyl groups in the surface modification step to be performed effectively. As a result, SAM molecules can be chemically adsorbed to the surface of the substrate at an even higher density, resulting in the formation of a SAM with even greater density and protective performance.

[0014] In order to solve the above-mentioned problems, the method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device that includes processing a substrate having a laminate provided on a surface thereof, wherein the laminate includes a layer to be protected that is to be protected from etching and a layer to be etched that is to be etched that are alternately stacked, and includes a step of selectively forming a self-assembled monolayer on at least the surface of the layer to be protected, and a step of selectively etching the layer to be etched using the self-assembled monolayer as a protective layer, and the step of forming the self-assembled monolayer includes a surface modification step of performing surface modification on the surface of the layer to be protected that enables the formation of the self-assembled monolayer. a first contacting step of contacting the surface of the layer to be protected after the surface modification step with a first treatment liquid containing first molecules capable of forming the self-assembled monolayer to form the self-assembled monolayer; and a second contacting step of contacting the surface of the substrate after the first contacting step with a second treatment liquid containing second molecules of the same or different species as the first molecules to chemically adsorb the second molecules to areas where the self-assembled monolayer is not formed, wherein the second contacting step is performed at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the layer to be protected becomes equal to or less than an arbitrarily set threshold value.

[0015] According to the above-described configuration, first, in the surface modification step, a surface modification that enables the formation of a SAM is performed on the surface of the protected layer. Then, in the first contact step, a first treatment liquid containing first molecules capable of forming a SAM is contacted with the surface of the protected layer after the surface modification. This causes the first molecules to chemisorb to the surface of the protected layer and self-assemble to form a SAM. The SAM formed in the first contact step may have film defects due to the first molecules being unable to chemisorb locally on the surface of the protected layer. In particular, if the contact time of the first molecules with the surface of the protected layer is short, the frequency of in-plane film defects increases or the area of ​​the film defects increases. However, in the above-described configuration, in the second contact step, a second treatment liquid containing second molecules, either identical or different to the first molecules, is contacted with the surface of the protected layer after the first contact step. This causes the second molecules to chemisorb to areas where no SAM has formed, thereby reducing or repairing the film defects in the SAM. Furthermore, this second contact step is performed at least once until the area ratio (%) of film defects in the SAM falls below an arbitrarily set threshold value. Therefore, with the above configuration, it is possible to suppress the occurrence of film defects without requiring the SAM molecules to be in contact with the surface of the layer to be protected for a long period of time in order to form a dense SAM, as in conventional semiconductor device manufacturing methods, and to efficiently form a SAM with excellent density and protective performance in a short period of time.

[0016] In the above configuration, it is preferable that the second molecule has a molecular chain length equal to or shorter than that of the first molecule. This prevents or reduces the possibility that the second molecule will be unable to chemisorb to the surface of the layer to be protected due to steric hindrance between the second molecule and the first molecule already chemisorbed to the surface of the layer to be protected. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0017] Furthermore, in the above-described configuration, when the second contact step is performed multiple times, it is preferable that the second molecule used in the earlier step has a molecular chain length equal to or longer than that of the second molecule used in the later step. This prevents or reduces the inability of the second molecule to be chemisorbed in the later step to chemisorb due to steric hindrance between the second molecule and the first molecule or second molecule already chemisorbed on the surface of the layer to be protected, even when the second contact step is performed multiple times. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0018] Furthermore, in the above-described configuration, it is preferable that the first molecule and the second molecule have functional groups capable of undergoing a dehydration condensation reaction with hydroxyl groups, the surface modification step is a step of adding the hydroxyl groups to the surface of the protected layer, and the first contact step and the second contact step are steps of chemically adsorbing the first molecule or the second molecule to the surface of the protected layer through a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the protected layer.

[0019] Furthermore, in the above-described configuration, the surface modification step can be a step of providing the hydroxyl groups to the surface of the substrate by contacting the surface of the substrate with a surface modification liquid consisting of an alkaline solution or by irradiating the surface of the substrate with ultraviolet light in an atmosphere containing oxygen atoms. This allows for the introduction of hydroxyl groups in the surface modification step to be performed effectively. As a result, SAM molecules can be chemically adsorbed to the surface of the protected layer with even higher density, resulting in the formation of a SAM with even greater density and protective performance.

[0020] In order to solve the above-mentioned problems, the substrate processing apparatus of the present invention is a substrate processing apparatus that forms a self-assembled monolayer on a surface of a substrate, and includes: a surface modification unit that performs surface modification on the surface of the substrate to enable the formation of the self-assembled monolayer; and a first processing liquid supply unit that forms the self-assembled monolayer by supplying a first processing liquid containing first molecules that can form the self-assembled monolayer to the surface of the substrate that has been surface-modified by the surface modification unit, and is characterized in that the second processing liquid supply unit supplies the second processing liquid at least once until the area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the substrate becomes equal to or less than an arbitrarily set threshold value.

[0021] According to the above-described configuration, the surface modification unit performs surface modification on the substrate surface, thereby enabling the formation of a SAM. Furthermore, the first processing liquid supply unit supplies a first processing liquid containing first molecules that enable the formation of a SAM to the surface-modified substrate surface, thereby chemically adsorbing the first molecules and forming a SAM. Here, in the SAM formed on the substrate surface, film defects may occur due to the first molecules being unable to chemically adsorb to the substrate surface in localized areas. In particular, if the contact time of the first molecules with the substrate surface is short, the frequency of film defects within the surface increases, or the area of ​​the film defects increases. However, the above-described configuration further includes a second processing liquid supply unit that supplies a second processing liquid containing second molecules, either identical or different to the first molecules, to the substrate surface. This allows the second molecules to chemically adsorb to areas where no SAM has formed, thereby reducing or repairing film defects in the SAM. Furthermore, the second processing liquid supply unit supplies the second processing liquid at least once until the area ratio (%) of film defects in the SAM becomes equal to or less than an arbitrarily set threshold value. Therefore, with the above configuration, unlike conventional substrate processing apparatuses, the occurrence of film defects can be suppressed without requiring SAM molecules to be in contact with the substrate surface for a long period of time in order to form a dense SAM, and a SAM with excellent denseness and protective performance can be efficiently formed in a short period of time.

[0022] In the above configuration, the second molecules may have a molecular chain length equal to or shorter than that of the first molecules. This prevents or reduces the possibility that the second molecules will be unable to chemisorb to the substrate surface due to steric hindrance between the second molecules and the first molecules already chemisorbed to the substrate surface. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0023] Furthermore, in the above configuration, when the second processing liquid supply unit supplies the second processing liquid to the surface of the substrate multiple times, it is preferable that the second molecules contained in the first supply of the second processing liquid have a molecular chain length equal to or longer than that of the second molecules contained in the second processing liquid supplied later. This prevents or reduces the inability of the second molecules to be chemisorbed in a later step to chemisorb due to steric hindrance between the second molecules and the first and second molecules already chemisorbed to the substrate surface, even when the second processing liquid supply unit supplies the second processing liquid multiple times. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0024] Furthermore, in the above configuration, it is preferable that the first molecule and the second molecule have functional groups capable of dehydration condensation reactions with hydroxyl groups, the surface modification unit performs the surface modification by adding the hydroxyl groups to the surface of the substrate, and the first processing liquid supply unit and the second processing liquid supply unit chemically adsorb the first molecule or the second molecule to the surface of the substrate by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the substrate.

[0025] Furthermore, in the above-described configuration, the surface modification unit is preferably a surface modification liquid supply unit that supplies a surface modification liquid consisting of an alkaline solution to the surface of the substrate to impart hydroxyl groups to the surface of the substrate, or an ultraviolet irradiation unit that imparts hydroxyl groups to the surface of the substrate by irradiating the surface of the substrate with ultraviolet light in an atmosphere containing oxygen atoms. The surface modification liquid supply unit and the ultraviolet irradiation unit can introduce more hydroxyl groups to the substrate surface. As a result, more SAM molecules can be chemically adsorbed to the substrate surface, forming a SAM with excellent density and protective performance.

[0026] In order to solve the above-mentioned problems, the semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus for processing a substrate having a laminate provided on its surface, the laminate including a layer to be protected that is an object to be protected from etching and a layer to be etched that is an object to be etched that are alternately stacked, the semiconductor manufacturing apparatus including a surface modification unit that performs surface modification on the surface of the layer to be protected to enable the formation of a self-assembled monolayer, a first processing liquid supply unit that supplies a first processing liquid containing first molecules capable of forming the self-assembled monolayer to the surface of the layer to be protected that has been surface-modified by the surface modification unit, thereby forming the self-assembled monolayer, and a second processing liquid supply unit that supplies a second processing liquid containing first molecules capable of forming the self-assembled monolayer to the surface of the layer to be protected that has been surface-modified by the surface modification unit, the first ... a second treatment liquid supply unit that supplies a second treatment liquid containing second molecules of the same or different species as the first molecules to the surface of the layer to be protected, on which a self-assembled monolayer has been formed, thereby chemically adsorbing the second molecules to areas where the self-assembled monolayer has not been formed; and an etching unit that selectively etches and removes the layer to be etched, using the self-assembled monolayer as a protective layer, wherein the second treatment liquid supply unit supplies the second treatment liquid at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the layer to be protected becomes equal to or less than an arbitrarily set threshold value.

[0027] The semiconductor manufacturing apparatus of the above configuration enables highly selective etching of the layer to be etched by forming a SAM on at least the surface of the layer to be protected before etching the layer to be etched. In the above configuration, the surface modification unit performs surface modification on the surface of the layer to be protected, thereby enabling the formation of a SAM. Furthermore, the first processing liquid supply unit supplies a first processing liquid containing first molecules that enable the formation of a SAM to the surface of the layer to be protected after the surface modification, thereby chemically adsorbing the first molecules and forming a SAM. However, in the SAM formed on the surface of the layer to be protected, film defects may occur due to localized inability of the first molecules to chemically adsorb to the surface of the layer to be protected. In particular, if the contact time of the first molecules with the surface of the layer to be protected is short, the frequency of film defects within the surface may increase, or the area of ​​the film defects may become larger. However, the above configuration further includes a second processing liquid supply unit that supplies a second processing liquid containing second molecules, the same or different from the first molecules, to the surface of the layer to be protected. This allows the second molecules to be chemically adsorbed even in areas where no SAM is formed, thereby reducing or repairing film defects in the SAM. Furthermore, the second processing liquid supply unit supplies the second processing liquid at least once until the area ratio (%) of film defects in the SAM falls below an arbitrarily set threshold. Therefore, with this configuration, unlike conventional semiconductor manufacturing equipment, the occurrence of film defects can be suppressed without requiring SAM molecules to be in contact with the surface of the protected layer for a long period of time to form a dense SAM, and a SAM with excellent density and protective performance can be efficiently formed in a short period of time.

[0028] In order to achieve the above object, the semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus for processing a substrate having a laminate provided on its surface, the laminate including an alternately stacked layer to be protected from etching and an etched layer to be etched, the apparatus comprising: a substrate processing unit for selectively forming a self-assembled monolayer on at least the surface of the protected layer; and an etching processing unit for selectively etching and removing the etched layer using the self-assembled monolayer as a protective layer, the substrate processing unit including a surface modification section for performing surface modification on the surface of the protected layer to enable the formation of the self-assembled monolayer; and a substrate processing unit for selectively etching and removing the etched layer by the surface modification section. and a second treatment liquid supply unit that supplies a second treatment liquid that contains second molecules, the same or different from the first molecules, to the surface of the protected layer on which the self-assembled monolayer has been formed, thereby chemically adsorbing the second molecules to areas where the self-assembled monolayer has not been formed, wherein the second treatment liquid supply unit supplies the second treatment liquid at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the protected layer becomes equal to or less than an arbitrarily set threshold value.

[0029] The semiconductor manufacturing apparatus having the above configuration includes at least a substrate processing unit that selectively forms a SAM on a layer to be protected and an etching processing unit that selectively etches and removes the layer to be etched. By forming a SAM on at least the surface of the layer to be protected in the substrate processing unit and protecting it before etching the layer to be etched in the etching processing unit, excellent selective etching of the layer to be etched is possible. In the above configuration, the surface modification unit performs surface modification on the surface of the layer to enable the formation of a SAM. Furthermore, the first processing liquid supply unit supplies a first processing liquid containing first molecules that enable the formation of a SAM to the surface of the layer to be protected after the surface modification, thereby chemically adsorbing the first molecules to form a SAM. The SAM formed on the surface of the layer to be protected may have film defects due to localized inability of the SAM molecules to chemically adsorb to the surface of the layer to be protected. In particular, if the contact time of the SAM molecules with the surface of the layer to be protected is short, the frequency of film defects within the surface may increase or the area of ​​the film defects may become larger. However, the above-described configuration further includes a second processing liquid supply unit that supplies a second processing liquid containing second molecules, either identical or different from the first molecules, to the surface of the protected layer. This allows the second molecules to be chemically adsorbed even in areas where SAMs are not formed, thereby reducing or repairing SAM film defects. Furthermore, the second processing liquid supply unit supplies the second processing liquid at least once until the area ratio (%) of SAM film defects falls below an arbitrarily set threshold. Therefore, the above-described configuration suppresses the occurrence of film defects without requiring prolonged contact of SAM molecules with the surface of the protected layer to form a dense SAM, as is the case with conventional semiconductor manufacturing equipment. This allows for efficient formation of a SAM with excellent density and protective performance in a short time.

[0030] In the above configuration, the second molecules may have a molecular chain length equal to or shorter than that of the first molecules. According to the above configuration, the surface modifying liquid supply unit supplies a surface modifying liquid composed of an alkaline solution to the surface of the layer to be protected, thereby imparting hydroxyl groups to the surface of the layer to be protected. This minimizes the area where SAM molecules with hydroxyl groups cannot be chemically adsorbed, allowing more SAM molecules to be chemically adsorbed to the surface of the layer to be protected at high density. As a result, a SAM with excellent density and protective performance can be formed.

[0031] Furthermore, in the above configuration, when the second processing liquid supply unit supplies the second processing liquid to the surface of the protected layer multiple times, it is preferable that the second molecules contained in the first processing liquid supply have a molecular chain length equal to or longer than that of the second molecules contained in the second processing liquid supplied later. This prevents or reduces the inability of the second molecules to be chemisorbed in a later step to chemisorb due to steric hindrance between the second molecules and the first and second molecules already chemisorbed to the surface of the protected layer, even when the second processing liquid supply unit supplies the second processing liquid multiple times. As a result, film defects in the SAM can be further reduced or repaired, and a SAM with excellent density and protective performance can be formed.

[0032] Furthermore, in the above configuration, it is preferable that the first molecule and the second molecule have functional groups capable of dehydration condensation reactions with hydroxyl groups, the surface modification unit performs the surface modification by adding the hydroxyl groups to the surface of the substrate, and the first processing liquid supply unit and the second processing liquid supply unit chemically adsorb the first molecule or the second molecule to the surface of the substrate by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the substrate.

[0033] Furthermore, in the above-described configuration, the surface modification unit is preferably a surface modification liquid supply unit that supplies a surface modification liquid consisting of an alkaline solution to the surface of the protected layer to impart hydroxyl groups to the surface of the protected layer, or an ultraviolet irradiation unit that imparts hydroxyl groups to the surface of the protected layer by irradiating the surface of the substrate with ultraviolet light in an atmosphere containing oxygen atoms. The surface modification liquid supply unit and the ultraviolet irradiation unit can introduce more hydroxyl groups to the surface of the protected layer. As a result, more SAM molecules can be chemically adsorbed to the surface of the protected layer, forming a SAM with excellent density and protective performance.

[0034] According to the present invention, it is possible to provide a substrate processing method and substrate processing apparatus, as well as a semiconductor device manufacturing method and semiconductor manufacturing apparatus, which are capable of effectively suppressing or reducing the occurrence of film defects and efficiently forming a self-assembled monolayer on a substrate surface that has high film density, fineness, and excellent protective performance in a shorter time than conventional methods.

[0035] 2A and 2B are cross-sectional views schematically showing a laminate provided on a substrate, in which FIG. 2A shows the state before the etching process and FIG. 2B shows the state after the etching process. FIG. 2A is a partially enlarged view of the portion surrounded by A in FIG. 1A, and FIG. 2B shows the SiO ２ 4(a) is a partial enlarged view showing a state in which a SAM is formed on the surface of the layer, and FIG. 4(c) is a partial enlarged view of the part surrounded by B in the stack of FIG. 1(b), showing a state in which the SiN layer has been etched. FIG. 4(a) is a flowchart showing an example of the overall flow of the method for manufacturing a semiconductor device according to the first embodiment of the present invention. FIG. 4(b) is a partial enlarged view showing a state in which a SAM is formed on the surface of the layer, and FIG. 4(c) is a partial enlarged view of the part surrounded by B in the stack of FIG. 1(b), showing a state in which the SiN layer has been etched. ２ FIG. 4(b) is an explanatory diagram conceptually showing the surface state of the SiO layer after surface modification. ２ 4(c) is a diagram conceptually illustrating the surface state of the layer, and FIG. 4(d) is a diagram conceptually illustrating the surface state of the layer when the first treatment liquid is SiO ２ 5A is an explanatory diagram showing how the first molecule is supplied to the surface of the layer. ２ FIG. 5(b) is an explanatory diagram showing the chemical adsorption of the first molecule to the surface of the layer. ２ 5(c) is an explanatory diagram showing the state in which the second treatment liquid self-assembles on the surface of the layer to form a SAM.２ 1 is an explanatory diagram showing a state in which a SAM is supplied to the surface of a layer; FIG. 2 is an explanatory diagram showing the state of a SAM after a densification treatment; FIG. 3 is an explanatory diagram showing a schematic configuration of a semiconductor manufacturing apparatus according to a first embodiment of the present invention; FIG. 4 is an explanatory diagram showing a schematic configuration of a pre-treatment liquid storage unit in a pre-treatment liquid supply unit in a semiconductor manufacturing apparatus according to a first embodiment of the present invention; FIG. 5 is an explanatory diagram showing a schematic configuration of a surface modification liquid storage unit provided in a surface modification liquid supply unit in a semiconductor manufacturing apparatus according to a first embodiment of the present invention; FIG. 6 is an explanatory diagram showing a schematic configuration of a first treatment liquid storage unit and an ultrasonic application unit in a first treatment liquid supply unit in a semiconductor manufacturing apparatus according to a first embodiment of the present invention; FIG. 7 is an explanatory diagram showing a schematic configuration of an etching liquid storage unit in an etching liquid supply unit in a first embodiment of the present invention;

[0036] First Embodiment A first embodiment of the present invention will be described below.

[0037] [Substrate Processing Method (Semiconductor Device Manufacturing Method)] First, a substrate processing method according to the present embodiment will be described below with reference to the drawings. The substrate processing method of the present embodiment provides a technique for enabling good selective etching when forming a three-dimensional structure, such as a three-dimensional NAND structure, on the surface of a substrate.

[0038] The substrate processing method of this embodiment can be applied to part of the process of forming a three-dimensional NAND structure on a substrate W made of silicon or the like. Therefore, hereinafter, an example in which the substrate processing method of this embodiment is applied to a semiconductor device manufacturing method will be described, more specifically, an example in which processing is performed on a substrate W provided with a three-dimensional stack 3 as shown in Fig. 1. Fig. 1 is a cross-sectional view schematically showing the stack provided on the substrate W, with Fig. 1(a) showing the state before the etching step and Fig. 1(b) showing the state after the etching step.

[0039] As shown in FIG. 2( a ), the laminate 3 is formed by depositing a SiO 2 film, which functions as an interlayer insulating layer, on a substrate W. ２ The stack 3 includes a structure in which a layer 1 and a SiN layer 2 functioning as a sacrificial layer are alternately stacked. The stack 3 is provided with a plurality of memory trenches 4 extending through the stack 3 in a direction perpendicular to the surface of the substrate W. Note that Fig. 2(a) is a partial enlarged view of the portion surrounded by A in the stack of Fig. 1(a).

[0040] 3, the method for manufacturing a semiconductor device according to this embodiment includes at least a self-assembled monolayer (hereinafter referred to as "SAM") formation step S1 and an etching step S2, and enables selective etching of the SiN layer 2 through the memory trench 4 to form a recess on the side surface of the memory trench 4 in the stack 3. FIG. 3 is a flowchart showing an example of the overall flow of the method for manufacturing a semiconductor device according to this embodiment.

[0041] <SAM Formation Step> In the SAM formation step S1, a SAM as a protective layer is formed on a SiO ２ 3, the SAM formation step S1 includes at least a pretreatment step S101, a surface modification step S102, a first treatment liquid preparation step S103, a first contact step S104, a second treatment liquid preparation step S105, and a second contact step S106. The SAM formation step S1 corresponds to the substrate processing method of the present invention.

[0042] 1. Pretreatment Step The pretreatment step S101 is to remove the SiO ２ It is physically adsorbed on the surface of layer 1 and formed into particles or thin films of SiO ２ The pretreatment step S101 is a step of removing organic molecules covering the surface of the layer 1. This step is optional, but is preferably performed from the viewpoint of improving the surface modification of the substrate W in the surface modification step S102 described below. Specifically, the pretreatment step S101 is performed by bringing a pretreatment liquid into contact with the surface of the substrate W.

[0043] The method for contacting the pretreatment liquid with the substrate W is not particularly limited, and examples thereof include a method of applying the pretreatment liquid to the surface of the substrate W, a method of spraying the pretreatment liquid onto the surface of the substrate W, and a method of immersing the substrate W in the pretreatment liquid.

[0044] One method for applying the pretreatment liquid to the surface of the substrate W is, for example, to supply the pretreatment liquid to the central portion of the surface of the substrate W while the substrate W is being rotated at a constant speed around its central portion as an axis. In this manner, the pretreatment liquid supplied to the surface of the substrate W flows from near the center of the surface of the substrate W toward the peripheral edge of the substrate W due to centrifugal force generated by the rotation of the substrate W, and is spread over the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the pretreatment liquid, and a liquid film of the pretreatment liquid is formed.

[0045] The conditions for contacting the substrate W with the pretreatment liquid are not particularly limited, but the time for which the substrate W is contacted with the pretreatment liquid (when the substrate W is immersed in the pretreatment liquid, the immersion time) is not particularly limited and can be set appropriately. However, by contacting the substrate W with the pretreatment liquid for 1 minute or less, the SiO ２ In this specification, the term "film defect" in the SAM refers to a defect in the SAM that occurs when the molecules constituting the SAM are not attached to the surface of the substrate W (in this embodiment, SiO ２ This means that the surface is not directly chemically adsorbed on the surface of the layer 1, but is exposed.

[0046] The temperature of the pretreatment solution is not particularly limited and can be set as needed, for example, to room temperature. In this specification, "room temperature" means a temperature range of 5°C to 35°C.

[0047] The pretreatment liquid is not particularly limited, and examples thereof include hydrofluoric acid (for example, HF:deionized water (DIW)=1:100 by volume).

[0048] 2. Surface Modification Step (Wet Method) The surface modification step S102 is carried out by, for example, applying a SiO ２This is a process for surface modification of the surface of layer 1, in which areas where chemical adsorption by the first molecules is difficult and where SAM formation is possible is made possible, into areas where chemical adsorption by the first molecules is possible. Furthermore, this is a process for making it possible to chemically adsorb the first molecules at a higher density in areas where chemical adsorption by the first molecules is possible. Figure 4(a) shows SiO before surface modification. ２ FIG. 2 is an explanatory diagram conceptually showing the surface state of layer 1.

[0049] Surface modification step S102 ２ When the surface of the layer 1 is subjected to surface modification, hydroxyl groups are added to the surface so that the first molecule can be chemically adsorbed, as shown in Figure 4(b). ２ FIG. 2 is an explanatory diagram conceptually showing the surface state of layer 1.

[0050] In this embodiment, SiO ２ The surface of the layer 1 is modified by a wet method. More specifically, the surface is modified by bringing a surface modification liquid into contact with the surface of the substrate W after the pretreatment step S101. The method for bringing the surface modification liquid into contact with the surface of the substrate W is not particularly limited, and examples thereof include a method of applying the surface modification liquid to the surface of the substrate W, a method of spraying the surface modification liquid onto the surface of the substrate W, and a method of immersing the substrate W in the surface modification liquid.

[0051] Furthermore, as a method for applying the surface modification liquid to the surface of the substrate W, for example, there is a method in which the surface modification liquid is supplied to the central portion of the surface of the substrate W while the substrate W is being rotated at a constant speed around its central portion as an axis. In this way, the surface modification liquid supplied to the surface of the substrate W flows from near the center of the surface of the substrate W toward the peripheral portion of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and is spread over the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the surface modification liquid, and a liquid film of the surface modification liquid is formed.

[0052] The surface modification liquid is SiO ２ There are no particular limitations on the surface modifying liquid as long as it can provide hydroxyl groups to the surface of the layer 1. Specific examples of the surface modifying liquid include an ammonia-hydrogen peroxide solution mixture (Standard Clean-1 (SC-1)) (in terms of volume ratio, ammonium water (NH ３Concentration 28%): Hydrogen peroxide (H ２ O ２ Examples of alkaline solutions include aqueous solutions containing 30% ammonium hydroxide (DIW:DIW=1:4:20), aqueous ammonia, tetramethylammonium hydroxide solution, and trimethyl-2-hydroxyethylammonium hydroxide solution. ２ From the viewpoint of being able to apply the solution to the layer well, an ammonia-hydrogen peroxide solution mixture or the like is preferred.

[0053] The conditions for contacting the substrate W with the surface modification liquid are not particularly limited, but the time for contacting the substrate W with the surface modification liquid (when the substrate W is immersed in the surface modification liquid, the immersion time) is not particularly limited and can be set appropriately. However, by contacting the substrate W with the surface modification liquid for 10 minutes or more, the SiO ２ It is possible to provide a sufficient number of hydroxyl groups on the surface of the layer 1. This reduces the area where the first molecules cannot be chemically adsorbed, and the first molecules are easily adsorbed onto the SiO ２ It can be chemically adsorbed at a high density onto the surface of layer 1. As a result, it is possible to suppress the occurrence of film defects and efficiently form a SAM with excellent density and protective performance in a short time.

[0054] The temperature of the surface modifying liquid is not particularly limited, and can be set to, for example, room temperature or the like as needed.

[0055] When the surface modification step S102 is performed using a wet method, a cleaning step to remove the surface modification liquid and a drying step may be performed sequentially immediately after the surface modification step S102. The cleaning method used in the cleaning step is not particularly limited, and examples include a method of supplying a cleaning liquid to the surface of the substrate W or a method of immersing the substrate W in a cleaning liquid. Examples of cleaning liquids include toluene, decane, and 1,3-bis(trifluoromethyl)benzene. These solvents can be used alone or in combination. The cleaning conditions, such as the cleaning time and the temperature of the cleaning liquid, are not particularly limited and can be set as needed. The drying step is intended to remove any remaining cleaning liquid from the surface of the substrate W. The drying method is not particularly limited, and examples include a method of spraying an inert gas, such as nitrogen gas, onto the surface of the substrate W. The drying conditions, such as the drying time and the drying temperature, are not particularly limited and can be set as needed.

[0056] 3. First Treatment Liquid Preparation Step The first treatment liquid preparation step S103 is a step of preparing a first treatment liquid containing first molecules. Examples of the first molecules contained in the first treatment liquid include those having a functional group capable of undergoing a dehydration condensation reaction with a hydroxyl group. When the first molecules have the functional group, the functional group and the SiO of the layer to be protected can be bonded to each other. ２ A dehydration condensation reaction can be caused between the first molecule and the hydroxyl group on the surface of the layer 1. As a result, the first molecule is condensed into the SiO ２ A SAM can be formed by direct chemical adsorption onto the surface of layer 1. In the following, an example will be described in which the functional group capable of undergoing a dehydration condensation reaction with a hydroxyl group is a hydroxyl group as the first molecule contained in the first treatment liquid.

[0057] First, a dispersion liquid in which water is uniformly dispersed in an organic solvent as a main solvent is prepared. "Uniform dispersion of water in an organic solvent" means, for example, that water is present in the organic solvent in the form of an emulsion. Furthermore, the "main solvent" refers to the solvent with the largest volume ratio when a mixed solvent consisting of multiple solvents is used.

[0058] Examples of organic solvents serving as the main solvent include ether solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, fluorine-containing solvents, and ketone-containing solvents. The ether solvent is not particularly limited, and examples thereof include tetrahydrofuran (THF). The aromatic hydrocarbon solvent is not particularly limited, and examples thereof include toluene. The aliphatic hydrocarbon solvent is not particularly limited, and examples thereof include decane. The fluorine-containing solvent is not particularly limited, and examples thereof include 1,3-bis(trifluoromethyl)benzene. The ketone-containing solvent is not particularly limited, and examples thereof include methyl ethyl ketone. These solvents can be used alone or in combination of two or more. Of the solvents listed above, aromatic hydrocarbon solvents are preferred, and toluene is particularly preferred, from the viewpoint of affinity with water. Furthermore, the organic solvent serving as the main solvent is preferably one having low water solubility. This allows water to be well dispersed in the organic solvent. Examples of organic solvents having low water solubility include the aforementioned toluene.

[0059] The amount of water added to the dispersion is preferably in the range of 50 ppm to 200 ppm, more preferably in the range of 50 ppm to 150 ppm. By adding 50 ppm or more of water, it is possible to prevent the hydrolysis reaction with water from resulting in insufficient introduction of hydroxyl groups (functional groups capable of dehydration condensation reactions with hydroxyl groups) into the first molecules. That is, a sufficient amount of first molecules with introduced hydroxyl groups can be present in the first treatment liquid at the stage of generating the first treatment liquid. As a result, unlike conventional substrate treatment methods, it is possible to suppress the occurrence of film defects and form a highly dense SAM without having to contact the treatment liquid with the substrate surface for a long period of time to form a dense SAM. On the other hand, by adding 200 ppm or less of water, it is possible to suppress excessive aggregation of first molecules with hydroxyl groups due to a dehydration condensation reaction. As a result, it is possible to suppress a decrease in the density of the first molecules chemically adsorbed to the substrate surface, thereby forming a highly dense SAM.

[0060] The method for preparing the dispersion is not particularly limited, and examples thereof include a method of mixing an organic solvent and water while applying ultrasonic waves, and a method of mixing an organic solvent and water and then applying ultrasonic waves. Applying ultrasonic waves can prevent the generation of a mixture separated into an organic solvent phase and an aqueous phase. The conditions for applying ultrasonic waves, specifically, for example, the application time, frequency, and sonic intensity, are not particularly limited as long as they are sufficient to disperse water in the organic solvent, and can be set appropriately as needed. The method for applying ultrasonic waves is also not particularly limited, and examples thereof include a method of immersing an ultrasonic vibrator in the mixture and vibrating the ultrasonic vibrator to apply ultrasonic waves.

[0061] The preparation of the dispersion is preferably carried out in an atmosphere of an inert gas such as nitrogen gas, for example. If the preparation is carried out in an environment in which moisture is present in the atmosphere, the moisture in the atmosphere will dissolve in the mixed liquid (or dispersion), making it impossible to obtain a dispersion with the desired moisture content, which is not preferable.

[0062] Next, a material capable of forming a SAM (hereinafter referred to as "SAM-forming material") is added to the prepared dispersion to prepare a first treatment liquid containing first molecules having hydroxyl groups. It is preferable to add the SAM-forming material to the dispersion without applying ultrasonic waves, and after adding the SAM-forming material to the dispersion. By not applying ultrasonic waves, the first treatment liquid can be generated so that the first molecules exist without agglomerating with each other. By generating the first treatment liquid so that the first molecules exist without agglomerating with each other, a SAM can be successfully formed in the first contact step S104 described below.

[0063] The SAM-forming material is not particularly limited as long as it has a functional group exhibiting hydrolysis reactivity and contains molecules capable of forming a SAM. Furthermore, the SAM-forming material is preferably one that has high affinity (solubility) for the aforementioned organic solvent. Specific examples of the SAM-forming material include octadecyltrichlorosilane (C １８ H ３７ SiCl ３ ), decyltrichlorosilane (C １０ H ２１ SiCl ３), trichloropropylsilane (C ３ H ７ SiCl ３ ), trichloromethylsilane (CH ３ SiCl ３ The exemplified organosilane compounds have a trichlorosilyl group as a functional group exhibiting hydrolysis reactivity.

[0064] Before being added to the first treatment liquid, the first molecule has a functional group exhibiting hydrolysis reactivity. Therefore, when the SAM-forming material is added to the dispersion, the functional group undergoes a hydrolysis reaction with the water molecules uniformly dispersed in the dispersion. As a result, the hydrolysis reactivity functional group becomes a functional group capable of undergoing a dehydration condensation reaction with a hydroxyl group. For example, when the first molecule is octadecyltrichlorosilane, the following reaction occurs: C １８ H ３７ SiCl ３ + 3H ２ O → C １８ H ３７ Si(OH) ３ + 3HCl ３ As a result, a first treatment liquid can be obtained in which the first molecules having hydroxyl groups introduced therein exist without agglomeration. By preparing a first treatment liquid containing first molecules having hydroxyl groups introduced therein in advance, the hydrolysis reaction, which is the rate-limiting step in the SAM film formation process, can be omitted. As a result, SAM film formation can be achieved in a shorter time than with conventional treatment liquids.

[0065] The amount of the SAM-forming material added is preferably within a range of 0.05% by mass or more and 5% by mass or less relative to the total mass of the first treatment liquid.

[0066] The first treatment liquid may contain known additives as long as they do not impair the effects of the present invention. The additives are not particularly limited, and examples thereof include stabilizers and surfactants.

[0067] The preparation of the first treatment liquid is preferably carried out in a stationary state. More specifically, when adding the SAM-forming material to the dispersion, it is not preferable to apply mechanical force such as stirring or shaking to the dispersion. If the SAM-forming material is added to the dispersion while applying mechanical force such as stirring or shaking to the dispersion, the first molecules may aggregate together. However, by preparing the first treatment liquid by adding the SAM-forming material to the dispersion in a stationary state, it is possible to further suppress the aggregation of the first molecules and generate the first treatment liquid.

[0068] The content of water in the first treatment liquid is preferably in the range of 50 ppm or more and 200 ppm or less, and more preferably in the range of 50 ppm or more and 150 ppm or less.

[0069] The first treatment liquid preparation step S103 can be performed, for example, at room temperature and atmospheric pressure. In this specification, "normal pressure" refers to pressure near the standard atmospheric state (standard atmospheric pressure), where the standard atmospheric state refers to a temperature of approximately 25°C and an atmospheric pressure of approximately 101 kPa absolute. "Normal pressure" also includes pressures that are slightly positive or negative relative to the standard atmospheric pressure.

[0070] 4. First Contacting Step The first contacting step S104 is a step of bringing a first processing liquid containing first molecules into contact with the surface of the substrate W to form a SAM.

[0071] The method for contacting the first processing liquid with the substrate W is not particularly limited, and examples include a method in which the first processing liquid is applied to the surface of the substrate W, a method in which the first processing liquid is sprayed onto the surface of the substrate W, and a method in which the substrate W is immersed in the first processing liquid.

[0072] One example of a method for applying the first processing liquid to the surface of the substrate W is to supply the first processing liquid to the central portion of the surface of the substrate W while rotating the substrate W at a constant speed around its central portion as an axis. As a result, the first processing liquid supplied to the surface of the substrate W flows from near the center of the surface of the substrate W toward the peripheral edge of the substrate W due to centrifugal force generated by the rotation of the substrate W, and is spread over the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the first processing liquid, and a liquid film of the first processing liquid is formed.

[0073] The conditions for bringing the first processing liquid into contact with the substrate W are not particularly limited. However, the first contacting step S104 of this embodiment can shorten the contact time of the first processing liquid compared to when a SAM is formed by a conventional method. Specifically, the time required for the SAM formation step S1 (when the SAM formation step S1 is performed by immersing the substrate W in the first processing liquid, the immersion time) can be appropriately set within a range of 1 minute to 1540 minutes, preferably 1 minute to 60 minutes, and more preferably 1 minute to 30 minutes, depending on the type and concentration of the SAM-forming material, the type of solvent, and the like.

[0074] Next, the SAM formation process will be described in more detail using an example in which the SAM-forming material is octadecyltrichlorosilane. As shown in Figure 4(c), when the first processing liquid is supplied to the surface of the substrate W, first molecules 5, in which hydroxyl groups have been introduced into octadecyltrichlorosilane, are dispersed in the first processing liquid at the beginning of the supply. Figure 4(c) shows the first processing liquid containing SiO ２ FIG. 1 is an explanatory diagram showing the state in which the material is supplied to the surface of layer 1.

[0075] Here, SiO ２ Hydroxyl groups have been introduced to the surface of the layer 1 in the surface modification step S102. Therefore, as shown in FIG. 5A, the first molecules 5 undergo a dehydration condensation reaction with the hydroxyl groups. More specifically, the hydroxyl groups of the first molecules 5 and the SiO ２ The first molecule 5 forms a siloxane bond by a dehydration condensation reaction with the hydroxyl group on the surface of the layer 1, and as a result, the first molecule 5 becomes SiO ２The first molecules 5 are chemically adsorbed on the surface of the layer 1. In the first treatment liquid, the first molecules 5 are present in a state where they are prevented from coagulating with each other. Therefore, the rate-determining step in the SAM film formation process is the separation of the hydroxyl groups of the first molecules 5 and the SiO ２ It is possible to promote the dehydration condensation reaction between the first molecules 5 and the hydroxyl groups on the surface of the layer 1. ２ The first molecule 5 can be chemically adsorbed on the surface of the layer 1. In addition, FIG. 5(a) shows the first molecule 5 being SiO ２ FIG. 2 is an explanatory diagram showing chemical adsorption on the surface of layer 1.

[0076] Next, the first molecule 5 is SiO ２ When the first molecules 5 are chemically adsorbed at a high density on the surface of the layer 1, an island-like structure of the first molecules 5 appears on the surface. Furthermore, in each island, the first molecules 5 self-organize and grow (expand) due to hydrophobic and electrostatic interactions with each other, and finally form a SAM 6 (see FIG. 5(b)). However, the first molecules 5 cannot enter the SAM 6, and the first molecules 5 are stuck between the boundaries between adjacent islands and in the SiO ２ Film defects 7 may occur in areas where the first molecules 5 are present adhering to the surface of the layer 1 without being chemically adsorbed. ２ FIG. 1 is an explanatory diagram showing the formation of a SAM 6 by self-organization on the surface of layer 1.

[0077] 5. Second Treatment Liquid Preparation Step The second treatment liquid preparation step S105 is a step of generating a second treatment liquid containing second molecules. The second molecules contained in the second treatment liquid have functional groups capable of dehydration condensation with hydroxyl groups, and SiO ２ Direct chemisorption onto the surface of layer 1 can reduce or repair film defects in the SAM.

[0078] The second treatment liquid can be prepared by the same method as the first treatment liquid, and the materials used for the first treatment liquid can be used without any restrictions as materials for preparing the second treatment liquid.

[0079] Here, the second molecules contained in the second treatment liquid may be the same or different from the first molecules. The second molecules preferably have the same or shorter molecular chain length as the first molecules, and more preferably have a shorter molecular chain length than the first molecules. For example, when the first molecules are C １８ H ３７ Si(OH) ３ In this case, the second molecule is C １０ H ２１ Si(OH) ３ , C ３ H ７ Si(OH) ３ , or CH ３ Si(OH) ３ and the like are preferred.

[0080] 6. Second Contacting Step The second contacting step S106 is a step of bringing a second processing liquid containing second molecules into contact with the surface of the substrate W after the first contacting step S104, repairing film defects 7 occurring in the SAM 6, and densifying the SAM 6. ２ This is repeated at least once until the area ratio (%) of film defects in the SAM formed on the surface of layer 1 becomes equal to or less than an arbitrarily set threshold. Here, the area ratio (%) of film defects in the SAM is defined by the following formula: Area ratio (%) of film defects = (total area of ​​film defects in an arbitrary region of the SAM) / (area in an arbitrary region of the SAM) × 100

[0081] The threshold value for the area ratio (%) of film defects is not particularly limited and can be set arbitrarily. The area ratio (%) of film defects can be calculated, for example, as follows. That is, for example, an atomic force microscope (AFM) is used to acquire an observation image (AFM image) of an arbitrary region where a SAM 6 is formed, and this observation image is binarized and further image processing is performed to map the film defects 7. This identifies the region of the film defects 7 on the SAM 6, calculates the area of ​​the identified region of the film defects 7 on the SAM 6, and then calculates the ratio of this region to the area of ​​the entire region in the observation image. In mapping the film defects 7, it is preferable to take the film thickness of the SAM 6 into consideration and perform image processing so that defects from the surface of the SAM 6 to a depth position not exceeding the film thickness of the SAM 6 are mapped.

[0082] When the second contact step S106 is performed multiple times, the second molecule contained in the second treatment solution may be changed for each step. In this case, it is preferable that the second molecule used in the earlier step has the same or longer molecular chain length as the second molecule used in the later step. For example, C １０ H ２１ Si(OH) ３ In the second contact step, C ３ H ７ Si(OH) ３ and CH ３ Si(OH) ３ It is preferable to use a second molecule such as SiO 2 or the like. As the number of times the second contact step is repeated, the second molecule is chemically adsorbed to the film defects 7 of the SAM 6, resulting in a reduction in the area of ​​the film defects 7. Therefore, in the subsequent step, it is preferable to use a second molecule with a short molecular chain length, since SiO 2 or the like is easily removed due to steric hindrance. ２ This reduces or prevents the layer 1 surface from becoming unable to perform chemical adsorption, thereby further improving the density.

[0083] The method of bringing the second processing liquid into contact with the substrate W is the same as that described in the first contacting step S104. Therefore, a detailed description thereof will be omitted. The conditions for bringing the second processing liquid into contact with the substrate W can be appropriately set depending on the type of the second processing liquid, etc.

[0084] When the SAM-forming material is octadecyltrichlorosilane, the surface of the SAM 6 in the second contact step S106 is as shown in Fig. 5(c). ２ 1 is an explanatory diagram showing a state in which the second processing liquid is supplied to the surface of the layer 1. That is, as shown in the figure, when the second processing liquid is supplied to the surface of the substrate W, second molecules 8 are dispersed in the second processing liquid at the beginning of supply. In the figure, the second molecules 8 are shown as trichloropropylsilane to which a hydroxyl group has been introduced. Here, the molecular chain length of the second molecules 8 is shorter than that of the first molecules 5' constituting the SAM 6. Therefore, the second molecules 8 can be easily mixed with the first molecules 5' constituting the SAM 6 without causing steric hindrance between them and the SiO 2 even in the region where the film defect 7 of the SAM 6 occurs. ２ The second molecules 8 undergo a dehydration condensation reaction with the hydroxyl groups on the surface of the layer 1. As a result, the second molecules 8 form siloxane bonds with the hydroxyl groups, resulting in SiO ２ The SAM 6 is chemically adsorbed onto the surface of the layer 1. As a result, the film defects 7 that occurred in the SAM 6 are repaired as shown in Figure 6, and a SAM 6' with excellent densification and protective performance is formed. Figure 6 is an explanatory diagram showing the state of the SAM 6' after the densification treatment.

[0085] 7. Other Steps Immediately after the first contact step S104 and the second contact step S106, a removal step and a drying step may be performed in sequence, respectively. ２ The first processing solution remaining on the surface of the layer 1 and the SiO ２ The second treatment liquid remaining on the surface of the layer 1 can be removed. As a result, the excess first molecules 5 and second molecules 8, more specifically, SiO ２ This allows the removal of the first molecules 5 and second molecules 8 that are not chemically adsorbed to the surface of the layer 1. As a result, it is possible to prevent a film made of the unadsorbed first molecules 5 and second molecules 8 from being formed on the SAM 6′, and it becomes possible to form a good monolayer.

[0086] The removal process is performed using SiO ２This is a step of replacing the first processing liquid or the second processing liquid (hereinafter, sometimes referred to as "first processing liquid, etc.") remaining on the surface of the layer 1 with a removing liquid. ２ The method for removing the layer 1 from the surface is not particularly limited, and examples include a method of applying the removal liquid to the surface of the substrate W, a method of spraying the removal liquid onto the surface of the substrate W, and a method of immersing the substrate W in the removal liquid.

[0087] One example of a method for applying the removing liquid to the surface of the substrate W is to rotate the substrate W at a constant speed around its central portion as an axis and supply the removing liquid to the central portion of the surface of the substrate W. As a result, the centrifugal force generated by the rotation of the substrate W causes the removing liquid supplied to the surface of the substrate W to flow from near the center of the surface of the substrate W toward the peripheral edge of the substrate W and spread over the entire surface of the substrate W. As a result, the first processing liquid and the like on the surface of the substrate W are replaced with the removing liquid, and the entire surface of the substrate W is covered with the removing liquid, forming a liquid film of the removing liquid.

[0088] The remover is not particularly limited, but an organic solvent that dissolves the SAM-forming material and has low water solubility is preferred. If the remover is capable of dissolving the SAM-forming material, it can effectively remove excess first molecules 5 and second molecules 8 that do not contribute to the formation of a SAM from the surface. More specific examples of the remover include toluene, decane, and 1,3-bis(trifluoromethyl)benzene. These solvents can be used alone or in combination of two or more.

[0089] The drying step is intended to remove the remover remaining on the surface of the substrate W. The drying method is not particularly limited, and examples thereof include a method of spraying an inert gas such as nitrogen gas onto the surface of the substrate W. Drying conditions such as drying time and drying temperature are not particularly limited as long as they are sufficient to remove the remover, and can be set appropriately as needed.

[0090] As a result, in the SAM formation step S1, as shown in FIG. ２ A SAM 6' having excellent density and protective properties can be formed on the surface of the layer 1. In this embodiment, in the surface modification step S102, SiO２ After introducing hydroxyl groups into the surface of the layer 1 in advance, a SAM 6 is formed in the first contact step S104. Furthermore, a densification treatment of the SAM 6 is performed in the second contact step S106, thereby repairing film defects 7 occurring in the SAM 6. As a result, in order to form a dense film, the treatment liquid is changed to SiO ２ Even if the surface of the layer 1 is not in contact for a long time, the occurrence of film defects is suppressed, and a SAM 6' having excellent density and protective performance can be efficiently formed in a short time.

[0091] In this embodiment, a rinsing step and another drying step may be performed immediately after the drying step. ２ The remover can be removed from the surface of the layer 1. Also, by carrying out another drying step, the rinse liquid used in the rinsing step can be removed.

[0092] The rinse liquid used in the rinse step is not particularly limited, and examples thereof include DIW, etc. The method for supplying the rinse liquid to the surface of the substrate W is not particularly limited, and examples thereof include a method of applying the rinse liquid to the surface of the substrate W, a method of spraying the rinse liquid onto the surface of the substrate W, and a method of immersing the substrate W in the rinse liquid.

[0093] One method for applying the rinse liquid to the surface of the substrate W is, for example, to supply the rinse liquid to the central portion of the surface of the substrate W while the substrate W is being rotated at a constant speed around its central portion as an axis. In this manner, the rinse liquid supplied to the surface of the substrate W flows from near the center of the surface of the substrate W toward the peripheral edge of the substrate W due to centrifugal force generated by the rotation of the substrate W, and is spread over the entire surface of the substrate W. As a result, the removing liquid on the surface of the substrate W is replaced with the rinse liquid, and the entire surface of the substrate W is covered with the rinse liquid, forming a liquid film of the rinse liquid.

[0094] The other drying step is intended to remove the rinse liquid remaining on the surface of the substrate W. The drying method is not particularly limited, and examples thereof include a method of spraying an inert gas such as nitrogen gas onto the surface of the substrate W. Drying conditions such as drying time and drying temperature are not particularly limited as long as they are sufficient to remove the rinse liquid, and can be set appropriately as needed.

[0095] <Etching Step (Single-Wafer Process)> The etching step S2 is a step of selectively etching the SiN layer 2, which is a sacrificial layer and also a layer to be etched. More specifically, this is a step of bringing an etching solution into contact with the SiN layer 2 through the memory trench 4 to remove the SiN layer 2. In this step, the SAM 6' is formed of SiO 2 as a protective layer. ２ It serves to protect layer 1. ２ This effectively prevents the layer 1 from being etched.

[0096] A method for applying the etching liquid to the surface of the substrate W, for example, in the case of a single-wafer process, is to supply the etching liquid to the central portion of the surface of the substrate W while rotating the substrate W at a constant speed around its central portion as an axis. In this way, the etching liquid supplied to the surface of the substrate W flows from near the center of the surface of the substrate W toward the peripheral edge of the substrate W due to the centrifugal force generated by the rotation of the substrate W, and is spread over the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the etching liquid, and a liquid film of the etching liquid is formed.

[0097] The etching liquid can be appropriately selected in consideration of the constituent material of the layer to be etched, the etching rate, etc. When the layer to be etched is a SiN layer 2 as in this embodiment, the etching liquid may be, for example, phosphoric acid (H ３ P.O. ４ For example, an aqueous solution of HF and DIW or hydrofluoric acid (for example, a volume ratio of HF:DIW=1:100) can be used. The concentration of the etching solution can also be appropriately set in consideration of the constituent material of the layer to be etched, the etching rate, etc.

[0098] The etching temperature (i.e., the temperature of the etching solution) and the etching rate for the layer to be etched can be appropriately set in consideration of the constituent material of the layer to be etched.

[0099] It is preferable to sequentially perform a rinsing step to remove the etching liquid and a drying step immediately after the etching step S2. The rinsing method in the rinsing step is not particularly limited, and examples thereof include a method of supplying a rinsing liquid to the surface of the substrate W and a method of immersing the substrate W in the rinsing liquid. The rinsing liquid is not particularly limited, and examples thereof include DIW. Furthermore, cleaning conditions such as the rinsing time and the temperature of the rinsing liquid are not particularly limited and can be set appropriately as needed. The drying step is intended to remove the rinsing liquid remaining on the surface of the substrate W. The drying method is not particularly limited, and examples thereof include a method of spraying an inert gas such as nitrogen gas onto the surface of the substrate W. Drying conditions such as the drying time and drying temperature are not particularly limited, and can be set appropriately as needed.

[0100] As a result, in the etching step S2, only the SiN layer 2 can be selectively removed as shown in FIG. ２ In the layer 1, the SAM 6' having excellent density and protective performance covers and protects the surface, so that the SiO ２ Layer 1 is etched, and the etched silicon component is precipitated, resulting in SiO ２ This prevents the silicon from adhering to the surface of the layer 1. Furthermore, it is possible to increase the tolerance for the silicon concentration contained in the etching solution such as phosphoric acid. Note that Fig. 2(c) is a partial enlarged view of the portion surrounded by B in the stack of Fig. 1(b), showing the state after the SiN layer 2 has been etched.

[0101] [Substrate Processing Apparatus (Semiconductor Manufacturing Apparatus)] Next, the substrate processing apparatus according to this embodiment will be described below by taking as an example a case where it is applied to a semiconductor manufacturing apparatus.

[0102] The semiconductor manufacturing apparatus 100 of this embodiment is a single-wafer processing unit used to form a SAM and etch a layer to be etched, and as shown in FIG. 7 , includes a substrate holding unit 110 that holds a substrate W, a pretreatment liquid supply unit 120 that supplies a pretreatment liquid to the front surface Wf of the substrate W, a surface modification liquid supply unit (surface modification unit) 130 that supplies a surface modification liquid to the front surface Wf of the substrate W, a first processing liquid supply unit 140 that supplies a first processing liquid to the front surface Wf of the substrate W, an ultrasonic wave application unit, a second processing liquid supply unit 150 that supplies a second processing liquid, an inert gas supply unit (not shown) that supplies an inert gas, an etching liquid supply unit (etching unit) 160, a chamber 170 that is a container for accommodating the substrate W, a splash prevention cup 180 that collects the processing liquid, a swivel drive unit 190 that independently swivels the arms of each unit (described later), and a control unit 300. The semiconductor manufacturing apparatus 100 may also be provided with a loading / unloading means (not shown) for loading and unloading the substrate W. Fig. 7 is an explanatory diagram showing the schematic configuration of the semiconductor manufacturing apparatus 100 according to this embodiment. In this figure, XYZ orthogonal coordinate axes are displayed as appropriate to clarify the directional relationships of the objects shown. Here, the XY plane represents the horizontal plane, and the +Z direction represents the vertically upward direction.

[0103] <Substrate Holding Unit> The substrate holding unit 110 is a means for holding the substrate W, and as shown in Fig. 7, holds and rotates the substrate W in a substantially horizontal position with the front surface Wf of the substrate W facing upward. The substrate holding unit 110 has a spin chuck 113 in which a spin base 111 and a rotation support shaft 112 are integrally connected. The spin base 111 has a substantially circular shape in a plan view, and a hollow rotation support shaft 112 extending substantially vertically is fixed to its center. The rotation support shaft 112 is connected to a rotation shaft of a chuck rotation mechanism 114 including a motor. The chuck rotation mechanism 114 is housed in a cylindrical casing 115, and the rotation support shaft 112 is supported by the casing 115 so as to be rotatable about a vertical rotation axis J1.

[0104] The chuck rotation mechanism 114 can rotate the rotation support shaft 112 about the rotation axis J1 by being driven by a chuck drive unit (not shown) of the control unit 300. As a result, the spin base 111 attached to the upper end of the rotation support shaft 112 rotates about the rotation axis J1 at a constant speed. The control unit 300 can adjust the rotation speed of the spin base 111 by controlling the chuck rotation mechanism 114 via the chuck drive unit.

[0105] A plurality of chuck pins 116 for gripping the peripheral edge of the substrate W are provided upright near the peripheral edge of the spin base 111. There is no particular limitation on the number of chuck pins 116 to be provided, but it is preferable to provide at least three or more in order to securely hold the circular substrate W. In this embodiment, three chuck pins 116 are arranged at equal intervals along the peripheral edge of the spin base 111. Each chuck pin 116 includes a substrate support pin that supports the peripheral edge of the substrate W from below, and a substrate holding pin that holds the substrate W by pressing against the outer peripheral edge surface of the substrate W supported by the substrate support pin.

[0106] <Pre-treatment liquid supply unit> The pre-treatment liquid supply unit 120 according to this embodiment is a unit that supplies a pre-treatment liquid to the front surface Wf of the substrate W. As shown in FIG. 7 , the pre-treatment liquid supply unit 120 includes a pre-treatment liquid storage unit 121, a nozzle 122, and an arm 123.

[0107] 8, the pretreatment liquid storage unit 121 includes a pressurizing unit 124 and a pretreatment liquid tank 125. Note that, FIG. 8 is an explanatory diagram illustrating a schematic configuration of the pretreatment liquid storage unit 121 in the pretreatment liquid supply unit 120.

[0108] The pressurizing unit 124 includes a nitrogen gas supply source 124a, which is a gas supply source for pressurizing the inside of the pretreatment liquid tank 125, a pump (not shown) for pressurizing the nitrogen gas, a nitrogen gas supply pipe 124b, and a valve 124c provided midway along the nitrogen gas supply pipe 124b.

[0109] The nitrogen gas supply pipe 124b is connected to the treatment liquid tank 125. The valve 124c is electrically connected to the control unit 300, and the opening and closing of the valve 124c can be controlled by an operation command from the control unit 300. When the valve 124c is opened by an operation command from the control unit 300, nitrogen gas can be supplied to the treatment liquid tank 125.

[0110] The pretreatment liquid tank 125 may include an agitation unit that agitates the pretreatment liquid in the pretreatment liquid tank 125 and a temperature adjustment unit that adjusts the temperature of the pretreatment liquid (neither is shown). The agitation unit may include a rotation unit that agitates the pretreatment liquid and an agitation control unit that controls the rotation of the rotation unit. The agitation control unit is electrically connected to the control unit 300, and the rotation unit includes, for example, a propeller-shaped agitation blade at the lower end of the rotation shaft. The control unit 300 issues an operation command to the agitation control unit to rotate the rotation unit, thereby agitating the pretreatment liquid with the agitation blade. As a result, the concentration and temperature of the pretreatment liquid can be made uniform in the pretreatment liquid tank 125.

[0111] Furthermore, a discharge pipe 125a for supplying the pretreatment liquid to the nozzle 122 is connected to the pretreatment liquid tank 125. A discharge valve 125b is provided midway along the discharge pipe 125a. The discharge valve 125b is also electrically connected to the control unit 300. This allows the opening and closing of these valves to be controlled by an operation command from the control unit 300. When the discharge valve 125b is opened by an operation command from the control unit 300, the pretreatment liquid is pressure-fed to the nozzle 122 via the discharge pipe 125a.

[0112] The nozzle 122 is attached to the tip of a horizontally extending arm 123, and is positioned above the spin base 111 when discharging the pretreatment liquid. The arm 123 is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to a control unit 300, and rotates the arm 123 in response to an operation command from the control unit 300. As the arm 123 rotates, the nozzle 122 also moves.

[0113] <Surface Modification Liquid Supply Unit (Surface Modification Unit)> The surface modification liquid supply unit 130 according to this embodiment is a unit that supplies a surface modification liquid to the front surface Wf of the substrate W. As shown in FIG. 7 , the surface modification liquid supply unit 130 includes a surface modification liquid storage unit 131, a nozzle 132, and an arm 133.

[0114] 9, the surface modification liquid storage unit 131 has a function of supplying the surface modification liquid to the nozzle 132, and includes a pressurizing unit 134 and a surface modification liquid tank 135. Fig. 9 is an explanatory diagram showing a schematic configuration of the surface modification liquid storage unit 131 in the surface modification liquid supply unit 130.

[0115] The pressurizing unit 134 includes a nitrogen gas supply source 134a, which is a gas supply source for pressurizing the surface modification liquid tank 135, a pump (not shown) for pressurizing the nitrogen gas, a nitrogen gas supply pipe 134b, and a valve 134c provided midway along the nitrogen gas supply pipe 134b.

[0116] The nitrogen gas supply pipe 134b is connected to the surface modification liquid tank 135. The valve 134c is electrically connected to the control unit 300, and the opening and closing of the valve 134c can be controlled by an operation command from the control unit 300. When the valve 134c is opened by an operation command from the control unit 300, nitrogen gas can be supplied to the surface modification liquid tank 135.

[0117] The surface modification liquid tank 135 may include an agitation unit that agitates the surface modification liquid in the surface modification liquid tank 135 and a temperature adjustment unit that adjusts the temperature of the surface modification liquid (neither is shown). Examples of the agitation unit include a rotation unit that agitates the surface modification liquid in the surface modification liquid tank 135 and an agitation control unit that controls the rotation of the rotation unit. The agitation control unit is electrically connected to the control unit 300, and the rotation unit is equipped with, for example, a propeller-shaped agitation blade at the lower end of the rotation shaft. The control unit 300 issues an operation command to the agitation control unit to rotate the rotation unit, thereby agitating the surface modification liquid with the agitation blade. As a result, the concentration and temperature of the surface modification liquid can be made uniform within the surface modification liquid tank 135.

[0118] Furthermore, a discharge pipe 135a for supplying the surface modification liquid to the nozzle 132 is connected to the surface modification liquid tank 135. A discharge valve 135b is provided midway along the discharge pipe 135a. The discharge valve 135b is electrically connected to the control unit 300. This allows the opening and closing of the discharge valve 135b to be controlled by an operation command from the control unit 300. When the discharge valve 135b is opened by an operation command from the control unit 300, the surface modification liquid is pressure-fed to the nozzle 132 via the discharge pipe 135a.

[0119] The nozzle 132 is attached to the tip of a horizontally extending arm 133, and is positioned above the spin base 111 when discharging the surface modification liquid. The arm 133 is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to the control unit 300, and rotates the arm 133 in response to an operation command from the control unit 300. As the arm 133 rotates, the nozzle 132 also moves.

[0120] <First Processing Liquid Supply Unit> The first processing liquid supply unit 140 according to this embodiment is a unit that supplies a first processing liquid to the front surface Wf of the substrate W. As shown in FIG. 7 , the first processing liquid supply unit 140 includes a first processing liquid storage unit 141, a first nozzle 142, and a first arm 143.

[0121] 10 , the first treatment liquid storage unit 141 includes a first organic solvent supply unit 144, a first water supply unit 145, a first SAM-forming material supply unit 146, a first treatment liquid tank 147, a first temperature adjustment unit 148, and a first inert gas supply unit 149. Note that, FIG. 10 is an explanatory diagram showing a schematic configuration of the first treatment liquid storage unit 141 and the ultrasonic wave application unit 191 in the first treatment liquid supply unit 140.

[0122] The first organic solvent supply unit 144 includes a first organic solvent reservoir 144a for storing an organic solvent, a first organic solvent supply pipe 144b for supplying the organic solvent to the first treatment liquid tank 147, and a first valve 144c provided along the first organic solvent supply pipe 144b. The first valve 144c is electrically connected to the control unit 300. This allows the opening and closing of the first valve 144c to be controlled by an operational command from the control unit 300. When the first valve 144c is opened by an operational command from the control unit 300, the organic solvent is supplied to the first treatment liquid tank 147 via the first organic solvent supply pipe 144b. The organic solvent in the first organic solvent reservoir 144a is pressurized by a pressurizing means (not shown) and sent to the first organic solvent supply pipe 144b. The pressurizing means is not particularly limited, and a known means such as a pump can be used.

[0123] The first water supply unit 145 includes a first water storage unit 145a that stores water, a first water supply pipe 145b for supplying water to the first treatment liquid tank 147, and a first valve 145c provided midway along the first water supply pipe 145b. The first valve 145c is electrically connected to the control unit 300. This allows the opening and closing of the first valve 145c to be controlled by an operational command from the control unit 300. When the first valve 145c is opened by an operational command from the control unit 300, water is supplied to the first treatment liquid tank 147 via the first water supply pipe 145b. The water in the first water storage unit 145a is pressurized by a pressurizing means (not shown) and sent to the first water supply pipe 145b. The pressurizing means is not particularly limited, and a known means such as a pump can be used.

[0124] The first SAM-forming material supply unit 146 includes a first SAM-forming material storage unit 146a that stores the SAM-forming material, a first SAM-forming material supply pipe 146b that supplies the SAM-forming material to the first processing liquid tank 147, and a first valve 146c that is provided midway along the first SAM-forming material supply pipe 146b. The first valve 146c is electrically connected to the control unit 300. This allows the opening and closing of the first valve 146c to be controlled by an operation command from the control unit 300. When the first valve 146c is opened by an operation command from the control unit 300, the SAM-forming material is supplied to the first processing liquid tank 147 via the first SAM-forming material supply pipe 146b. The SAM-forming material in the first SAM-forming material storage unit 146a is pressurized by a pressurizing means (not shown) and then sent to the first SAM-forming material supply pipe 146b. The pressurizing means is not particularly limited, and known means such as a pump can be used.

[0125] The first treatment liquid tank 147 mixes the organic solvent supplied from the first organic solvent supply unit 144 with the water supplied from the first water supply unit 145, and the ultrasonic application unit 191 applies ultrasonic waves to the resulting mixture, thereby producing a dispersion in which water is uniformly dispersed in the organic solvent. Alternatively, the ultrasonic application unit 191 can apply ultrasonic waves while mixing the organic solvent supplied from the first organic solvent supply unit 144 with the water supplied from the first water supply unit 145, thereby producing the dispersion. Furthermore, a treatment liquid can be produced by supplying a SAM-forming material from the first SAM-forming material supply unit 146 while the produced dispersion is stored in the tank.

[0126] The first treatment liquid tank 147 may include a first temperature adjustment unit 148 for adjusting the temperature of the dispersion liquid and the first treatment liquid stored therein. The first temperature adjustment unit 148 is electrically connected to the control unit 300. The control unit 300 issues an operation command to the first temperature adjustment unit 148, thereby controlling the liquid temperature of the dispersion liquid when the dispersion liquid is produced. This makes it possible to prevent water in the dispersion liquid from evaporating (evaporating) and causing a change in the composition of the dispersion liquid.

[0127] The first inert gas supply unit 149 includes a first inert gas supply source 149a which is a supply source for supplying inert gas into the first processing liquid tank 147, a pump (not shown) for pressurizing the inert gas, a first inert gas supply pipe 149b, and a first valve 149c provided midway along the first inert gas supply pipe 149b.

[0128] The first inert gas supply pipe 149b is connected to the first treatment liquid tank 147. The first valve 149c is electrically connected to the control unit 300, and the opening and closing of the first valve 149c can be controlled by an operation command from the control unit 300. When the valve is opened by an operation command from the control unit 300, the inert gas can be supplied to the first treatment liquid tank 147. This allows the dispersion liquid and the first treatment liquid to be produced in an inert gas atmosphere. The inert gas is not particularly limited, and examples thereof include nitrogen gas.

[0129] Furthermore, a first discharge pipe 147a is connected to the first treatment liquid tank 147 to supply the first treatment liquid to the first nozzle 142. A first discharge valve 147b is provided midway along the first discharge pipe 147a. The first discharge valve 147b is also electrically connected to the control unit 300. This allows the opening and closing of the first discharge valve 147b to be controlled by an operation command from the control unit 300. When the first discharge valve 147b and the first valve 149c are opened and the first valves 144c, 145c, and 146c are closed in response to an operation command from the control unit 300, the first treatment liquid is pressure-fed to the first nozzle 142 via the first discharge pipe 147a.

[0130] The first nozzle 142 is attached to the tip of a first arm 143 that extends horizontally, and is positioned above the spin base 111 when discharging the first processing liquid. The first arm 143 is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to a control unit 300, and rotates the first arm 143 in response to an operation command from the control unit 300. As the first arm 143 rotates, the first nozzle 142 also moves.

[0131] <Second Processing Liquid Supply Unit> The second processing liquid supply unit 150 according to this embodiment is a unit that supplies the second processing liquid to the front surface Wf of the substrate W. As shown in FIG. 7 , the second processing liquid supply unit 150 includes a second processing liquid storage unit 151, a second nozzle 152, and a second arm 153.

[0132] The second processing liquid storage section 151 may have the same configuration as the first processing liquid storage section 141 shown in Fig. 10. Therefore, a detailed description thereof will be omitted.

[0133] The second nozzle 152 is attached to the tip of a second arm 153 that extends horizontally, and is positioned above the spin base 111 when discharging the second treatment liquid. The second arm 153 is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to a control unit 300, and rotates the second arm 153 in response to an operation command from the control unit 300. As the second arm 153 rotates, the second nozzle 152 also moves.

[0134] 10 , the ultrasonic wave application unit 191 is a unit that applies ultrasonic waves when a dispersion is produced in the first treatment liquid tank 147 of the first treatment liquid supply unit 140. The ultrasonic wave application unit 191 is also a unit that applies ultrasonic waves when a dispersion is produced in the second treatment liquid tank of the second treatment liquid supply unit 150. The ultrasonic wave application unit 191 is electrically connected to the control unit 300, and the application of ultrasonic waves can be controlled by operation commands from the control unit 300.

[0135] The ultrasonic wave application unit 191 includes, for example, at least an ultrasonic vibrator provided in the first treatment liquid tank 147 (in the second treatment liquid tank in the second treatment liquid storage unit 151) and an oscillator (both not shown) that applies a drive voltage to the ultrasonic vibrator. Examples of ultrasonic vibrators include a piezoelectric body such as a piezoelectric ceramic and a pair of electrodes provided on the piezoelectric body. The pair of electrodes are in contact with the piezoelectric body and are also electrically connected to the oscillator. When the oscillator outputs, for example, a high-frequency voltage as a drive voltage to the ultrasonic vibrator in response to an operation command from the control unit 300, the drive voltage is applied between the pair of electrodes, thereby applying the drive voltage to the piezoelectric body. When the drive voltage is applied, the piezoelectric body vibrates by alternately contracting and expanding in response to the drive voltage from the oscillator. This allows ultrasonic waves to be applied to the mixture of water and organic solvent stored in the first treatment liquid tank 147 or the second treatment liquid tank.

[0136] <Removing Liquid Supply Unit> The removing liquid supply unit according to this embodiment is a unit that supplies the removing liquid to the front surface Wf of the substrate W. This removing liquid supply unit has a removing liquid storage unit, a nozzle, and an arm (none of which are shown).

[0137] The removing liquid reservoir has a function of supplying the removing liquid to the nozzle, and includes a pressurizing unit and a removing liquid tank.

[0138] The pressurizing unit includes a nitrogen gas supply source that supplies gas to pressurize the inside of the removal liquid tank, a pump that pressurizes the nitrogen gas, a nitrogen gas supply pipe, and a valve provided midway along the nitrogen gas supply pipe.

[0139] The nitrogen gas supply pipe is connected to the removal liquid tank. The valve is electrically connected to the control unit 300, and the opening and closing of the valve can be controlled by an operation command from the control unit 300. When the valve is opened by an operation command from the control unit 300, nitrogen gas can be supplied to the removal liquid tank.

[0140] The remover tank may include an agitator that agitates the remover liquid in the remover liquid tank and a temperature adjuster that adjusts the temperature of the remover liquid (neither is shown). Examples of the agitator include a rotor that agitates the remover liquid in the remover liquid tank and an agitation controller that controls the rotation of the rotor. The agitation controller is electrically connected to the controller 300, and the rotor has, for example, a propeller-shaped agitator blade at the bottom end of the rotation shaft. The controller 300 issues an operation command to the agitation controller to rotate the rotor, thereby agitating the remover liquid with the agitator blade. As a result, the concentration and temperature of the remover liquid can be made uniform within the remover liquid tank.

[0141] Furthermore, a discharge pipe for supplying the removal liquid to the nozzle is connected to the removal liquid tank. A discharge valve is provided midway along this discharge pipe. This discharge valve is electrically connected to the control unit 300. This allows the opening and closing of the discharge valve to be controlled by an operation command from the control unit 300. When the discharge valve is opened by an operation command from the control unit 300, the removal liquid is pressure-fed to the nozzle via the discharge pipe.

[0142] The nozzle is attached to the tip of a horizontally extending arm, and is positioned above the spin base 111 when discharging the removal solution. The arm is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to a control unit 300, and rotates the arm in response to an operation command from the control unit 300. As the arm rotates, the nozzle also moves.

[0143] <Inert Gas Supply Unit> The inert gas supply unit is a unit that supplies an inert gas to the front surface Wf of the substrate W. The inert gas supply unit has an inert gas reservoir, a nozzle, and an arm (none of which are shown).

[0144] The inert gas storage unit has a function of supplying an inert gas to the nozzle, and includes an inert gas tank for storing the inert gas, an inert gas temperature adjusting unit for adjusting the temperature of the inert gas stored in the inert gas tank, and piping. The inert gas stored in the inert gas tank can be, for example, nitrogen gas.

[0145] The inert gas temperature adjusting unit is electrically connected to the control unit 300, and adjusts the temperature by heating or cooling the inert gas stored in the inert gas tank in response to an operation command from the control unit 300. The inert gas temperature adjusting unit is not particularly limited, and any known temperature adjusting mechanism such as a Peltier element or a pipe through which temperature-adjusted water flows can be used.

[0146] The inert gas storage section is connected to the nozzle via a pipe, and a valve is inserted in the middle of the pipe. The inert gas in the inert gas tank is pressurized by a pressurizing means (not shown) and sent to the pipe. The pressurizing means can be realized by pressurizing with a pump or the like, or by compressing and storing the inert gas in the inert gas tank.

[0147] The valve is electrically connected to the control unit 300 and is normally closed. Opening and closing of the valve is controlled by an operation command from the control unit 300. When the valve is opened by an operation command from the control unit 300, an inert gas is supplied from the nozzle to the front surface Wf of the substrate W through a pipe.

[0148] The nozzle is attached to the tip of a horizontally extending arm, and is positioned above the spin base 111 when discharging the inert gas. The arm is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to the control unit 300, and rotates the arm in response to an operation command from the control unit 300. As the arm rotates, the nozzle also moves.

[0149] <Etching Liquid Supply Unit (Etching Unit)> The etching liquid supply unit 160 is a unit that supplies an etching liquid to the front surface Wf of the substrate W. As shown in FIG. 7 , the etching liquid supply unit 160 has an etching liquid storage unit 161, a nozzle 162, and an arm 163.

[0150] 11, the etching liquid storage unit 161 includes at least an etching liquid tank 164, a temperature regulator 165, a liquid feed pump 166, and a particle filter 167. Note that, FIG. 11 is an explanatory diagram showing a schematic configuration of the etching liquid storage unit 161 in the etching liquid supply unit 160.

[0151] The etching solution tank 164 may include an agitation unit (not shown) that agitates the etching solution in the etching solution tank 164. Examples of the agitation unit include a rotation unit that agitates the etching solution and an agitation control unit that controls the rotation of the rotation unit. The agitation control unit is electrically connected to the control unit 300, and the rotation unit is equipped with, for example, a propeller-shaped agitation blade at the lower end of the rotation shaft. The control unit 300 issues an operation command to the agitation control unit to rotate the rotation unit, thereby agitating the etching solution with the agitation blade. As a result, the concentration and temperature of the etching solution in the etching solution tank 164 can be made uniform.

[0152] The etching solution tank 164 is provided with a mixer 168 that can mix chemicals and DIW from an external supply source (not shown) to prepare an etching solution of a predetermined concentration. The chemicals are solutes that function as etchants. Examples of chemicals include the aforementioned phosphoric acid and hydrogen fluoride.

[0153] A discharge pipe 169 for supplying the etching liquid to the nozzle 162 is also connected to the etching liquid tank 164. A temperature regulator 165, a liquid feed pump 166, and a particle filter 167 are sequentially installed along the discharge pipe 169 from upstream to downstream. The temperature regulator 165 and the liquid feed pump 166 are electrically connected to the control unit 300. This allows the temperature of the etching liquid supplied to the nozzle 162 to be controlled by an operation command from the control unit 300. Furthermore, when the liquid feed pump 166 is controlled by an operation command from the control unit 300, the etching liquid can be pressure-fed to the nozzle 162 via the discharge pipe 169. The particle filter 167 can remove foreign matter such as particles from the etching liquid.

[0154] The nozzle 162 is attached to the tip of a horizontally extending arm 163, and is positioned above the spin base 111 when discharging the etching solution. The arm 163 is connected to a rotation drive unit 190 via a rotation shaft (not shown). The rotation drive unit 190 is electrically connected to a control unit 300, and rotates the arm 163 in response to an operation command from the control unit 300. As the arm 163 rotates, the nozzle 162 also moves.

[0155] <Scatter prevention cup> The scatter prevention cup 180 is provided to surround the spin base 111. The scatter prevention cup 180 is connected to a lifting drive mechanism (not shown) and is capable of moving up and down in the vertical direction. When supplying a processing liquid or the like to the front surface Wf of the substrate W, the scatter prevention cup 180 is positioned at a predetermined position by the lifting drive mechanism and surrounds the substrate W held by the chuck pins 116 from a lateral position. This makes it possible to collect processing liquid or the like that splashes from the substrate W and the spin base 111.

[0156] <Control Unit> The control unit 300 is electrically connected to each component of the semiconductor manufacturing equipment and controls the operation of each component. The control unit 300 is configured as a computer having an arithmetic unit and a memory unit. The arithmetic unit uses a CPU that performs various arithmetic operations. The memory unit also includes a ROM (read-only memory) that stores the substrate processing program and the etching processing program, a RAM (readable / writable memory) that stores various information, and a magnetic disk that stores control software and data. The magnetic disk pre-stores processing conditions, including the conditions for generating (mixing) the dispersion liquid and the processing liquid; the supply conditions for the pre-processing liquid, surface modification liquid, first processing liquid, second processing liquid, removal liquid, inert gas, and etching liquid; the application conditions for ultrasonic waves; the rinsing conditions; the drying conditions; the processing conditions for the first contact step and the second contact step; and the etching conditions. The CPU loads the processing conditions into the RAM and controls each component of the semiconductor manufacturing equipment according to the contents of the loaded conditions.

[0157] Second Embodiment A second embodiment of the present invention will be described below. This embodiment differs from the first embodiment in that the surface modification process is performed by a dry method using ultraviolet irradiation. It also differs in that the etching process is performed by a batch method instead of a single-wafer method. Even with this configuration, a SAM with high film density and excellent compactness, which effectively suppresses or reduces the occurrence of film defects and has excellent protective performance, can be formed on the substrate surface more efficiently and in a shorter time than conventional film formation methods.

[0158] [Substrate Processing Method (Semiconductor Device Manufacturing Method)] A substrate processing method (semiconductor device manufacturing method) according to this embodiment will be described below. Fig. 12 is a flowchart showing an example of the overall flow of a substrate processing method according to a second embodiment of the present invention.

[0159] 12, the pretreatment step S101, the first treatment liquid preparation step S103, the first contact step S104, the second treatment liquid preparation step S105, and the second contact step S106 are the same as those in the first embodiment, and therefore, detailed descriptions of these steps will be omitted.

[0160] 1. Surface Modification Step (Dry Method) The surface modification step S102′ is the same as the surface modification step S102 in the first embodiment, except for SiO ２ This is a process for modifying the surface of layer 1 so that regions where SAM molecules are difficult to chemisorb are converted into regions where SAM molecules can chemisorb, and also to regions where SAM molecules can chemisorb at high density.

[0161] In this embodiment, SiO ２ The surface of the layer 1 is modified by a dry method using ultraviolet irradiation. In the case of ultraviolet irradiation, the ultraviolet irradiation conditions such as the wavelength of the light source, irradiation intensity, and irradiation time are set to a value that allows the first molecule 5 and the second molecule 8 to be chemically adsorbed on SiO 2 . ２ There are no particular limitations as long as hydroxyl groups can be introduced onto the surface of the layer 1. The ultraviolet irradiation is carried out in an atmosphere containing oxygen atoms, such as air.

[0162] <Etching Step (Batch Method)> The etching step S2' is a step of selectively etching the SiN layer 2, which is the layer to be etched, by immersing the substrate W after the SAM formation in an etching solution.

[0163] The method of immersing the substrate W in the etching solution is, for example, performed with the substrate W in an upright position. Here, "upright position" refers to a position in which the surface of the substrate W is aligned in a direction approximately perpendicular to a horizontal plane, and includes a vertical position. The etching solution may be the same as that described in the first embodiment. Furthermore, the etching temperature (i.e., the liquid temperature of the etching solution) and the etch rate for the layer to be etched may be appropriately set in consideration of the constituent material of the layer to be etched, as in the first embodiment.

[0164] [Substrate Processing Apparatus (Semiconductor Manufacturing Apparatus)] Next, the substrate processing apparatus according to this embodiment will be described below by taking as an example a case where it is applied to a semiconductor manufacturing apparatus.

[0165] The semiconductor manufacturing apparatus of this embodiment differs from the substrate processing apparatus of the first embodiment in that it includes at least a single-wafer substrate processing unit for forming a SAM and a batch-type etching processing unit for etching the layer to be etched.

[0166] <Substrate Processing Unit> As shown in FIG. 13 , the substrate processing unit 200 of this embodiment differs from the semiconductor manufacturing apparatus 100 of the first embodiment in that it includes an ultraviolet irradiation unit 210 as a surface modification unit instead of a surface modification liquid supply unit. FIG. 13 is an explanatory diagram showing the schematic configuration of the substrate processing unit of this embodiment. In this figure, some of the components common to the semiconductor manufacturing apparatus 100 of the first embodiment are omitted. In addition, in this figure, XYZ orthogonal coordinate axes are displayed as appropriate to clarify the directional relationships of the illustrated objects. Here, the XY plane represents the horizontal plane, and the +Z direction represents the vertical upward direction.

[0167] The ultraviolet ray irradiation unit 210 is disposed above the substrate holding unit 110 (in the direction indicated by arrow Z in FIG. 13 ) inside the chamber 170 so as to be able to irradiate ultraviolet rays onto the front surface Wf of the substrate W held by the substrate holding unit 110. The ultraviolet ray irradiation unit 210 includes at least a plurality of light source units 211 and quartz glass 212.

[0168] The light source unit 211 shown in FIG. 13 is a line light source, and is arranged so that its longitudinal direction is parallel to the direction indicated by Y in FIG. 13. The light source units 211 are also arranged in the direction indicated by arrow X so that they are equally spaced from one another. However, the light source unit 211 of the present invention is not limited to this form. For example, ring-shaped light source units with different diameters may be arranged concentrically. The light source unit may also be a point light source. In this case, it is preferable that the multiple light source units are arranged so that they are equally spaced from one another in a plane.

[0169] The type of light source unit 211 is not particularly limited, and for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a potassium lamp, a mercury-xenon lamp, a flash lamp, an excimer lamp, a metal halide lamp, and a UV (ultraviolet)-LED (Light Emitting Diode) can be used. The multiple light source units 211 may be of the same type or different types. When multiple different types of light source units 211 are used, they can be arranged so that the peak wavelengths, light intensities, etc. are different from each other.

[0170] The quartz glass 212 is disposed between the light source unit 211 and the substrate W. The quartz glass 212 is a plate-like body and is disposed parallel to the horizontal direction. The quartz glass 212 is optically transparent to ultraviolet light, heat-resistant, and corrosion-resistant, and allows the ultraviolet light irradiated from the light source unit 211 to pass through, enabling irradiation of the surface Wf of the substrate W. Furthermore, the quartz glass 212 can protect the light source unit 211 from the atmosphere inside the chamber 170.

[0171] <Etching Processing Unit> The etching processing unit of this embodiment is a batch-type processing unit used to etch a layer to be etched, and performs an etching step S2' on substrates W on which SAMs have been formed in the substrate processing unit. As shown in FIGS. 14 and 15 , the etching processing unit includes at least a substrate transport unit (not shown), a lifter 220, and a processing tank 230 for storing an etching solution. FIG. 14 is a side view showing a schematic configuration of the lifter 220 in the semiconductor manufacturing apparatus of this embodiment. Also, FIG. 15 is a cross-sectional view showing a state in which multiple substrates W on which SAMs have been formed according to this embodiment are immersed in the etching solution.

[0172] The substrate transport unit transports the substrates W on which the SAM has been formed in the substrate processing unit to the etching processing unit. The substrate transport unit includes, for example, an articulated robot capable of transporting the substrates W. The tip of the articulated robot includes a transport arm capable of loading the substrates W all at once in a horizontal position.

[0173] As shown in FIG. 14 , the lifter 220 includes a flat back plate 221, multiple (three) holding bars 222, and a lifting mechanism (not shown). The back plate 221 is erected, and at its lower end, the holding bars 222 each extend in one direction perpendicular to the back plate 221. The holding bars 222 are provided with a plurality of grooves 223 arranged in the extending direction. The grooves 223 are spaced apart and equally spaced from one another. Each groove 223 extends in a direction perpendicular to the extending direction of the holding bar 222, allowing multiple substrates W to be fitted into the grooves 223 in an upright position. This allows the holding bars 222 to abut against and support the group of substrates W from below in an upright position, thereby holding them collectively. The number of holding bars 222 is not particularly limited, as long as there is more than one. The number of grooves 223 formed in the holding rod 222 is not particularly limited and may be set appropriately depending on the number of substrates W to be held. The lifting mechanism can raise or lower the lifter 220 in the Z direction shown in Fig. 15. This allows the lifter 220, which collectively holds the group of substrates W, to be moved into or removed from the processing bath 230.

[0174] 15 , the treatment tank 230 includes an injection pipe 231 that supplies the etching solution into the treatment tank 230, an inner tank 232 that stores the etching solution, and an outer tank 233 that is provided around the periphery of the upper opening of the inner tank 232. The injection pipe 231 is provided at the bottom of the inner tank 232 and enables the etching solution to be supplied in an upflow manner to the inner tank 232. The outer tank 233 also enables the etching solution that overflows from the inner tank 232 to be collected. The injection pipe 231 may be connected to the etching solution storage section 161 described in the first embodiment via a discharge pipe 169, for example.

[0175] (Other Matters) In the above description, the most preferred embodiment of the present invention has been described. However, the present invention is not limited to this embodiment. For example, in the first embodiment, SiN ２ Although the etching process for the layer has been described as being performed by a single wafer process, the etching process may also be performed by a batch process as described in the second embodiment. Furthermore, although the surface modification process has been described as being performed by a wet process as an example in the first embodiment, the surface modification process may also be performed by a dry process using ultraviolet light irradiation as described in the second embodiment. Even in these modes, a SAM with high film density and excellent compactness, in which the occurrence of film defects is effectively suppressed or reduced, and excellent protective performance can be formed on the substrate surface more efficiently and in a shorter time than with conventional film formation methods.

[0176] Preferred examples of the present invention are described in detail below. However, the materials, amounts, conditions, etc. described in these examples are not intended to limit the scope of the present invention unless otherwise specified.

[0177] (Example 1) SiO ２ A substrate having a film (thickness 100 nm) formed thereon was prepared and immersed in a hydrogen fluoride aqueous solution (pretreatment solution) for 1 minute (pretreatment step) in which the volume ratio of hydrogen fluoride to DIW was 1:100.

[0178] Next, the substrate was removed from the hydrogen fluoride solution and immersed in a surface modification liquid for 10 minutes (surface modification step). The surface modification liquid was SC-1 (volume ratio: ammonium water (NH ３ Concentration 28%): Hydrogen peroxide (H ２ O ２ A concentration of 30% (DIW:DIW=1:4:20) was used.

[0179] On the other hand, a first treatment liquid was also prepared separately from the surface modification process of the substrate. That is, in a sealed container in a stationary state, 100 ppm of water was added to toluene as an organic solvent under conditions of a temperature of 23°C and normal pressure. Furthermore, ultrasonic waves were applied to the mixture of toluene and water in a stationary state for 30 minutes. This prepared a dispersion liquid in which water was uniformly dispersed in toluene as the main solvent. The ultrasonic wave application conditions were a frequency of 45 Hz. Next, octadecyltrichlorosilane (C) as a SAM-forming material was added to the stationary dispersion liquid. １８ H ３７ SiCl ３ The content (concentration) of octadecyltrichlorosilane was 5% by mass relative to the total mass of the first treatment liquid.

[0180] Next, the substrate is removed from the surface modification liquid and immersed in the first treatment liquid for 5 minutes to remove the SiO ２ A SAM (approximately 1 nm thick) was formed on the film surface (first contact step). The substrate was then removed from the first treatment solution and immersed in toluene as a removal solution for 1 minute to remove any unadsorbed SAM-forming material remaining on the substrate surface (removal step). Furthermore, the substrate was removed from the toluene and dried by spraying nitrogen gas onto the surface on which the SAM was formed (drying step). The temperature of the nitrogen gas was room temperature, and the drying time was 1 minute.

[0181] Next, the substrate after the drying process was immersed in a second treatment liquid for 5 minutes to perform a SAM densification process (second contact process). The second treatment liquid was the same as the first treatment liquid. Next, the substrate removed from the second treatment liquid was immersed in toluene as a removal liquid for 1 minute to remove any unadsorbed SAM-forming material remaining on the substrate surface (removal process). Furthermore, the surface of the substrate removed from the toluene on which the SAM was formed was dried by spraying nitrogen gas (drying process). The temperature of the nitrogen gas was room temperature, and the drying time was 1 minute.

[0182] Next, the obtained sample was subjected to an etching treatment. Specifically, the substrate was immersed in an etching solution, and the area on the substrate surface that was not protected by SAM was etched. The etching conditions were as follows: SiO ２ The immersion time in the etching solution (etching time) was set to 195 seconds so that the etching depth was about 10 nm. The etching solution used was an aqueous hydrogen fluoride solution, and the volume ratio of hydrogen fluoride to DIW was set to hydrogen fluoride:DIW=1:100.

[0183] Next, the substrate was removed from the etching solution and immersed in DIW, and then removed from the DIW (rinsing step with DIW). The etched surface was then dried by spraying nitrogen gas at room temperature (drying step).

[0184] Example 2 In this example, trichloropropylsilane (C ) was used as the SAM-forming material of the second treatment liquid. ３ H ７ SiCl ３ Except for this, samples were prepared in the same manner as in Example 1, and the obtained samples were subjected to an etching treatment.

[0185] Example 3 In this example, trichloromethylsilane (CH ３ SiCl ３ Except for this, samples were prepared in the same manner as in Example 1, and the obtained samples were subjected to an etching treatment.

[0186] Example 4 In this example, the cycle of the second contact step and the subsequent removal and drying steps was repeated twice. In the second second contact step, decyltrichlorosilane (C １０ H ２１ SiCl ３ Except for the above, a sample was prepared in the same manner as in Example 1, and the obtained sample was subjected to an etching treatment.

[0187] Example 5 In this example, the cycle of the second contact step and the subsequent removal and drying steps was repeated twice. In the second second contact step, trichloropropylsilane (C ３ H ７ SiCl ３ Except for the above, a sample was prepared in the same manner as in Example 1, and the obtained sample was subjected to an etching treatment.

[0188] Example 6 In this example, the cycle of the second contact step and the subsequent removal and drying steps was repeated twice. In the second second contact step, trichloromethylsilane (CH ３ SiCl ３ Except for the above, a sample was prepared in the same manner as in Example 1, and the obtained sample was subjected to an etching treatment.

[0189] Comparative Example 1 In this comparative example, the second contacting step and the subsequent removing and drying steps were not performed. Otherwise, a sample was prepared in the same manner as in Example 1, and the obtained sample was then subjected to an etching treatment.

[0190] (Evaluation of SAM Density) For each sample according to Examples 1 to 6 and Comparative Example 1, the area ratio (%) of the SAM film defects was calculated to evaluate the SAM density.

[0191] Specifically, the SAM of each sample was imaged using an atomic force microscope (AFM) (trade name: Dimension Icon, manufactured by Bruker Japan Co., Ltd.) to obtain a 500 nm square observation image (AFM image). Next, each obtained observation image was binarized and then image processed to map the film defects and identify the locations (regions) of the SAM film defects. The identification of the locations (regions) of the SAM film defects by mapping was performed by taking into account that the SAM film thickness was approximately 1 nm, and image processing was performed so that defects located at a depth of less than 1 nm from the SAM surface were mapped. This ensured that locations (regions) deeper than 1 nm from the SAM surface, more specifically, etched regions, were mapped as SAM film defect regions and were not included in the area. Next, the areas of the SAM film defects identified by image processing were calculated, and the ratio of their areas to the total area in the observation image was calculated. The results are shown in Table 1.

[0192] (Results) As can be seen from Table 1, in Examples 1 to 6, in which densification treatment was performed by the second contact step, the area ratio of SAM film defects was reduced compared to Comparative Example 1, in which the second contact step was not performed, and it was confirmed that all had good densification. Furthermore, in Examples 2 and 3, the SAM-forming material of the second treatment liquid used in the second contact step had a shorter molecular chain length than the SAM-forming material of the first treatment liquid, thereby making it possible to reduce the area ratio of SAM film defects more than in Example 1. Furthermore, in Examples 4 to 6, the cycle of the second contact step and the subsequent removal and drying steps was repeated twice, making it possible to further reduce the area ratio of SAM film defects more than in Examples 2 and 3.

[0193] Furthermore, from the results of each of these Examples, it can be seen that when the threshold value of the area ratio (%) of the SAM film defects is set to, for example, 15% or less, it is sufficient to use the second molecule used in the second contacting step as at least the same type as that used in the first contacting step, as in Example 1. Furthermore, when the threshold value is set to, for example, 10% or less, it is sufficient to use the second molecule used in the second contacting step as a molecule with a shorter molecular chain length than that used in the first contacting step, as in Examples 2 and 3, or to perform the second contacting step multiple times and use the second molecule in the second contacting step as a molecule with a shorter molecular chain length than that used in the first second contacting step, as in Example 4. Furthermore, when the threshold value is set to 5% or less, it can be seen that when the second contacting step is performed multiple times and use the second molecule in the second contacting step as a molecule with an even shorter molecular chain length than that used in the first second contacting step, as in Examples 5 and 6.

[0194]

[0195] 1 SiO ２ DESCRIPTION OF SYMBOLS 1 Layer (protected layer) 2 SiN layer (etched layer) 3 Laminate 4 Memory trench 5 First molecule 6 SAM (self-assembled monolayer) 7 Film defect 8 Second molecule 100 Semiconductor manufacturing apparatus 110 Substrate holder 120 Pre-treatment liquid supply unit 121 Pre-treatment liquid reservoir 130 Surface modification liquid supply unit 131 Surface modification liquid reservoir 140 First treatment liquid supply unit 141 First treatment liquid reservoir 150 Second treatment liquid supply unit 151 Second treatment liquid reservoir 160 Etching liquid supply unit 161 Etching liquid reservoir 190 Swivel drive unit 200 Substrate processing unit 210 Ultraviolet irradiation unit 220 Lifter 230 Processing tank 231 Injection pipe 232 Inner tank 233 Outer tank 300 Control unit S1 SAM (self-assembled monolayer) formation step S2, S2' Etching steps S101 Pretreatment step S102 Surface modification step S103 First treatment liquid preparation step S104 First contact step S105 Second treatment liquid preparation step S106 Second contact step W Substrate Wf Substrate surface

Claims

1. A substrate processing method for forming a self-assembled monolayer on a surface of a substrate, comprising: a surface modification step of performing surface modification on the surface of the substrate to enable the formation of the self-assembled monolayer; a first contact step of contacting the surface of the substrate after the surface modification step with a first treatment liquid containing first molecules capable of forming the self-assembled monolayer, thereby forming the self-assembled monolayer; and a second contact step of contacting the surface of the substrate after the first contact step with a second treatment liquid containing second molecules identical or different to the first molecules, thereby chemically adsorbing the second molecules to areas where the self-assembled monolayer is not formed, wherein the second contact step is performed at least once until the area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the substrate becomes equal to or less than an arbitrarily set threshold value.

2. The substrate processing method according to claim 1, wherein the second molecule has a molecular chain length that is the same as or shorter than that of the first molecule.

3. A substrate processing method as described in claim 1, wherein when the second contact step is performed multiple times, the second molecule used in an earlier step has a molecular chain length that is the same as or longer than the second molecule used in a later step.

4. A substrate processing method as described in claim 1, wherein the first molecule and the second molecule have functional groups capable of undergoing a dehydration condensation reaction with a hydroxyl group, the surface modification process is a process of imparting the hydroxyl group to the surface of the substrate, and the first contact process and the second contact process are processes of chemically adsorbing the first molecule or the second molecule to the surface of the substrate by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the substrate.

5. The substrate processing method according to claim 4, wherein the surface modification step is a step of imparting hydroxyl groups to the surface of the substrate by contacting the surface of the substrate with a surface modification liquid consisting of an alkaline solution, or by irradiating the surface of the substrate with ultraviolet light in an atmosphere containing oxygen atoms.

6. A method for manufacturing a semiconductor device, comprising the treatment of a substrate having a laminate on its surface, the laminate comprising an alternating layer of a protected layer to be protected during etching and a layer to be etched to be etched, the method comprising the steps of: selectively forming a self-assembled monolayer on at least the surface of the protected layer; and selectively etching the layer to be etched using the self-assembled monolayer as a protective layer, the step of forming the self-assembled monolayer comprising: a surface modification step of performing surface modification on the surface of the protected layer to enable the formation of the self-assembled monolayer; a first contact step of contacting the surface of the protected layer after the surface modification step with a first treatment liquid containing first molecules capable of forming the self-assembled monolayer to form the self-assembled monolayer; and a second contact step of contacting the surface of the substrate after the first contact step with a second treatment liquid containing second molecules identical or different to the first molecules to chemically adsorb the second molecules to regions where the self-assembled monolayer is not formed. the second contact step is performed at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the protective layer becomes equal to or less than an arbitrarily set threshold value.

7. The method for manufacturing a semiconductor device according to claim 6, wherein the second molecule has a molecular chain length that is the same as or shorter than that of the first molecule.

8. The method for manufacturing a semiconductor device described in claim 6, wherein when the second contact step is performed multiple times, the second molecule used in an earlier step has a molecular chain length that is the same as or longer than that of the second molecule used in a later step.

9. The method for manufacturing a semiconductor device described in claim 6, wherein the first molecule and the second molecule have functional groups capable of undergoing a dehydration condensation reaction with a hydroxyl group, the surface modification process is a process of imparting the hydroxyl group to the surface of the protected layer, and the first contact process and the second contact process are processes of chemically adsorbing the first molecule or the second molecule to the surface of the protected layer by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the protected layer.

10. The method for manufacturing a semiconductor device according to claim 9, wherein the surface modification step is a step of imparting hydroxyl groups to the surface of the substrate by contacting the surface of the substrate with a surface modification liquid consisting of an alkaline solution, or by irradiating the surface of the substrate with ultraviolet light in an atmosphere containing oxygen atoms.

11. A substrate processing apparatus for forming a self-assembled monolayer on a surface of a substrate, comprising: a surface modification section for performing surface modification on the surface of the substrate to enable the formation of the self-assembled monolayer; a first processing liquid supply section for forming the self-assembled monolayer by supplying a first processing liquid containing first molecules capable of forming the self-assembled monolayer to the surface of the substrate modified by the surface modification section; and a second processing liquid supply section for supplying a second processing liquid containing second molecules identical or different to the first molecules to the surface of the substrate on which the self-assembled monolayer has been formed, thereby chemically adsorbing the second molecules to areas where the self-assembled monolayer is not formed, wherein the second processing liquid supply section supplies the second processing liquid at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the substrate becomes equal to or less than an arbitrarily set threshold value.

12. The substrate processing apparatus of claim 11, wherein the second molecules have a molecular chain length that is the same as or shorter than that of the first molecules.

13. The substrate processing apparatus of claim 11, wherein when the second processing liquid supply unit supplies the second processing liquid to the surface of the substrate multiple times, the second molecules contained in the second processing liquid supplied earlier have the same or longer molecular chain length as the second molecules contained in the second processing liquid supplied later.

14. The substrate processing apparatus of claim 11, wherein the first molecule and the second molecule have functional groups capable of undergoing a dehydration condensation reaction with a hydroxyl group, the surface modification unit performs the surface modification by imparting the hydroxyl group to the surface of the substrate, and the first processing liquid supply unit and the second processing liquid supply unit chemically adsorb the first molecule or the second molecule to the surface of the substrate by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the substrate.

15. The substrate processing apparatus according to claim 14, wherein the surface modification unit is a surface modification liquid supply unit which provides hydroxyl groups to the surface of the substrate by supplying a surface modification liquid consisting of an alkaline solution to the surface of the substrate, or an ultraviolet irradiation unit which provides hydroxyl groups to the surface of the substrate by irradiating the surface of the substrate with ultraviolet rays in an atmosphere containing oxygen atoms.

16. A semiconductor manufacturing apparatus for processing a substrate having a laminate provided on its surface, the laminate including an alternating layer of a protected layer to be protected by etching and an etched layer to be etched, the apparatus comprising: a surface modification section for modifying the surface of the protected layer to enable the formation of a self-assembled monolayer; a first processing liquid supply section for forming the self-assembled monolayer by supplying a first processing liquid containing a first molecule capable of forming the self-assembled monolayer to the surface of the protected layer modified by the surface modification section; a second processing liquid supply section for supplying a second processing liquid containing a second molecule identical or different to the first molecule to the surface of the protected layer on which the self-assembled monolayer has been formed, thereby chemically adsorbing the second molecule to an area where the self-assembled monolayer has not been formed; and an etching section for selectively etching and removing the etched layer using the self-assembled monolayer as a protective layer. the second processing liquid supply unit supplies the second processing liquid at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the protective layer becomes equal to or less than an arbitrarily set threshold value.

17. A semiconductor manufacturing apparatus for processing a substrate having a laminate on its surface, the laminate including an alternating layer of a protected layer to be protected by etching and a layer to be etched to be etched, the apparatus comprising: a substrate processing unit for selectively forming a self-assembled monolayer on at least the surface of the protected layer; and an etching processing unit for selectively etching and removing the layer to be etched using the self-assembled monolayer as a protective layer, the substrate processing unit comprising: a surface modification section for performing surface modification on the surface of the protected layer to enable the formation of the self-assembled monolayer; a first processing liquid supply section for forming the self-assembled monolayer by supplying a first processing liquid containing a first molecule capable of forming the self-assembled monolayer to the surface of the protected layer modified by the surface modification section; and a second processing liquid supply section for chemically adsorbing the second molecule to an area where the self-assembled monolayer is not formed by supplying a second processing liquid containing a second molecule identical or different to the first molecule to the surface of the protected layer on which the self-assembled monolayer has been formed. the second processing liquid supply unit supplies the second processing liquid at least once until an area ratio (%) of film defects in the self-assembled monolayer formed on the surface of the protective layer becomes an arbitrarily set threshold value or less.

18. The semiconductor manufacturing apparatus according to claim 16 or 17, wherein the second molecule has a molecular chain length that is the same as or shorter than that of the first molecule.

19. A semiconductor manufacturing apparatus as described in claim 16 or 17, wherein when the second processing liquid supply unit supplies the second processing liquid to the surface of the protected layer multiple times, the second molecules contained in the second processing liquid supplied earlier have the same or longer molecular chain length as the second molecules contained in the second processing liquid supplied later.

20. A semiconductor manufacturing apparatus as described in claim 16 or 17, wherein the first molecule and the second molecule have functional groups capable of dehydration condensation reactions with hydroxyl groups, the surface modification unit performs the surface modification by imparting the hydroxyl groups to the surface of the substrate, and the first processing liquid supply unit and the second processing liquid supply unit chemically adsorb the first molecule or the second molecule to the surface of the substrate by a dehydration condensation reaction between the functional group of the first molecule or the second molecule and the hydroxyl group on the surface of the substrate.

21. A semiconductor manufacturing apparatus as described in claim 16 or 17, wherein the surface modification unit is a surface modification liquid supply unit which provides hydroxyl groups to the surface of the protected layer by supplying a surface modification liquid consisting of an alkaline solution to the surface of the protected layer, or an ultraviolet irradiating unit which provides hydroxyl groups to the surface of the protected layer by irradiating the surface of the substrate with ultraviolet rays in an atmosphere containing oxygen atoms.

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