Method for processing semiconductor substrates, method for manufacturing semiconductor devices, and processing solution for semiconductor devices.

Abstract

The present invention provides a method for processing a semiconductor substrate, a method for manufacturing a semiconductor device, and a processing solution for a semiconductor device, all of which offer excellent removal capabilities for metal nitrides and corrosion protection of the metal layer. [Solution] The present invention provides a method for processing a semiconductor substrate, a method for manufacturing a semiconductor device, and a semiconductor device processing solution usable for these, comprising a processing step of processing a semiconductor substrate having a layer containing a metal nitride with a semiconductor device processing solution; wherein the semiconductor device processing solution contains NH3, a corrosion inhibitor, and water, and the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the content of NH3 to the content of the corrosion inhibitor (NH3 / corrosion inhibitor) is 5 to 60.

Description

Technical Field

[0001] Cross - reference to related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 723,746, filed on November 22, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a method for processing a semiconductor substrate, a method for manufacturing a semiconductor device, and a processing liquid for a semiconductor device.

Background Art

[0003] In the wiring formation process of a semiconductor device, for example, a method is adopted in which after forming a hard mask layer (HM layer) on a substrate on which a metal wiring layer, an interlayer insulating film such as a silicon - based film, etc. are laminated, etching is performed. Then, by using the patterned HM layer as a mask layer and etching the substrate, a wiring pattern such as a metal wiring is formed.

[0004] In such wiring formation processing of a semiconductor device, miniaturization of metal wiring is required. From the perspective of meeting such requirements, metals such as copper are used as materials for metal wiring. And as a film that can function as a barrier film while ensuring adhesion to copper wiring, etc., metal nitride films such as tantalum nitride (tantalum nitride, TaN) films (tantalum nitride films) are used.

[0005] On the other hand, as a processing liquid for the above - mentioned etching application, for example, a processing liquid containing an acidic component such as hydrogen peroxide and an alkaline component such as NH3 or tetramethylammonium hydroxide (TMAH) is used. Among the processing liquids having such a composition, there are those used for the purpose of removing metal nitride films such as tantalum nitride described above and protecting metal wirings such as copper described above.

[0006] Regarding the composition of such a processing liquid for etching application, for example, Patent Document 1 discloses an etching liquid containing (A) oxalic acid, (B) polyvinylpyrrolidone, and (C) water. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-216444 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, conventional etching solutions are insufficient to achieve both the ability to remove metal nitrides such as tantalum nitride and the corrosion protection of metal layers containing metal atoms such as copper atoms, and therefore there is room for improvement.

[0009] For example, even if a treatment solution can ensure a certain degree of metal nitride removal and can etch layers containing metal nitride (e.g., metal nitride films) to some extent, it still has the problem of insufficient corrosion protection of the metal layer because it does not adequately suppress damage to the metal layer containing metal atoms such as copper atoms. Conversely, even if a treatment solution can reduce damage to the metal layer containing metal atoms such as copper atoms to some extent, it still has the problem of insufficient metal nitride removal.

[0010] The present invention has been made in view of the above circumstances, and aims to provide a method for processing a semiconductor substrate, a method for manufacturing a semiconductor device, and a processing solution for a semiconductor device that are excellent in removing metal nitrides and preventing corrosion of the metal layer. [Means for solving the problem]

[0011] As a result of diligent research to achieve the above-mentioned objectives, the present inventors have found a method for treating a semiconductor substrate that includes a processing step of treating a semiconductor substrate having a layer containing a metal nitride with a semiconductor device processing solution; the semiconductor device processing solution contains NH3, a corrosion inhibitor, and water, the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the content of NH3 to the content of the corrosion inhibitor (NH3 / corrosion inhibitor) is 5 to 60, thereby completing the present invention. That is, the present invention is as follows.

[0012] <1> The method for processing a semiconductor substrate includes a processing step of processing a semiconductor substrate having a layer containing a metal nitride with a processing solution for semiconductor devices; the processing solution for semiconductor devices contains NH3, a corrosion inhibitor, and water, the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the content of NH3 to the content of the corrosion inhibitor (NH3 / corrosion inhibitor) is 5 to 60. <2> The aforementioned semiconductor device processing solution further contains hydrogen peroxide. <1> This is a method for processing semiconductor substrates as described above. <3> The aforementioned processing solution for semiconductor devices further contains a surfactant. <1> or <2> This is a method for processing semiconductor substrates as described above. <4> The aforementioned processing solution for semiconductor devices further contains a chelating agent. <1> ~ <3> This is a method for processing a semiconductor substrate as described in any one of the items. <5> Prior to the processing step, the preparation step further includes mixing a first chemical solution containing NH3, the corrosion inhibitor, and water, and a second chemical solution containing hydrogen peroxide, to prepare the processing solution for semiconductor devices. <2> This is a method for processing semiconductor substrates as described above. <6> A method for manufacturing a semiconductor device comprising the steps of: preparing a semiconductor substrate having a layer containing a metal nitride that has been etched; and processing the etched semiconductor substrate with a semiconductor device processing solution; wherein the semiconductor device processing solution contains NH3, a corrosion inhibitor, and water, the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the content of NH3 to the content of the corrosion inhibitor (NH3 / corrosion inhibitor) is 5 to 60. <7> The aforementioned semiconductor device processing solution further contains hydrogen peroxide. <6> This is a method for manufacturing semiconductor devices as described above. <8> The aforementioned processing solution for semiconductor devices further contains a surfactant. <6> or <7> This is a method for manufacturing semiconductor devices as described above. <9> The aforementioned processing solution for semiconductor devices further contains a chelating agent. <6> ~ <8> This is a method for manufacturing a semiconductor device as described in any one of the items. <10> Prior to the processing step, the preparation step further includes mixing a first chemical solution containing NH3, the corrosion inhibitor, and water, and a second chemical solution containing hydrogen peroxide, to prepare the processing solution for semiconductor devices. <7> This is a method for manufacturing semiconductor devices as described above. <11> A semiconductor device processing solution containing NH3, a corrosion inhibitor, and water, wherein the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content (NH3 / corrosion inhibitor) is 5 to 60. <12> Furthermore, containing surfactants, <11> This is a processing solution for semiconductor devices as described above. <13> Furthermore, it contains hydrogen peroxide, <11> or <12> This is a processing solution for semiconductor devices as described above. <14> Furthermore, it is a processing liquid for a semiconductor device according to any one of <11> to <13>, containing a chelating agent. <15> The processing liquid for a semiconductor device is a processing liquid kit for a semiconductor device, including a first chemical solution containing the NH3, the anticorrosive agent, and the water, and a second chemical solution containing the hydrogen peroxide; the anticorrosive agent in the first chemical solution is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the content of the NH3 to the content of the anticorrosive agent in the first chemical solution is 5 to 60; it is the processing liquid for a semiconductor device according to <13>.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a method for processing a semiconductor substrate, a method for manufacturing a semiconductor device, and a processing liquid for a semiconductor device, which are excellent in the removability of metal nitrides and the corrosion resistance of metal layers.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a semiconductor element (semiconductor substrate) to be processed. [Figure 2] FIG. 2 is a cross-sectional view showing another example of a semiconductor element (semiconductor substrate) to be processed.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of its gist.

[0016] Furthermore, identical elements in the drawings will be given the same reference numeral, and redundant explanations will be omitted. Unless otherwise specified, positional relationships such as top, bottom, left, and right will be based on those shown in the drawings. Moreover, the dimensional ratios in the drawings are not limited to those shown.

[0017] <Processing method for semiconductor substrates>

[0018] The semiconductor substrate processing method according to this embodiment includes a processing step of processing a semiconductor substrate having a layer containing a metal nitride with a semiconductor device processing solution; the semiconductor device processing solution contains NH3, a corrosion inhibitor, and water, the corrosion inhibitor being at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content (NH3 / corrosion inhibitor) is 5 to 60. According to the semiconductor substrate processing method according to this embodiment, it is possible to achieve both the removal of metal nitrides such as tantalum nitride and the corrosion inhibition of metal layers containing metal atoms such as copper atoms.

[0019] The inventors focused on the fact that conventional processing solutions are insufficiently effective in suppressing damage to the metal layer of semiconductor substrates being processed, and diligently researched this issue. As a result, they concluded that when a metal nitride film is formed on the laminated substrate being processed, the corrosion inhibitor is adsorbed or adheres to the metal nitride film, thereby reducing the effectiveness of the added corrosion inhibitor.

[0020] For example, some conventional processing solutions contain alkaline components such as NH3 or TMAH to clean and remove layers containing metal nitrides. The inventors of this invention investigated the problems associated with such conventional processing solutions and concluded the following: When such a processing solution comes into contact with a layer containing metal nitrides, the alkaline components in the solution act to dissolve the metal nitrides in the solution as metal hydroxyl complexes. This allows the layer containing metal nitrides to be cleaned and removed. However, the inventors considered that this action may also dissolve metal layers containing metal atoms such as copper atoms in the solution, potentially damaging those metal layers as well.

[0021] The inventors, taking into account the problems of the conventional treatment solutions described above, conducted further investigations and surprisingly found that the above-mentioned problems can be solved by using a treatment solution containing NH3, a corrosion inhibitor, and water, wherein the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content (NH3 / corrosion inhibitor) is 5 to 60. The reason for this is not entirely clear, but it is thought to be as follows.

[0022] The treatment solution used in this embodiment contains NH3 and at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, in a mass ratio of 5 to 60 (NH3 / corrosion inhibitor). With this composition, the NH3, which is an alkaline component in the treatment solution, acts to dissolve the metal nitride in the solution as a metal hydroxyl complex. Furthermore, the corrosion inhibitor in the treatment solution does not unintentionally adsorb onto the metal nitride, and therefore does not hinder the dissolution of the metal nitride in the solution. Thus, it is considered that the removal of metal nitride can be ensured. On the other hand, since the corrosion inhibitor in the treatment solution acts effectively as a corrosion inhibitor for metal layers containing metal atoms such as copper atoms, the corrosion resistance of the metal layers can also be ensured. Thus, it is considered that the semiconductor substrate treatment method according to this embodiment can achieve both the removal of metal nitrides such as tantalum nitride and the corrosion resistance of metal layers containing metal atoms such as copper atoms (however, the effects and benefits of this embodiment are not limited to these).

[0023] The processing solution used in this embodiment can further contain any components described later, or satisfy the conditions described later, to achieve an even higher level of balance between the removal of metal nitrides and the corrosion protection of the metal layer, as described above. In addition, by adopting various preferred embodiments of this embodiment, it is expected that various effects other than the removal of metal nitrides and the corrosion protection of the metal layer can be further imparted, as described below (however, the functions and effects of this embodiment are not limited to these).

[0024] The processing solution used in this embodiment can further contain any components described later, or satisfy any conditions described later, to improve damage suppression to the CHM layer (corrosion resistance of the CHM layer) when processing a semiconductor substrate containing an organic layer, such as a carbon hard mask (CHM) layer.

[0025] Furthermore, when etching is performed using fluorine-based gases such as fluorocarbon gas (CF gas), fluorocarbon polymers (CF polymers) are generated as reaction products. Even if these CF polymers are removed from the semiconductor substrate by the processing solution (or cleaning solution), the removed CF polymers may reattach to the substrate and remain as foreign matter. Therefore, the ability to remove CF polymers is also desirable. In this regard, the processing solution used in this embodiment can be made to have improved CF polymer removal capabilities by further containing optional components such as surfactants described later, or by further satisfying optional conditions described later.

[0026] Furthermore, if the treatment solution contains hydrogen peroxide, the composition of the treatment solution is likely to change over time because hydrogen peroxide has the property of decomposing over time. However, even if the treatment solution used in this embodiment contains hydrogen peroxide, its stability over time can be improved by further including any components described later or by further satisfying any conditions described later.

[0027] First, let me explain the semiconductor substrate that will be processed.

[0028] (Semiconductor substrate)

[0029] The semiconductor substrate processing method according to this embodiment applies to semiconductor substrates having a layer containing a metal nitride. According to the semiconductor substrate processing method according to this embodiment, at least the removal of the metal nitride and corrosion protection of the metal layer are excellent. Specific examples of the semiconductor substrate include, for example, a laminated substrate including a substrate and a metal layer formed on the substrate, and a semiconductor substrate after dry etching. The semiconductor substrate to be processed (laminated substrate) only needs to have a layer containing a metal nitride, but it is preferable that the semiconductor substrate comprises a first layer containing a metal nitride and a second layer containing metal atoms. Specific examples of the metal nitride are preferably at least one selected from the group consisting of, for example, tantalum nitride, titanium nitride, aluminum nitride, and titaniumaluminum nitride. The metal atoms of the second layer are preferably at least one selected from the group consisting of, for example, copper atoms, tungsten atoms, cobalt atoms, and ruthenium atoms. As a specific example of the second layer, it is more preferable that it be at least one selected from the group consisting of metal oxides, metal nitrides, metal chlorides, and metal fluorides of metal atoms; it is even more preferable that it be at least one selected from the group consisting of metal oxides, metal nitrides, metal chlorides, and metal fluorides of metal atoms, and that the metal atom is at least one selected from the group consisting of copper atoms and tantalum atoms. By including such a layer, the advantages of this embodiment, which will be described later, can be exhibited even more effectively.

[0030] Figure 1 is a cross-sectional view showing an example of a semiconductor device (semiconductor substrate) to be processed.

[0031] The semiconductor device 100 shown in Figure 1 consists of a substrate 10, a metal wiring layer 20, an etching stop layer 30, and a tantalum nitride film (TaN film) 50 stacked in this order, with a hard mask layer (HM layer) 60 formed on the tantalum nitride film (TaN film) 50 (substrate 10 / metal wiring layer 20 / etching stop layer 30 / tantalum nitride film (TaN film) 50 / HM layer 60).

[0032] This semiconductor element 100 is masked by an HM layer 60 that corresponds to the original wiring pattern. The semiconductor element 100 is in the state before etching the exposed surface of the tantalum nitride film 50 (the unmasked portion of the hard mask layer 60).

[0033] In the unmasked areas of the hard mask layer 60 with the wiring pattern shape, the tantalum nitride film 50 is exposed. In addition, residue 70 is attached to the hard mask layer 60.

[0034] For example, the substrate 10 can be made of materials such as silicon, amorphous silicon, SiC, GaN, or glass.

[0035] The metal wiring layer 20 may include a wiring layer containing at least one selected from the group consisting of metals such as molybdenum (Mo), tungsten (W), ruthenium (Ru), copper (Cu), iron (Fe), gold (Au), silver (Ag), nickel (Ni), aluminum (Al), lead (Pb), zinc (Zn), tin (Sn), tantalum (Ta), magnesium (Mg), cobalt (Co), bismuth (Bi), cadmium (Cd), titanium (Ti), zirconium (Zr), antimony (Sb), manganese (Mn), beryllium (Be), chromium (Cr), germanium (Ge), vanadium (V), gallium (Ga), hafnium (Hf), indium (In), niobium (Nb), rhenium (Re), and thallium (Tl), as well as metal oxides, metal nitrides, metal chlorides, and metal fluorides thereof.

[0036] The metal wiring layer 20 includes layers formed using the various metals mentioned above, as well as their metal oxides, metal nitrides, metal chlorides, and metal fluorides.

[0037] The etching stop layer 30 has the function of preventing the etching solution from penetrating the metal wiring layer 20. In the case of dry etching, when ILDs or the like are dry etched, the etching stop layer 30 stops the etching and protects the underlying layer. Examples of the etching stop layer 30 include one selected from the group consisting of aluminum oxide, carbon-doped oxide (SiOC), silicon nitride, SiOCN, and aluminum nitride.

[0038] The tantalum nitride film 50 is an example of the metal nitride film described above.

[0039] The material of the HM layer 60 can be any material that functions as a protective film against etching, and is not particularly limited; a suitable material can be selected as appropriate considering the manufacturing conditions, etc. The HM layer 60 is preferably, for example, a carbon hard mask (CHM) layer, a layer containing titanium and titanium alloys, a layer containing Si, or a layer containing tungsten carbide. For example, a CHM layer is suitably used as a mask layer when deep etching is performed in the semiconductor device manufacturing process.

[0040] The residue 70 mainly includes etching residue, deposits such as CF-based polymers, CMP residue, organic residue, etc. Examples of etching residue include residues of various metal types and residues of various inorganic substances as described above. The semiconductor substrate processing method according to this embodiment can also be expected to efficiently clean such residues, and therefore can also be expected to suppress the remaining foreign matter on the surface of the semiconductor substrate after processing.

[0041] Figure 2 is a cross-sectional view showing another example of a semiconductor device (semiconductor substrate) to be processed.

[0042] The semiconductor device 200 shown in Figure 2 consists of a substrate 10, an interlayer insulating film 40, an etching stop layer 30, and a tantalum nitride film (TaN film) 50 stacked in this order, with a hard mask layer (HM layer) 60 formed on the tantalum nitride film (TaN film) 50 (substrate 10 / interlayer insulating film 40 / etching stop layer 30 / tantalum nitride film (TaN film) 50 / HM layer 60). The semiconductor device 200 has the same configuration as the semiconductor device 100 shown in Figure 1, but with the metal wiring layer 20 replaced by an interlayer insulating film 40. The substrate 10, etching stop layer 30, tantalum nitride film (TaN film) 50, and hard mask layer (HM layer) 60 can be those described for semiconductor device 100.

[0043] The material of the interlayer insulating film 40 can be any insulating material, and is not particularly limited; a suitable material can be selected as appropriate considering the manufacturing conditions, etc. Examples of the interlayer insulating film 40 include layers containing silicon-based materials such as SiO2, SiN, SiOC, and SiOCN.

[0044] Next, we will describe the processing solutions used for semiconductor devices.

[0045] (Processing solution for semiconductor devices)

[0046] The semiconductor device processing solution (hereinafter sometimes simply referred to as "processing solution") used in the semiconductor substrate processing method according to this embodiment will be described below. The processing solution contains NH3, a corrosion inhibitor, and water. The corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole (5MBTA), imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content (NH3 / corrosion inhibitor) is 5 to 60.

[0047] The treatment solution contains NH3. NH3 may be added as, for example, ammonium hydroxide (NH4OH).

[0048] The treatment solution contains at least one selected from the group consisting of 5-methyl-1H-benzotriazole (5MBTA), imidazole, and 5-amino-1H-tetrazole as a first corrosion inhibitor. These may be used individually or in combination of two or more. The first corrosion inhibitor is expected to suppress damage to various metal layers, but in particular, it can more effectively suppress damage to copper atom-containing components and cobalt atom-containing components, thus contributing to the corrosion protection of metal layers.

[0049] The content of the first corrosion inhibitor in the treatment solution is not particularly limited, but is preferably 0.0001 to 10% by mass. The upper limit of this content is more preferably 6% by mass or less, even more preferably 3% by mass or less, and even more preferably 1% by mass or less. The lower limit of this content is more preferably 0.001% by mass or more, even more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more. When two or more types of the first corrosion inhibitor are included, it is preferable that the total amount is within the above range. By setting the content of the first corrosion inhibitor within this range, it is possible to achieve an even higher level of balance between the removal of metal nitrides and the corrosion protection of the metal layer. The treatment solution can also be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content at the time of use (concentration of the diluted solution) is within the above range.

[0050] Furthermore, the treatment solution may further contain other corrosion inhibitors as a second corrosion inhibitor. Examples of the second corrosion inhibitor include nitrogen-containing heterocyclic compounds, mercapto group-containing compounds, aliphatic amine compounds, and salts thereof. By including the second corrosion inhibitor, corrosion can be prevented not only from the metal components protected by the first corrosion inhibitor but also from other metal components.

[0051] Examples of nitrogen-containing heterocyclic compounds include imidazole ring-containing compounds, triazole ring-containing compounds, pyridine ring-containing compounds, pyrimidine ring-containing compounds, phenanthroline ring-containing compounds, tetrazole ring-containing compounds, pyrazole ring-containing compounds, and purine ring-containing compounds.

[0052] Specific examples of imidazole ring-containing compounds include 1-decyl-3-methylimidazolium chloride, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-propylimidazole, 2-butylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 2-undecylimidazole, 2-aminoimidazole, and 2,2'-biimidazole.

[0053] Specific examples of triazole ring-containing compounds include 1,2,4-triazole, 1,2,3-benzotriazole, 1,2,3-triazole, 3-amino-1H-1,2,4-triazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-carboxyl-1H-benzotriazole methyl ester, 4-carboxyl-1H-benzotriazole butyl ester, 4-carboxyl-1H-benzotriazole octyl ester, 5-hexylbenzotriazole, [1,2,3-benzotriazolyl-1-methyl][1,2,4-triazolyl-1-methyl][2-ethylhexyl]amine, tolyltriazole, naphthotriazole, bis[(1-benzotriazolyl)methyl]phosphonic acid, and 3-aminotriazole.

[0054] Specific examples of pyridine ring-containing compounds include 1H-1,2,3-triazolo[4,5-b]pyridine, 1,2,4-triazolo[4,3-a]pyridine-3(2H)-one, 3H-1,2,3-triazolo[4,5-b]pyridine-3-ol, 1-acetyl-1H-1,2,3-triazolo[4,5-b]pyridine, 3-aminopyridine, 4-aminopyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetamidopyridine, 4-pyrrolidinopyridine, 2-cyanopyridine, 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, and 4,4-dinonyl-2,2-bipyridyl.

[0055] Specific examples of pyrimidine ring-containing compounds include pyrimidine, 1,2,4-triazolo[1,5-a]pyrimidine, 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine, 1,3-diphenyl-pyrimidine-2,4,6-trione, 1,4,5,6-tetrahydropyrimidine, 2,4,5,6-tetraaminopyrimidine sulfate, 2,4,5-trihydroxypyrimidine, 2,4,6-triaminopyrimidine, 2,4,6-trichloropyrimidine, 2,4,6-trimethoxypyrimidine, and 2,4,6-tri Examples include phenylpyrimidine, 2,4-diamino-6-hydroxylpyrimidine, 2,4-diaminopyrimidine, 2-acetamidopyrimidine, 2-aminopyrimidine, 2-methyl-5,7-diphenyl-(1,2,4)triazolo(1,5-a)pyrimidine, 2-methylsulfanyl-5,7-diphenyl-(1,2,4)triazolo(1,5-a)pyrimidine, 2-methylsulfanyl-5,7-diphenyl-4,7-dihydro-(1,2,4)triazolo(1,5-a)pyrimidine, and 4-aminopyrazolo[3,4-d]pyrimidine.

[0056] Specific examples of phenanthroline ring-containing compounds include 1,10-phenanthroline.

[0057] Specific examples of tetrazole ring-containing compounds include 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, and 1-(2-diaminoethyl)-5-mercaptotetrazole.

[0058] Specific examples of pyrazole ring-containing compounds include 3,5-dimethylpyrazole, 3-amino-5-methylpyrazole, 4-methylpyrazole, and 3-amino-5-hydroxypyrazole.

[0059] Specific examples of purine ring-containing compounds include purines.

[0060] Specific examples of mercapto group-containing compounds include, for example, 1-thioglycerol, 3-(2-aminophenylthio)-2-hydroxypropyl mercaptan, 3-(2-hydroxyethylthio)-2-hydroxypropyl mercaptan, 2-mercaptopropionic acid, and 3-mercaptopropionic acid.

[0061] Specific examples of aliphatic amine compounds include alkylamines, dialkylamines, and trialkylamines.

[0062] The content of the second corrosion inhibitor in the treatment solution is not particularly limited, but is preferably 0.0001 to 10% by mass. The upper limit of this content is more preferably 6% by mass or less, even more preferably 3% by mass or less, and even more preferably 1% by mass or less. The lower limit of this content is more preferably 0.001% by mass or more, even more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more. When two or more types of second corrosion inhibitors are included, it is preferable that the total amount is within the above range. By setting the content of the second corrosion inhibitor within this range, it is possible to exert a damage suppression effect on a wider variety of metal layers, and to achieve an even higher level of balance between the removal of metal nitrides and the corrosion protection of the metal layers. The treatment solution can be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content at the time of use (concentration of the diluted solution) is within the above range.

[0063] Furthermore, the first and second corrosion inhibitors may be salts of the compounds described above. Specific examples of salts are not particularly limited, but include, for example, sodium salts, potassium salts, ammonium salts, alkylammonium salts (e.g., tetramethylammonium salt). Alternatively, the compounds may be hydrates. In the case of hydrates, it is preferable that the net content, excluding the water of hydration contained in the hydrate, is within the range described above.

[0064] The total content of corrosion inhibitors in the treatment solution (the sum of the content of the first corrosion inhibitor and the content of the second corrosion inhibitor) is not particularly limited, but is preferably 0.0001 to 10% by mass. The upper limit of this content is more preferably 6% by mass or less, even more preferably 3% by mass or less, and even more preferably 1% by mass or less. The lower limit of this content is more preferably 0.001% by mass or more, even more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more. The treatment solution can also be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content at the time of use (concentration of the diluted solution) is within the range described above.

[0065] The treatment solution has a mass ratio of NH3 content to the content of the corrosion inhibitor (first corrosion inhibitor) (NH3 / first corrosion inhibitor) of 5 to 60. The upper limit of this mass ratio is preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, even more preferably 20 or less, even more preferably 10 or less, and even more preferably 9 or less. The lower limit of this mass ratio is preferably 5.5 or more, and more preferably 6 or more. By controlling this mass ratio within this range, it is possible to achieve a higher level of both metal nitride removal and corrosion protection of the metal layer.

[0066] The treatment solution preferably further contains hydrogen peroxide. This is preferable because the inclusion of hydrogen peroxide allows for effective etching of tantalum nitride and the like. Furthermore, some conventional treatment solutions containing hydrogen peroxide suffer from a decrease in effectiveness due to the decomposition of hydrogen peroxide over time. However, the treatment solution used in this embodiment, even when containing hydrogen peroxide, effectively suppresses the decomposition of hydrogen peroxide over time through interaction with other components.

[0067] The hydrogen peroxide content in the treatment solution is not particularly limited, but is preferably 1 to 20% by mass. The upper limit of this content is more preferably 18% by mass or less, even more preferably 16% by mass or less, and even more preferably 15% by mass or less. The lower limit of this content is more preferably 2% by mass or more, even more preferably 2.5% by mass or more, even more preferably 3% by mass or more, and even more preferably 4% by mass or more. By keeping the hydrogen peroxide content within the above range, the effect of adding hydrogen peroxide described above can be further improved. The treatment solution can also be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content at the time of use (concentration of the diluted solution) is within the above range.

[0068] The treatment solution preferably further contains a surfactant. Since this surfactant tends to have a high affinity for hydrophobic CF-based polymers, the inclusion of a surfactant allows for more effective removal of residual CF-based polymers. This is presumed to be because, for example, when washing and removing CF-based polymers after etching, the surfactant can be adsorbed onto and removed from the CF-based polymers due to the affinity between the surfactant and the CF-based polymers (however, the effects and benefits of this embodiment are not limited to these). Furthermore, this effect of the surfactant can be further enhanced by controlling the pH.

[0069] The type of surfactant is not particularly limited, but from the viewpoint of removing CF-based polymers, those with high affinity to CF-based polymers are preferred. From this viewpoint, it is preferable that the surfactant is a polymer-based surfactant and / or has a hydrophilic group. Specific examples of surfactants include nonionic surfactants, more preferably nonionic polymer-based surfactants, and even more preferably polyvinylpyrrolidone and poly(2-ethyl-2-oxazoline). Since such surfactants tend to have an even higher affinity for hydrophobic CF-based polymers, using such surfactants can further improve the removal of CF-based polymers.

[0070] The surfactant content in the treatment solution is not particularly limited, but is preferably 0.001 to 1% by mass. The upper limit of this content is more preferably 0.75% by mass or less, even more preferably 0.5% by mass or less, even more preferably 0.25% by mass or less, and even more preferably 0.1% by mass or less. The lower limit of this content is more preferably 0.005% by mass or more, even more preferably 0.007% by mass or more, and even more preferably 0.01% by mass or more. By keeping the surfactant content within the above range, the effect of adding the surfactant described above can be further improved. The treatment solution can also be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content at the time of use (concentration of the diluted solution) is within the above range.

[0071] The treatment solution preferably further contains a chelating agent. The inclusion of a chelating agent can stabilize hydrogen peroxide (however, the action and effects of this embodiment are not limited to these).

[0072] The type of chelating agent is not particularly limited, but 1,2-cyclohexanediaminetetraacetic acid, ethylenediaminetetraacetic acid, etidronic acid, phenylphosphonic acid, citric acid, acetylacetone, ethylenediaminetetra(methylenephosphonic acid), 3-morpholinopropanesulfonic acid, 1,3-phenylenediacetic acid, tetraethylenepentamine, pentaethylenehexamine, etc. are preferred, and trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA) is more preferred. By using such a chelating agent, the decomposition of hydrogen peroxide over time can be suppressed more effectively.

[0073] The content of the chelating agent in the treatment solution is not particularly limited, but is preferably 0.001 to 10% by mass. The upper limit of this content is more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.2% by mass or less. The lower limit of this content is more preferably 0.01% by mass or more, even more preferably 0.05% by mass or more, and even more preferably 0.07% by mass or more. By keeping the chelating agent content within the above range, the effect of adding the chelating agent described above can be further improved. The treatment solution can also be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content at the time of use (concentration of the diluted solution) is within the above range.

[0074] The processing solution may also contain components other than those mentioned above. Examples of such components include pH adjusters and buffering agents.

[0075] The treatment solution preferably contains a pH adjusting agent for the purpose of adjusting it to a desired pH. As the pH adjusting agent, known inorganic acids, organic acids, organic basic compounds, and inorganic basic compounds can be used as appropriate, as long as the effects of this embodiment can be obtained.

[0076] Specific examples of pH adjusters include phosphoric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid (MSA), citric acid, acetic acid, sodium dihydrogen phosphate, trisodium phosphate, sodium acetate, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate, monoethanolamine, ammonia, ammonium carbonate, 2-amino-2-methyl-1-propanol, tripotassium citrate, and diammonium hydrogen phosphate.

[0077] The pH adjusting agent may be used alone or in combination of two or more types. Alternatively, the treatment solution used in this embodiment does not need to contain a buffering agent.

[0078] The processing solution according to this embodiment may contain a buffering agent. The buffering agent is a compound that has the effect of suppressing changes in the pH of the processing solution. By including a buffering agent, the pH of the processing solution can be efficiently controlled to a predetermined value. The buffering agent is not particularly limited as long as it is a compound that has pH buffering capacity. An example of a buffering agent is Good's buffering agent.

[0079] The buffering agent may be used alone or in combination of two or more types. Alternatively, the processing liquid used in this embodiment may not contain a buffering agent.

[0080] The treatment solution used in this embodiment may contain a solvent. Preferably, the solvent is water. In this case, the treatment solution can be suitably used as an aqueous treatment solution. An example of an aqueous treatment solution is one in which water is the remainder after removing the active ingredient.

[0081] The water content in the treatment solution is not particularly limited, but is preferably 1 to 99.99% by mass. From the viewpoint of providing water solubility as an aqueous treatment solution while maintaining high levels of residue removal and corrosion prevention, the lower limit of this content is more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more. Furthermore, from the viewpoint of providing water solubility as an aqueous treatment solution while maintaining high levels of residue removal and corrosion prevention, the upper limit of this content is more preferably 99.9% by mass or less, even more preferably 99% by mass or less, even more preferably 98% by mass or less, and even more preferably 95% by mass or less. By keeping the water content within the above range, other components can be dissolved uniformly and stably.

[0082] In the semiconductor substrate processing method according to this embodiment, it is preferable that the water content of the processing solution used to process the semiconductor substrate with the semiconductor device processing solution is within the range described above. However, it is also possible to concentrate the processing solution to reduce the water content before use in the processing step, and then add water to bring the water content within the range described above when using it in the processing step.

[0083] The processing solution used in this embodiment may contain an organic solvent. Specific examples of organic solvents are not particularly limited, but at least one selected from the group consisting of alcohol-based solvents, glycol ester-based solvents, sulfoxide-based solvents, sulfone-based solvents, amide-based solvents, lactone-based solvents, imidazolidinone-based solvents, nitrile-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, pyrrolidone-based solvents, and urea-based solvents is preferred. Furthermore, it is more preferable that the processing solution contains only at least one organic solvent selected from the group consisting of alcohol-based solvents, glycol ester-based solvents, sulfoxide-based solvents, sulfone-based solvents, amide-based solvents, lactone-based solvents, imidazolidinone-based solvents, nitrile-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, pyrrolidone-based solvents, and urea-based solvents, and does not contain any other solvents. Also, if the processing solution contains an organic solvent, it is preferable to use a water-soluble organic solvent from the viewpoint of water solubility of the processing solution.

[0084] Organic solvents may be used individually or in combination of two or more types.

[0085] The processing liquid used in this embodiment can be sufficiently effective even without containing an organic solvent, but it can also be sufficiently effective with an organic solvent. In other words, the processing liquid according to this embodiment may contain an organic solvent. From this viewpoint, the organic solvent content in this embodiment can be 0 to 95% by mass. The lower limit of the organic solvent content may be 0% by mass, or depending on the components of the processing liquid, for example, 5% or more by mass, 10% or more by mass, 20% or more by mass, 30% or more by mass, 40% or more by mass, 50% or more by mass, or 60% or more by mass. The upper limit of the organic solvent content may be, for example, 90% or less by mass, 80% or less by mass, or 70% or less by mass. The processing liquid can also be stored as a concentrated liquid with concentrated components before use in the processing step, and when used in the processing step, the concentrated liquid can be diluted by adding a solvent such as water and used as a diluted solution (processing liquid).

[0086] (pH)

[0087] The pH of the treatment solution is not particularly limited, but is preferably between 7.0 and 14.0. The upper limit is more preferably 13.0 or less, even more preferably 12.0 or less, and even more preferably 11 or less. The lower limit is more preferably 8.0 or higher, even more preferably 9.0 or higher, and even more preferably 10.0 or higher. By having the pH of the treatment solution within this range, it is possible to achieve a higher level of both metal nitride removal and corrosion protection of the metal layer. Furthermore, the removal of CF-based polymers can also be further improved. The treatment solution can be stored as a concentrated solution with concentrated components before use in the treatment process, and when used in the treatment process, the concentrated solution can be diluted by adding a solvent such as water and used as a diluted solution (treatment solution). In that case, it is preferable that the content (concentration of the diluted solution) at the time of use is within the range described above.

[0088] (Impurities in the processing solution, etc.)

[0089] The processing solution used in this embodiment may contain metallic impurities, such as at least one metal atom selected from the group consisting of Fe atoms, Cr atoms, Ni atoms, Zn atoms, Ca atoms, and Pb atoms.

[0090] The total content of metal atoms in the processing solution used in this embodiment is preferably 100 ppt by mass or less relative to the total mass of the processing solution. The lower limit of the total content of metal atoms is preferable as it is lower, but for example, 0.001 ppt by mass or more is acceptable. For example, the total content of metal atoms can range from 0.001 to 100 ppt by mass. It is believed that by setting the total content of metal atoms below the above-mentioned preferred upper limit, the defect suppression and residue suppression properties of the processing solution will be improved. It is believed that by setting the total content of metal atoms above the above-mentioned preferred lower limit, metal atoms will be less likely to be freed and exist in the system, thus reducing the likelihood of adverse effects on the overall manufacturing yield of the processed product.

[0091] The content of metal impurities can be adjusted, for example, by purification treatment such as filtering. This purification treatment may be performed on part or all of the raw materials before preparing the treatment solution, or after preparing the treatment solution.

[0092] The processing solution used in this embodiment may contain, for example, impurities of organic origin (organic impurities). The total content of the above-mentioned organic impurities in the processing solution used in this embodiment is preferably 5000 ppm by mass or less. The lower limit of the organic impurity content is preferable as it is lower, but for example, 0.1 ppm by mass or more is acceptable. The total content of organic impurities can range from 0.1 to 5000 ppm by mass, for example.

[0093] The processing solution used in this embodiment may contain countable particles of a size that can be counted by, for example, a light scattering type liquid particle counter. The size of the countable particles is, for example, 0.04 μm or larger. The number of countable particles in the processing solution used in this embodiment is, for example, 1000 or less per 1 mL of processing solution, with a lower limit of, for example, 0.1 or more. It is believed that the metal corrosion suppression effect and defect suppression effect of the processing solution are improved by keeping the number of countable particles in the processing solution within the above range (however, the operation and effects of this embodiment are not limited to these).

[0094] The organic impurities and / or substances to be counted described above may be added to the treatment solution, or they may be inevitably introduced into the treatment solution during the manufacturing process of the treatment solution. Examples of cases where organic impurities are inevitably introduced during the manufacturing process of the treatment solution include, but are not limited to, cases where organic impurities are contained in the raw materials used in the manufacture of the treatment solution (e.g., organic solvents), and cases where they are introduced from the external environment during the manufacturing process of the treatment solution (e.g., contamination).

[0095] When adding the substance to be measured to the processing solution, the ratio of each specific size may be adjusted considering the surface roughness of the object being processed.

[0096] Next, the steps of the semiconductor substrate processing method according to this embodiment will be described.

[0097] (Each process)

[0098] The semiconductor substrate processing method according to this embodiment includes a processing step of processing the semiconductor substrate with a semiconductor device processing solution. The processing step involves, for example, bringing the processing solution into contact with the semiconductor substrate to be processed (for example, the semiconductor element 100 shown in Figure 1) to remove a predetermined film to be removed (such as a layer containing metal nitride) and to remove any residue without damaging the metal layer to be protected. The following explanation will use the cleaning of the semiconductor element 100 shown in Figure 1 as an example.

[0099] The processing method according to this embodiment is a step of processing the semiconductor element 100 after dry etching has been performed by the wiring process using the processing solution described above. The processing method is not particularly limited, and known methods can be used.

[0100] Before processing, the processing solution may be stored as a highly concentrated solution, and immediately before processing, a solvent may be added to dilute it to the desired concentration to prepare the processing solution. For example, the solution may be concentrated 2 to 2000 times from the desired concentration at the time of use, and then diluted to the desired concentration at the time of processing (use) to create a diluted solution (processing solution), and this diluted solution may be used for processing.

[0101] Examples of processing methods include continuously applying the processing solution onto a semiconductor element 100 that is rotating at a constant speed (rotary coating method), immersing the semiconductor element 100 in the processing solution for a certain period of time (dip method), and spraying the processing solution onto the surface of the semiconductor element 100 (spray method).

[0102] The processing temperature (temperature of the processing solution) is not particularly limited, but it is preferable to carry out the process under conditions of 10 to 80°C. The lower limit is more preferably 20°C or higher, and even more preferably 40°C or higher. The upper limit is more preferably 75°C or lower, and even more preferably 70°C or lower. By setting the lower limit of the processing temperature within the above range, the removal of etching residue can be further improved. Furthermore, by setting the upper limit of the processing temperature within the above range, unintended compositional changes of the processing solution can be more effectively suppressed, and cleaning can be performed more efficiently from the viewpoint of workability, safety, and cost.

[0103] The processing time can be appropriately selected to be sufficient to remove the tantalum nitride film 50. For example, a processing time of 10 seconds to 30 minutes is preferable. The lower limit is more preferably 20 seconds or more, and even more preferably 30 seconds or more. The upper limit is more preferably 15 minutes or less, and even more preferably 10 minutes or less.

[0104] Because the processing is performed using a processing solution, the tantalum nitride film 50 can be removed from the semiconductor device 100 with residue 70 attached while minimizing damage to the metal wiring layer 20. In addition, it is expected that dry etching residues originating from the protective HM layer 60 will also be cleaned and removed.

[0105] Furthermore, the processing solution used in this embodiment has the advantage of being able to achieve a practical level of cleaning effect without using conventionally available hydroxylamine, etc., thus enabling safer manufacturing of semiconductor devices and the like.

[0106] Furthermore, if the treatment solution used contains hydrogen peroxide, it is preferable to include a preparation step before the above-described treatment step in which a first chemical solution containing NH3, a corrosion inhibitor, and water is mixed with a second chemical solution containing hydrogen peroxide to prepare the treatment solution. By preparing the first and second chemical solutions in advance and mixing them before the treatment step (preferably immediately before) to prepare the treatment solution before use, the decomposition of hydrogen peroxide over time can be effectively suppressed, thereby further improving the desired treatment effect.

[0107] The first chemical solution may contain other components besides NH3, a corrosion inhibitor, and water. For example, it may further contain other components such as the pH adjuster and buffer mentioned above. The first chemical solution may also further contain the organic solvent mentioned above as a solvent.

[0108] The second chemical solution may contain other components besides hydrogen peroxide and water. For example, it may further contain other components such as the pH adjusters and buffers mentioned above. The second chemical solution may also further contain the organic solvents mentioned above as solvents. However, from the viewpoint of suppressing the decomposition of hydrogen peroxide over time, it is preferable to contain only hydrogen peroxide and water. For example, it is preferable to use hydrogen peroxide solution as the second chemical solution.

[0109] Furthermore, other chemical solutions (e.g., a third chemical solution, a fourth chemical solution, etc.) besides the first and second chemical solutions may also be prepared, and the first chemical solution, the second chemical solution, and the other chemical solutions may be mixed before the processing step to prepare the processing solution. Examples of other chemical solutions include those containing the above-mentioned pH adjusters, buffers, and other components, along with water. In addition, the other chemical solutions may further contain the above-mentioned organic solvents as solvents.

[0110] When the first and second chemical solutions are prepared separately in this manner, they can be used as a semiconductor device processing solution kit (hereinafter sometimes simply referred to as "processing solution kit"). That is, the semiconductor substrate processing method can further include the steps of preparing a processing solution kit containing the first and second chemical solutions before the processing steps described above, and mixing the first and second chemical solutions to prepare a processing solution.

[0111] <Manufacturing methods for semiconductor devices>

[0112] The semiconductor substrate processing method according to the embodiment described above can be suitably used as one step in the manufacturing method of a semiconductor device. Specifically, the manufacturing method of a semiconductor device according to the embodiment includes the steps of preparing a semiconductor substrate having a layer containing a metal nitride that has been etched, and processing the etched semiconductor substrate with a semiconductor device processing solution; the semiconductor device processing solution contains NH3, a corrosion inhibitor, and water, the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content (NH3 / corrosion inhibitor) is 5 to 60.

[0113] (1) Process of preparing an etched semiconductor substrate

[0114] An etched semiconductor substrate can be prepared by etching a substrate (substrate before etching) that has a layer containing a metal nitride. For example, in the case of Figure 1, although not shown, a laminate (substrate 10 / metal wiring layer 20 / etching stop layer 30 / tantalum nitride (TaN film) 50 / HM layer 60) having the substrate 10, metal wiring layer 20, etching stop layer 30, tantalum nitride film (TaN film) 50, and hard mask layer (HM layer) 60 corresponding to a protective film in this order can be prepared, and an etched semiconductor substrate can be prepared by performing the etching process on this laminate. The method of sequentially laminating the substrate 10, metal wiring layer 20, etching stop layer 30, tantalum nitride (TaN film) 50, and hard mask layer (HM layer) 60 corresponding to a protective film on the substrate 10 is not particularly limited, and known methods can be used.

[0115] The etching method is not particularly limited; it may be wet etching or dry etching, but dry etching is preferred. Dry etching is advantageous because it allows for nano-level metal wiring through anisotropic etching and also allows for control of the gas used. Furthermore, while dry etching can cause relatively large damage to the substrate, using the processing solution used in this embodiment is desirable because it can effectively suppress such damage, thus more effectively reflecting the advantages of this embodiment.

[0116] In the case of dry etching, plasma can be used. Normally, when performing plasma etching, problems such as the substrate being easily damaged and the generation of plasma etching residue that needs to be cleaned with a processing solution can be considered. However, this embodiment is preferable because it can effectively suppress these problems.

[0117] (2) A processing step in which an etched semiconductor substrate is processed with the processing solution described above.

[0118] (2) The above-described semiconductor substrate processing method can be used as the process. This will allow you to obtain a semiconductor device 100. The processing conditions can be appropriately adopted from those described in the semiconductor substrate processing method. The composition and characteristics of the processing solution used can also be appropriately adopted from those described in the semiconductor substrate processing method.

[0119] If the treatment solution contains hydrogen peroxide, it is preferable to further include a preparation step before the treatment step in which a first chemical solution containing NH3, a corrosion inhibitor, and water is mixed with a second chemical solution containing hydrogen peroxide to prepare the treatment solution. By preparing the first and second chemical solutions in advance and mixing them before the treatment step (preferably immediately before) to prepare the treatment solution before use, the decomposition of hydrogen peroxide over time can be effectively suppressed, thereby further improving the desired treatment effect.

[0120] The first and second chemical solutions can be those described as a semiconductor substrate processing method. When the first and second chemical solutions are prepared individually in this way, they can be used as a semiconductor device processing solution kit (hereinafter sometimes simply referred to as a "processing solution kit"). That is, the semiconductor substrate processing method can further include the steps of preparing a processing solution kit containing the first and second chemical solutions before the processing steps described above, and mixing the first and second chemical solutions to prepare a processing solution.

[0121] Furthermore, when other chemical solutions (for example, a third chemical solution, a fourth chemical solution, etc.) other than the first and second chemical solutions are used in combination, the methods described for processing semiconductor substrates can also be adopted for these other solutions.

[0122] Furthermore, if necessary, post-processing such as a rinsing step can be performed after the processing step. The rinsing step can be carried out, for example, using ultrapure water, isopropyl alcohol, aqueous ammonia, or a mixture thereof, or a composition containing various additives, under washing conditions of 30 seconds at room temperature.

[0123] <Processing solutions for semiconductor devices, processing solution kits for semiconductor devices>

[0124] The semiconductor device processing solution (processing solution) according to this embodiment contains NH3, a corrosion inhibitor, and water, wherein the corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content (NH3 / corrosion inhibitor) is 5 to 60. Such a processing solution is suitably used in the semiconductor substrate processing method and semiconductor device manufacturing method described above. The composition and characteristics of the processing solution can be appropriately adopted from the contents described above in the semiconductor substrate processing method and semiconductor device manufacturing method.

[0125] The processing solution according to this embodiment can also be provided as a semiconductor device processing solution kit (processing solution kit) composed of multiple chemical solutions, depending on its usage. For example, if the processing solution contains hydrogen peroxide, it is preferable to provide it as a processing solution kit from the viewpoint of ensuring the stability of hydrogen peroxide over time. An example of a processing solution kit is a semiconductor device processing solution kit that includes a first chemical solution containing NH3, a corrosion inhibitor, and water, and a second chemical solution containing hydrogen peroxide; the corrosion inhibitor in the first chemical solution is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole, and the mass ratio of the NH3 content to the corrosion inhibitor content in the first chemical solution is 5 to 60.

[0126] The components of the processing solution kit (first chemical solution, second chemical solution, and other chemical solutions that can be used as needed) can be appropriately adopted from those described in the above-mentioned semiconductor substrate processing method and semiconductor device manufacturing method.

[0127] The processing solution according to this embodiment is suitable for removing etching residue, and is particularly suitable for removing dry etching residue. Normally, dry etching residue is removed before the next process in order to improve semiconductor yield and prevent deterioration of electrical properties. For example, the processing solution according to this embodiment is suitable for cleaning semiconductor substrates after dry etching has been performed by a wiring process. [Examples]

[0128] The present invention will be described in more detail by the following examples and comparative examples, but the present invention is not limited in any way by the following examples.

[0129] The abbreviations and English names for the ingredients are as follows: • 5MBTA: 5-methyl-1H-benzotriazole P2E2O: Poly(2-ethyl-2-oxazoline) • CyDTA:trans-1,2-cyclohexanediaminetetraacetic acid monohydrate Imidazole: Imidazole • 1,2,4-Triazole: 1,2,4-triazole 1,2,3-Benzotriazole: 1,2,3-benzotriazole 5-Aminotetrazole: 5-amino-1H-tetrazole • DBS: Dodecylbenzenesulfonic acid POEAGE: Polyoxyethylene acetylene glycol ether • PVP: Polyvinylpyrrolidone • DIW: Deionized water

[0130] 1. Preparation of the treatment solution (Examples 1-13, Comparative Examples 1-7) The semiconductor device processing solutions for each example and comparative example were prepared by mixing each component with water as the remainder in the proportions shown in Tables 1 to 3. Specifically, aqueous solutions of components other than hydrogen peroxide and hydrogen peroxide solution were prepared and mixed to prepare the semiconductor device processing solutions, which were then immediately subjected to each evaluation. For example, Example 1 is an aqueous processing solution containing 4.1% by mass of NH3, 12% by mass of hydrogen peroxide (H2O2), 0.5% by mass of 5MBTA, and 83.4% by mass of water as the remainder (see Table 1). The mass ratio of NH3 to the corrosion inhibitor (5MBTA) is 8.2, and the pH of the aqueous processing solution is 10.2. Unless otherwise specified, the hydrate content (by mass%) in each table refers to the content excluding the water of hydration contained in the hydrate.

[0131] (Method for measuring pH) The pH of the treatment solution was measured at a temperature of 22°C using a pH / ORP meter (portable pH meter "ORION STAR A324", manufactured by Thermo Scientific).

[0132] 2. Evaluation of the removeability of tantalum nitride films

[0133] The removability of the tantalum nitride film in each example and comparative example ("TaN removability" in Tables 1 to 3) was evaluated by the following method (evaluation based on removal time).

[0134] First, a laminate (substrate having Cu layer, SiOC layer, TaN layer, and CHM layer) was prepared on a substrate (12-inch silicon substrate) by CVD and dry etching, having a Cu layer (thickness 65 nm), an SiOC layer (thickness 2 nm), a TaN layer (thickness 9 nm), and a CHM layer (thickness 70 nm). A test sample (laminated structure) was fabricated by cutting this laminate into a 2 cm x 2 cm section when viewed from above.

[0135] Next, the obtained samples (laminated structures) were washed. Washing was performed by the following method. First, the processing solution for each example and comparative example was heated to 58°C. Then, the etched samples were immersed in the processing solution for each example and comparative example at 58°C. After that, the samples were removed from the processing solution, washed with isopropyl alcohol, and then dried by nitrogen blowing. For Examples 6-13 and Comparative Examples 5-7 (see Tables 2 and 3), the processed samples were rinsed with water (DIW). The remaining amount of TaN film on these samples was then checked using TEM (imaging magnification: 330kx). Specifically, TaN removability was evaluated by measuring the time required until the TaN film could no longer be seen on the exposed surface. A shorter removal time indicated better removability.

[0136] 3. Evaluation of the corrosion resistance of the Cu layer

[0137] The corrosion resistance of the Cu layer in each example and comparative example ("Cu corrosion @ 10 min" in Tables 1 to 3) was evaluated by the following method.

[0138] First, a laminate (substrate with a Cu metal layer) was prepared by depositing a Cu metal layer (film thickness 65 nm) on a substrate (12-inch silicon substrate) using CVD and dry etching. Test samples (wafer coupons) were obtained by cutting this laminate into 2 cm × 2 cm sections when viewed from above. Then, 80 mL of the processing solution for each example and comparative example was placed in a 100 mL cup. The sample was then placed in the solution and immersed in the solution for 10 minutes at the temperature indicated in the table. During immersion, the solution was stirred at 300 rpm. After immersion, the sample was removed from the solution, washed with water at room temperature for 30 seconds, and dried by nitrogen blowing. For Examples 6-13 and Comparative Examples 5-7 (see Tables 2 and 3), the processed samples were rinsed with water (DIW). Then, using a scanning electron microscope (SEM), the surface of the treated sample was observed under imaging conditions of 10kx magnification, and the corrosion resistance of the Cu layer was evaluated based on the degree of remaining Cu layer.

[0139] The corrosion resistance of the Cu layer ("Cu corrosion @ 10 min") was then evaluated based on the following criteria. A: No surface abnormalities were found, and no corrosion of the copper wiring was detected. B: Some of the copper wiring was corroded. C: Many of the copper wirings were corroded. D: Most of the copper wiring was corroded.

[0140] As shown in Tables 1 to 3 below, Comparative Examples 1 to 7 showed insufficient results in at least one of the following: the removability of the tantalum nitride film ("TaN removability") and the corrosion resistance of the Cu layer ("Cu corrosion @ 10 min"). In contrast, Examples 1 to 13 showed good results in both the removability of the tantalum nitride film and the corrosion resistance of the Cu layer. Therefore, for Examples 1 to 13, the corrosion resistance of the CHM layer, the cleanability of the CF-based polymer, and the decomposition properties were also evaluated as further additional evaluations. These are described below.

[0141] 4. Evaluation of the corrosion resistance of the CHM layer

[0142] The corrosion resistance of the carbon hard mask (CHM) layer in each example ("CHM@Clean time" in Tables 1-3) was evaluated by the following method.

[0143] First, a laminate (substrate with CHM layer) having a CHM layer (film thickness 70 nm) was prepared on a substrate (12-inch silicon substrate) by CVD and etching. Test samples (laminated layers) were obtained by cutting this laminate into 2 cm × 2 cm sections when viewed from above. Then, 80 mL of the treatment solution for each example was placed in a 100 mL cup. The sample was placed in the solution and immersed in the treatment solution for 10 minutes at the temperature indicated in the table. During immersion, the treatment solution was stirred at 300 rpm. After immersion, the sample was removed from the treatment solution, washed with water at room temperature for 30 seconds, and dried by nitrogen blowing. For Examples 6 to 13 (see Tables 2 and 3), the treated samples were rinsed with water (DIW). Then, the surface of the treated samples was observed using a scanning electron microscope (SEM) at a magnification of 10 kx, and the corrosion resistance of the CHM layer was evaluated based on the degree of remaining CHM layer.

[0144] The corrosion resistance of the CHM layer ("CHM@Clean time") was evaluated based on the following criteria. A: The CHM layer remained. B: A portion of the CHM layer had been removed. The entire C:CHM layer had been removed.

[0145] 5. Evaluation of the cleanability of CF-based polymers

[0146] The cleanability of the CF polymers in each example ("CF polymer@Clean time" in Tables 1-3) was evaluated by the following method.

[0147] The test samples prepared in "2. Evaluation of Tantalum Nitride Film Removability" were used as the samples for this evaluation. 80 mL of the treatment solution for each example was placed in a 100 mL cup. The sample was then added and immersed in the treatment solution for 10 minutes at the temperature indicated in the table. During immersion, the treatment solution was stirred at 300 rpm. After immersion, the sample was removed from the treatment solution, washed with water at room temperature for 30 seconds, and dried by nitrogen blowing. For Examples 6-13 (see Tables 2 and 3), the treated samples were rinsed with water (DIW). The surface of the treated samples was then observed using a scanning electron microscope (SEM) at a magnification of 10 kx. The cleanability of the CF-based polymer was then evaluated based on the degree of cleaning of the CF-based polymer.

[0148] The cleanability of CF polymers ("CF polymer@Clean time") was evaluated based on the following criteria. A: No CF-based polymers were detected on the surface of the sample. B: It was confirmed that CF-based polymers remained on the surface of the sample.

[0149] 6. Evaluation of degradability (stability over time)

[0150] The decomposition properties (stability over time) of the treatment solution in each example (see "Decomposition" in Tables 1 to 3) were evaluated by the following method.

[0151] 100 mL of the treatment solution from each example was placed in a transparent container made of PFA (perfluoroalkoxyalkane), heated to 58°C, and four small pieces (2 cm x 5 cm) of TaN substrate (film thickness 20 nm) were immersed for 30 minutes. Subsequently, the degree of decomposition of the treatment solution was evaluated by observing the frequency of large bubbles, approximately 0.5 cm in diameter, that rose from the solution to the surface of the solution from the side of the container.

[0152] The decomposition properties (stability over time, "Decomposition") of the treatment solution were evaluated based on the following criteria. A: The frequency of bubbles was low (less than 9 per minute). B: There was a high frequency of bubbles (more than 10 per minute).

[0153] Tables 1 to 3 show the composition, characteristics, treatment conditions, and evaluation results of the treatment solutions for each example and comparative example.

[0154] [Table 1]

[0155] [Table 2]

[0156] [Table 3]

[0157] From the above, it has been confirmed that this embodiment provides excellent removeability of metal nitrides and corrosion resistance of the metal layer. Furthermore, it has been confirmed that in the more preferred embodiment, in addition to the removeability of metal nitrides and corrosion resistance of the metal layer, one or more of the following properties can also be improved: corrosion resistance of the CHM layer, cleanability of the CF-based polymer, and decomposability. [Explanation of Symbols]

[0158] 10: Circuit board 20: Metal wiring layer 30: Etching stop layer 40: Interlayer insulating film 50: Tantalum nitride film (TaN film) 60: Hard mask layer (HM layer) 70:Residue 100, 200: Semiconductor devices (semiconductor substrates)

Claims

1. The process includes treating a semiconductor substrate having a layer containing a metal nitride with a semiconductor device processing solution; The aforementioned processing solution for semiconductor devices is NH ３ It contains a corrosion inhibitor and water. The aforementioned corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole. The NH content relative to the content of the corrosion inhibitor ３ Mass ratio of the content (NH ３ The amount of the corrosion inhibitor is 5 to 60. A method for processing semiconductor substrates.

2. The aforementioned semiconductor device processing solution further contains hydrogen peroxide. The method for processing a semiconductor substrate according to claim 1.

3. The aforementioned processing solution for semiconductor devices further contains a surfactant. The method for processing a semiconductor substrate according to claim 1.

4. The aforementioned processing solution for semiconductor devices further contains a chelating agent. The method for processing a semiconductor substrate according to claim 1.

5. Before the aforementioned processing step, Said NH ３ The process further includes a preparation step of mixing a first chemical solution containing the corrosion inhibitor and water, and a second chemical solution containing hydrogen peroxide, to prepare the processing solution for semiconductor devices. The method for processing a semiconductor substrate according to claim 2.

6. A process for preparing a semiconductor substrate having a layer containing a metal nitride that has been etched, The process includes a step of treating the semiconductor substrate that has undergone the etching process with a semiconductor device processing solution; The aforementioned processing solution for semiconductor devices is NH ３ It contains a corrosion inhibitor and water. The aforementioned corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole. The NH content relative to the content of the corrosion inhibitor ３ Mass ratio of the content (NH ３ The amount of the corrosion inhibitor is 5 to 60. A method for manufacturing semiconductor devices.

7. The aforementioned semiconductor device processing solution further contains hydrogen peroxide. A method for manufacturing a semiconductor device according to claim 6.

8. The aforementioned processing solution for semiconductor devices further contains a surfactant. A method for manufacturing a semiconductor device according to claim 6.

9. The aforementioned processing solution for semiconductor devices further contains a chelating agent. A method for manufacturing a semiconductor device according to claim 6.

10. Before the aforementioned processing step, Said NH ３ The process further includes a preparation step of mixing a first chemical solution containing the corrosion inhibitor and water, and a second chemical solution containing hydrogen peroxide, to prepare the processing solution for semiconductor devices. A method for manufacturing a semiconductor device according to claim 7.

11. NH ３ containing NH, a corrosion inhibitor, and water, The aforementioned corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole. The NH content relative to the content of the corrosion inhibitor ３ Mass ratio of the content (NH ３ The amount of the corrosion inhibitor is 5 to 60. Processing solution for semiconductor devices.

12. Furthermore, containing surfactants, The processing solution for semiconductor devices according to claim 11.

13. Furthermore, it contains hydrogen peroxide, The processing solution for semiconductor devices according to claim 11.

14. Furthermore, it contains a chelating agent. The processing solution for semiconductor devices according to claim 11.

15. The aforementioned processing solution for semiconductor devices is Said NH ３ A first chemical solution containing the aforementioned corrosion inhibitor and the aforementioned water, The second chemical solution containing the hydrogen peroxide, This is a processing solution kit for semiconductor devices, including; The corrosion inhibitor in the first chemical solution is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, imidazole, and 5-amino-1H-tetrazole. The NH content of the first chemical solution relative to the content of the corrosion inhibitor ３ The mass ratio of the content is 5 to 60; The processing solution for semiconductor devices according to claim 13.

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