Processing solution, substrate processing method, and semiconductor substrate manufacturing method

Abstract

To provide a processing solution, a substrate processing method, and a semiconductor substrate manufacturing method that are excellent in terms of removability of embedding materials and corrosion inhibition of low-k materials.SOLUTION: A processing solution for a semiconductor device is provided, and the processing solution includes (a) a water-soluble organic solvent, (b) water, and (c) ions of a main group metal element.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a processing liquid, a method for processing a substrate, and a method for manufacturing a semiconductor substrate.

Background Art

[0002] A semiconductor device is formed by laminating a metal wiring layer, a low dielectric layer, an insulating layer, etc. on a substrate such as a silicon wafer. Such a semiconductor device is manufactured by processing each of the above-described layers by a lithography method in which an etching process is performed using a resist pattern as a mask.

[0003] Then, in the lithography method, a resist pattern, an embedding material (temporary laminated film, sacrificial layer, sacrificial film, spin-on glass (SOG) material, trench filling, etc.), and further residues derived from the metal wiring layer and the low dielectric layer generated in the etching process are removed using a cleaning liquid so as not to interfere with the semiconductor device and not to hinder the next process.

[0004] In recent years, with the increase in the density and integration of semiconductor devices, a wiring formation method using the damascene method has been adopted. In such a wiring formation method, copper, which is likely to corrode, is adopted as the metal wiring material constituting the metal wiring layer of the semiconductor device. Furthermore, for the low dielectric material (also referred to as an ILD material) constituting the low dielectric layer, the dielectric constant is increasingly reduced, and an ILD material that is likely to corrode is being adopted. Therefore, there is a demand for the development of a cleaning liquid that does not cause corrosion to these easily corrodible materials during cleaning of the substrate.

[0005] In addition, in the wiring formation method using the damascene method, the composition of the material used as the temporary laminated film (sacrificial layer, sacrificial film, etc.) during the etching process is very similar to that of the ILD material. There is a demand for the development of a cleaning liquid that can leave one of such similar materials (ILD material) on the device without causing corrosion and efficiently remove the other (temporary laminated film).

[0006] As a technology related to a cleaning liquid for lithography used in such a semiconductor device manufacturing process, Patent Document 1 discloses that in the formation of a dual damascene structure, an etching process is performed on a low dielectric constant layer laminated on a substrate having a metal layer to form a first etching space, and after filling a sacrificial layer in the first etching space, the low dielectric constant layer and the sacrificial layer are further partially etched to form a second etching space communicating with the first etching space. Then, a cleaning liquid used for removing the sacrificial layer remaining in the first etching space is disclosed, which contains (a) 1 to 25% by mass of a quaternary ammonium hydroxide, (b) 30 to 70% by mass of a water-soluble organic solvent, and (c) 20 to 60% by mass of water.

Prior Art Document

Patent Document

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] By the way, for example, when an etching process is performed on a low dielectric constant layer using a resist pattern as a mask, after the etching process, it is necessary to remove the remaining resist pattern, unnecessary layers and films to be removed using a processing liquid. However, it is difficult to remove the resist altered by etching and layers and films with a high crosslink density, while the Low-k material constituting the low dielectric constant layer is easily corroded. Therefore, while suppressing the corrosion of the Low-k material, it is required to effectively remove the embedded material, but in fact, there is still room for improvement in this regard.

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to provide a processing liquid, a method for processing a substrate, and a method for manufacturing a semiconductor substrate, which are excellent in the peelability of the embedded material and the suppression of corrosion of the Low-k material.

Means for Solving the Problems

[0010] As a result of intensive studies to achieve the above object, the present inventors have found that a treatment liquid for a semiconductor device containing (a) a water-soluble organic solvent, (b) water, and (c) ions of a typical metal element, and have completed the present invention.

[0011] That is, the present invention is as follows. <1> A treatment liquid for a semiconductor device, comprising (a) a water-soluble organic solvent, (b) water, and (c) ions of a typical metal element. <2> The treatment liquid according to <1>, wherein the ion of the (c) typical metal element is at least one ion selected from the group consisting of (c-1) an ion of a Group 1 metal element, (c-2) an ion of a Group 2 metal element, and (c-3) an ion of a Group 13 metal element. <3> The treatment liquid according to <1> or <2>, wherein the ion of the (c) typical metal element includes (c-1) an ion of a Group 1 metal element, (c-2) an ion of a Group 2 metal element, and (c-3) an ion of a Group 13 metal element. <4> The treatment liquid according to <2> or <3>, wherein the ion of the (c-1) Group 1 metal element is a potassium ion and / or a sodium ion. <5> The treatment liquid according to any one of <2> to <4>, wherein the ion of the (c-2) Group 2 metal element is a magnesium ion and / or a calcium ion. <6> The treatment liquid according to any one of <2> to <5>, wherein the ion of the (c-3) Group 13 metal element is a boron ion and / or an aluminum ion. <7> The treatment liquid according to any one of <2> to <6>, containing the ion of the (c-1) Group 1 metal element in an amount of 5×10 4 ppb mass% to 1×10 7 ppb mass% based on the total mass of the treatment liquid. <8> The ions of the group 2 metal element in (c-2) are in an amount of 1×10 1 ppb mass% to 1×10 3 ppb mass% and is the treatment liquid according to any one of <2> to <7>. <9> The ions of the group 13 metal element in (c-3) are in an amount of 1×10 0 ppb mass% to 1×10 2 ppb mass% and is the treatment liquid according to any one of <2> to <8>. <10> Furthermore, (d) it is the treatment liquid according to any one of <1> to <9>, which contains a base other than the component (a), the component (b), and the component (c). <11> The treatment liquid according to <10>, wherein the base (d) is a quaternary ammonium hydroxide compound. <12> A preparation step of obtaining a laminated substrate including a substrate, a low dielectric layer laminated on the substrate, and a resist pattern laminated on the substrate, and a treatment step of treating the laminated substrate with the treatment liquid according to any one of <1> to <11>, which is a method for treating a substrate. <13> The method for treating a substrate according to <12>, wherein the preparation step is a step of obtaining the laminated substrate using a damascene method. <14> A preparation step of obtaining a laminated substrate including a substrate, a low dielectric layer laminated on the substrate, and a resist pattern laminated on the substrate, and a treatment step of treating the laminated substrate with the treatment liquid according to any one of <1> to <11>, which is a method for manufacturing a semiconductor substrate. <15> The method for manufacturing a semiconductor substrate according to <14>, including a step of forming a metal wiring by embedding a metal in the pattern space of the resist pattern after the treatment step. <16> The method for manufacturing a semiconductor substrate according to <14> or <15>, wherein the preparation step is a step of obtaining the laminated substrate using a damascene method.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a treatment liquid, a method for treating a substrate, and a method for manufacturing a semiconductor substrate, which are excellent in the releasability of the embedded material and the corrosion inhibition of the Low-k material.

Embodiments for Carrying Out the Invention

[0013] 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.

[0014] <Treatment Liquid>

[0015] The treatment liquid according to the present embodiment is a treatment liquid for a semiconductor device, which contains (a) a water-soluble organic solvent, (b) water, and (c) ions of a typical metal element.

[0016] ((a) Water-soluble organic solvent)

[0017] The treatment liquid according to the present embodiment contains (a) a water-soluble organic solvent. Examples of the component (a) include highly polar solvents having a dipole moment of 3.0 D or more, glycol ether solvents, polyhydric alcohols, and the like.

[0018] Specific examples of the high-polarity solvent include, for example, sulfoxides such as dimethyl sulfoxide (DMSO) (dipole moment: 4.6 D); sulfones such as dimethyl sulfone (dipole moment: 5.1 D), diethyl sulfone (dipole moment: 4.7 D), and tetramethylene sulfone (dipole moment: 5.0 D); amides such as N,N-dimethylformamide (DMF) (dipole moment: 4.5 D), N-methylformamide (dipole moment: 4.6 D), N,N-dimethylacetamide (DMAc) (dipole moment: 4.6 D), N-methylacetamide (dipole moment: 4.3 D), and N,N-diethylacetamide (dipole moment: 4.7 D); lactams such as N-methyl-2-pyrrolidone (NMP) (dipole moment: 4.6 D), N-ethyl-2-pyrrolidone (dipole moment: 4.7 D), N-hydroxymethyl-2-pyrrolidone (dipole moment: 3.1 D), and N-hydroxyethyl-2-pyrrolidone (dipole moment: 6.1 D); lactones such as β-propiolactone (dipole moment: 4.6 D), γ-butyrolactone (GBL) (dipole moment: 5.1 D), γ-valerolactone (dipole moment: 5.3 D), δ-valerolactone (dipole moment: 5.4 D), γ-caprolactone (dipole moment: 5.2 D), and ε-caprolactone (dipole moment: 5.5 D); imidazolidinones such as 1,3-dimethyl-2-imidazolidinone (DMI) (dipole moment: 4.5 D), 1,3-diethyl-2-imidazolidinone (dipole moment: 4.5 D), and 1,3-diisopropyl-2-imidazolidinone (dipole moment: 4.3 D); and one or more selected from the group consisting of these.

[0019] Among these, high-polarity solvents with a dipole moment of 3.5 to 7.0 D are preferred, and high-polarity solvents with a dipole moment of 4.0 to 6.0 D are more preferred. In particular, from the viewpoints of stability in alkaline chemical solutions and the like, it is preferably at least one selected from the group consisting of sulfoxides, amides, lactams, and lactones, and more preferably at least one selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and γ-butyrolactone.

[0020] Examples of the glycol ether-based solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (EDG), diethylene glycol monopropyl ether, and diethylene glycol monobutyl ether (BDG).

[0021] Among these, from the viewpoints of water solubility, resist pattern removal performance, flammability, etc., it is preferably at least one selected from the group consisting of diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (EDG), diethylene glycol monopropyl ether, and diethylene glycol monobutyl ether (BDG), and more preferably at least one selected from the group consisting of diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (EDG), and diethylene glycol monobutyl ether (BDG).

[0022] Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, butylene glycol, glycerin, etc. Among these, from the viewpoints of safety, viscosity, etc., it is preferably at least one selected from the group consisting of ethylene glycol, propylene glycol, and glycerin.

[0023] (a) As the water-soluble organic solvent, one of the above-mentioned solvents may be used alone, or two or more thereof may be used in combination. As an example of a preferred combination, it preferably contains two or more selected from the group consisting of a highly polar solvent having a dipole moment of 3.0 D or more, a glycol ether solvent, and alcohols; more preferably, it contains a highly polar solvent having a dipole moment of 3.0 D or more, a glycol ether solvent, and polyhydric alcohols; still more preferably, it contains at least one selected from the group consisting of one or more selected from the group consisting of sulfoxides, amides, lactams, and lactones as the highly polar solvent, at least one selected from the group consisting of diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (EDG), and diethylene glycol monobutyl ether (BDG) as the glycol ether solvent, and at least one selected from the group consisting of ethylene glycol, propylene glycol, and glycerin as the polyhydric alcohols; even more preferably, it contains at least one selected from the group consisting of one or more selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and γ-butyrolactone as the highly polar solvent, at least one selected from the group consisting of diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (EDG), and diethylene glycol monobutyl ether (BDG) as the glycol ether solvent, and at least one selected from the group consisting of ethylene glycol, propylene glycol, and glycerin as the polyhydric alcohols.

[0024] (a) The content of the water-soluble organic solvent is preferably 15 to 80% by mass based on the total amount of the treatment liquid. The lower limit is more preferably 20% by mass or more, and still more preferably 25% by mass or more. The upper limit is more preferably 70% by mass or less, and still more preferably 60% by mass or less.

[0025] When including a high-polarity solvent, the content of the high-polarity solvent is preferably 5 to 60% by mass based on the total amount of the treatment liquid. The lower limit is more preferably 10% by mass or more, and still more preferably 20% by mass or more. The upper limit is more preferably 50% by mass or less, and still more preferably 30% by mass or less. By setting the content of the high-polarity solvent within the above range, the peelability of the embedded material and the effect of suppressing the corrosion of the Low-k material can be further improved.

[0026] When including a glycol ether-based solvent, the content of the glycol ether-based solvent is preferably 5 to 55% by mass based on the total amount of the treatment liquid. The lower limit is more preferably 10% by mass or more, and still more preferably 15% by mass or more. The upper limit is more preferably 30% by mass or less, and still more preferably 20% by mass or less. By setting the content of the glycol ether-based solvent within the above range, the peelability of the embedded material and the effect of suppressing the corrosion of the Low-k material can be further improved.

[0027] When including a polyhydric alcohol, the content of the polyhydric alcohol is preferably 5 to 30% by mass based on the total amount of the treatment liquid. The lower limit is more preferably 10% by mass or more, and still more preferably 15% by mass or more. The upper limit is more preferably 25% by mass or less. By setting the content of the polyhydric alcohol within the above range, the peelability of the embedded material and the effect of suppressing the corrosion of the Low-k material can be further improved.

[0028] ((b) Water)

[0029] The treatment liquid according to this embodiment contains (b) water. The content of (b) water may be included as the remainder of the components other than water. The content of (b) water is preferably 15% by mass to 85% by mass based on the total amount of the treatment liquid. This lower limit may be 20% by mass or more, may be 25% by mass or more, or may be a value greater than 40% by mass. This upper limit may be less than 80% by mass, may be less than 75% by mass, may be less than 65% by mass, or may be less than 60% by mass. By setting the water content within the above range, the peelability of the embedding material and the effect of suppressing the corrosion of the Low-k material can be further improved.

[0030] ((c) Ions of typical metal elements)

[0031] The treatment liquid according to this embodiment contains (c) ions of typical metal elements. As the component (c), it is preferable to contain at least one kind of metal ion belonging to one kind selected from the group consisting of (c-1) ions of Group 1 metal elements, (c-2) ions of Group 2 metal elements, and (c-3) ions of Group 13 metal elements.

[0032] (c-1) Examples of the ions of Group 1 metal elements include lithium (Li) ions, sodium (Na) ions, potassium (K) ions, rubidium (Rb) ions, cesium (Cs) ions, etc. Among these, potassium ions and sodium ions are preferable. It is more preferable that the treatment liquid according to this embodiment contains potassium ions and / or sodium ions.

[0033] (c-2) Examples of the ions of Group 2 metal elements include beryllium (Be) ions, magnesium (Mg) ions, calcium (Ca) ions, strontium (Sr) ions, barium (Ba) ions, etc. Among these, magnesium ions and calcium ions are preferable. It is more preferable that the treatment liquid according to this embodiment contains magnesium ions and / or calcium ions.

[0034] (c-3) As ions of Group 13 metal elements, boron (B) ions, aluminum (Al) ions, gallium (Ga) ions, indium (In) ions, etc. can be mentioned. Among these, boron ions and aluminum ions are preferable. It is more preferable that the treatment liquid according to the present embodiment contains boron ions and / or aluminum ions.

[0035] (c) When including ions of (c-1) Group 1 metal elements as a component, the content of the ions of (c-1) Group 1 metal elements is 5×10 4 ppb mass% to 1×10 7 ppb mass% is preferable. This lower limit is preferably 1×10 5 ppb mass% or more, more preferably 3×10 5 ppb mass% or more, even more preferably 4×10 5 ppb mass% or more. This upper limit is more preferably 1×10 6 ppb mass% or less, even more preferably 9×10 5 ppb mass% or less, even more preferably 8×10 5 ppb mass% or less. When including two or more types of ions as the (c-1) component, it is preferable that the total amount of the (c-1) component is within the above range.

[0036] (c) When including ions of (c-2) Group 2 metal elements as a component, the content of the ions of (c-2) Group 2 metal elements is 1×10 1 ppb mass% to 1×10 3 ppb mass% is preferable. This lower limit is more preferably 5×10 1 ppb mass% or more, even more preferably 1×10 2 ppb mass% or more, even more preferably 1.5×10 2 ppb mass% or more. This upper limit is more preferably 7×10 2 ppb mass% or less, even more preferably 6×10 2 ppb mass% or less, even more preferably 5×10 2It is more preferably at ppb mass% or less. When two or more types of ions are included as the component (c-2), it is preferable that the total amount of the component (c-2) is within the above range.

[0037] (c) When the component contains ions of a Group 13 metal element as the component (c-3), the content of the ions of the Group 13 metal element as the component (c-3) is 1×10 0 ppb mass% to 1×10 2 ppb mass% is preferable. The lower limit is 5×10 0 ppb mass% or more is more preferable, 1×10 1 ppb mass or more is still more preferable, 1.5×10 1 ppb mass or more is even more preferable. The upper limit is 9×10 1 ppb mass% or less is more preferable, 7×10 1 ppb mass% or less is still more preferable, 6×10 1 ppb mass% or less is more preferable, 5×10 1 ppb mass% or less is even more preferable. When two or more types of ions are included as the component (c-3), it is preferable that the total amount of the component (c-3) is within the above range.

[0038] ((d) Base)

[0039] The treatment liquid according to the present embodiment preferably further contains a (d) base. The (d) base is a base other than the (a) component, the (b) component, and the (c) component. Examples of the (d) base include quaternary ammonium hydroxide compounds such as tetramethylammonium hydroxide (TMAH) and tetraethylammonium hydroxide (TEAH). Among these, quaternary ammonium hydroxide compounds are preferable, and tetramethylammonium hydroxide (TMAH) and tetraethylammonium hydroxide (TEAH) are more preferable.

[0040] (d) When containing a base, the content of the (d) base is preferably 0.5% by mass to 20% by mass based on the total amount of the treatment liquid. This lower limit is more preferably 2% by mass or more, and even more preferably 4% by mass or more. This upper limit is more preferably 18% by mass or less, and even more preferably 15% by mass or less. By setting the content of the (d) base within the above range, the peelability of the embedded material and the effect of suppressing the corrosion of the Low-k material can be further improved. When two or more bases are included as the (d) component, it is preferable that the total amount of the (d) component is within the above range.

[0041] ((e) Corrosion inhibitor)

[0042] The treatment liquid according to this embodiment may further contain an (e) corrosion inhibitor. It can be expected that the treatment liquid according to this embodiment can also achieve the corrosion prevention effect by the (e) corrosion inhibitor. The (e) corrosion inhibitor is preferably at least one selected from the group consisting of benzotriazole-based compounds and mercapto group-containing compounds.

[0043] Examples of the above benzotriazole-based compounds include compounds represented by the following general formula (1).

[0044]

Chemical formula

[0045] In the above general formula (1), R 1 , R 2 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a carboxyl group, an amino group, a hydroxyl group, a cyano group, a formyl group, a sulfonylalkyl group, or a sulfo group, and P represents a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 14 carbon atoms which may have a substituent (provided that the hydrocarbon group may be interrupted by an amide bond or an ester bond), or a group represented by the following general formula (2).

[0046]

Chemical formula

[0047] In the general formula (2) above, R 3 represents an alkylene group having 1 to 6 carbon atoms, and R 4 , R 5 each independently represents a hydrogen atom, a hydroxyl group, or a hydroxyalkyl group or alkoxyalkyl group having 1 to 6 carbon atoms.

[0048] In the general formula (1) above, in the respective definitions of R 1 , R 2 , and P, the hydrocarbon group may be either an aromatic hydrocarbon group or an aliphatic hydrocarbon group, may have an unsaturated bond, and may be linear, branched, or cyclic. Examples of the aromatic hydrocarbon group include a phenyl group, a p-tolyl group, etc. Examples of the linear aliphatic hydrocarbon group include a methyl group, an n-propyl group, a vinyl group, etc. Examples of the branched aliphatic hydrocarbon group include an isobutyl group, a tert-butyl group, etc. Examples of the cyclic aliphatic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, etc. Examples of the hydrocarbon group having a substituent include a hydroxyalkyl group, an alkoxyalkyl group, etc.

[0049] Also, in the general formula (1) above, P is preferably a group represented by the general formula (2). Particularly among the groups represented by the general formula (2), it is preferable to select a group in which R 4 , R 5 are each independently a hydroxyalkyl group or alkoxyalkyl group having 1 to 6 carbon atoms.

[0050] Furthermore, P is preferably selected such that the compound represented by the general formula (1) exhibits water solubility. Specifically, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (i.e., a methyl group, an ethyl group, a propyl group, an isopropyl group), a hydroxyalkyl group having 1 to 3 carbon atoms, a hydroxyl group, etc. are preferable.

[0051] Examples of the benzotriazole compounds include benzotriazole, 5,6-dimethylbenzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 1-aminobenzotriazole, 1-phenylbenzotriazole, 1-hydroxymethylbenzotriazole, methyl 1-benzotriazolecarboxylate, 5-benzotriazolecarboxylic acid, 1-methoxy-benzotriazole, 1-(2,2-dihydroxyethyl)-benzotriazole, 1-(2,3-dihydroxypropyl)benzotriazole, 2,2'-{[(4-methyl-1H-benzotriazol-1-yl)methyl]imino}bisethanol, 2,2'-{[(5-methyl-1H-benzotriazol-1-yl)methyl]imino}bisethanol, 2,2'-{[(4-methyl-1H-benzotriazol-1-yl)methyl]imino}bisethane, 2,2'-{[(4-methyl-1H-benzotriazol-1-yl)methyl]imino}bispropane, and the like. Among these, 1-(2,3-dihydroxypropyl)-benzotriazole, 2,2'-{[(4-methyl-1H-benzotriazol-1-yl)methyl]imino}bisethanol, 2,2'-{[(5-methyl-1H-benzotriazol-1-yl)methyl]imino}bisethanol, and the like are preferably used. These may be used alone or in combination of two or more.

[0052] As the mercapto group-containing compound, a compound having a hydroxyl group and / or a carboxyl group at at least one of the α-position and the β-position of the carbon atom bonded to the mercapto group is preferable. Examples of such compounds include 1-thioglycerol, 3-(2-aminophenylthio)-2-hydroxypropyl mercaptan, 3-(2-hydroxyethylthio)-2-hydroxypropyl mercaptan, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and the like. Among these, 1-thioglycerol is preferable. These may be used alone or in combination of two or more.

[0053] (Surfactant)

[0054] The processing liquid according to this embodiment may contain a surfactant as necessary. As such a surfactant, an acetylene alcohol-based surfactant or the like can be preferably used. The content of the surfactant is preferably less than 0.5% by mass with respect to the total amount of the processing liquid.

[0055] <Processing method, method for manufacturing a semiconductor substrate, wiring formation method, etc.>

[0056] The processing liquid according to this embodiment is a processing liquid for lithography, but can be suitably used for processing an etched laminated substrate. For example, a method for processing a substrate includes a preparation step of obtaining a laminated substrate including a substrate, a low dielectric constant layer laminated on the substrate, and a resist pattern laminated on the substrate, and a processing step of processing the laminated substrate with the above-described processing liquid.

[0057] Note that the above-described preparation step of obtaining a laminated substrate may include a step (previous step) of preparing a laminated substrate including a substrate, a low dielectric constant layer formed on the surface of the substrate, and a resist pattern formed on the surface of the substrate, and a step (etching step) of forming an etching space in the resist pattern of the laminated substrate by an etching process.

[0058] The preparation step of obtaining a laminated substrate is preferably obtained using the damascene method. That is, the above-described preparation step is preferably a step of obtaining a laminated substrate using the damascene method.

[0059] Note that the layer structure of the laminated substrate to be processed only needs to include a substrate, a low dielectric constant layer, and a resist pattern layer, and may be a multilayer structure including other layers. For example, various layers described later may be provided between the substrate and the low dielectric constant layer, or between the low dielectric constant layer and the resist pattern layer, or a further layer may be provided on the resist pattern layer.

[0060] And the treatment liquid and treatment method according to the present embodiment can be suitably used in a method for manufacturing a semiconductor substrate. For example, in a method for manufacturing a semiconductor substrate, it can be suitably used when treating an etched laminated substrate. As a preferred example of the method for manufacturing a semiconductor substrate, a method for manufacturing a semiconductor substrate including a preparation step of obtaining a laminated substrate including a substrate, a low dielectric layer laminated on the substrate, and a resist pattern laminated on the substrate, and a treatment step of treating the laminated substrate with the above-described treatment liquid can be mentioned.

[0061] Furthermore, as a method for manufacturing a semiconductor substrate, it is preferable to include a step of forming a metal wiring by embedding a metal in the pattern space of the resist pattern after the treatment step. By performing such a step, a fine metal wiring can be formed in a space such as a via hole or a trench, and a semiconductor substrate having a damascene structure described later can be obtained.

[0062] And the preparation step of obtaining the laminated substrate is preferably obtained by using the damascene method. That is, the above-described preparation step is preferably a step of obtaining the laminated substrate by using the damascene method.

[0063] As described above, the treatment liquid according to the present embodiment is a treatment liquid for lithography, but can be suitably used particularly for a wiring formation method using the damascene method. More specifically, it can be used in a wiring formation method using the damascene method in which a metal wiring layer is formed by embedding a metal in a pattern space (etching space, etc.) formed in a low dielectric layer using a resist pattern. Note that the treatment liquid according to the present embodiment can be suitably used for both a single damascene process and a dual damascene process. Several modes will be exemplarily described below.

[0064] As an example of a wiring formation method using the damascene process, a resist pattern (for example, a trench resist pattern) is formed as a mask on a low dielectric layer formed on a substrate. Subsequently, the low dielectric layer is etched to form an etching space (trench pattern, groove), and a metal wiring is formed by embedding a metal in this etching space. Note that an anti-reflection film (BARC) or the like may be formed under the resist pattern. Further, a sacrificial film may be temporarily embedded in the etching space.

[0065] As a more specific example, the case of a semiconductor substrate having a dual damascene structure of Cu metal wiring will be described. In the case of Cu metal wiring, since the etching resistance of Cu may be low, a method of forming a Cu multilayer wiring using the damascene process can be preferably used. Although various methods have been proposed as the dual damascene process, as an example, after providing a Cu layer on a substrate, a low dielectric layer is laminated, and then a photoresist pattern is formed on the uppermost layer by lithography technology. Using this photoresist pattern as a mask, the low dielectric layer is etched to form a via hole communicating with the Cu layer. Then, the photoresist pattern is peeled off. Subsequently, a sacrificial layer such as an alkoxysilane material is filled in the via hole. Next, a new photoresist pattern is formed on the uppermost layer of the remaining multilayer stack, and using this as a mask, the low dielectric layer and the sacrificial layer are etched to form a wiring groove (trench) communicating with the via hole. Then, the sacrificial layer remaining in the via hole is washed and removed. After peeling off the photoresist pattern, a multilayer Cu wiring can be formed by filling Cu in the via hole and the trench by plating or the like.

[0066] And the processing liquid according to this embodiment can effectively remove the resist pattern after the etching process, and residues derived from the low-dielectric constant layer and the metal wiring layer generated in the etching process. In addition, since the processing liquid according to this embodiment is excellent in the peelability of the embedding material and the corrosion suppression of the Low-k material, it is possible to effectively remove the resist pattern, the underlying anti-reflection film, etc. while suppressing the corrosion of the ILD material. Therefore, it can also be suitably used when removing at least the resist pattern and the underlying anti-reflection film after forming an etching space in the low-dielectric constant layer using the resist pattern and the underlying anti-reflection film.

[0067] The method for removing the resist pattern and residues using the processing liquid according to this embodiment is not particularly limited as long as it is a commonly used removal method. Specifically, for example, the processing liquid according to this embodiment is brought into contact with the substrate using a dipping method, a paddle method, a shower method, etc. for processing. The dipping time is not particularly limited, but is, for example, 5 seconds to 60 minutes, and the dipping temperature is not particularly limited, but is, for example, 20 to 80°C.

[0068] Here, as the material for forming the resist pattern, a resist material commonly used for (KrF, ArF, F2, EUV) excimer lasers or electron beams can be used by a conventional method. In addition, as the material for forming the underlying anti-reflection film, a commonly used inorganic or organic underlying anti-reflection film material can be used by a conventional method.

[0069] Using such a resist material and an underlying anti-reflection film material, a resist pattern and an underlying anti-reflection film are formed on the interlayer insulating layer or the barrier layer on its upper layer. After pattern exposure through a mask, a resist pattern is formed by development processing. Next, the resist pattern residues after etching using this resist pattern as a mask are removed by the processing liquid according to this embodiment together with other residues derived from the underlying anti-reflection film, the sacrificial film, and the metal wiring layer and the low-dielectric constant layer generated in the etching process.

[0070] As the low-dielectric constant layer such as the above-mentioned Low-k film, specifically, for example, it is a layer formed of a material such as a carbon-doped oxide (SiOC) system, a methylsilsesquioxane (MSQ) system, or a hydroxysilsesquioxane (HSQ) system. Since it does not affect the electrical characteristics of the metal wiring layer, it is preferably a low-dielectric constant layer with a dielectric constant (k) of 3.0 or less.

[0071] In addition, examples of the barrier layer include SiC, SiN, SiCN, Ta, TaN, etc. Such a barrier layer may be formed between the low-dielectric constant layers.

[0072] Also, as the metal material for forming the metal wiring layer used in the damascene method, it is mainly Cu, but conductor materials such as Al, Ti, and W other than Cu are also laminated on the same substrate. According to the treatment liquid according to the present embodiment, corrosion can be effectively suppressed even when the cleaning liquid comes into contact with these metal materials.

[0073] The treatment liquid according to the present embodiment is particularly useful in the damascene method, especially in the wiring formation method by the damascene method in which a sacrificial film is temporarily provided in the formed etching space. As the material (filling material) for forming such a sacrificial film, specifically, a spin-on glass (SOG) material obtained by a condensation reaction is suitable. Note that the spin-on glass material can also be used for step relaxation of the interlayer insulating film, filling of grooves between wirings, etc.

[0074] As the spin-on glass material for forming the sacrificial film, for example, those described in JP-A-2001-092122 can be used. Further, as a specific example of the spin-on glass material, a compound obtained by hydrolyzing at least one compound selected from the compounds represented by the following general formulas (3) to (5) by the action of an acid in the presence of water is suitable. From such a viewpoint, as the spin-on glass material, a compound obtained by combining the compound represented by the following general formula (3) and the compound represented by the following general formula (4) and hydrolyzing by the action of an acid in the presence of water is more suitable.

[0075]

Chem.

[0076] In the above general formulas (3) to (5), R 6 ~R 9 、R 11 ~R 13 、R 16 、and R 17 each independently represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, and R 10 、R 14 、and R 15 each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0077] Among the compounds represented by the above general formula (3), tetramethoxysilane or tetraethoxysilane, or their oligomers are preferred. Also, among the compounds represented by the above general formula (4), trimethoxysilane or triethoxysilane, or their oligomers are preferred. Further, among the compounds represented by the above general formula (5), dimethoxysilane, diethoxysilane, or methyldimethoxysilane, or their oligomers are preferred. These spin-on glass materials can be appropriately selected and used singly or in combination of two or more.

[0078] Furthermore, a highly absorbent substance may be appropriately blended with the compounds represented by the above general formulas (3) to (5). Such a highly absorbent substance has a substituent capable of condensing with the spin-on glass material in its structure, has a high absorption ability for light in the photosensitive characteristic wavelength range of the photosensitive component in the resist material, and can prevent standing waves caused by reflected light from the substrate and irregular reflection caused by steps on the substrate surface, and there is no particular limitation as long as it meets these requirements. For example, sulfone-based compounds, benzophenone-based compounds, anthracene-based compounds, naphthalene-based compounds, etc. substituted with a hydroxyl group and / or a carboxyl group can be mentioned. In particular, bisphenylsulfone-based compounds and benzophenone-based compounds having at least two hydroxyl groups, anthracene-based compounds having at least one hydroxyl group and / or hydroxyalkyl group, anthracene-based compounds having a carboxyl group and / or a hydroxyl group, and naphthalene-based compounds substituted with at least one carboxyl group and / or a hydroxyl group are preferable.

[0079] The content of the above highly absorbent substance is preferably 10 to 50% by mass in terms of the solid content concentration in terms of SiO2 in the spin-on glass material, and more preferably 15 to 40% by mass.

Examples

[0080] The present invention will be described in more detail with the following examples and comparative examples, but the present invention is not limited to the following examples in any way. Unless otherwise specified below, the experiments were carried out under the conditions of 25°C and atmospheric pressure.

[0081] (Preparation of Processing Liquid for Lithography)

[0082] Based on the compositions and blending amounts shown in Tables 1 to 4, a cleaning liquid for lithography was prepared. For each reagent, unless otherwise specified, generally commercially available reagents were used. Also, the numerical values in the tables are shown in units of mass% unless otherwise specified.

[0083] The abbreviations in the table are as follows. TMAH: Tetramethylammonium Hydroxide TEAH: Tetraethylammonium Hydroxide DMSO: Dimethyl Sulfoxide NMP: N-Methyl-2-Pyrrolidone DMF: N,N-Dimethylformamide GBL: γ-Butyrolactone EDG: Diethylene Glycol Monoethyl Ether MDG: Diethylene Glycol Monomethyl Ether BDG: Diethylene Glycol Monobutyl Ether PG: Propylene Glycol EG: Ethylene Glycol

[0084] For example, the cleaning liquid for lithography in Example 1 contains (a) as a water-soluble organic solvent, 5% by mass of dimethyl sulfoxide (DMSO), 35% by mass of diethylene glycol monoethyl ether (EDG), and 20% by mass of propylene glycol (PG), and (c-1) as ions of Group 1 metal elements, 2×10 2 ppb by mass of Na ions and 5×10 5 ppb by mass of K ions, (c-2) as ions of Group 2 metal elements, 2×10 2 ppb by mass of Mg ions and 5×10 -1 ppb by mass of Ca ions, (c-3) as ions of Group 13 metal elements, 2×10 1 ppb by mass of B ions and 4×10 -1 ppb by mass of Al ions, and (d) as a base, 10% by mass of tetramethylammonium hydroxide (TMAH), with the balance being (b) water.

[0085]

Table 1

[0086]

Table 2

[0087]

Table 3

[0088]

Table 4

[0089] (Release property of the embedded material)

[0090] First, a sample substrate was prepared by forming an embedded material made of a spin-on glass material on a laminated substrate having a Cu layer on a Si substrate. The spin-on glass material used was based on the description in JP-A-2001-092122. Subsequently, the sample substrate was immersed in the cleaning liquid for lithography of each example and each comparative example at 50°C for 1 minute, and then rinsed with pure water. The peeling state of the embedded material at this time was evaluated by measuring the film thickness of the Cu layer. The results are shown in Table 5.

[0091] (Corrosion suppression of Low-k material)

[0092] First, a sample substrate was prepared by forming a low dielectric constant layer (dielectric constant 2.7 to 2.8) formed by CVD deposition on a laminated substrate having a Cu layer on a Si substrate. Subsequently, a trench resist pattern was formed on the low dielectric constant layer of the sample substrate using lithography as a mask. As the low dielectric constant layer, a material of the same type as the spin-on glass material disclosed in JP-A-2001-092122, which was formed by firing at a temperature lower than the crystallization temperature, was used. Then, the low dielectric constant layer was dry-etched to form a trench pattern, thereby obtaining a pattern substrate.

[0093] This pattern substrate was immersed in the lithography cleaning liquids of each example and each comparative example under the conditions of 50 °C for 10 minutes, and then rinsed with pure water. The corrosion state of the Low-k material at this time was evaluated by observing it with an SEM (scanning electron microscope, "S-5200" manufactured by Hitachi, Ltd.). The results are shown in Table 5.

[0094] Regarding the evaluation results in Table 5, "A" and "B" indicate those with good peelability or corrosion inhibition, and among them, "A" indicates those with particularly good peelability or corrosion inhibition. On the other hand, "C" indicates those with insufficient peelability or corrosion inhibition.

[0095]

Table 5

[0096] From the above, it was at least confirmed that the treatment liquid of this example is excellent in the peelability of the embedded material and the corrosion inhibition of the Low-k material.

Claims

1. (a) A water-soluble organic solvent, (b) Water, (c) Ions of a typical metal element, A processing liquid for a semiconductor device, comprising the same.

2. As the ions of the typical metal element in (c), one kind of ion selected from the group consisting of (c-1) ions of a Group 1 metal element, (c-2) ions of a Group 2 metal element, and (c-3) ions of a Group 13 metal element, containing at least one kind of, The processing liquid according to Claim 1.

3. As the ions of the typical metal element in (c), (c-1) ions of a Group 1 metal element, (c-2) ions of a Group 2 metal element, and (c-3) ions of a Group 13 metal element, containing the same, The processing liquid according to Claim 1.

4. The ions of the Group 1 metal element in (c-1) are potassium ions and / or sodium ions, The processing liquid according to Claim 2 or 3.

5. The ions of the Group 2 metal element in (c-2) are magnesium ions and / or calcium ions, The processing liquid according to Claim 2 or 3.

6. The ions of the Group 13 metal element in (c-3) are boron ions and / or aluminum ions, The processing liquid according to Claim 2 or 3.

7. The ions of the Group 1 metal element in (c-1) are contained in an amount of 5×10 ４ ppb by mass to 1×10 ７ ppb by mass, based on the total mass of the treatment liquid. The processing liquid according to Claim 2 or 3.

8. The ions of the Group 2 metal element in (c-2) are contained in an amount of 1×10 １ ppb by mass to 1×10 ３ ppb by mass with respect to the total mass of the treatment liquid. The processing liquid according to Claim 2 or 3.

9. The ions of the group 13 metal element in (c-3) are contained in an amount of 1×10 ０ ppb by mass to 1×10 ２ ppb by mass, based on the total mass of the treatment liquid. The processing liquid according to Claim 2 or 3.

10. Furthermore, (d) a base other than the components (a), (b), and (c) is included, The processing liquid according to Claim 1 or 2.

11. The base in (d) is a quaternary ammonium hydroxide compound, The processing liquid according to Claim 10.

12. A preparation step of obtaining a laminated substrate including a substrate, a low dielectric constant layer laminated on the substrate, and a resist pattern laminated on the substrate, A processing step of processing the laminated substrate with the processing liquid according to Claim 1 or 2, A method for processing a substrate, comprising the same.

13. The preparation step is a step of obtaining the laminated substrate using a damascene method, The method for processing a substrate according to Claim 12.

14. A preparation step of obtaining a laminated substrate including a substrate, a low dielectric constant layer laminated on the substrate, and a resist pattern laminated on the substrate, A processing step of processing the laminated substrate with the processing liquid according to Claim 1 or 2, A method for manufacturing a semiconductor substrate, comprising the same.

15. After the processing step, a step of forming a metal wiring by embedding a metal in the pattern space of the resist pattern is included. The method for manufacturing a semiconductor substrate according to claim 14.

16. The preparation step is a step of obtaining the laminated substrate using the damascene method. The method for manufacturing a semiconductor substrate according to claim 14.

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