JP4485786B2 - Cleaning solution for semiconductor substrates - Google Patents

Description

  The present invention relates to a cleaning liquid for a semiconductor substrate.

In recent years, Cu wiring has been introduced in semiconductor devices, and a chemical mechanical polishing process (CMP process) has been adopted for forming the Cu wiring.
In this CMP process, grooves and connection holes are formed in an insulating film having a low dielectric constant such as carbon-containing SiO ₂ (SiOC) planarized in advance, and then Cu is formed by plating or the like to form the grooves and connection holes. By polishing with a slurry containing embedding and special abrasive grains and additives, Cu other than the grooves and connection holes is removed to flatten the surface and form wirings and connection holes.
Since a large amount of fine foreign particles such as abrasive grains and polishing debris in the polishing slurry and ionic foreign matters such as metal impurities are adhered on the semiconductor substrate after the CMP process, the particulate foreign matter and the ionic foreign matter Development of a cleaning solution that can simultaneously remove water is desired.
Examples of such a cleaning liquid include a nonionic surfactant having a phenylene group such as polyoxyethylene nonylphenyl ether, a compound that forms a complex with a metal such as aminoacetic acid or quinaldic acid, and an alkali component. A cleaning solution is known (see Patent Document 1).
However, when the hydrophobic low dielectric constant insulating film such as SiOC is used as the cleaning liquid, the wettability with the insulating film is poor, and removal of particulate foreign matter and ionic foreign matter on the semiconductor substrate after the CMP process is performed. There was a problem that was difficult.

JP2002-270656

  An object of the present invention is to provide a cleaning solution having excellent removability of particulate foreign matters and ionic foreign matters on a semiconductor substrate after the CMP process.

  As a result of intensive studies to find a cleaning solution that can solve the above-described problems, the present inventors have found that among nonionic surfactants having no phenylene group represented by the following formulas (1) and (2) The present inventors have found that a cleaning liquid containing at least one kind, a chelating agent, and a chelating accelerator is excellent in removal of particulate foreign matter and ionic foreign matter on a semiconductor substrate, and completed the present invention. .

That is, the present invention relates to the general formula (1)
_{CH 3 - (CH 2) l} -O- (C m H 2m O) n -X (1)
(In the formula, l, m and n each independently represent a positive number, and X represents a hydrogen atom or a hydrocarbon group)
And / or general formula (2),
_{CH 3 - (CH 2) a} -O- (C b H 2b O) d - (C x H 2x O) y -X (2)
(Wherein a, b, d, x and y each independently represents a positive number, b and x are different from each other, X represents a hydrogen atom or a hydrocarbon group)
A cleaning solution for a semiconductor substrate, characterized by comprising a nonionic surfactant represented by the formula (1), a chelating agent, and a chelating accelerator.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the cleaning liquid excellent in the removal property of the particulate foreign material on the semiconductor substrate after CMP process, and an ionic foreign material.

As the surfactant contained in the cleaning liquid of the present invention, the general formula (1)
_{CH 3 - (CH 2) l} -O- (C m H 2m O) n -X (1)
(In the formula, l, m and n each independently represent a positive number, and X represents a hydrogen atom or a hydrocarbon group)
And general formula (2)
_{CH 3 - (CH 2) a} -O- (C b H 2b O) d - (C x H 2x O) y -X (2)
(Wherein a, b, d, x and y each independently represents a positive number, b and x are different from each other, X represents a hydrogen atom or a hydrocarbon group)
The nonionic surfactant shown by these is mentioned.

In general formula (1) or (2), l and a represent a positive number, and are preferably 8 to 18, more preferably 8 to 11, and still more preferably 9 to 11.
When l and a are less than 8 or more than 18, the wettability with an insulating film having a low dielectric constant tends to deteriorate, and the removability of particulate foreign matter tends to decrease. Since the action becomes strong, it tends to be difficult to dissolve in an aqueous solution.
X is a hydrogen atom or a hydrocarbon group, and examples of the hydrocarbon group include a methyl group and an ethyl group.

In general formula (1), m represents a positive number, is 2 or 3, and is more preferably 2.
n represents a positive number, preferably 4 to 20, and more preferably 5 to 10.
If n is less than 4, the solubility in an aqueous solution tends to be poor, and if it exceeds 20, the wettability with an insulating film having a low dielectric constant tends to be poor.

In general formula (2), b and d represent positive numbers, and b is usually 2.
Moreover, d is 1-20 normally, Preferably it is 1-10. If d exceeds 20, the wettability with an insulating film having a low dielectric constant tends to be poor.

In General formula (2), x and y represent a positive number, and x is usually 3 to 10, preferably 3 to 5, and more preferably 3. When x exceeds 10, the solubility in water tends to deteriorate.
Moreover, y is 1-10 normally, Preferably it is 1-5. When y exceeds 10, the wettability with an insulating film having a low dielectric constant tends to be deteriorated.

  The nonionic surfactant represented by the general formula (2) is a form in which two types of alkylene oxide are polymerized, and the polymerization form is not particularly limited, and there are various forms such as random copolymerization and block copolymerization. sell.

In the nonionic surfactants represented by the general formulas (1) and (2), the starting material of the lipophilic group is a primary alcohol, and those in which l and a are 9 to 11 are suitable. Even if the total number of carbon atoms in the lipophilic group is 10 to 12, a nonionic surfactant using a secondary alcohol as a starting material, such as the following general formula (4) or (5)
General formula (4)
_{(CH 3 - (CH 2)} 4) 2 CH-O- (C m H 2m O) n -X (4)
General formula (5)
_{(CH 3 - (CH 2)} 4) 2 CH-O- (C b H 2b O) d - (C x H 2x O) y -X
(5)
(M, n, b, d, x, y and X have the same meaning as above.)
The nonionic surfactant indicated by is satisfactory even if the wettability with the low dielectric constant insulating film is improved, the surfactant remains on the surface, or the particulate foreign matter is not sufficiently removed. Cleaning performance is difficult to obtain.

Examples of the nonionic surfactant represented by the general formula (1) or (2) include polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene. Examples include polyoxypropylene lauryl ether, polyoxyethylene polyoxypropylene stearyl ether, polyoxyethylene polyoxypropylene decyl ether, and the like.
Among these, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene polyoxypropylene decyl ether, and polyoxyethylene polyoxypropylene lauryl ether are preferably used.

The concentration of the nonionic surfactant (the sum of the general formulas (1) and (2)) in the cleaning liquid is preferably 0.0001 to 1% by weight, and preferably 0.001 to 1% by weight. More preferred.
If it is less than 0.0001% by weight, the wettability with an insulating film having a low dielectric constant tends to be poor, and if it exceeds 1% by weight, the foaming property of the cleaning liquid becomes violent and the workability during cleaning tends to deteriorate. is there.

The chelating agent is not particularly limited as long as it can remove a metal. For example, polyaminocarboxylic acids, polycarboxylic acids, compounds having a phosphonic acid group, oxycarboxylic acids, phenols, heterocyclic compounds, and tropolone And at least one selected from the group consisting of groups. Here, “class” usually means including a salt or derivative of the compound.
Examples of polyaminocarboxylic acids include ethylenediaminetetraacetic acid (EDTA), trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), and N- (2-hydroxyethyl). And ethylenediamine-N, N ′, N′-triacetic acid (EDTA-OH).
Of these, ethylenediaminetetraacetic acid (EDTA) is preferably used.

Examples of polycarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, methylmalonic acid, 2-carboxybutyric acid, and ammonium salts thereof.
Of these, oxalic acid and ammonium oxalate are preferably used.

Examples of the compounds having a phosphonic acid group include ethylenediaminetetramethylenephosphonic acid, ethylenediaminedimethylenephosphonic acid, nitrilotrismethylenephosphonic acid, and 1-hydroxyethylidenediphosphonic acid.
Of these, 1-hydroxyethylidene diphosphonic acid is preferably used.

Examples of oxycarboxylic acids include gluconic acid, tartaric acid, citric acid and the like.
Of these, citric acid and ammonium citrate are preferably used.

Examples of phenols include phenol, cresol, ethylphenol, t-butylphenol, methoxyphenol, catechol, resorcinol, hydroquinone, 4-methylpyrocatechol, 2-methylhydroquinone, pyrogallol, 3,4-dihydroxybenzoic acid, gallic acid. 2,3,4-trihydroxybenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid, ethylenediaminedioltohydroxyphenylacetic acid [EDDHA], N, N-bis (2-hydroxybenzyl) ethylenediamine-N, N -2 acetic acid [HBED], ethylenediaminedihydroxymethylphenylacetic acid [EDDHMA] and the like.
Among these, catechol and ethylenediaminedioltohydroxyphenylacetic acid [EDDHA] are preferably used.

Examples of the heterocyclic compounds include 8-quinolinol, 2-methyl-8-quinolinol, quinolinediol, 1- (2-pyridylazo) -2-naphthol, 2-amino-4,6,7-pteridinetriol, 5,7,3′4′-tetrahydroxyflavone [luteoline], 3,3′-bis [N, N-bis (carboxymethyl) aminomethyl] fluorescein [calcein], 2,3-hydroxypyridine, etc. .
Of these, 8-quinolinol is preferably used.

Examples of tropolones include tropolone and 6-isopropyl tropolone.
Of these, tropolone is preferably used.

The concentration of the chelating agent in the cleaning solution is preferably 0.00001 to 10% by weight, and more preferably 0.0001 to 1% by weight.
If it is less than 0.00001% by weight, the metal removal performance tends to decrease as a chelating agent, and if it exceeds 10% by weight, the solubility in the cleaning liquid tends to decrease.

The chelate promoter is added in order to more effectively chelate metal impurities adhering to the semiconductor substrate.
Examples of chelate promoters include general acidic compounds, alkaline compounds, and salts thereof. Examples of the acidic compound include fluoride or a salt thereof, and examples of the alkaline compound include hydroxide.

Here, examples of the fluoride or a salt thereof include hydrofluoric acid, potassium fluoride, sodium fluoride, and ammonium fluoride.
Of these, ammonium fluoride is preferably used.

Here, examples of the hydroxide include compounds having a hydroxyl group, specifically, inorganic compounds such as sodium hydroxide, potassium hydroxide and ammonium hydroxide, and quaternary ammonium such as tetramethylammonium hydroxide and choline. Hydroxide, monoethanolamine, diethanolamine, triethanolamine, 2-methylaminoethanol, 2-ethylaminoethanol, N-methyldiethanolamine, dimethylaminoethanol, 2- (2-aminoethoxy) ethanol, 1-amino- Examples include alkanolamines such as 2-propanol, monopropanolamine, and dibutanolamine.
Among these, from the viewpoint of preventing the surface of the semiconductor substrate (silicon wafer) from being contaminated with metal, compounds containing no metal such as ammonium hydroxide, tetramethylammonium hydroxide and choline are preferably used.

  The chelate promoter preferably contains a hydroxide and fluoride or a salt thereof. Those containing only hydroxides, or fluorides and their salts tend not to be fully effective, and chelate promoters containing both improve metal removal by chelating agents. It is preferable because it can be used.

The concentration of the fluoride or salt thereof in the cleaning liquid is preferably 0.0001 to 40% by weight, and more preferably 0.01 to 5% by weight.
If it is less than 0.0001% by weight, the metal removability tends to be reduced. If it exceeds 40% by weight, the quality of the underlying low dielectric constant insulating film is deteriorated even though the metal removability is not improved. Tend to.

  The concentration of hydroxide in the cleaning liquid is preferably 0.0001 to 30% by weight, and more preferably 0.001 to 1% by weight. If it is less than 0.0001% by weight, the metal removability tends to decrease, and if it exceeds 30% by weight, the quality of the underlying low dielectric constant insulating film tends to deteriorate.

Regarding the relationship between the concentration of hydroxide and fluoride or a salt thereof, the concentration of hydroxide is preferably less than or equal to the concentration of fluoride.
When the hydroxide concentration is higher than the fluoride concentration, the quality of the underlying low dielectric constant insulating film tends to deteriorate.

The cleaning liquid of the present invention aims to remove particulate foreign matter and ionic foreign matter on a semiconductor substrate (wafer) from which a low dielectric constant insulating film is exposed in the process of manufacturing a semiconductor device, but also exposes Cu wiring. Therefore, the cleaning liquid of the present invention preferably further contains a metal anticorrosive.
The metal anticorrosive agent preferably contains an organic compound having at least one of a nitrogen atom, an oxygen atom, a phosphorus atom and a sulfur atom in the molecule, and in particular, a compound having at least one azole group in the molecule Specifically, it is more preferable to contain benzotriazole, toltriazole, 4-methylimidazole, 5-hydroxymethyl-4-methylimidazole, 3-aminotriazole and the like.
Further, the metal anticorrosive has at least one mercapto group, and the carbon atom to which the mercapto group is bonded is adjacent to the carbon atom to which the hydroxyl group is bonded, and has 2 or more carbon atoms. More preferably, it contains an aliphatic alcohol compound.
Examples of the metal anticorrosive include thioglycerol and thioglycol.

  The pH of the cleaning liquid of the present invention is preferably 7 to 12, and more preferably 7 to less than 9. When the pH is less than 7 (acidic), not only the removability of the fine particles tends to decrease, but also corrosion due to the battery effect tends to occur between Cu and the barrier metal during cleaning.

The cleaning liquid of the present invention is excellent in removal of particulate foreign matters and ionic foreign matters on a semiconductor substrate (wafer) from which an insulating film having a low dielectric constant is exposed.
Examples of the low dielectric constant insulating film include inorganic materials such as FSG (F-containing SiO ₂ ), SiOC (carbon-containing SiO ₂ ), and SiON (N-containing SiO ₂ ), MSQ (methylsilsesquioxane), and HSQ. (Hydrogensilsesquioxane), polyorganosiloxanes such as MHSQ (methylated hydrogensilsesquioxane), aromatics such as PAE (polyarylether), BCB (divinylsiloxane-bis-benzocyclobutene) Organic film systems such as Silk and Porous Silk.
Here, the low dielectric constant insulating film means a film having a relative dielectric constant of 3.0 or less.
The cleaning liquid of the present invention can be used regardless of the type of the low dielectric constant insulating film and the film forming method, but is particularly effective for insulating films such as SiOC, MSQ, and PAE (polyaryl ether). Therefore, it is preferably used for these insulating films.

The cleaning liquid of the present invention may be used alone, but may be used by mixing with other chemicals as long as the object of the present invention is not impaired.
Examples of other chemical solutions include various anionic, cationic, and nonionic surfactants, dispersants, metal anticorrosives, and hydrogen peroxide.
Moreover, you may add the antifoamer for suppressing the bubble property by surfactant.
Examples of antifoaming agents include silicone-based, polyether-based, special nonionic, and fatty acid ester-based antifoaming agents, methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-1-propanol, and acetone. And water-soluble organic compounds such as methyl ethyl ketone.

As a method for cleaning a semiconductor substrate (silicon wafer or the like) using the cleaning liquid of the present invention, a method for immersing a wafer directly in the cleaning liquid, a method using ultrasonic cleaning for the immersion cleaning method, a cleaning liquid on the substrate surface Examples thereof include spray cleaning for spraying, brush scrub cleaning for cleaning with a brush while spraying a cleaning liquid, and a method for using ultrasonic irradiation therewith.
Further, the cleaning liquid may be heated when cleaning.

Next, as a cleaning example using the cleaning liquid of the present invention, a case where a wafer with a low dielectric constant insulating film exposed is cleaned in the manufacture of a semiconductor device will be described.
First, as shown in FIG. 1A, after a silicon oxide film 1 and a silicon nitride film 2 are formed on a semiconductor substrate (not shown) on which elements such as transistors are formed, a low dielectric constant insulating film 3 and a low dielectric constant are formed. A cap layer film (eg, SiO ₂ film) 4 for protecting the insulating film is formed. Then, after forming a groove using a known lithography process, a barrier metal film 5 and a copper film 6 are formed as shown in FIG. 1B, and the copper film and the barrier metal are formed using a known CMP process. A copper wiring is formed by polishing the film. Thereafter, as shown in FIG. 1C, polishing scraps adhered to the surface by polishing, a slurry component in the abrasive, metal impurities, and the like are removed. However, when the CMP process enables uniform polishing within the wafer surface, the low dielectric constant insulating film is not exposed on the surface, but in the case of non-uniformity, as shown in FIG. 1 (c-2), the cap layer In some cases, a part of the film is removed by polishing, and the low dielectric constant insulating film is exposed. In such a case, it is difficult to clean the exposed low dielectric constant insulating film with the conventional cleaning liquid, but the cleaning liquid of the present invention can be applied.
In addition, in the case of a wide width wiring, dishing is likely to occur, and after cleaning, when the cap layer 7 is formed on the copper wiring and the upper layer low dielectric constant insulating film 8 is formed, as shown in FIG. The concave portion at the center of the Cu wiring is reflected on the upper low dielectric constant insulating film 8 and is not flat. As described above, if the low dielectric constant insulating film 8 is concave, there is a possibility that the focus is not focused in the lithography of the next process. Therefore, the low dielectric constant insulating film is planarized by the CMP process. There is a need to. The cleaning liquid of the present invention can also be applied to cleaning foreign matter on the surface after such a low dielectric constant insulating film is polished by a CMP process.

  The cleaning liquid of the present invention is excellent in removing particulate foreign matter and ionic foreign matter on the semiconductor substrate after the CMP process, and in particular, cleaning the surface where the low dielectric constant insulating film having hydrophobic surface is exposed. It can be suitably applied to.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, it cannot be overemphasized that this invention is not what is limited by an Example.

Example 1
In accordance with the composition described in Table 1, cleaning liquid 1 or cleaning liquid 2 was prepared. Using these cleaning liquids 1 and 2, a wafer on which a SiOC film, which is a kind of low dielectric constant insulating film previously contaminated with fine particles and metal impurities, was prepared and cleaned using a brush cleaning apparatus. Table 1 also shows the number of residual fine particles and residual metal impurity concentration.
In addition, the fine particle contamination on the SiOC film | membrane wafer before washing | cleaning made the film | membrane surface contaminate the abrasive grain particle | grains by immersing in the slurry for CuCMP. The number of contaminated particles before washing is 3000 / sheet. In addition, the metal impurities contaminated the exposed SiOC film by actually polishing the Cu film by CuCMP, and the amount of metal contamination before cleaning was 5 × 10 ¹² atoms / cm ² for Cu.

＊１ ｌが１１、ｍが２、ｎが８、Ｘが水素原子である一般式（１）で表される非イオン性界面活性剤
＊２
ａが１１、ｂが２、ｄが１０、ｘが３、ｙ１が１、Ｘが水素原子である一般式２で表される界面活性剤

* 1 Nonionic surfactant represented by general formula (1) in which l is 11, m is 2, n is 8, and X is a hydrogen atom * 2
Surfactant represented by Formula 2 wherein a is 11, b is 2, d is 10, x is 3, y1 is 1, and X is a hydrogen atom

  As shown in Table 1, fine particles and Cu impurities on the SiOC film were removed to a level necessary for semiconductor device manufacturing by cleaning with the cleaning liquid of the present invention.

Example 2 and Comparative Examples 1 and 2
Using a SiOC film contaminated with fine particles by the same method as in Example 1 and a brush washer, the particles were washed with the washing liquid shown in Table 2 (the type of the surfactant in the washing liquid was changed), and the fine particle removability was compared. The results are shown in Table 2. Further, the wettability of each cleaning solution to the SiOC film was compared by measuring the contact angle between the cleaning solution and the SiOC film.

＊１ ｌが１１、ｍが２、ｎが８、Ｘが水素原子である一般式（１）で表される非イオン性界面活性剤
＊３ 日本触媒社製 第２級高級アルコールエトキシレート
親油基炭素数１２の第２級アルコールを用い、ｍが２、ｎが７、Ｘが水素原子である一般式（４）で対応する非イオン性界面活性剤

* 1 Nonionic surfactant represented by general formula (1) in which l is 11, m is 2, n is 8, and X is a hydrogen atom * 3 Secondary higher alcohol ethoxylate made by Nippon Shokubai Co., Ltd. Nonionic surfactant corresponding to general formula (4) using a secondary alcohol having 12 carbon atoms, m being 2, n being 7 and X being a hydrogen atom

  As shown in Table 2, in Comparative Example 2 containing no surfactant, the wettability with the SiOC film was poor and fine particles were hardly removed. On the other hand, the wettability can be improved by adding a surfactant. However, the surfactant of Comparative Example 1 has poor fine particle removability and is insufficient for semiconductor device production.

Example 3 and Comparative Examples 3 and 4
A cleaning liquid having the composition shown in Table 3 was prepared, and a silicon oxide film wafer was immersed in the cleaning liquid for 2 minutes. Thereafter, the metal adhesion amount remaining on the wafer surface was analyzed. In addition, the silicon oxide film wafer before cleaning is rotated on a spin coater rotating at 200 rpm, and 40 ml of ultrapure water containing 1 ppm of Fe and Al is dropped on the surface to cause metal contamination on the surface of the silicon oxide film. Used. Metal deposition amount before washing Fe is ^{490 × 10 10 atom / cm 2} , Al was ^{340 × 10 10 atom / cm 2} .

＊１ ｌが１１、ｍが２、ｎが８、Ｘが水素原子である一般式（１）で表される非イオン性界面活性剤

* 1 Nonionic surfactant represented by the general formula (1), wherein l is 11, m is 2, n is 8, and X is a hydrogen atom.

  As a result of Table 3, the cleaning liquid 1 showed good metal removal performance. However, in Comparative Example 4 containing no chelating agent and Comparative Example 3 containing no chelating accelerator, sufficient metal removing properties could not be obtained. It was.

Examples 4-5, Comparative Examples 5-6
The contact angle with the low dielectric constant film in the cleaning liquid 1, 2, 7 or 8 in which various surfactants adjusted with the compositions shown in Table 4 were dissolved was measured. The results are shown in Table 4. In addition, the solubility of the surfactant in that case was evaluated by visual observation of the liquid turbidity. Note that a PAE film was used as the low dielectric constant film, and the surfactant concentration in the cleaning liquid was 0.1%.

＊１ ｌが１１、ｍが２、ｎが８、Ｘが水素原子である一般式（１）で示される非イオン性界面活性剤
＊４ ａが１１、ｂが２、ｄが１０、ｙが１、Ｘが水素原子である一般式（２）で表される非イオン界面活性剤。
＊５青木油脂社製 ポリオキシエチレンノニルフェニルエーテル
一般式（１）においてＣＨ_３−（ＣＨ_２）_ｌの親油基がノニルフェニル基に相当、ｍが２、ｎが２０、Ｘが水素原子である界面活性剤。
＊６青木油脂社製 ポリオキシエチレン２−エチルヘキシルエーテル
一般式（１）においてＣＨ_３−（ＣＨ_２）_ｌの親油基が２−エチルヘキシル基に相当、ｍが２、ｎが６、Ｘが水素原子である界面活性剤。

* 1 l is 11, m is 2, n is 8, and X is a hydrogen atom. Nonionic surfactant represented by the general formula (1) * 4 a is 11, b is 2, d is 10, y is 1. A nonionic surfactant represented by the general formula (2) wherein X is a hydrogen atom.
* 5 Polyoxyethylene nonylphenyl ether manufactured by Aoki Yushi Co., Ltd. In general formula (1), the lipophilic group of CH _3- (CH ₂ ) ₁ corresponds to nonylphenyl group, m is 2, n is 20, and X is a hydrogen atom Some surfactant.
* 6 Polyoxyethylene 2-ethylhexyl ether manufactured by Aoki Yushi Co., Ltd. In general formula (1), the lipophilic group of CH _3- (CH ₂ ) ₁ corresponds to 2-ethylhexyl group, m is 2, n is 6, and X is hydrogen A surfactant that is an atom.

  As shown in Table 4, the surfactants represented by the general formulas (1) and (2) have good wettability with the low dielectric constant film. On the other hand, even when a surfactant similar to the general formula (1) is used, when a lipophilic group having a different structure is used, the contact angle with the low dielectric constant film is high and the wettability is deteriorated. A phenomenon was observed in which the solution became cloudy without dissolving in the cleaning solution.

It is process sectional drawing which shows an example of the manufacturing process of the semiconductor device using the washing | cleaning liquid of this invention. Following FIG. 1, process sectional views are shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Silicon oxide film 2 Silicon nitride film 3 Low dielectric constant insulating film 4 Cap layer film 5 Barrier metal film 6 Copper film 7 Cap layer film 8 Low dielectric constant insulating film

Claims (17)

General formula (1)
_{CH 3 - (CH 2) l} -O- (C m H 2m O) n -X (1)
(In the formula, l, m and n each independently represent a positive number, and X represents a hydrogen atom or a hydrocarbon group)
A cleaning solution for a semiconductor substrate comprising a nonionic surfactant represented by formula (1), a chelating agent, and a chelating accelerator, wherein the nonionic surfactant represented by the general formula (1) The starting liquid of the lipophilic group of 1 is a primary alcohol, and l is 9 to 11.   The cleaning liquid according to claim 1, wherein m is 2 and n is 5 to 10. Furthermore, the general formula (2),
_{CH 3 - (CH 2) a} -O- (C b H 2b O) d - (C x H 2x O) y -X (2)
(In the formula, a, b, d, x and y each independently represent a positive number, and b and x are different from each other. X represents a hydrogen atom or a hydrocarbon group.)
3. The semiconductor substrate cleaning solution according to claim 1, comprising a nonionic surfactant represented by formula (2), wherein the lipophilic group of the nonionic surfactant represented by the general formula (2) The cleaning liquid, wherein the starting material is a primary alcohol and a is 9 to 11. General formula (2)
_{CH 3 - (CH 2) a} -O- (C b H 2b O) d - (C x H 2x O) y -X (2)
(In the formula, a, b, d, x and y each independently represent a positive number, and b and x are different from each other. X represents a hydrogen atom or a hydrocarbon group.)
A cleaning solution for a semiconductor substrate comprising a nonionic surfactant represented by formula (1) , a chelating agent and a chelating accelerator, wherein the nonionic surfactant represented by the general formula (2) The starting liquid of the lipophilic group is a primary alcohol, wherein a is 9-11.   The cleaning liquid according to claim 4, wherein b is 2, x is 3 to 5, d is 10 or less, and y is 5 or less.   2. The chelating agent is at least one selected from the group consisting of polyaminocarboxylic acids, polycarboxylic acids, compounds having a phosphonic acid group, oxycarboxylic acids, phenols, heterocyclic compounds, and tropolones. The washing | cleaning liquid in any one of -5.   The chelating agent is at least one selected from the group consisting of ethylenediaminetetraacetic acid, oxalic acid, ammonium oxalate, 1-hydroxyethylidene diphosphonic acid, citric acid, ammonium citrate, catechol, 8-quinolinol, and tropolone Item 7. A cleaning liquid according to Item 6.   The cleaning liquid according to any one of claims 1 to 7, wherein the chelate accelerator contains a hydroxide and a fluoride or a salt thereof.   The cleaning liquid according to claim 8, wherein the hydroxide is a compound containing no metal.   The cleaning liquid according to claim 8 or 9, wherein the hydroxide is at least one selected from the group consisting of ammonium hydroxide, tetramethylammonium hydroxide, and choline.   The cleaning liquid according to claim 8, wherein the fluoride or a salt thereof is hydrofluoric acid or ammonium fluoride.   Furthermore, the washing | cleaning liquid in any one of Claims 1-11 formed by containing a metal anticorrosive.   The cleaning liquid according to claim 12, wherein the metal anticorrosive is an organic compound having at least one of a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom in the molecule.   The cleaning liquid according to claim 12 or 13, wherein the metal anticorrosive is a compound having at least one azole group in the molecule.   The metal anticorrosive agent is an aliphatic alcohol compound having at least one mercapto group, wherein the carbon atom to which the mercapto group is bonded and the carbon atom to which the hydroxyl group is bonded are adjacent to each other. 14. The cleaning liquid according to any one of 14.   The cleaning liquid according to any one of claims 1 to 15, which has a pH of 7 or more.   A method for manufacturing a semiconductor device, comprising: cleaning an insulating film having a low dielectric constant exposed on a semiconductor substrate using the cleaning liquid according to claim 1.

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