Effective reduction of post-CMP defects using cleaners containing oxidizing agents

Abstract

The present invention relates to effective reduction of post-CMP defects using a cleaner comprising an oxidizing agent.The present technology generally relates to liquid compositions for cleaning semiconductor surfaces after CMP, and methods of cleaning semiconductor surfaces having cerium oxide (CeO2) particles thereon.

Description

Technical Field

[0001] The present technology generally relates to liquid compositions for cleaning semiconductor surfaces after CMP, and methods for cleaning semiconductor surfaces having cerium oxide (CeO2) particles thereon. Background Art

[0002] The manufacturing of semiconductor device nodes requires a shallow trench isolation (STI) process. The STI chemical mechanical polishing (CMP) process requires a combination of high SiO2 removal rate, high SiO2:Si3N4 selectivity, and low surface defects. Typically, the CeO2 particles used in CMP obtain the best combination of high SiO2 removal rate and high SiO2:Si3N4 selectivity. However, CeO2 CMP tends to produce wafers with a high defect count that are mainly composed of residual CeO2 particles. There is therefore a major technical problem in the post-CMP cleaning of CeO2 polished wafers. An effective and low-cost post-CMP cleaning chemistry for CeO2 is needed to enable STI technology.

[0003] Commodity-based cleaning methods for CeO2 post-CMP typically utilize harsh chemical conditions such as SCI (5 parts H2O, 1 part NH4OH, 1 part H2O2), dilute hydrofluoric acid (DHF), or SPM (1 part H2SO4, 4 parts H2O2). These methods are effective in reducing post-CMP CeO2 defects, but are not without significant drawbacks: SCI leaves a large amount of residue on the wafer surface, DHF causes unacceptably high material loss, and SPM burdens costs associated with longer processing times and additional infrastructure expenditures.

[0004] It is against this background that the embodiments described herein need to be developed. Summary of the invention

[0005] Provided herein are compositions and methods for cleaning post-CMP semiconductor surfaces and semiconductor surfaces having CeO 2 particles thereon.

[0006] Certain embodiments include a liquid composition for cleaning a semiconductor surface after CMP, the liquid composition comprising: an oxidant composition, wherein the standard reduction potential (E°) of the oxidant composition is >2.0V; and at least one of a basic amine compound and a surfactant. In some embodiments, the liquid composition further comprises an acid. In some embodiments, the acid is selected from phosphonic acid and bisphosphonic acid. In some embodiments, the acid is selected from 1-hydroxyethylidene-1,1-diphosphonic acid, NTMP (Nitrilotris(Methylene Phosphonic Acid)), PBTC (phosphonic acid butane tricarboxylic acid), EDTMP (ethylenediaminetetra(methylenephosphonic acid)), pyrophosphoric acid, aminoethylene phosphonic acid, medronic acid, and (2-carboxyethylidene)bisphosphonicacid. In some embodiments, the composition comprises a surfactant and a base. In some embodiments, the surfactant is a carboxylic acid surfactant. In some embodiments, the surfactant is selected from capryleth-9carboxylic acid or other polyoxyethylene alkyl ether carboxylic acids known in the art to be suitable for use as surfactants. In some embodiments, the basic amine compound is an alkylated amine. In some embodiments, the basic amine compound is selected from 3-amino-4-octanol, 2-(diethylamino)ethanethiol, captamine, diethylethanolamine, methylcysteamine, 2-(tert-butylamino)ethanethiol, 2,2′-dimethoxy-1,1-dimethyl-dimethylamine, 3-butoxypropylamine, N-acetylcysteamine, homocysteamine, N,N-dimethylhydroxylamine, 2-(isopropylamino)ethanol, 2-(methylthioethyl)amine, 1-aminopropane- 2-thiol, leucine, cysteamine, at least one selected from the group consisting of N, O-dimethylhydroxylamine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol, 2-amino-2-(hydroxymethyl)propane-1,2-diol, 2-dimethylamino-2-methyl-1-propanol, dimethyl 2-amino-2-methyl-1,3-propanediol, dimethyl 2-amino-2-ethyl-1,3-propanediol, tris(hydroxymethyl)(dimethylamino)methane, and 2-amino-1-butanol. In some embodiments, the oxidant composition has a standard reduction potential (E°)>2.5V. In some embodiments, the oxidant composition comprises at least two different oxidizing compounds. In some embodiments, the at least two different oxidizing compounds comprise persulfate and hydrogen peroxide.In some embodiments, the persulfate is selected from ammonium persulfate, sodium persulfate, potassium persulfate, calcium persulfate, and magnesium persulfate. In some embodiments, the pH of the composition is 2 to 6. In some embodiments, the oxidant composition is less than 5% by weight of the liquid composition for cleaning the semiconductor surface after CMP. In some embodiments, the water content of the liquid composition for cleaning the semiconductor surface after CMP accounts for at least 95% by weight.

[0007] Other embodiments include a method for cleaning a semiconductor surface having CeO2 particles on the semiconductor surface, the method comprising applying a liquid composition as described in any of the foregoing embodiments. Other embodiments include a method for cleaning a semiconductor surface having CeO2 particles on the semiconductor surface, the method comprising applying a liquid composition comprising an oxidant composition, wherein the standard reduction potential (E°) of the oxidant composition is >2.0V. In some embodiments, the semiconductor surface having CeO2 particles is pre-chemically mechanically polished. In some embodiments, the semiconductor surface comprises TEOS. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The relationship between the post-cleaning TEOS SP1 defect count and the standard reduction potential of the oxidant additive is shown for certain embodiments of the present disclosure. DETAILED DESCRIPTION

[0009] Provided herein are compositions and related methods and systems for cleaning semiconductor surfaces after CMP and semiconductor surfaces having CeO2 particles thereon. As used herein, the term "chemical mechanical polishing" or "planarization" refers to a process for planarizing (polishing) a surface using a combination of surface chemical reaction and mechanical abrasion. In some embodiments, a chemical reaction is initiated by applying a composition capable of reacting with a surface material (interchangeably referred to as 'polishing slurry', 'polishing composition', 'slurry composition' or simply 'slurry') to the surface, thereby converting the surface material into a product that can be more easily removed by synchronous mechanical abrasion. In some embodiments, mechanical abrasion is performed by contacting a polishing pad with the surface and moving the polishing pad relative to the surface.

[0010] Composition

[0011] The liquid composition for cleaning a post-CMP semiconductor surface may include, consist essentially of, or consist of the following components.

[0012] The composition may include an oxidant composition, and at least one of a basic amine compound and a surfactant. In some embodiments, the composition further includes an acid. In some embodiments, the composition further includes water, such as deionized water.

[0013] Oxidants

[0014] The composition may include an oxidant composition. In some embodiments, the standard reduction potential (E°) of the oxidant composition is >2.0V (e.g., >2.1V, >2.2V, >2.3V, >2.4V, >2.5V, >2.6V, >2.7V, >2.8V, >2.9V, or >3.0V). In some embodiments, the standard reduction potential (E°) of the oxidant composition is less than 4V, or less than 3.5V, or less than 3V. In some embodiments, the oxidant composition includes at least two different oxidizing compounds. For example, in some embodiments, at least two different oxidizing compounds include persulfate and peroxide. Persulfate is not particularly limited, and includes, for example, ammonium persulfate, sodium persulfate, potassium persulfate, calcium persulfate, and magnesium persulfate. In some embodiments, the peroxide is hydrogen peroxide.

[0015] The oxidant composition can account for about 0.05 to about 4 weight % of the composition. In some embodiments, the persulfate oxidant can account for about 0.05 to about 0.2 weight % (e.g., 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.2 weight %) of the composition. In some embodiments, the peroxide oxidant can account for about 0 to about 4 weight % of the composition. In some embodiments, the peroxide oxidant is only added when used. It will be appreciated by those skilled in the art that these concentrations are concentrations when used, and if a concentrated composition is formulated before use, the composition may include a higher weight percentage of the oxidant.

[0016] Basic amine compounds

[0017] The composition may include one or more basic amine compounds. In some embodiments, the basic amine compound is an alkylated amine. There is no particular limitation on the basic amine compound, and includes, for example, 3-amino-4-octanol, 2-(diethylamino)ethanethiol, capramine, diethylethanolamine, methylcysteamine, 2-(tert-butylamino)ethanethiol, 2,2′-dimethoxy-1,1-dimethyl-dimethylamine, 3-butoxypropylamine, N-acetylcysteamine, homocysteamine, N,N-dimethylhydroxylamine, 2-(isopropylamino)ethanol, 2-(methylthioethyl)amine, 1-aminopropane-2-thiol, leucine. amino acid, cysteamine, and at least one selected from the group consisting of N,O-dimethylhydroxylamine, aminomethylpropanol, aminomethylpropylene glycol, aminoethylpropylene glycol, 2-amino-2-(hydroxymethyl)propane-1,2-diol, 2-dimethylamino-2-methyl-1-propanol, dimethyl 2-amino-2-methyl-1,3-propanediol, dimethyl 2-amino-2-ethyl-1,3-propanediol, tris(hydroxymethyl)(dimethylamino)methane, and 2-amino-1-butanol.

[0018] The basic amine compound can comprise from about 0.05 to about 0.2 wt % of the composition (e.g., 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.2 wt %). It will be appreciated by those skilled in the art that these concentrations are concentrations at the time of use, and that the composition can include a higher weight percentage of the basic amine compound if formulated as a concentrated composition prior to use.

[0019] Surfactants

[0020] The composition may include one or more surfactants. In some embodiments, the surfactant is a carboxylic acid surfactant. The surfactant is not particularly limited and includes, for example, octanol polyether-9 carboxylic acid or other polyoxyethylene alkyl ether carboxylic acids known in the art that are suitable for use as a surfactant.

[0021] The surfactant may comprise from about 0 to about 0.02 wt % (e.g., 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019 or 0.02 wt %) of the composition. It will be appreciated by those skilled in the art that these concentrations are concentrations at the time of use, and that the composition may include a higher weight percentage of surfactant if formulated as a concentrated composition prior to use.

[0022] acid

[0023] The composition may include one or more acids. In some embodiments, the acid is a phosphonic acid or a bisphosphonic acid. For example, in some embodiments, the acid is selected from 1-hydroxyethylidene-1,1-diphosphonic acid, NTMP (nitrilotri(methylenephosphonic acid)), PBTC (phosphonic acid butanetricarboxylic acid), EDTMP (ethylenediaminetetra(methylenephosphonic acid)), pyrophosphoric acid, aminoethylidenephosphonic acid, methylenephosphonic acid, and (2-carboxyethylidene)bisphosphonic acid.

[0024] The acid can comprise from about 0 to about 0.2% by weight of the composition (e.g., 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.2% by weight). It will be appreciated by those skilled in the art that these concentrations are concentrations at the time of use, and that the composition can include a higher weight percentage of acid if formulated as a concentrated composition prior to use.

[0025] Additional components / aspects

[0026] In some embodiments, the composition further comprises water, such as deionized water. The water may be present in an amount greater than 90 wt %, such as 91, 92, 93, 94, 95, 96, 97, 98 or 99 wt %.

[0027] The pH of the composition is generally in the range of about 2 to about 6 (eg, about 2, 3, 4, or 5). Suitable pH adjusters and / or buffers may be included in the composition to adjust the pH.

[0028] method

[0029] In another aspect of the present disclosure, a cleaning method for a surface with cerium oxide particles is provided herein, comprising contacting a surface with a composition of the present disclosure. In some embodiments, the surface is a semiconductor surface comprising TEOS. In some embodiments, chemical mechanical polishing (CMP) is performed in advance on the surface with cerium oxide particles. In some embodiments, the cleaning method is performed in a unit separated from the polishing area comprising a platen. In some embodiments, the unit is a brush box. In some embodiments, the cleaning method is performed without pre-stage CMP rinsing. In some embodiments, the cleaning method is performed by contacting a surface with a composition of the present disclosure that does not include an abrasive. In some embodiments, the cleaning method further comprises a step of subsequently washing with, for example, water.

[0030] In another aspect of the present disclosure, a rinsing method for a surface with cerium oxide particles is provided herein, comprising contacting the surface with a composition of the present disclosure. In some embodiments, the surface is a semiconductor surface comprising TEOS. In some embodiments, chemical mechanical polishing (CMP) is performed in advance on the surface with cerium oxide particles. In some embodiments, the rinsing method of the surface is performed on a platen after polishing, or on a subsequent platen. In some embodiments, the platen is a platen different from the platen used for CMP. In some embodiments, the rinsing method is performed by contacting the surface with a composition of the present disclosure that does not include an abrasive, or a composition of the present disclosure that includes an abrasive less than the amount of the polishing composition for CMP. In some embodiments, the rinsing method is performed without a subsequent cleaning step.

[0031] In another aspect of the present disclosure, provided herein is a method for rinsing and cleaning a surface having cerium oxide particles, comprising performing a rinsing method as disclosed herein, followed by a cleaning method as disclosed herein. In some embodiments, the combined method of rinsing and cleaning can reduce the time required to clean a surface having cerium oxide particles compared to a surface having cerium oxide particles that is not subjected to a rinsing treatment.

[0032] Example

[0033] Example 1

[0034] To test the Ceria removal performance, cleaning compositions were formulated with the following materials listed in Table 1. All cleaners were formulated in PoU at pH 3.3 + / - 0.3, some variation in pH was allowed since no additional pH adjuster was added to the formulation. Oxidants (except H2O2) were used in equimolar amounts; in the case of H2O2, the oxidants were used at 3 wt% due to the addition of H2O2 in PoU. Defect counts were generated on a 200mm TEOS BTW in a brush box. Polishing conditions: Ebara, 200mm, IC1010, 1.4psi, 100 / 95rpm, 200ml / min, rinse at 1000ml / min for 30 seconds (BB clean).

[0035] Table 1. Cleaners used in this study, cleaner compositions, and the number of SP1 defects obtained from each cleaner.

[0036]

[0037] The above compositions were used for post-conditioning polishing under the following parameters listed in Table 2.

[0038] Table 2. P1 polishing conditions for ceria CMP.

[0039]

[0040] Figure 1 The relationship between the number of defects in TEOS SP1 after cleaning and the standard reduction potential of the oxidant additive measured from SP1 is shown. The reduction potential is reported as the standard reduction potential, taken as E°. 4+ The standard reduction potential of is shown as a vertical dashed line. The defect count for reference cleaner A without added oxidant is shown as a horizontal grey dashed line (cleaner D).

[0041] Figure 1 The results plotted in highlight a clear negative correlation between the oxidant additive E° and the number of SP1 defects after cleaning. Cleaner formulation D deviates from this trend. Formulation D utilizes KMnO4 as the oxidant, which under acidic conditions will precipitate MnO 2(s) , as shown in Table 2. Even though the standard reduction potential of KMnO4 is higher than 1.61 V, the precipitated solid leads to a high number of SP1 defects.

[0042] Comparison of "E", "F" and "G" clearly shows the synergistic reduction of TEOS defect count by combining NH4S2O8 and H2O2 ("G" compared to "E" and "F"). This synergistic effect can be explained by the sulfate generated by H2O2 activation of persulfate. This method is significantly different from piranha etching (H2SO4+H2O2+Δ) by not using acid, can be applied under mild acidic conditions (pH>3), and can generate sulfate at near room temperature.

[0043] Equivalent situation

[0044] The present technology is not limited to the specific embodiments described in the present application, which are intended to be a single description of the various aspects of the present technology. Without departing from the spirit and scope of the present technology, many modifications and changes can be made to it, which will be obvious to those skilled in the art. In addition to those listed herein, the functionally equivalent methods and equipment within the scope of the present technology will be obvious to those skilled in the art from the foregoing description. Such modifications and changes are intended to fall within the scope of the present technology. It should be understood that the present technology is not limited to specific methods, reagents, compound compositions or biosystems, which can certainly change. It should also be understood that the terms used herein are only used to describe the purpose of specific embodiments and are not intended to be limited.

[0045] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0046] As will be appreciated by those skilled in the art, for any and all purposes, particularly in providing a written description, all ranges disclosed herein also include any and all possible sub-ranges and combinations of sub-ranges thereof. Any listed ranges can be easily identified as fully describing and capable of decomposing the same range into at least equal halves, thirds, quarters, fifths, tenths, etc. As non-limiting examples, each range discussed herein can be easily divided into lower thirds, middle thirds, and upper thirds, etc. As will be appreciated by those skilled in the art, for example, all languages ​​such as "up to", "at least", "greater than", and "less than" include the numbers listed and refer to the ranges that can be subsequently divided into sub-ranges as described above. Finally, as will be appreciated by those skilled in the art, ranges include each individual member.

[0047] All numerical designations, such as pH, temperature, time, concentration, amount and molecular weight, including ranges, are approximate values, which vary (+) or (-) 10%, 1% or 0.1% as appropriate. It should be understood that, although not always explicitly stated, all numerical designations may be preceded by the term "about". As used herein, the term "about" will be understood by those of ordinary skill in the art and will vary to a certain extent depending on the context in which it is used. If the use of the term in the context in which the term is used is unclear to those of ordinary skill in the art, "about" will mean up to plus or minus 10% of the particular term. It should also be understood that, although not always explicitly stated, the agents described herein are exemplary only and equivalents thereof are known in the art.

[0048] All patents, patent applications, provisional applications, and publications mentioned or cited herein are incorporated by reference in their entirety, including all tables, to the extent they are not inconsistent with the explicit teachings of this specification.

[0049] Further embodiments are set forth in the dependent claims.

Claims

1. A liquid composition for cleaning a semiconductor surface after CMP, comprising: An oxidant composition, wherein the standard reduction potential E° of the oxidant composition is >2.0V; and at least one of a basic amine compound and a surfactant, The oxidant composition comprises at least two different oxidizing compounds, and the at least two different oxidizing compounds comprise persulfate and hydrogen peroxide.

2. The liquid composition according to claim 1, further comprising an acid.

3. The liquid composition according to claim 2, wherein the acid is selected from phosphonic acid and bisphosphonic acid.

4. The liquid composition according to claim 3, wherein the acid is selected from the group consisting of 1-hydroxyethylidene-1,1-diphosphonic acid, nitrilotri(methylenephosphonic acid), phosphonobutanetricarboxylic acid, ethylenediaminetetra(methylenephosphonic acid), pyrophosphoric acid, aminoethylidenephosphonic acid, methylenephosphonic acid, and (2-carboxyethylidene)bisphosphonic acid.

5. The liquid composition according to any one of claims 1 to 4, comprising a surfactant and a base.

6. The liquid composition according to any one of claims 1 to 4, wherein the surfactant is a carboxylic acid surfactant.

7. The liquid composition according to any one of claims 1 to 4, wherein the surfactant is selected from capryleth-9 carboxylic acid or other polyoxyethylene alkyl ether carboxylic acids.

8. The liquid composition according to any one of claims 1 to 4, wherein the basic amine compound is an alkylated amine.

9. The liquid composition according to any one of claims 1 to 4, wherein the basic amine compound is selected from 3-amino-4-octanol, 2-(diethylamino)ethanethiol, capramine, diethylethanolamine, methylcysteamine, 2-(tert-butylamino)ethanethiol, 2,2′-dimethoxy-1,1-dimethyl-dimethylamine, 3-butoxypropylamine, N-acetylcysteamine, homocysteamine, N,N-dimethylhydroxylamine, 2-(isopropylamino)ethanol, 2-(methylthioethyl)amine, 1-amino At least one of the group consisting of propane-2-thiol, leucine, cysteamine, N,O-dimethylhydroxylamine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol, 2-amino-2-(hydroxymethyl)propane-1,2-diol, 2-dimethylamino-2-methyl-1-propanol, dimethyl 2-amino-2-methyl-1,3-propanediol, dimethyl 2-amino-2-ethyl-1,3-propanediol, tris(hydroxymethyl)(dimethylamino)methane, and 2-amino-1-butanol.

10. The liquid composition according to any one of claims 1 to 4, wherein the standard reduction potential E° of the oxidant composition is >2.5V.

11. The liquid composition according to any one of claims 1 to 4, wherein the persulfate is selected from ammonium persulfate, sodium persulfate, potassium persulfate, calcium persulfate, and magnesium persulfate.

12. The liquid composition according to any one of claims 1 to 4, wherein the pH of the composition is from 2 to 6.

13. The liquid composition according to any one of claims 1 to 4, wherein the oxidizing agent composition is less than 5 wt% of the liquid composition for cleaning a semiconductor surface after CMP.

14. The liquid composition according to any one of claims 1 to 4, wherein the water content of the liquid composition for cleaning a semiconductor surface after CMP is at least 95 wt%.

15. A method for cleaning a semiconductor surface having CeO2 particles on the semiconductor surface, the method comprising applying a liquid composition according to any one of claims 1 to 14.

16. A method for cleaning a semiconductor surface having CeO2 particles on the semiconductor surface, the method comprising applying a liquid composition comprising an oxidant composition, wherein the standard reduction potential E° of the oxidant composition is >2.0V, The oxidant composition comprises at least two different oxidizing compounds, and the at least two different oxidizing compounds comprise persulfate and hydrogen peroxide.

17. The method according to claim 15 or 16, wherein the semiconductor surface having CeO2 particles is previously subjected to chemical mechanical polishing.

18. The method of claim 15 or 16, wherein the semiconductor surface comprises TEOS.

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