TW202402985A - Cmp slurry composition for polishing a copper barrier layer - Google Patents

Abstract

The present invention relates to a slurry composition for polishing a copper barrier layer for chemical mechanical planarizing (CMP) of tantalum nitride or tantalum as a diffusion barrier in the presence of an interconnect structure in an integrated circuit device. The slurry composition according to the present invention comprises polishing particles, a heterocyclic compound, an organic acid, a surface-protecting agent, a nitride, a pH adjuster, and the remainder of deionized water, and there is the effect of providing a slurry composition exhibiting high polishing selectivity and less dishing and defects.

Description

CMP slurry composition for grinding copper barrier layer

The present invention relates to a CMP slurry composition for polishing copper barrier layers, which is used to treat tantalum nitride used as a diffusion barrier film in the presence of interconnection structural components in integrated circuit devices. Or tantalum is subjected to chemical mechanical planarizing (CMP). The CMP slurry composition provided by the present invention is an effective composition including abrasive particles, heterocyclic compounds, organic acids, surface protective agents, nitrides, pH regulators, and the balance of deionized water, and can provide an excellent CMP A slurry composition that has excellent dispersion and stability of abrasive particles, a high grinding selectivity, and fewer dishings and defects than the CMP slurry composition according to the related art.

Recently, with the development of semiconductor manufacturing process technology, the semiconductor industry's reliance on copper electronic interconnects for forming integrated circuits is increasing. These copper interconnects have low resistivity and excellent electromigration characteristics.

Since copper has many advantages in terms of efficiency, such as excellent electromigration characteristics and low resistance, it has been mainly used as a limited conductor for semiconductor integrated circuits such as refined and highly integrated ULSI. Connection materials.

However, there is a limitation that copper cannot be used in integrated circuits due to the difficulty in patterning by dry etching. In order to overcome this problem, it is proposed to form copper through a CMP process based on a dual damascene process. method of interconnection. In the CMP process, copper forms a porous oxide film layer composed of CuO, CuO ₂ , Cu(OH) ₃ , etc. containing Cu ⁺ or Cu ²⁺ as copper oxide ions.

However, compared with other materials such as silicon-based tetraethoxysilane (TEOS) or tungsten, copper is relatively soft and electrochemically corrodes more easily than tungsten. Therefore, although the polishing rate is high, it is replaced by It is easy to produce dishing or erosion caused by over-polishing and scratches, especially the components of the polishing slurry and foreign matter such as oxides generated during the polishing process pass through the porous membrane. The phenomenon of pores penetrating into the copper oxide film layer. Such a phenomenon may cause problems in the next process, that is, the photolithography process, especially in the case of highly integrated circuits composed of more than 6 to 7 layers depending on the wiring design. , since the performance of the circuit differs depending on the degree of planarization of each layer, it may become the cause of a fatal flaw.

Copper is very corrosive in many dielectric materials, such as silicon dioxide and low-K or doped versions of silicon dioxide, so a diffusion barrier layer is necessary to prevent copper from diffusing into the underlying dielectric material.

Typical barrier materials include tantalum, tantalum nitride, tantalum silicon nitride, titanium, titanium nitride, titanium silicon nitride, titanium-titanium nitride, titanium-tungsten, tungsten, tungsten nitride, and tungsten silicon nitride.

In response to the increased demand for high-density integrated circuits, manufacturers are currently assembling integrated circuits that include multiple overlying layers of metal interconnect structures. In the process of assembling devices, as long as the interconnection layer is planarized, it can improve packaging density, process uniformity and production quality. Most importantly, it can allow chip manufacturers to assemble multi-layer integrated circuits. As a more efficient way to create flat surfaces, wafer manufacturers rely on chemical mechanical polishing (CMP).

The CMP process is typically performed in two stages. First, the grinding process uses a "stage 1" slurry designed to remove copper quickly.

After the initial copper removal, the "stage 2" slurry removes the barrier material. Stage 2 slurries are typically required to have excellent selectivity for removing barrier materials without adversely affecting the physical structure or electrical properties of the interconnect structure. Since alkaline polishing slurries traditionally have much faster Ta/TaN removal rates than acidic slurries, commercial stage 2 slurries typically have an alkaline to neutral pH. Another factor that emphasizes the advantages of a barrier metal grinding slurry with a neutral to alkaline pH involves the need to preserve the metal overlying the barrier metal during the stage 2 grinding process. To reduce dishing of metal interconnects, metal removal rates must be very low.

Therefore, in chemical mechanical polishing methods, such barrier slurry compositions require high barrier removal rates, very low post-grinding topography, no corrosion defects, and very low scratches or corrosion. Depending on which abrasive, oxidant or additive is selected, the changes in the surface defects, surface roughness, surface defects, erosion and corrosion, which are important variables in the semiconductor process, can be minimized and the target can be effectively utilized. The polishing ratio is to polish the metal insulating film, diffusion wall or metal layer.

Experiments were conducted using CMP slurry compositions based on the prior art. As a result, there were problems with CMP work throughput caused by poor grinding amounts of copper and tantalum compounds, and reduced equipment performance and product yields caused by corrosion of copper substances. problems, layer planarization problems, and dents produced during grinding. In addition, in the case of a process of polishing copper film, it is necessary to achieve a lower level of surface defects at an appropriate polishing rate. However, according to the CMP slurry composition of the prior art, the polishing process time becomes longer or surface defects appear, etc. problem. [Prior art documents]

[Patent Document] (Patent document 0001) Korean Patent Registration No. 10-1465604; (Patent document 0002) Korean Patent Registration No. 10-1548715; (Patent document 0003) Korean Patent Registration No. 10-1698490; (Patent Document 0004) Korean Patent Publication No. 10-2021-0095548.

[The problem that the invention aims to solve]

The purpose of the present invention is to solve the following problems existing in the CMP slurry composition according to the prior art: the CMP work throughput problem caused by poor grinding amount of copper and tantalum compounds, equipment performance and equipment performance caused by corrosion of copper substances, and Problems such as reduced product yield, layer planarization, and dents produced during grinding.

Furthermore, the object of the present invention is to provide a CMP slurry composition for polishing a copper barrier layer. Compared with the existing slurry, it not only has an appropriate polishing rate in the process of polishing the copper film quality, but also has a significantly higher polishing rate. Reduce dents, corrosion, and defects.

Furthermore, the object of the present invention is to provide a CMP slurry composition for polishing a copper barrier layer, which has greater resolution than existing slurries in terms of the above-mentioned problems arising in the copper CMP process. Step difference removal rate of silicon oxide film and copper film. [Technical means to solve problems]

In order to achieve the above object, the present invention provides a CMP slurry composition for grinding a copper barrier layer, including: abrasive particles composed of colloidal silica, heterocyclic compounds, organic acids, surface protective agents, nitrides , pH adjuster, and the balance of deionized water, by adjusting the content of the additives and solvents, and adjusting the particle size of the colloidal silicon dioxide, the grinding selection relative to the silicon oxide film, tantalum film, and copper film is adjusted ratio and grinding rate for grinding.

In a preferred embodiment of the present invention, the particle size of the colloidal silica is 75 to 95 nm.

In a preferred embodiment of the present invention, the heterocyclic compound has more than two nitrogen atoms and is selected from the group consisting of 1,2,4H-triazole, 5-methylbenzotriazole, tetrazole, imidazole, One or more of the group consisting of 1,2-dimethylimidazole, benzotriazole (BTA), 1H-benzotriazoleacetonitrile, and piperazole.

In a preferred embodiment of the present invention, the surface protective agent, as a nonionic surface protective agent, can be selected from the group consisting of polyvinyl alcohol (PVA), ethylene glycol (EG), glycerol, and polyethylene glycol. (PEG), polypropylene glycol (PPG), or polyvinylpyrrolidone (PVP), etc.; and, as the anionic surface protective agent, it can be selected from ammonium dodecyl benzene sulfonate (ammonium dodecyl benzene sulfonate), polyoxyethylene alkane Ammonium polyoxyethylene alkyl sulfonate, ammonium polyoxyethylene alkyl aryl sulfonate, etc.; two or more types selected from these surface protective agents can also be mixed and used. Optimally, nonionic polyvinylpyrrolidone (PVP) and anionic ammonium dodecyl benzene sulfonate are used in combination.

In a preferred embodiment of the present invention, the organic acid may be selected from the group consisting of citric acid, glutaric acid, malic acid, maleic acid, and oxalic acid. Any one of the carboxylic acid group consisting of (oxalic acid), phthalic acid, succinic acid, tartaric acid, and acetic acid; it can also be selected from Nitrilotriacetic acid (NTA), Iminodiacetic acid (IDA), Methyl iminodiacetic acid (MIDA), Hydroxyethyl iminodiacetic acid (Hydroxyethyl iminodiacetic acid) , HIDA), Diethylenetriamine pentaacetic acid (DPTA), Ethylenediamine tetraacetic acid (EDTA), N-hydroxyethyl ethylenediamine tetraacetic acid (HEDTA) ), methylethylenediamine tetraacetic acid (MEDTA), and triethylene tetraamine hexaacetic acid (TTHA).

In a preferred embodiment of the present invention, the antioxidant is selected from the group consisting of ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives ( ascorbic acid derivatives), gallic acid, formamidinesulfinic acid, uric acid, tartaric acid, and cysteine More than one of them.

In a preferred embodiment of the present invention, in order to adjust the pH value range to alkaline, the pH adjuster can be used alone or mixed with KOH, NH ₄ OH, NaOH, TMAH, TBAH, KNO ₃ , NH ₄ NO ₃ , HNO ₃ , etc. Since the pH value is closely related to the particle stability and grinding rate of the slurry, it must be adjusted precisely.

In a preferred embodiment of the present invention, the CMP slurry composition includes: 13 to 15% by weight of abrasive particles composed of colloidal silica, abrasive particles, heterocyclic compounds, Organic acids, surface protective agents, nitrogen compounds, pH adjusters, and the balance of deionized water.

In a preferred embodiment of the present invention, the pH value of the CMP slurry composition is 9 to 12.

In a preferred embodiment of the present invention, the CMP slurry composition simultaneously polishes the polished film composed of two or more films selected from the group consisting of silicon oxide film, tantalum film and copper film.

In a preferred embodiment of the present invention, in the polishing, the polishing selectivity ratio of the tantalum nitride film (TaN), the silicon oxide film (Silicon oxide), and the copper film (Cu) is 1:1 to 4: 0.5～1. [Compare the effectiveness of previous technologies]

The CMP slurry composition for polishing the copper barrier layer according to the present invention exhibits a high step difference removal efficiency between the silicon oxide film and the copper film layer, thereby improving productivity.

Furthermore, the CMP slurry composition for polishing the copper barrier layer according to the present invention exhibits the following effect: it can polish the copper film layer while minimizing dents, corrosion, defects, etc., thereby efficiently polishing the copper barrier layer. It forms copper wiring layers and other semiconductor device layers with excellent reliability and characteristics, thereby greatly contributing to the achievement of high-performance semiconductor devices.

Generally, the nomenclature used in this specification is well known and commonly used in the technical field to which the present invention belongs. Unless otherwise defined, all technical terms and scientific terms used in this specification have the same meanings as commonly understood by a person of ordinary skill in the technical field to which this invention belongs.

Throughout this specification, when it is stated that a certain part "includes" a certain constituent element, it means that other constituent elements are not excluded but may also include other constituent elements, unless otherwise stated.

Typically, in the first stage, after excess copper is removed, the polished wafer surface has uneven local and overall flatness due to differences in step heights at different locations. Low-density features typically have higher copper step differences, while high-density features typically have lower step differences.

Due to the step difference after stage 1, there is a strong need for a stage 2 CMP slurry with selective milling of oxide removal rates compared to copper.

In the present invention, "selectivity ratio" refers to different removal rates for different substances under the same grinding conditions.

The barrier slurry in the CMP process stage 2 of the wafer after patterning preferably provides one or more of the following: better removal rates for multiple types of films, low degree of in-wafer polishing non-uniformity ( within wafer non-uniformity: WIW NU), less residue on the polished wafer after the CMP process, polishing selectivity for multiple polishing layers.

Specific featured distortion that is not suitable for semiconductor manufacturing is damage to copper vias or metal pipes caused by the interaction of chemical components with copper vias or metal pipes and additional corrosion during the CMP process. Therefore, it is very important to use corrosion inhibitors in the barrier CMP slurry to reduce additional corrosion of copper vias or trenches during the CMP process and reduce defects.

In the second-stage CMP process, chemical reactions that block the CMP composition include oxidation reactions caused by oxidants such as H ₂ O ₂ used in the CMP slurry. Surfaces of metals such as copper, pipes, vias or trenches, barrier materials such as Ta are oxidized into corresponding metal oxide films.

Generally speaking, copper is oxidized to cuprous oxide or a copper oxide mixture, and Ta is oxidized to Ta ₂ O ₅ . By using chelates, ligands or other chemical additives that can chemically bond with copper cations and tantalum cations in the barrier slurry, the dissolution of copper oxides and tantalum oxides can be promoted, thereby improving the quality of copper, pipes, and vias. Or the removal rate of trenches and barrier layers or barrier films.

Therefore, what the present invention aims to develop is a slurry composition for CMP, which, compared with existing slurries, can significantly reduce corrosion or defects produced in the copper CMP process, and can effectively treat silicon oxide films, copper films, and tantalum films. The membrane is quickly ground.

The slurry for grinding the copper barrier layer according to the present invention includes: abrasive particles composed of colloidal silica, heterocyclic compounds, organic acids, surface protective agents, nitrides, pH adjusters, and the remaining amount of Ionized water.

The colloidal silica refers to a colloidal solution in which nanometer-sized silica particles are stably dispersed in a solvent without settling. From the viewpoint of maintaining scratches and removal rate appropriately, the particle size of the colloidal silica is preferably 75 to 95 nm, more preferably 80 to 90 nm.

If the particle size of colloidal silica is less than 75 nm, the removal rate relative to the film quality will be reduced and the process will take longer; if it exceeds 95 nm, scratches will easily form, so Not good.

Preferably, the amount of colloidal silica is 13% to 15% by weight relative to the total weight of the composition.

If the amount of colloidal silica is less than 13% by weight, the removal rate (Removal rate) will be reduced due to insufficient solid content; if the amount exceeds 15% by weight, excessive content will cause aggregation, which is not good.

In the CMP slurry composition according to an embodiment of the present invention, the heterocyclic compound has more than two nitrogen atoms and is selected from the group consisting of 1,2,4H-triazole, 5-methylbenzotriazole, tetrazole, One or more of the group consisting of azole, imidazole, 1,2-dimethylimidazole, benzotriazole (BTA), 1H-benzotriazole acetonitrile, or piperazole. From the aspects of corrosion inhibition effect, grinding rate and stability of the slurry composition, the anti-corrosion agent may also be 0.005% to 0.5% by weight of the slurry composition.

If the anti-corrosion agent is less than 0.005% by weight, the polishing control of the copper film cannot be performed, and denting may occur; if the anti-corrosion agent exceeds 0.5% by weight, the polishing rate of the copper film becomes low, and residues may occur. The problem of residue.

Grinding rate enhancers of tantalum compounds that can be used in the CMP slurry of the present invention are nitride compounds that serve as pH adjusters. Nitride is a substance used in etching solutions for tantalum or titanium compounds, and can effectively remove tantalum during CMP polishing.

As the nitride used in the present invention, potassium nitrate (KNO ₃ ), nitric acid (HNO ₃ ), ammonium nitrate (NH ₄ NO ₃ ), iron nitrate (Fe(NO ₃ ) ₂ ), and copper nitrate (Cu( NO ₃ ) ₂ ), etc., these nitrides can also be mixed and used. Generally, titanium or tantalum compounds are relatively stable substances, easily etched by a mixture of hydrofluoric acid and nitric acid, and have the characteristic of slow reaction to alkaline and aqua regia. Generally, the amount of nitride used in the slurry is preferably in the range of about 0.05 to 10% by weight, more preferably in the range of about 0.1 to 1% by weight.

The surface protective agent used in the present invention, as a non-ionic surface protective agent, can be selected from polyvinyl alcohol (PVA), ethylene glycol (EG), glycerol, polyethylene glycol (PEG), polypropylene glycol (PPG) ), or polyvinylpyrrolidone (PVP), etc.; and, as the anionic surface protective agent, it can be selected from ammonium dodecyl benzene sulfonate, ammonium polyoxyethylene alkyl sulfonate), polyoxyethylene alkyl aryl sulfonate (ammonium polyoxyethylene alkyl aryl sulfonate), etc.; two or more types selected from these surface protective agents may be mixed and used. It is best to use a mixture of nonionic polyvinylpyrrolidone (PVP) and anionic ammonium dodecyl benzene sulfonate.

The non-ionic protective agent is adsorbed on the particle surface in the solution. Since it contains more than one functional group with affinity to the particles, it can be strongly and continuously adsorbed on the particle surface, thereby increasing the particle size. Therefore, the silicon oxide film also plays a role in appropriately increasing the polishing rate. Furthermore, dispersion stability is maintained through steric repulsion. Therefore, if the content of the protective agent is less than 0.15% by weight relative to the total weight of the composition, the dispersion force is low and sedimentation occurs quickly. Therefore, sedimentation occurs when the polishing liquid is transported, and the polishing material cannot be uniformly supplied. In contrast, if the content of the dispersant exceeds 1.0% by weight relative to the total weight of the composition, a protective layer of buffering agent will be thickly formed around the abrasive particles, making it difficult for the abrasive surface to contact the surface to be polished. , which may result in a lower grinding rate.

Surface protective agents play a role in protecting the wafer surface from the residues of the polishing pad or metal residues and organic residues during grinding to reduce the number of wafer defects, especially when anionic ammonium sulfonate derivatives are mixed. In this case, it plays the role of cleaning various residues on the wafer surface, further improving the number of defects. Generally, preferably, the amount of surface protective agent used in the slurry is in the range of about 0.15 to 1.0% by weight, and most preferably in the range of about 0.3 to 0.8% by weight.

In order to adjust the copper removal rate relative to the barrier metal removal rate, organic acids are used in the CMP slurry of the present invention.

The organic acid inhibits the oxidized copper oxide from being adsorbed again on the copper layer as the polished layer through the chelation reaction with the copper oxide, thereby increasing the polishing rate of copper and reducing surface defects. CMP planarization of the dielectric/metal composite structure can be further improved by adding an organic acid selective to the target metal component into the slurry.

This increases the erosion rate of the metallic phase and increases the grinding selectivity for metal to dielectric phase removal, making the planarization process more efficient.

Organic acids that can be used in the present invention include carboxylic acid-based organic acids and amino acid-based organic acids. First, the carboxylic acid-based organic acids are selected from citric acid, glutaric acid, and malic acid. , maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, and acetic acid. More than one of them.

Secondly, the amino acid organic acid is selected from Nitrilotriacetic acid (NTA), Iminodiacetic acid (IDA), Methyl iminodiacetic acid (MIDA), hydroxyethyl Hydroxyethyl iminodiacetic acid (HIDA), Diethylenetriamine pentaacetic acid (DPTA), Ethylenediamine tetraacetic acid (EDTA), N-hydroxyethylethylenediaminetetraacetic acid In the group consisting of (N-hydroxyethyl ethylenediamine tetraacetic acid, HEDTA), methylethylenediamine tetraacetic acid (MEDTA), and triethylene tetraamine hexaacetic acid (TTHA), etc. More than one kind.

Relative to the weight of the slurry composition, the amount of organic acid added is 0.05 to 5% by weight, the preferred concentration is 0.1 to 3% by weight, and the optimum concentration is 0.1 to 1% by weight. If the dosage is too small, the chelating agent will not exhibit the desired effect of the present invention; if the dosage is too large, the chelating agent will be consumed without further effects.

In a preferred embodiment of the present invention, the antioxidant is selected from the group consisting of ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, and ascorbic acid derivatives. (ascorbic acid derivatives), gallic acid, formamidinesulfinic acid, uric acid, tartaric acid, and cysteine More than one type in the group. Relative to the weight of the slurry composition, the amount of antioxidant added is 0.05 to 1% by weight, the preferred concentration is 0.1 to 0.5% by weight, and the optimum concentration is 0.2 to 0.3% by weight. If the dosage is too small, the antioxidant effect of the metal will not be shown; if the dosage is too large, the antioxidant will be consumed without further effect, or it will remain on the wafer surface and become the cause of defects.

From the perspective of the stability of the composition, preferably, the pH value of the CMP slurry composition according to an embodiment of the present invention is 9 to 12. If the pH value range is less than 9, the aggregation phenomenon of the colloidal silica particles and the removal rate (Removal rate) are unstable. If the pH value range exceeds 12, the removal rate (Removal rate) is unstable, which is not good.

In order to adjust the pH value to the above range, KOH, NH ₄ OH, NaOH, TMAH, TBAH, KNO ₃ , NH ₄ NO ₃ , etc. can be used alone or in mixture as alkaline substances, since the pH value is stable with the particles of the slurry composition. The properties and grinding rate are closely related and therefore must be adjusted precisely.

In the CMP slurry composition according to an embodiment of the present invention, the solvent is used to adjust the concentration of the composition to adjust the removal rate of the membrane quality. The solvent can be deionized water, water, etc., but deionized water is preferably used. .

The polishing target film of the slurry composition may further include a copper-containing film.

Furthermore, the composition of the slurry can adjust a desired polishing rate for a thin film used as a copper-containing film and a barrier film or an oxide film used for a semiconductor insulating film, the thin film including titanium (Ti), tantalum Any one of the group consisting of (Ta), ruthenium (Ru), molybdenum (Mo), cobalt (Co) or gold (Au). Therefore, the slurry composition can also exhibit excellent polishing selectivity between the film to be polished and other films.

Hereinafter, the present invention will be described in more detail through examples. However, these embodiments are only for illustrating the present invention and shall not be used to limit the scope of the present invention. This will be obvious to those with ordinary skill in the technical field to which the present invention belongs. [ Examples 1 to 7 and Comparative Examples 1 and 2]

The slurry compositions for polishing the copper barrier layer of Examples 1 to 7 and Comparative Examples 1 and 2 were manufactured according to the contents described in Table 1 below.

Here, the content of colloidal silica is set to 13% by weight, and the particle size of the colloidal silica used is 90 nm. KOH was used as the pH adjuster, and KNO ₃ was used as the nitride, and each was set to 0.5% by weight. Ascorbic acid was used as an antioxidant and was set to 0.2% by weight.

[Table 1] Silica particle size Heterocyclic compounds organic acid surface protectant (nm) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Example 1 90 BTA 0.1 AA 0.06 PVP 0.15 Example 2 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.1 PVP 0.2 Example 3 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.3 PVP 0.2 Example 4 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.5 PVP 0.2 Example 5 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.5 PVP 0.3 Example 6 90 BTA 0.1 IDA 0.5 AA 0.06 ADBS 0.5 PVP 0.3 Example 7 90 BTA 0.1 IDA 1.0 AA 0.06 ADBS 0.5 PVP 0.3 Comparative example 1 90 BTA 0.1 Comparative example 2 90 BTA 0.02 BTA: Benzotriazole IDA: Iminodiacetic acid AA: Acetic acid ADBS: Ammonium dodecylbenzenesulfonate PVP: Polyvinylpyrrolidone [ Experimental Examples 1 to 7 and Comparative Experimental Examples 1 and 2]

The removal rate and dishing based on the slurry compositions of Examples 1 to 7 and Comparative Examples 1 and 2, Experimental Examples 1 to 7 and Comparative Experimental Examples 1 and 2 were measured respectively. The results of Comparative Experiment Example 2 are shown in Table 2 below.

[Grinding conditions] 1. Grinding equipment: 12-inch (300 mm) CMP equipment-AP-300 (CTS company) 2. Polishing pad: IC1010 (Dow Company) 3. Platen speed: 103 rpm 4. Head speed: 97 rpm 5. Flow rate: 300 cc/min 6. Pressure: 2.2 psi

Regarding the measurement of the polishing rate, when polishing using a 12-inch (300mm) CMP equipment, a four-point probe (CMT-SR 5000, AIT Co., Ltd) was used to calculate the polishing rate of Cu and Ta.

For PTEOS as an oxide, the thickness change before and after CMP was measured using Atlas equipment from Nanometrics to calculate the grinding rate.

The polishing selectivity ratio is calculated as follows based on the polishing rate of each film quality. - Polishing selectivity ratio of silicon oxide film to tantalum nitride film (TaN) = polishing rate of silicon oxide film / polishing rate of tantalum nitride film (TaN) - Polishing selectivity ratio of copper film (Cu) to tantalum nitride film (TaN) = polishing rate of copper film (Cu) / polishing rate of tantalum nitride film (TaN)

Regarding dishing measurement, the thickness of each film quality was measured using a transmission electron microscope (JEM-2000, JEOL) as follows and calculated. - Cu depression = (Cu edge thickness – Cu center thickness) - Ox depression = (Ox edge thickness – Ox center thickness)

[Table 2] Grinding rate (Å/min) selection ratio Depression(Å) Cu N silicon oxide film Silicon oxide film/TaN Cu/TaN 1-1μm Experimental example 1 157 215 750 3.49 0.73 37 Experimental example 2 162 320 815 2.55 0.51 30 Experimental example 3 182 320 830 2.59 0.57 20 Experimental example 4 200 325 820 2.52 0.62 17 Experimental example 5 205 323 970 3.00 0.63 16 Experimental example 6 214 310 915 2.95 0.69 17 Experimental example 7 215 320 961 3.00 0.67 19 Comparative Experiment Example 1 107 260 498 1.92 0.41 69 Comparative Experiment Example 2 127 295 578 1.96 0.43 118

The polishing rate, selectivity ratio, and dishing value of Experimental Examples 1 to 7 and Comparative Experimental Examples 1 and 2 described in Table 2 were evaluated as follows.

First, it was confirmed that in Experimental Examples 1 to 7 using complexing agents, the polishing rate of the copper film was significantly increased compared to the conventional Comparative Examples 1 and 2.

Second, it was confirmed that in Experimental Examples 1 to 7 using polyvinylpyrrolidone (PVP) as a surface protective agent, the polishing rate of the silicon oxide film was significantly increased compared to the conventional Comparative Examples 1 and 2. .

Third, it can be confirmed that in Experimental Examples 1 to 7, as the content of iminodiacetic acid (IDA) as a complexing agent increases, the polishing rate of the copper film increases; while dodecane as a surface protective agent As the content of ammonium benzene sulfonate (ADBS) increases, the depression of the copper film layer decreases.

For this reason, the selection ratios of Experimental Examples 1 to 7 are superior to the selection ratios of Comparative Experimental Example 1 and Comparative Experimental Example 2.

In the case of Comparative Experimental Example 2, the following problem occurred: since the content of benzotriazole (BTA) as an anticorrosive agent was small, although the polishing rate of the copper film layer was increased, dents increased. [ Examples 8 to 11 and Comparative Examples 3 to 5]

The slurry compositions for polishing the copper barrier layer of Examples 8 to 11 and Comparative Examples 3 to 5 were manufactured according to the contents described in Table 3 below. A slurry composition for grinding the copper barrier layer is manufactured according to the particle size of the colloidal silica and the content of the surface protective agent ADBS.

Here, the content of colloidal silica is always set to 15% by weight. BTA was used as the heterocyclic compound and was set to 0.05% by weight, AA was used as the organic acid and was set to 0.1% by weight, PVP was used as the surface protective agent and was set to 0.2% by weight, KOH was used as the pH adjuster and was set to 0.2% by weight, and nitride was used KNO ₃ and set to 1.0 wt%.

[table 3] Silica particle size Heterocyclic compounds organic acid surface protectant (nm) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Comparative example 3 35 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Comparative example 4 60 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Example 8 80 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Example 9 90 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Comparative example 5 100 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Example 10 90 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.1 PVP 0.2 Example 11 90 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.3 PVP 0.2 [ Experimental Examples 8 to 11 and Comparative Experimental Examples 3 to 5]

The removal rate (Removal Rate), selectivity ratio, and defect (number of defects) based on the slurry compositions of Examples 8 to 11 and Comparative Examples 3 to 5 were measured respectively. Experimental Examples 8 to 11 and The results of Comparative Experiment Example 3 to Comparative Experiment Example 5 are shown in Table 4 below.

Regarding the Defect (number of defects) measurement, the measurement was performed using a light source with a spot size of 10 μm of a device with a trade name [AIT-XP+] manufactured by KLA-Tencor Corporation.

[Table 4] Grinding rate (Å/min) selection ratio Number of defects(n) Cu N silicon oxide film Silicon oxide film/TaN Cu/TaN Comparative Experiment Example 3 97 260 296 1.14 0.37 twenty four Comparative Experiment Example 4 105 287 430 1.50 0.37 38 Experimental example 8 146 290 720 2.48 0.50 35 Experimental example 9 150 300 711 2.37 0.50 37 Comparative Experiment Example 5 175 382 757 1.98 0.46 119 Experimental example 10 161 318 842 2.65 0.51 27 Experimental example 11 163 337 852 2.53 0.48 twenty three

In Table 4, the polishing rate increases as the particle size increases, but there is a problem of an increase in the number of defects. In the case of Comparative Experimental Examples 3 and 4 with a particle size of 70 nm or less, the polishing rate of the film quality of both are significantly reduced, causing process time delays and becoming a problem in terms of productivity.

Furthermore, it was confirmed that as the content of ammonium dodecylbenzene sulfonate (ADBS) as a surface protective agent increases, the number of defects decreases. [ Examples 12 to 18 and Comparative Examples 6 and 7]

The slurry compositions for polishing the copper barrier layer of Examples 12 to 18 and Comparative Examples 6 and 7 were manufactured according to the contents described in Table 5 below.

Here, the content of colloidal silica is set to 15% by weight, and the particle size of the colloidal silica used is 90 nm. KOH was used as the pH adjuster, and KNO ₃ was used as the nitride, and each was set to 0.5% by weight. Ascorbic acid was used as an antioxidant and was set to 0.2% by weight.

[table 5] Silica particle size Heterocyclic compounds organic acid surface protectant (nm) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Example 12 90 BTA 0.1 AA 0.06 PVP 0.15 Example 13 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.1 PVP 0.2 Example 14 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.3 PVP 0.2 Example 15 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.5 PVP 0.2 Example 16 90 BTA 0.1 IDA 0.1 AA 0.06 ADBS 0.5 PVP 0.3 Example 17 90 BTA 0.1 IDA 0.5 AA 0.06 ADBS 0.5 PVP 0.3 Example 18 90 BTA 0.1 IDA 1.0 AA 0.06 ADBS 0.5 PVP 0.3 Comparative example 6 90 BTA 0.1 Comparative example 7 90 BTA 0.02 BTA: Benzotriazole IDA: Iminodiacetic acid AA: Acetic acid ADBS: Ammonium dodecylbenzenesulfonate PVP: Polyvinylpyrrolidone [ Experimental Examples 12 to 18 and Comparative Experimental Examples 6 and 7]

The removal rate (Removal Rate), selectivity ratio, and dishing based on the slurry compositions of Examples 12 to 18 and Comparative Examples 6 and 7 were measured respectively. Experimental Examples 12 to 18 and Comparison The results of Experimental Example 6 and Comparative Experimental Example 7 are shown in Table 6 below.

[Table 6] Grinding rate (Å/min) selection ratio selection ratio Depression(Å) Cu N Ox Ox/TaN Cu/TaN 1-1μm Experimental example 12 185 370 887 2.40 0.50 39 Experimental example 13 191 376 960 2.55 0.51 31 Experimental example 14 215 378 972 2.57 0.57 twenty three Experimental example 15 233 382 968 2.53 0.61 19 Experimental example 16 240 380 1140 3.00 0.63 19 Example 17 252 368 1080 2.93 0.68 18 Experimental example 18 254 379 1130 2.98 0.67 twenty one Comparative Experiment Example 6 127 309 586 1.90 0.41 75 Comparative Experiment Example 7 149 347 680 1.96 0.43 128

The polishing rate, selectivity ratio, and dishing value of Experimental Examples 12 to 18 and Comparative Experimental Examples 6 and 7 described in Table 6 were evaluated as follows.

First, it was confirmed that in Experimental Examples 12 to 18 using complexing agents, the polishing rate of the copper film was significantly increased compared to the conventional Comparative Experimental Example 6 and Comparative Experimental Example 7.

Secondly, it was confirmed that in Experimental Examples 12 to 18 using polyvinylpyrrolidone (PVP) as a surface protective agent, the polishing rate of the silicon oxide film was lower than that of the conventional Comparative Experimental Example 6 and Comparative Experimental Example 7. Significant increase.

Third, it was confirmed that in Experimental Examples 12 to 18, as the content of iminodiacetic acid (IDA) as a complexing agent increases, the polishing rate of the copper film increases; while IDA as a surface protective agent As the content of alkyl ammonium benzene sulfonate (ADBS) increases, the depression of the copper film layer decreases.

For this reason, the selection ratios of Experimental Examples 12 to 18 are superior to the selection ratios of Comparative Experimental Example 6 and Comparative Experimental Example 7.

In the case of Comparative Experimental Example 7, the following problem occurred: since the content of benzotriazole (BTA) as an anticorrosive agent was small, although the polishing rate of the copper film layer was increased, dents increased. [ Examples 19 to 22 and Comparative Examples 8 to 10]

The slurry compositions for polishing the copper barrier layer of Examples 19 to 22 and Comparative Examples 8 to 10 were manufactured according to the contents described in Table 7 below.

A slurry composition for polishing the copper barrier layer was produced according to the particle size of the colloidal silica and the content of the surface protective agent ADBS used in Table 7 below.

Here, the content of colloidal silica (colloidal silica) is all set to 15% by weight, BTA is used as the heterocyclic compound and is set to 0.05% by weight, AA is used as the organic acid and is set to 0.1% by weight, and PVP is used as the surface protective agent. It was 0.2 weight%, KOH was used as a pH adjuster, and it was 0.2 weight%, and _KNO3 was used as a nitride and it was 1.0 weight%.

[Table 7] Silica particle size Heterocyclic compounds organic acid surface protectant (nm) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Element Content(wt%) Comparative example 8 35 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Comparative example 9 60 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Example 19 80 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Example 20 90 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Comparative example 10 100 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.05 PVP 0.2 Example 21 90 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.1 PVP 0.2 Example 22 90 BTA 0.05 IDA 0.1 AA 0.06 ADBS 0.3 PVP 0.2 [ Experimental Examples 19 to 22 and Comparative Experimental Examples 8 to 10]

The removal rate (Removal Rate) and the defect (number of defects) based on the slurry compositions of Examples 19 to 22 and Comparative Examples 8 to 10, Experimental Examples 19 to 22 and Comparative Experimental Example 8 were respectively measured. The results up to Comparative Experiment Example 10 are shown in Table 8 below.

Regarding the Defect (number of defects) measurement, the measurement was performed using a light source with a spot size of 10 μm of a device with a trade name [AIT-XP+] manufactured by KLA-Tencor Corporation.

[Table 8] Grinding rate (Å/min) selection ratio Number of defects(n) Cu N Ox Ox/TaN Cu/TaN Comparative Experiment Example 8 115 310 348 1.12 0.37 27 Comparative Experiment Example 9 125 338 510 1.51 0.37 41 Experimental example 19 172 341 846 2.48 0.50 47 Experimental example 20 178 354 956 2.70 0.50 46 Comparative Experiment Example 10 209 452 891 1.97 0.46 135 Experimental example 21 187 376 994 2.64 0.50 39 Experimental example 22 194 397 1007 2.54 0.49 28

The polishing rates, selectivity ratios, and defect values of Experimental Examples 19 to 22 and Comparative Experimental Examples 8 to 10 described in Table 8 were evaluated as follows.

That is, as the particle size of colloidal silica increases, the polishing rate increases, but there is a problem that the number of defects increases. In the case of Comparative Experimental Examples 8 and 9 with a particle size of 70 nm or less, the difference in film quality between the two The grinding rate is significantly reduced, resulting in a delay in process time, which becomes a problem in terms of productivity.

Furthermore, it was confirmed that as the content of ammonium dodecylbenzene sulfonate (ADBS) as a surface protective agent increases, the number of defects decreases.

When the colloidal silica was 13% and 15%, the results showed the same tendency, ensuring reproducibility.

As mentioned above, the present invention has been described through limited embodiments. However, the present invention is not limited to the above-mentioned embodiments. A person with ordinary knowledge in the field to which the present invention belongs can make various modifications and changes based on such description. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be defined not only by the scope of the patent application described below, but also by parts equal to the scope of the patent application.

without

without.

Claims (17)

A CMP slurry composition for grinding copper barrier layers, including: grinding particles; Heterocyclic compounds; nitrogen compounds; organic acids; surface protective agents; antioxidants; pH adjusters; and the balance of deionized water. The CMP slurry composition for grinding a copper barrier layer as described in claim 1, wherein the grinding particles are colloidal particles of nanometer-sized silica particles stably dispersed in a solvent without settling. Silica. The CMP slurry composition for grinding a copper barrier layer as claimed in claim 2, wherein the abrasive particles are present in the slurry composition in an amount of 13 to 15% by weight. The CMP slurry composition for grinding a copper barrier layer as described in claim 3, wherein the particle size of the grinding particles is 75 to 95 nm. The CMP slurry composition for polishing a copper barrier layer as described in claim 1, wherein the heterocyclic compound has more than two nitrogen atoms and is selected from the group consisting of 1,2,4-H-triazole, One of the group consisting of 5-methylbenzotriazole, tetrazole, imidazole, 1,2-dimethylimidazole, benzotriazole (BTA), 1H-benzotriazole acetonitrile, and piperazole above. The CMP slurry composition for polishing the copper barrier layer as described in claim 1, wherein the nitride is selected from the group consisting of potassium nitrate (KNO ₃ ), nitric acid (HNO ₃ ), and ammonium nitrate (NH ₄ NO ₃ ) , iron nitrate (Fe(NO ₃ ) ₂ ), and copper nitrate (Cu(NO ₃ ) ₂ ). The CMP slurry composition for polishing a copper barrier layer as described in claim 6, wherein the nitride is present in the slurry composition in an amount of 0.1 to 10% by weight. The CMP slurry composition for polishing the copper barrier layer as described in claim 1, wherein the organic acid: i) As carboxylic acid organic acids, include those selected from citric acid, glutaric acid, malic acid, maleic acid, oxalic acid, phthalic acid, etc. One or more from the group consisting of phthalic acid, succinic acid, tartaric acid, and acetic acid; ii) As amino acids, organic acids include those selected from the group consisting of Nitrilotriacetic acid (NTA), Iminodiacetic acid (IDA), Methyl iminodiacetic acid (MIDA), Hydroxyethyl iminodiacetic acid (HIDA), Diethylenetriamine pentaacetic acid (DPTA), Ethylenediamine tetraacetic acid (EDTA), N-hydroxyethylethylenediamine The group consisting of N-hydroxyethyl ethylenediamine tetraacetic acid (HEDTA), methylethylenediamine tetraacetic acid (MEDTA), and triethylene tetraamine hexaacetic acid (TTHA) More than one of them. The CMP slurry composition for polishing the copper barrier layer as described in claim 8, wherein, The organic acid is present in the slurry composition in an amount of 0.1 to 3% by weight. The CMP slurry composition for polishing the copper barrier layer as described in claim 1, wherein the surface protective agent: Non-ionic surface protective agents include polyvinyl alcohol (PVA), ethylene glycol (EG), glycerin, polyethylene glycol (PEG), polypropylene glycol (PPG), and polyvinylpyrrolidone (PVP). More than one type of group; The anionic surface protective agent includes ammonium dodecyl benzene sulfonate, ammonium polyoxyethylene alkyl sulfonate, and polyoxyethylene alkyl aryl sulfonate. One or more of the group consisting of ammonium polyoxyethylene alkyl aryl sulfonate. The CMP slurry composition for polishing the copper barrier layer according to claim 10, wherein the surface protective agent is present in the slurry composition in an amount of 0.3 to 0.8% by weight. The CMP slurry composition for polishing the copper barrier layer according to claim 1, wherein the antioxidant includes ascorbic acid, L(+)-ascorbic acid (L(+)-ascorbic acid) ), isoascorbic acid, ascorbic acid derivatives, gallic acid, formamidinesulfinic acid, uric acid, tartaric acid, and One or more of the group consisting of cysteine. The CMP slurry composition for polishing a copper barrier layer as claimed in claim 12, wherein the antioxidant is present in the slurry composition in an amount of 0.1 to 0.5% by weight. A CMP slurry composition for polishing a copper barrier layer, wherein the pH adjuster is at least one selected from the group consisting of KOH, NH ₄ OH, NaOH, TMAH, TBAH and HNO ₃ . The CMP slurry composition for polishing the copper barrier layer according to claim 14, wherein the pH value of the slurry composition is 9 to 12. The CMP slurry composition for polishing a copper barrier layer as claimed in claim 1, wherein the polishing target film of the slurry composition includes a film used as a copper-containing film and a barrier film or as a semiconductor insulator. The oxide film of the film includes any one selected from the group consisting of titanium (Ti), tantalum (Ta), ruthenium (Ru), molybdenum (Mo), cobalt (Co) and gold (Au). The CMP slurry composition for polishing the copper barrier layer as described in claim 16, wherein the CMP slurry composition is effective for tantalum nitride film (TaN), silicon oxide film (Silicon oxide), and copper film The grinding selectivity ratio of (Cu) is 1:1~4:0.5~1.