CMP slurry composition for polishing copper barrier layer

Abstract

The present invention relates to a slurry composition for copper barrier layer polishing for chemical mechanical planarizing (CMP) of tantalum nitride or tantalum as an anti-diffusion film in the presence of an interconnect structure material in an integrated circuit device. The slurry composition according to the present invention contains abrasive particles, a heterocyclic compound, an organic acid, a surface protecting agent, a nitride, a pH adjuster, and a balance of deionized water, and exhibits the effect of providing an excellent slurry composition having a large polishing selectivity and few dishing and defect numbers.

Description

Technical Field

[0001] The present invention relates to a CMP slurry composition for polishing a copper barrier layer for chemical mechanical planarizing (CMP) of tantalum nitride or tantalum as a diffusion prevention film in the presence of an interconnect structure material in an integrated circuit device. The CMP slurry composition according to the present invention is a useful composition containing abrasive particles, a heterocyclic compound, an organic acid, a surface protective agent, a nitride, a pH adjuster, and a balance of deionized water, and has excellent dispersibility and stability of the abrasive particles compared to the CMP slurry composition according to the prior art, a large polishing selectivity ratio, and excellent CMP slurry composition with less dishing and fewer defects can be provided.

Background Art

[0002] In recent years, with the development of semiconductor manufacturing process technology, the semiconductor industry has increasingly relied on copper electrical interconnects when forming integrated circuits. These copper interconnects have low electrical resistivity and excellent electromigration characteristics.

[0003] Copper has many advantages in terms of efficiency such as excellent electromigration characteristics and low electrical resistance, and has been widely used as a main electrical connection material for semiconductor integrated circuits such as miniaturized and highly integrated ULSIs.

[0004] However, since patterning by dry etching is difficult and there is a limit that copper cannot be used in integrated circuits, in order to overcome this, a method of forming a copper interconnect by a CMP process using a dual damascene process has been proposed. Copper forms a porous oxide film layer composed of CuO, CuO2, Cu(OH)3, etc. containing Cu+ or Cu2+ which are copper oxide ions during the CMP process.

[0005] However, copper is relatively soft compared to other materials such as tetraethoxysilane (TEOS) of silicon material or tungsten, and is electrochemically more sensitive to corrosion than tungsten. Therefore, although the polishing rate can be high, in turn, over-polishing, dishing and erosion due to scratches are likely to occur. In particular, a phenomenon occurs in which components of the polishing slurry and foreign substances such as oxides generated during the polishing process penetrate the copper oxide film layer through the holes of the porous film. Such a phenomenon may cause problems in the next process, such as the photolithography process. In particular, in the case of a highly integrated circuit composed of 6 to 7 or more layers according to the wiring design, considering that the performance of the circuit depends on the flatness of each layer, it can be a cause of fatal defects.

[0006] Copper has a very high reactivity with many dielectric materials, such as silicon dioxide and doped versions of low-K or silicon dioxide. Therefore, a diffusion barrier layer is necessary to prevent the diffusion of copper into the underlying dielectric material.

[0007] 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.

[0008] In response to the increasing requirements of high-density integrated circuits, manufacturers, etc. are currently assembling integrated circuits containing multiple overlying layers of metal interconnect structure materials. During the assembly of the device, planarizing each interconnect layer improves the packing density, process uniformity, and production quality. Most importantly, it enables chip manufacturers to assemble multi-layer integrated circuits. Chip manufacturers, etc. rely on chemical-mechanical-planarization (CMP) as a relatively efficient means of manufacturing the flat plate surface.

[0009] The CMP process is typically carried out in two stages. First, the polishing process uses a "first stage" slurry designed to rapidly remove copper in particular.

[0010] After initially removing the copper, the "second stage" slurry removes the barrier material. Typically, the second stage slurry is required to have excellent selectivity for removing the barrier material without adversely affecting the physical structure or electrical properties of the interconnect structure material. Traditionally, since alkaline polishing slurries have a much higher Ta / TaN removal rate than acidic slurries, commercial second stage slurries typically have a basic or neutral pH. Another factor highlighting the advantages of neutral or basic pH barrier metal polishing slurries relates to the need to preserve the metal overlying the barrier metal during the second stage of polishing. The metal removal rate must be very low so as to reduce dishing of the metal interconnects.

[0011] Therefore, in a chemical mechanical polishing method, such a barrier slurry composition is required to have a high barrier removal rate, very low post-polishing topography, no corrosion defects, and very low scratching or corrosion, and depending on the choice of which type of abrasive, oxidizing agent or additive, while minimizing the variation range of each variable important in semiconductor processes such as unfinishedness, surface roughness, surface defects, erosion and corrosion of the polished surface, can effectively polish the metal insulating film, diffusion barrier or metal layer at the desired polishing ratio.

[0012] As a result of conducting experiments using a CMP slurry composition according to the prior art, there are problems such as the problem of the CMP operation throughput due to poor polishing amounts of copper and tantalum compounds, the problem of the degradation of equipment performance and the reduction of production yield due to the corrosion of copper substances, the problem of layer planarization, and the dishing phenomenon that occurs during polishing. Also, in the case of the process of polishing the copper film quality, while achieving an appropriate polishing rate, a low surface defect level must be achieved. However, in the case of the CMP slurry composition according to the prior art, there is a problem that the polishing process time becomes long or surface defects appear.

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0014] An object of the present invention is to solve problems such as the problem of the CMP operation throughput due to poor polishing amounts of copper and tantalum compounds in a CMP slurry composition according to the prior art, the problem of the degradation of equipment performance and the reduction of production yield due to the corrosion of copper substances, the layer planarization problem, and the dishing phenomenon that occurs during polishing.

[0015] Also, an object of the present invention is to provide a CMP slurry composition for polishing a copper barrier layer that has an appropriate polishing rate in the process of polishing the copper film quality and significantly reduces dishing, corrosion, and the number of defects compared to existing slurries.

[0016] Another object of the present invention is to provide a CMP slurry composition for polishing a copper barrier layer, among the problems in the copper CMP process mentioned above, having a greater step removal rate for silicon oxide films and copper films than conventional slurries.

Means for Solving the Problems

[0017] To achieve the above object, the present invention is composed of polishing particles made of colloidal silica, a heterocyclic compound, an organic acid, a surface protective agent, a nitride, a pH adjuster, and the balance of deionized water. By adjusting the contents of the additives and the solvent and the particle size of the colloidal silica, a CMP slurry composition for polishing a copper barrier layer is provided, which adjusts the polishing selectivity and polishing rate for silicon oxide films, tantalum films, and copper films and then polishes them.

[0018] In a preferred embodiment of the present invention, the colloidal silica is characterized in that the particle size is 75 nm to 95 nm.

[0019] In a preferred embodiment of the present invention, the heterocyclic compound has two or more nitrogen atoms and is one or more selected from the group consisting of 1,2,4H-triazole, 5-methylbenzotriazole, tetrazole, imidazole, 1,2-dimethylimidazole, benzotriazole (BTA), 1H-benzotriazoleacetonitrile, and piperazine.

[0020] In a preferred embodiment of the present invention, as non-ionic types, polyvinyl alcohol (PVA), ethylene glycol (EG), glycerin, polyethylene glycol (PEG), polypropylene glycol (PPG), or polyvinyl pyrrolidone (PVP) etc. can be selected. As anionic types, ammonium dodecyl benzene sulfonate, ammonium polyoxyethylene alkyl sulfonate, ammonium polyoxyethylene alkyl aryl sulfonate etc. can be selected. Two or more of these can be mixed and used. Most preferably, polyvinyl pyrrolidone (PVP) as a non-ionic type and ammonium dodecyl benzene sulfonate as anionic type are mixed and used.

[0021] In a preferred embodiment of the present invention, the organic acid may be any one selected from the group of carboxylic acids consisting of citric acid, glutaric acid, malic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, and acetic acid. Further, it is characterized by being one or more selected from the group of amino acids 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-hydroxyethyl ethylenediamine tetraacetic acid (HEDTA), Methyl ethylenediamine tetraacetic acid (MEDTA), Triethylene tetraamine hexaacetic acid (TTHA), and the like.

[0022] In a preferred embodiment of the present invention, the antioxidant is characterized in that it is at least one selected from the group consisting of ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives, gallic acid, formamidinesulfinic acid, uric acid, tartaric acid, cysteine, and the like.

[0023] In a preferred embodiment of the present invention, for the purpose of adjusting the pH range to be basic, KOH, NH4OH, NaOH, TMAH, TBAH, KNO3, NH4NO3, HNO3, etc. can be used alone or in combination. Since the pH is closely related to the particle stability and polishing rate of the slurry, it must be precisely adjusted.

[0024] In a preferred embodiment of the present invention, the CMP slurry composition contains, based on the total weight of the composition, 13 wt% to 15 wt% of polishing particles composed of colloidal silica, polishing particles, heterocyclic compounds, organic acids, surface protectants, nitrides, pH adjusters, and the balance of deionized water.

[0025] In a preferred embodiment of the present invention, the CMP slurry composition is characterized in that the pH is 9 to 12.

[0026] In a preferred embodiment of the present invention, the CMP slurry composition is characterized in that it simultaneously polishes a polished film formed of two or more selected from a silicon oxide film, a tantalum film, and a copper film.

[0027] In a preferred embodiment of the present invention, the polishing is characterized in that the polishing selectivity ratio of a tantalum nitride film (TaN), a silicon oxide film (Silicon oxide), and a copper film (Cu) is 1:1 to 4:0.5 to 1.

Advantages of the Invention

[0028] The CMP slurry composition for polishing a copper barrier layer according to the present invention exhibits the effect of improving productivity because it has a high step removal efficiency between a silicon oxide film and a copper film layer.

[0029] In addition, the CMP slurry composition for polishing a copper barrier layer according to the present invention can polish while minimizing dishing, corrosion, defects, etc. with respect to the copper film layer, and can efficiently form a copper wiring layer of a semiconductor device layer having excellent reliability and characteristics. Therefore, it exhibits the effect of greatly contributing to obtaining a high-performance semiconductor device.

Mode for Carrying Out the Invention

[0030] Generally, the nomenclature in this specification is well-known and commonly used in the technical field. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present invention pertains.

[0031] Throughout this specification, when one part "includes" one component, this means that, unless otherwise stated to the contrary, it does not exclude other components, but may further include other components.

[0032] Generally, in stage 1, after removal of overburden copper, the polished wafer surface has non-uniform local and overall flatness due to differences in step height at various positions. The low-density pitch has a high copper step, while the high-density pitch tends to have a low step.

[0033] Due to the steps after stage 1, a CMP slurry for stage 2 having selective polishing with respect to the removal rates of copper and oxide is highly required.

[0034] In the present invention, the "Selectivity ratio" means different removal rates for different substances under the same polishing conditions.

[0035] The barrier slurry preferably provides one or more of the following in two stages of the CMP process of the patterned wafer. Providing a preferred removal rate for various types of films, providing a low level of within wafer non-uniformity (WIW NU) of the polished wafer, having low residues on the polished wafer after the CMP process, and providing a polishing selectivity ratio for various polishing layers.

[0036] Specific featured distortion not suitable for semiconductor manufacturing is damage to copper vias or metal lines caused by chemical components interacting with copper vias or metal lines in the CMP process and additional corrosion. Therefore, it is very important to use a corrosion inhibitor in the barrier CMP slurry to reduce additional corrosion of copper vias or trenches during the CMP process and to reduce defects.

[0037] The chemical reaction of the barrier CMP composition in the stage 2 CMP process includes an oxidation reaction induced by an oxidizing agent used in the CMP slurry, such as H2O2. For example, surfaces such as metals like copper, lines, vias, or trenches and Ta are oxidized to their respective metal oxide films.

[0038] Typically, copper is oxidized to cuprous oxide or cupric oxide mixture, and Ta is oxidized to Ta2O5. Chelates, ligands, or other chemical additives that can be chemically bonded to copper cations and tantalum cations are used in the barrier slurry to promote the dissolution of copper oxide and tantalum oxide and to improve the removal rates of copper, lines, vias, or trenches, and the barrier layer or barrier film.

[0039] Therefore, the slurry to be developed in the present invention aims to provide a CMP slurry composition that can significantly reduce corrosion or defects generated in the copper CMP process and enhance the polishing removal rates for silicon oxide films, copper films, and tantalum films compared to conventional slurries, enabling faster polishing.

[0040] The slurry for polishing a copper barrier layer according to the present invention is composed of polishing particles made of colloidal silica, a heterocyclic compound, an organic acid, a surface protective agent, a nitride, a pH adjuster, and the balance of deionized water.

[0041] The colloidal silica means a colloidal solution in which sedimentation does not occur in silica particles with a nano-sized particle diameter and is stably dispersed in a solvent. The colloidal silica with a particle size of 75 nm to 95 nm is preferable in terms of appropriately maintaining scratch and removal rate, and the colloidal silica with a particle size of 80 nm to 90 nm is even more preferable.

[0042] When the particle size of the colloidal silica is less than 75 nm, the removal rate for the film quality decreases and the process progress time becomes longer. When the particle size of the colloidal silica exceeds 95 nm, it is not preferable because it is vulnerable to scratches.

[0043] The colloidal silica preferably contains 13% to 15% by weight based on the total weight of the composition.

[0044] When the colloidal silica is used in an amount less than 13% by weight, the solid content is insufficient, resulting in a decrease in the removal rate. When the colloidal silica is used in an amount exceeding 15% by weight, an aggregation phenomenon due to an excessive content occurs, which is not preferable.

[0045] In the CMP slurry composition according to an embodiment of the present invention, the heterocyclic compound has two or more nitrogen atoms and is at least one selected from the group consisting of 1,2,4H-triazole, 5-methylbenzotriazole, tetrazole, imidazole, 1,2-dimethylimidazole, benzotriazole (BTA), 1H-benzotriazole acetonitrile, or piperazine. The corrosion inhibitor may be 0.005 wt% to 0.5 wt% in the slurry composition in terms of corrosion inhibition effect, polishing rate, and stability of the slurry composition.

[0046] When the corrosion inhibitor is less than 0.005 wt%, it is impossible to control the polishing of the copper film, so dishing problems may occur. On the other hand, when the corrosion inhibitor exceeds 0.5 wt%, the polishing rate of the copper film becomes low, and problems such as residues remaining may occur.

[0047] The polishing rate improver for tantalum compounds that can be used in the CMP slurry of the present invention is a nitride used as a pH adjuster. The nitride is a substance used as an etching solution for tantalum and tantalum compounds and is effective for removing tantalum during CMP polishing.

[0048] As the nitride used in the present invention, potassium nitrate (KNO3), nitric acid (HNO3), ammonium nitrate (NH4NO3), iron nitrate (Fe(NO3)2), copper nitrate (Cu(NO3)2), etc. can be used, and these can also be used in a mixed composition. Generally, titanium and tantalum compounds are relatively stable substances, are easily etched by a mixture of hydrofluoric acid and nitric acid, and have the property of reacting slowly with bases and aqua regia. Generally, the amount of nitride used in the slurry preferably ranges from about 0.05 wt% to 10 wt%, and more preferably ranges from about 0.1 wt% to 1 wt%.

[0049] The surface protectant used in the present invention can be selected from non-ionic types such as polyvinyl alcohol (PVA), ethylene glycol (EG), glycerin, polyethylene glycol (PEG), polypropylene glycol (PPG), or polyvinyl pyrrolidone (PVP). As anionic types, ammonium dodecyl benzene sulfonate, ammonium polyoxyethylene alkyl sulfonate, ammonium polyoxyethylene alkyl aryl sulfonate, etc. can be selected, and two or more of these can be mixed and used. Most preferably, polyvinyl pyrrolidone (PVP) as a non-ionic type and ammonium dodecyl benzene sulfonate as anionic type are mixed and used.

[0050] The non-ionic protectant adsorbs on the particle surface in the solution phase, but contains one or more functional groups having an affinity for the particles, strongly and continuously adsorbing on the particle surface, thus playing a role in increasing the particle size. Therefore, it also appropriately plays a role in improving the polishing rate for the silicon oxide film. Also, the dispersion stability is maintained by the steric repulsive force. Therefore, when the content of the protectant is less than 0.15% by weight based on the total weight of the composition, the dispersing force is low and precipitation occurs quickly, so precipitation occurs during the transfer of the polishing liquid and the abrasive cannot be supplied uniformly. On the other hand, when the content of the dispersant exceeds 1.0% by weight based on the total weight of the composition, a protectant layer that acts as a kind of cushion is thickly formed around the abrasive particles, making it difficult for the abrasive surface to contact the polishing surface and potentially reducing the polishing rate.

[0051] The surface protectant plays a role in protecting the wafer surface from residues of the polishing pad, metal residues, or organic residues during polishing, so the number of defects on the wafer decreases. In particular, when an anionic ammonium sulfonate derivative is mixed and used, it plays a role in cleaning various residues from the wafer surface, so the number of defects is further improved. Generally, the amount of the surface protectant used in the slurry preferably exists in the range of about 0.15% to 1.0% by weight, and most preferably exists at about 0.3% to 0.8% by weight.

[0052] In the CMP slurry of the present invention, an organic acid is used to adjust the copper removal rate with respect to the barrier metal removal rate.

[0053] The organic acid suppresses the re-adsorption of the copper oxide oxidized by the chelation reaction with the copper oxide onto the copper layer which is the layer to be polished, increases the polishing rate for copper, and reduces surface defects. By selectively adding the organic acid to the slurry according to the target metal component, the CMP planarization of the dielectric / metal composite structure can be further improved.

[0054] This increases the erosion rate of the metal phase, increases the polishing selectivity of the metal with respect to the removal of the dielectric phase, and makes the planarization process more efficient.

[0055] The organic acids that can be used in the present invention include carboxylic acid-based and amino acid-based ones. First, the carboxylic acid-based organic acid is characterized in that it is at least one selected from the group of carboxylic acids consisting of citric acid, glutaric acid, malic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, and acetic acid.

[0056] Second, the amino acid-based organic acid is at least one selected from the group consisting of nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), methyliminodiacetic acid (MIDA), hydroxyethyliminodiacetic acid (HIDA), diethylenetriamine pentaacetic acid (DPTA), ethylenediaminetetraacetic acid (EDTA), N-hydroxyethyl ethylenediamine tetraacetic acid (HEDTA), methyl ethylenediamine tetraacetic acid (MEDTA), triethylenetetraamine hexaacetic acid (TTHA), etc.

[0057] The organic acid is added in an amount of 0.05 wt% to 5 wt% based on the weight of the slurry composition. Preferably, the concentration is 0.1 wt% to 3 wt%. Most preferably, the concentration is 0.1 wt% to 1 wt%. If the amount is too small, the chelating agent will not show the desired effect of the present invention. If the amount is too large, the chelating agent will be consumed without additional effect.

[0058] In a preferred embodiment of the present invention, the antioxidant is characterized in that it is one or more selected from the group consisting of ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives, gallic acid, formamidine sulfinic acid, uric acid, tartaric acid, cysteine, etc. The antioxidant is added in an amount of 0.05 wt% to 1 wt% based on the weight of the slurry composition. Preferably, the concentration is 0.1 wt% to 0.5 wt%. Most preferably, the concentration is 0.2 wt% to 0.3 wt%. If the amount is too small, the antioxidant effect of the metal is not shown. If the amount is too large, it is consumed without an additional effect or remains on the wafer surface, which causes defects.

[0059] For the CMP slurry composition according to an embodiment of the present invention, those having a pH of 9 to 12 are preferable in terms of the stability of the composition. When the pH range is less than 9, the aggregation phenomenon and removal rate of the colloidal silica particles become unstable. When the pH range exceeds 12, the removal rate becomes unstable, which is not preferable.

[0060] In order to adjust to the above pH range, as the basic substance, KOH, NH4OH, NaOH, TMAH, TBAH, KNO3, NH4NO3, etc. can be used alone or in combination. Since the pH is closely related to the particle stability and polishing rate of the slurry composition, it must be precisely adjusted.

[0061] In the CMP slurry composition according to an embodiment of the present invention, the solvent is used to adjust the concentration of the composition and the removal rate of the film quality. As the solvent, deionized water, water, etc. can be used, but it is preferable to use deionized water.

[0062] The film to be polished of the slurry composition may include a copper-containing film.

[0063] In addition, the composition of the slurry can adjust the desired polishing rate with respect to a thin film or an oxide film used as a semiconductor insulating film containing any one selected from the group consisting of titanium (Ti), tantalum (Ta), ruthenium (Ru), molybdenum (Mo), cobalt (Co), or gold (Au) used for a copper-containing film and a barrier film. Thereby, the slurry composition can also exhibit an excellent polishing selectivity ratio between the film to be polished and other thin films.

[0064] Hereinafter, the present invention will be described in more detail through examples. However, it will be apparent to those having ordinary knowledge in the art that these examples are merely for illustrating the present invention and should not be construed as limiting the scope of the present invention by these examples.

Examples

[0065] [Examples 1 to 7 and Comparative Examples 1 to 2] Copper barrier layer polishing slurry compositions of Examples 1 to 7 and Comparative Examples 1 to 2 were produced according to the contents described in Table 1 below.

[0066] Here, the content of colloidal silica was all 13% by weight, and the particle size of the colloidal silica used was 90 nm. As the pH adjuster, KOH was used for all, and as the nitride, KNO3 was used for all, each being 0.5% by weight. As the antioxidant, ascorbic acid was used, and this was 0.2% by weight.

[0067]

Table 1

[0068] [Experimental Examples 1 to 7 and Comparative Experimental Examples 1 to 2] After measuring the polishing rate (Removal Rate) and dishing by the slurry compositions such as Examples 1 to 7 and Comparative Examples 1 and 2, they were shown in Experimental Examples 1 to 7 and Comparative Experimental Examples 1 and 2 and described in Table 2 below.

[0069] [Polishing Conditions] 1. Polishing Equipment: 12-inch (300 mm) CMP Equipment - AP-300 (CTS Corporation) 2. Polishing Pad: IC1010 (Dow Chemical Company) 3. Platen Speed: 103 rpm 4. Head Speed: 97 rpm 5. Flow Rate: 300 cc / min 6. Pressure: 2.2 psi

[0070] In the measurement of the polishing rate, when polishing using 12-inch (300 mm) CMP equipment, the polishing rates of Cu and Ta were calculated using a 4-point probe (CMT-SR5000, AIT Co., Ltd).

[0071] For PTEOS, which is an oxide, the thickness change before and after CMP was measured using the Atlas equipment of Nanometrics, and the polishing rate was calculated.

[0072] The polishing selectivity was calculated based on the polishing rates of each film quality as follows. - Polishing Selectivity of Silicon Oxide Film to Tantalum Nitride Film (TaN) = Polishing Rate of Silicon Oxide Film / Polishing Rate of Tantalum Nitride Film (TaN) - Polishing Selectivity of Copper Film (Cu) to Tantalum Nitride Film (TaN) = Polishing Rate of Copper Film (Cu) / Polishing Rate of Tantalum Nitride Film (TaN)

[0073] In the measurement of dishing, the thickness of each film quality was measured and calculated as follows using a transmission electron microscope (JEM-2000, JEOL). - Cu dishing = (Cu edge thickness - Cu center thickness) - Ox dishing = (Ox edge thickness - Ox center thickness)

[0074]

Table 2

[0075] When evaluating the polishing rate, selectivity, and dishing value of Experimental Examples 1 to 7 and Comparative Experimental Examples 1 and 2 described in Table 2, the results are as follows.

[0076] First, it can be seen that in Experimental Examples 1 to 7 using complexing agents, the polishing rate of the copper film increases significantly compared to existing Comparative Examples 1 and 2.

[0077] Second, it can be seen that in Experimental Examples 1 to 7 using polyvinylpyrrolidone (PVP) as a surface protectant, the polishing rate of the silicon oxide film increases significantly compared to existing Comparative Examples 1 and 2.

[0078] Third, it can be seen that as the content of iminodiacetic acid (IDA), which is a complexing agent, increases in Experimental Examples 1 to 7, the polishing rate of the copper film increases, and as the content of ammonium dodecylbenzenesulfonate (ADBS), which is a surface protectant, increases, the dishing of the copper film layer decreases.

[0079] For these reasons, Experimental Examples 1 to 7 were superior in selectivity compared to existing Comparative Experimental Examples 1 and 2.

[0080] In the case of Comparative Experimental Example 2, due to the low content of benzotriazole (BTA), which is a corrosion inhibitor, although the polishing rate of the copper film layer improves, the problem of increased dishing appears.

[0081] [Examples 8 to 11 and Comparative Examples 3 to 5] According to the contents described in Table 3 below, slurry compositions for polishing the copper barrier layer of Examples 8 to 11 and Comparative Examples 3 to 5 were manufactured. Slurry compositions for polishing the copper barrier layer were manufactured according to the particle size of colloidal silica and the content of ADBS, which is a surface protectant.

[0082] Here, the content of colloidal silica was set to 15% by weight for all. As the heterocyclic compound, 0.05% by weight of BTA was used, as the organic acid, 0.1% by weight of AA was used, as the surface protective agent, 0.2% by weight of PVP was used, as the pH adjuster, KOH was used and this was set to 0.2% by weight, and as the nitride, KNO3 was used and this was set to 1.0% by weight.

[0083]

Table 3

[0084] [Experimental Examples 8 to 11 and Comparative Experimental Examples 3 to 5] After measuring the polishing rate, selectivity ratio, and number of defects for the slurry compositions such as those in Examples 8 to 11 and Comparative Examples 3 to 5 respectively, they were shown in Experimental Examples 8 to 11 and Comparative Experimental Examples 3 to 5 and described in Table 4 below.

[0085] In the measurement of the number of defects, it was measured using a 10 μm spot size light source equipped with the product name [AIT-XP+] manufactured by KLA Tencor.

[0086]

Table 4

[0087] In Table 4 above, as the particle size increases, the polishing rate increases, but there is a problem that the number of defects increases. In the cases of Comparative Experimental Examples 3 and 4 with a particle size of 70 nm or less, the polishing rates of all two film qualities are significantly reduced and the process time is delayed, so there is a problem in productivity.

[0088] Also, it can be seen that as the content of ammonium dodecylbenzenesulfonate (ADBS), which is a surface protective agent, increases, the number of defects decreases.

[0089] [Examples 12 to 18 and Comparative Examples 6 to 7] Slurry compositions for polishing a copper barrier layer of Examples 12 to 18 and Comparative Examples 6 to 7 were manufactured according to the contents described in Table 5 below.

[0090] Here, the content of colloidal silica is all 15% by weight, and the particle size of the colloidal silica used is 90 nm. As the pH adjuster, all use KOH, and as the nitride, all use KNO3, each being 0.5% by weight. Ascorbic acid is used as the antioxidant, and this is 0.2% by weight.

[0091]

Table 5

[0092] [Experimental Examples 12 to 18 and Comparative Experimental Examples 6 to 7] After measuring the polishing rate, selectivity, and dishing of the slurry compositions such as Examples 12 to 18 and Comparative Examples 6 and 7 respectively, they were shown in Experimental Examples 12 to 18 and Comparative Experimental Examples 6 and 7, and described in Table 6 below.

[0093]

Table 6

[0094] When evaluating the polishing rate, selectivity, and dishing values of Experimental Examples 12 to 18 and Comparative Experimental Examples 6 and 7 described in Table 6, it is as follows.

[0095] First, it can be seen that in Experimental Examples 12 to 18 using the complexing agent, the polishing rate of the copper film increases significantly compared to the existing Comparative Experimental Examples 6 and 7.

[0096] Second, it can be seen that in Experimental Examples 12 to 18 using polyvinylpyrrolidone (PVP) as the surface protectant, the polishing rate of the silicon oxide film increases significantly compared to the existing Comparative Experimental Examples 6 and 7.

[0097] Thirdly, it can be seen that as the content of iminodiacetic acid (IDA), which is a complexing agent, increases in Experimental Examples 12 to 18, the polishing rate of the copper film increases, and as the content of ammonium dodecylbenzenesulfonate (ADBS), which is a surface protective agent, increases, the dishing of the copper film layer decreases.

[0098] For these reasons, Experimental Examples 12 to 18 were superior in selectivity compared to existing Comparative Examples 6 and 7.

[0099] In the case of Comparative Example 7, since the content of benzotriazole (BTA), which is a corrosion inhibitor, is low, the polishing rate of the copper film layer improves, but the problem of increased dishing appears.

[0100] [Examples 19 to 22 and Comparative Examples 8 to 10] Copper barrier layer polishing slurry compositions of Examples 19 to 22 and Comparative Examples 8 to 10 were produced according to the contents described in Table 7 below.

[0101] As shown in Table 7 below, copper barrier layer polishing slurry compositions were produced according to the particle size of the colloidal silica used and the content of ADBS, which is a surface protective agent.

[0102] Here, the content of colloidal silica was all 15% by weight. As the heterocyclic compound, 0.05% by weight of BTA was used. As the organic acid, 0.1% by weight of AA was used. As the surface protective agent, 0.2% by weight of PVP was used. As the pH adjuster, KOH was used and this was 0.2% by weight. As the nitride, KNO3 was used and this was 1.0% by weight.

[0103]

Table 7

[0104] [Experimental Examples 19 to 22 and Comparative Experimental Examples 8 to 10] After measuring the polishing rate and the number of defects of the slurry compositions such as those in Examples 19 to 22 and Comparative Examples 8 to 10, they were presented in Experimental Examples 19 to 22 and Comparative Experimental Examples 8 to 10 and described in Table 8 below.

[0105] In the measurement of the number of defects, measurement was carried out using a light source having a spot size of 10 μm equipped with [AIT-XP+] of the product name manufactured by KLA Tencor Corporation.

[0106]

Table 8

[0107] When evaluating the values of the polishing rate, selectivity, and the number of defects of Experimental Examples 19 to 22 and Comparative Experimental Examples 8 to 10 described in Table 8 above, the following results are obtained.

[0108] 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 polishing rates of both film qualities are significantly reduced, and the process time is delayed, resulting in a problem in productivity.

[0109] Also, it can be seen that as the content of ammonium dodecylbenzenesulfonate (ADBS), which is a surface protecting agent, increases, the number of defects decreases.

[0110] The above results showed the same tendency for 13% and 15% of colloidal silica, ensuring reproducibility.

[0111] As described above, the present invention has been described with limited examples, but it is not limited to the above examples. Those having ordinary knowledge in the field to which the present invention pertains can make various modifications and variations from such descriptions. Therefore, the scope of the present invention should not be determined by limiting it to the described examples, but should be determined by not only the scope of the claims described below but also those equivalent to the scope of these claims.

Claims

1. A CMP slurry composition for polishing a copper barrier layer, which is composed of abrasive particles, a heterocyclic compound, a nitride, an organic acid, a surface protective agent, an antioxidant, a pH adjuster, and the balance deionized water.

2. The CMP slurry composition for polishing a copper barrier layer according to claim 1, wherein the abrasive particles are colloidal silica with a nano particle size that does not sediment and is stably dispersed in a solvent.

3. The CMP slurry composition for polishing a copper barrier layer according to claim 2, wherein the abrasive particles are 13% to 15% by weight in the slurry composition.

4. The CMP slurry composition for polishing a copper barrier layer according to claim 3, wherein the abrasive particles have a particle size of 75 nm to 95 nm.

5. The CMP slurry composition for polishing a copper barrier layer according to claim 1, wherein the heterocyclic compound has two or more nitrogen atoms and is at least one selected from the group consisting of 1,2,4-H-triazole, 5-methylbenzotriazole, tetrazole, imidazole, 1,2-dimethylimidazole, benzotriazole (BTA), 1H-benzotriazole acetonitrile, and piperazine.

6. The nitride is one or more selected from the group consisting of 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 ), and the CMP slurry composition for polishing a copper barrier layer according to claim 1, characterized in that it is one or more selected from the group consisting of

7. The CMP slurry composition for polishing a copper barrier layer according to claim 6, wherein the nitride is 0.1% to 10% by weight in the slurry composition.

8. The organic acid is i) including, as carboxylic acid-based, at least one selected from the group consisting of citric acid, glutaric acid, malic acid, maleic acid, oxalic acid, phthalic acid, succinic acid, tartaric acid, and acetic acid; ii) As the amino acid-based ones, those containing at least one selected from the group consisting of nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), methyliminodiacetic acid (MIDA), hydroxyethyliminodiacetic acid (HIDA), diethylenetriaminepentaacetic acid (DPTA), ethylenediaminetetraacetic acid (EDTA), N-hydroxyethyl ethylenediaminetetraacetic acid (HEDTA), methylethylenediaminetetraacetic acid (MEDTA), and triethylenetetraminehexaacetic acid (TTHA); The CMP slurry composition for polishing a copper barrier layer according to claim 1, characterized in that.

9. The CMP slurry composition for polishing a copper barrier layer according to claim 8, characterized in that the organic acid is 0.1% by weight to 3% by weight in the slurry composition.

10. The CMP slurry composition for polishing a copper barrier layer according to claim 1, characterized in that the surface protective agent includes, as the nonionic type, at least one selected from the group consisting of polyvinyl alcohol (PVA), ethylene glycol (EG), glycerin, polyethylene glycol (PEG), polypropylene glycol (PPG), and polyvinylpyrrolidone (PVP); and includes, as the anionic type, at least one selected from the group consisting of ammonium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl sulfonate, and ammonium polyoxyethylene alkyl aryl sulfonate.

11. The CMP slurry composition for polishing a copper barrier layer according to claim 10, characterized in that the surface protective agent is 0.3% by weight to 0.8% by weight in the slurry composition.

12. The antioxidant is one or more selected from the group consisting of ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives, gallic acid, formamidine sulfinic acid, uric acid, tartaric acid, cysteine, etc.; The CMP slurry composition for polishing a copper barrier layer according to claim 1, characterized in that.

13. The CMP slurry composition for polishing a copper barrier layer according to claim 12, characterized in that the antioxidant is 0.1% by weight to 0.5% by weight in the slurry composition.

14. The pH adjuster is one or more selected from the group consisting of KOH, NH ４ OH, NaOH, TMAH, TBAH, and HNO ３ A CMP slurry composition for polishing a copper barrier layer, characterized in that it is one or more selected from the group consisting of

15. The CMP slurry composition for polishing a copper barrier layer according to claim 14, characterized in that the slurry composition has a pH of 9 to 12.

16. The CMP slurry composition for polishing a copper barrier layer according to claim 1, characterized in that the film to be polished includes a thin film containing any one selected from the group consisting of titanium (Ti), tantalum (Ta), ruthenium (Ru), molybdenum (Mo), cobalt (Co), and gold (Au) used for a copper-containing film and a barrier film, or an oxide film used as a semiconductor insulating film.

17. The CMP slurry composition for polishing a copper barrier layer according to claim 16, characterized in that the polishing selectivity ratio of a tantalum nitride film (TaN), a silicon oxide film, and a copper film (Cu) is 1:1 to 4:0.5 to 1.

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