KR20210012866A - Metal structure and method of manufacturing the same and metal wire and semiconductor device and electronic device - Google Patents

Abstract

The present invention relates to a manufacturing method of a metal structure, a metal structure, a semiconductor element including the same, and an electronic device. The manufacturing method of the metal structure comprises the steps of: forming a metal layer comprising a metal and a nano-abrasive having a diameter of less than 5 nm; and performing chemical mechanical polishing by supplying slurry to a surface of the metal layer. Therefore, polishing rate can be improved.

Description

Metal structures and their manufacturing methods, metal wiring, semiconductor devices, and electronic devices {METAL STRUCTURE AND METHOD OF MANUFACTURING THE SAME AND METAL WIRE AND SEMICONDUCTOR DEVICE AND ELECTRONIC DEVICE}

It relates to a metal structure and a method of manufacturing the same, a metal wiring, a semiconductor device, and an electronic device.

In recent years, according to the miniaturization of electronic devices and the resulting miniaturization of integrated circuits, various methods of forming microscopic metal structures such as several nanometers of metal wiring have been studied.

In the step of forming such a fine metal structure, a polishing process may be performed to make a flat surface of the fine metal structure. One of the polishing processes is chemical mechanical polishing (CMP). Chemical mechanical polishing is a process of flattening the surface of the substrate by providing a polishing slurry containing an abrasive between a semiconductor substrate to be polished and a polishing pad, and then bringing the semiconductor substrate into contact with the polishing pad.

However, conventional polishing slurries including an abrasive such as silica may cause damage and shape deformation of fine metal structures.

One embodiment provides a method of manufacturing a metal structure capable of improving a polishing rate while reducing damage and shape deformation of the metal structure.

Another embodiment provides a metal structure obtained by the above method.

Another embodiment provides a method of manufacturing a semiconductor device using the method of manufacturing the metal structure.

Another embodiment provides a metal wiring including the metal structure.

Another embodiment provides a semiconductor device including the metal wiring.

Another embodiment provides an electronic device including the metal wiring or the semiconductor device.

According to one embodiment, there is provided a method of manufacturing a metal structure including forming a metal layer including a metal and a nano-abrasive, and performing chemical mechanical polishing by supplying a slurry to a surface of the metal layer.

The slurry may not contain an abrasive having an average particle diameter of about 3 nm or more.

The slurry may be an abrasive-free slurry.

The slurry may contain amino acids or derivatives thereof.

The nano abrasive may include a carbon abrasive.

The carbon abrasive may include fullerene or a derivative thereof, graphene, graphite, carbon nanotubes, carbon dots, or a combination thereof.

The metal may include copper, silver, gold, aluminum, calcium, zinc, tungsten, iron, tin, platinum, nickel, or a combination thereof.

The forming of the metal layer includes preparing an electrodeposition coating solution containing a metal salt, the nano-abrasive agent, and a solvent, and disposing a substrate including a conductive layer and an opposite electrode in the electrodeposition coating solution, and between the conductive layer and the opposite electrode. It may include the step of performing electrodeposition by flowing a current in the.

The metal salt may include a copper salt, a silver salt, a gold salt, an aluminum salt, a calcium salt, a zinc salt, a tungsten salt, an iron salt, a tin salt, a platinum salt, a nickel salt, or a combination thereof.

The substrate may include an insulating layer having a plurality of trenches, and the metal structure may be filled in the trench.

According to another embodiment, there is provided a method of manufacturing a semiconductor device including forming a metal wire by the manufacturing method.

According to another embodiment, a metal structure obtained by the above method is provided.

According to another embodiment, there is provided a metal structure comprising a metal and a nano-abrasive having an average particle diameter of less than about 5 nm.

The metal may include copper, silver, gold, aluminum, calcium, zinc, tungsten, iron, tin, platinum, nickel, or a combination thereof.

The nano-abrasive may include fullerene or a derivative thereof, graphene, graphite, carbon nanotubes, carbon dots, or a combination thereof.

The average particle diameter of the nano-abrasive may be about 2 nm or less.

The specific resistance of the metal structure may be about 0.8 to 1.2 times the specific resistance of the metal.

The width of the metal structure may be about 20 nm or less.

According to yet another embodiment, a metal wiring including the metal structure is provided.

According to another embodiment, a semiconductor device including the metal wiring is provided.

According to another embodiment, an electronic device including the metal wiring or the semiconductor device is provided.

It is possible to improve the polishing rate while reducing damage and shape deformation of the metal structure.

1 to 6 are cross-sectional views sequentially showing a method of manufacturing a metal structure according to an embodiment.

Hereinafter, implementation examples will be described in detail so that those of ordinary skill in the art can easily implement them. However, the structure that is actually applied may be implemented in various different forms, and is not limited to the embodiments described herein.

In the drawings, the thicknesses are enlarged to clearly express various layers and regions. The same reference numerals are assigned to similar parts throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where there is another part in the middle. Conversely, when one part is "directly above" another part, it means that there is no other part in the middle.

Hereinafter, a method of manufacturing a metal structure according to an embodiment will be described.

The metal structure may be a pattern having a predetermined width and thickness, for example, a metal wiring having a fine line width of about 20 nm or less, about 15 nm or less, or about 10 nm or less.

1 to 6 are cross-sectional views sequentially showing a method of manufacturing a metal structure according to an embodiment.

Referring to FIG. 1, an insulating layer 20 is formed on the substrate 10.

The substrate 10 may be an insulating substrate, a metal plate, or a silicon wafer, but is not limited thereto.

The insulating layer 20 includes, for example, a siloxane-based insulating material such as tetraethylolsosilicate (TEOS), an inorganic material such as SiOF-based and SiOC-based; Organic-inorganic substances such as hydrogen-containing polysiloxane-based insulating materials and methyl-containing polysiloxane-based materials; Organic materials including polyimide, parylene, and polytetrafluoroethylene such as Teflon; It may be an air gap or the like, but is not limited thereto. The insulating layer 20 may be formed by, for example, vapor deposition such as chemical vapor deposition or a solution process such as spin coating, but is not limited thereto.

Referring to FIG. 2, a plurality of trenches 20a are formed in the insulating layer 20. The trench 20a may have a fine line width of about 20 nm or less, about 15 nm or less, or about 10 nm or less. The trench 20a may be formed by, for example, photolithography, but is not limited thereto.

Referring to FIG. 3, a conductive layer 30 is formed on the insulating layer 20. The conductive layer 30 may be formed by physical vapor deposition such as sputtering, but is not limited thereto. The conductive layer 30 may be formed to have a substantially uniform thickness along the surface of the insulating layer 20. The conductive layer 30 may be a barrier layer, a diffusion barrier layer, or an electrodeposition auxiliary layer, but is not limited thereto. The conductive layer 30 may include, for example, Ta, TaN, or a combination thereof, but is not limited thereto.

Referring to FIG. 4, a metal layer 40 is formed on the conductive layer 30. The metal layer 40 is a portion where a metal structure is to be formed, and may be filled in the plurality of trenches 20a of the insulating layer 20 and formed thereon to have a predetermined thickness.

The metal layer 40 may include a metal and an abrasive.

The metal may include, for example, a low-resistance metal, such as copper (Cu), silver (Ag), gold (Au), aluminum (Al), calcium (Ca), zinc (Zn), tungsten (W), iron ( Fe), tin (Sn), platinum (Pt), nickel (Ni), alloys thereof, or combinations thereof.

The abrasive may be a nano-abrasive with a size of several nanometers, for example a nano-abrasive with an average particle diameter of less than about 5 nm. The nano abrasive may be nano abrasive particles. The average particle diameter of the nano-abrasive is about 4 nm or less, about 3 nm or less, about 2 nm or less, about 1 nm or less, about 0.01 nm or more and less than 5 nm, about 0.01 nm to 4 nm, about 0.01 nm to 3 nm, about 0.01 nm to 2 nm within the above range. Alternatively, it may be about 0.01 nm to 1 nm.

The abrasive may be, for example, a carbon abrasive containing carbon or made of carbon, and may be, for example, a two-dimensional or three-dimensional nanoparticle made of carbon or containing carbon as a main component. The carbon abrasive may include, for example, fullerene or a derivative thereof, graphene, graphite, carbon nanotubes, carbon dots, or combinations thereof.

For example, the carbon abrasive may be fullerene or a derivative thereof. Fullerene may be, for example, C60, C70, C74, C76 or C78, but is not limited thereto.

For example, the fullerene derivative may be hydrophilic fullerene, and the hydrophilic fullerene may have a structure in which at least one hydrophilic functional group is bonded to the fullerene core. The fullerene core may be, for example, C60, C70, C74, C76 or C78, but is not limited thereto. Hydrophilic functional groups are, for example, a hydroxyl group (-OH), an amino group (-NHR ₂ , where R is hydrogen or an organic group such as a C1-C12 organic group), a carbonyl group (-C( =O)-), carboxyl group (-C(=O)OG, where G is hydrogen or counterion), sulfhydryl group (-SH) and phosphate group (- P(=O)(OH)(OR ₂ ), wherein R may be at least one selected from hydrogen or an organic group such as a C1-C12 organic group, but is not limited thereto. Hydrophilic functional groups can be, for example, hydroxyl groups.

Hydrophilic fullerene may have an average of two or more hydrophilic functional groups bound per fullerene core, for example, an average of 2 to 44 hydrophilic functional groups may be bound, for example, an average of 8 to 44 hydrophilic functional groups may be bound. , For example, an average of 12 to 44 hydrophilic functional groups may be bound, for example, an average of 24 to 44 hydrophilic functional groups may be bound, for example, an average of 24 to 40 hydrophilic functional groups may be bound, for example An average of 24 to 38 hydrophilic functional groups may be bound, for example, an average of 32 to 44 hydrophilic functional groups may be bound, for example, an average of 32 to 40 hydrophilic functional groups may be bound, such as an average of 32 Dogs to 38 hydrophilic functional groups may be bound.

For example, the hydrophilic fullerene may be fullerene hydroxide, for example, C _x (OH) _y (here, x may be 60, 70, 74, 76 or 78 and y may be 2 to 44). . Here, the average number of hydroxyl groups of the fullerene hydroxide can be confirmed by methods such as elemental analysis, thermogravimetric analysis, spectroscopic analysis, and mass spectrometry, and may be, for example, the average value of the two highest peaks in the liquid chromatography mass spectrum (LCMS).

For example, the hydrophilic fullerene may be fullerene hydroxide represented by C _x (OH) _y (here, x may be 60, 70, 74, 76 or 78 and y may be 12 to 44).

For example, the hydrophilic fullerene may be fullerene hydroxide represented by C _x (OH) _y (here, x may be 60, 70, 74, 76, or 78 and y may be 24 to 44).

For example, the hydrophilic fullerene may be fullerene hydroxide represented by C _x (OH) _y (here, x may be 60, 70, 74, 76, or 78 and y may be 32 to 44).

The metal layer 40 may be formed by, for example, a wet deposition process such as electrodeposition or electroless deposition, or a dry deposition process such as sputtering or chemical vapor deposition (CVD).

For example, the metal layer 40 may be formed by electrodeposition, for example, preparing an electrodeposition coating solution, and disposing the substrate 10 and the counter electrode in the electrodeposition coating solution, and the conductive layer 30 It can be formed by the step of performing electrodeposition by flowing a current between the and the opposite electrode.

The electrodeposition coating solution may include a metal salt that is a precursor of the metal described above and the aforementioned abrasive. The metal salt is a compound consisting of a metal cation and an anion, and may be a metal salt that can be reduced to a low-resistance metal, such as copper salt, silver salt, gold salt, aluminum salt, calcium salt, zinc salt, tungsten salt, iron salt, tin salt, Platinum salts, nickel salts, or combinations thereof. The metal salt may be a copper salt such as Cu(II), for example, copper sulfate (CuSO ₄ ·5H ₂ O), copper acetate (Cu(CH ₃ COO) ₂ ·H ₂ O), copper nitrate (Cu(NO ₃ ) ₂ ), copper formate (Cu(HCOO) ₂ ), copper chloride (CuCl ₂ ·H ₂ O), copper cyanide (CuCN), or a combination thereof, but is not limited thereto.

The metal salt may be included in an amount that provides sufficient metal cations to perform electrodeposition, for example, about 0.05 to 1% by weight based on the electrodeposition coating solution. It may be included as about 0.07 to 0.8% by weight within the above range, it may be included as about 0.1 to 0.5% by weight within the above range, and may be included as about 0.1 to 0.3% by weight within the above range.

As described above, the abrasive may be a nano abrasive and may be a carbon abrasive. Details are as described above.

The abrasive may be included in an amount of about 10 to 100 parts by weight based on 100 parts by weight of the metal salt. It may be included in about 15 to 100 parts by weight within the above range, it may be included in about 15 to 80 parts by weight within the range, it may be included in about 15 to 70 parts by weight within the above range, and about 15 to 60 parts by weight within the above range It may be included and may be included in about 15 to 50 parts by weight within the above range, it may be included in about 15 to 40 parts by weight within the above range, and may be included in about 15 to 30 parts by weight within the above range.

The electrodeposition coating solution may further include a metal-polishing agent composite. The metal-polishing agent complex may be a reaction product of the metal cation of the metal salt and the aforementioned abrasive, and may be chemically bonded between the metal cation of the metal salt and the abrasive. The metal-polishing agent composite may be formed by a spontaneous reaction in an electrodeposition coating solution, for example at room temperature (about 25° C.).

The electrodeposition coating solution may further contain an acid. The acid may be, for example, at least one selected from sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl), acetic acid (CH ₃ COOH), fluoroboric acid (HBF ₄ ), alkylsulfonic acid, arylsulfonic acid, and phosphoric acid, but is not limited thereto. .

The acid may be included in an amount of about 0.01 to 10% by weight based on the electrodeposition coating solution. It may be included as about 0.01 to 8% by weight within the above range, it may be included as about 0.01 to 7% by weight within the above range, it may be included as about 0.01 to 5% by weight within the above range, and about within the above range It may be included in 0.01 to 3% by weight.

The electrodeposition coating solution may further contain, for example, a leveler, a suppressor, a catalyst, a brightner, a reducing agent and/or various additives.

Leveling agents are polyethylene imine and derivatives thereof, quaternized polyethylene imine, polyglycine, poly(allylamine), polyaniline, polyurea, polyacrylamide, poly(melamine-co-formaldehyde), amine and epichlorohydrin. Reaction product, reaction product of amine, epichlorohydrin and polyalkylene oxide, reaction product of amine and polyepoxide, polyvinylpyridine, polyvinylimidazole, polyvinylpyrrolidone or a copolymer thereof, nigrosine , Pentamethyl-para-losaniline halide, hexamethyl-pararosaniline halide, trialkanolamine and derivatives thereof, or formula NRS (wherein R is a substituted alkyl, unsubstituted alkyl, substituted aryl or unsubstituted It may include at least one of the compounds having a functional group of (are aryl), but is not limited thereto.

The inhibitor may be, for example, a polymer material, and may be, for example, a polyethylene glycol copolymer and/or a polyethylene glycol polypropylene glycol copolymer, but is not limited thereto.

The accelerator may include a sulfur-containing compound, a sulfonic acid, a phosphonic acid, or a salt thereof, but is not limited thereto.

Each of the above components may be independently included in trace amounts of, for example, about 1 ppm to 100,000 ppm.

The electrodeposition coating solution may further include a solvent capable of dissolving or dispersing the above-described components, and the solvent may be water, for example. The water can be any water, such as distilled and/or deionized water.

The electrodeposition coating solution may be acidic, for example a strong acidity of pH 3.5 or less. The electrodeposition coating solution may be, for example, a pH of 3.0 or less, for example, a pH of 2.5 or less, and, for example, a pH of 2.0 or less.

Electrodeposition may be performed by disposing the substrate 10 on which the conductive layer 30 is formed and the counter electrode in the electrodeposition coating solution described above, and passing a current between the conductive layer 30 and the counter electrode. At this time, the current density may be about 0.1 to 1.0A/m2, but is not limited thereto.

At this time, the nano-abrasive agent having an average particle diameter of several nanometers effectively enters the trench 20a having a fine width of about 20 nm or less, about 15 nm or less, or about 10 nm or less and effectively fills the trench 20a, thereby having a metal structure having a fine line width. Can be formed effectively.

A metal layer 40 of a predetermined thickness is formed by electrodeposition. As described above, the metal layer 40 may include a metal derived from a metal salt and an abrasive, and the metal and the abrasive may be mixed. The metal layer 40 may optionally further include a metal-polishing agent composite.

The metal layer 40 includes an abrasive having an average particle diameter of several nanometers, so that electromigration can be effectively suppressed compared to a pure metal (not including an abrasive). Electromigration refers to a phenomenon in which metal atoms diffuse in one direction according to the movement of electrons, and may cause voids and short circuits in wiring. While not intending to be bound by any particular theory, abrasives with a size of several nanometers inhibit the migration of metal atoms by causing relatively strong electronic interactions with metals, while abrasives with a stable structure can produce heat or current. It can be understood that it is possible to suppress the electro-migration by reducing the vibration of metal atoms by absorbing the vibration energy generated by

The metal layer 40 may include an abrasive having an average particle diameter of several nanometers, thereby increasing the allowable ampacity of the metal layer 40. The allowable current capacity indicates a maximum current-carrying capacity, and the metal layer 40 may mean that the metal layer 40 has a higher current carrying capacity compared to a pure metal (not including an abrasive). The allowable current capacity of the metal layer 40 may be, for example, about 1.5 times or more higher than the allowable current capacity of pure metal (not including a polishing agent), and for example, about 2 times or more, about 3 times or more, about 4 times or more, about 1.5 times To 20 times, about 2 to 20 times, about 3 to 20 times, or about 4 to 30 times higher.

The abrasive having an average particle diameter of several nanometers included in the metal layer 40 may not deteriorate the electrical properties of the metal layer 40. For example, the resistivity of the metal layer 40 may be equal to or lower than that of a pure metal (not including an abrasive), and, for example, the resistivity of the metal layer 40 may be that of a pure metal (without an abrasive). Compared with, it may be about 0.8 to 1.2 times.

When the metal layer 40 contains an abrasive having an average particle diameter of several nanometers, it can effectively enter the trench 20a having a fine line width and fill the trench 20a during electrodeposition. Accordingly, a metal structure having a fine line width without voids can be effectively formed, and thus, it can be effectively applied to form a fine wiring without voids.

Referring to FIG. 5, the metal structure 40a is formed by flattening the surface of the metal layer 40 to match the surface of the insulating layer 20. The metal structure 40a may be a metal layer buried in the trench 20a.

Planarization may be performed by chemical mechanical polishing (CMP). In the chemical mechanical polishing, after supplying a slurry between the metal layer 40 and the polishing pad, the metal layer 40 and the polishing pad are contacted and rotated to flatten the surface of the substrate by pressing and rotating.

The slurry may chemically and mechanically polish the surface of the metal layer 40 by contacting the metal layer 40, and, for example, chemical polishing may predominate. The slurry may be polished by chemically adsorbing or dissolving the metal of the metal layer 40, and the surface of the metal layer 40 may be effectively removed by the abrasive included in the metal layer 40.

As described above, since the metal layer 40 to be polished contains an abrasive, the slurry may not contain an abrasive having a predetermined size or more. Accordingly, it is possible to reduce or prevent damage to the metal layer 40 such as scratches, dishing, and/or erosion caused by the large abrasive contained in the slurry. For example, the slurry may not include an abrasive having an average particle diameter of about 10 nm or more, and for example, may not include an abrasive having an average particle diameter of about 10 nm to 100 nm. For example, the slurry may not include an abrasive having an average particle diameter of about 5 nm or more, for example, may not include an abrasive having an average particle diameter of about 5 nm to 100 nm. For example, the slurry may not include an abrasive having an average particle diameter of about 3 nm or more, for example, may not include an abrasive having an average particle diameter of about 3 nm to 100 nm. For example, the slurry may not include an abrasive having an average particle diameter of about 2 nm or more, for example, may not include an abrasive having an average particle diameter of about 2 nm to 100 nm. For example, the slurry may not include an abrasive having an average particle diameter of about 1 nm or more, for example, may not include an abrasive having an average particle diameter of about 1 nm to 100 nm. For example, the slurry may not include an abrasive having an average particle diameter of about 0.7 nm or more, for example, may not contain an abrasive having an average particle diameter of about 0.7 nm to 100 nm. For example, the slurry may not contain metal oxides and/or metalloid oxides, and may not contain silica, alumina, germania, titania, ceria and/or zirconium oxide.

For example, the slurry may be an abrasive-free slurry that does not contain an abrasive.

The slurry may contain amino acids or derivatives thereof. Since amino acids have amino and carboxyl groups, they can be effectively adsorbed to metals or dissolved metals effectively. Amino acids or derivatives thereof include, for example, glycine, lysine, glutamine, alanine, betaalanine, iminoacetic acid, asparagine, aspartic acid. , Bicine, tricine, proline, valine, saracosine, or a combination thereof, but is not limited thereto. For example, the slurry may include two or more amino acids or derivatives thereof, for example, glycine as an essential component and amino acids other than glycine or derivatives thereof may be included together. Amino acids or derivatives thereof may be included in an amount of about 0.01 to 20% by weight based on the total content of the slurry (including solvent), and within the above range, about 0.01 to 16% by weight, about 0.01 to 10% by weight, about 0.01 to 8% by weight , About 0.05 to 5% by weight, about 0.1 to 3% by weight, or about 0.2 to 2% by weight.

The slurry may further contain an antioxidant. The antioxidant may be, for example, a nitrogen-containing compound, such as triazole, benzotriazole, methylbenzotriazole, hydroxybenzotriazole, benzoimidazole, benzothiazole, triazinethiol, triazinedithiol, triazinetriol Or a combination thereof. Antioxidants may be included in an amount of 0.1 to 20,000 ppm by weight based on the total content (including solvent) of the slurry, and within the above range, about 20 to 10,000 ppm by weight, and about 50 to 1,000 ppm by weight. .

The slurry may further contain an oxidizing agent. The oxidizing agent may be, for example, hydrogen peroxide, a permanganic acid compound, ammonium persulfate, sodium persulfate, perbenzoic acid, peracetic acid, sodium hydroxide, potassium hydroxide, or a combination thereof, but is not limited thereto. The oxidizing agent is, for example, about 0.001 to 10% by weight, such as about 0.001 to 5% by weight, such as about 0.001 to 4% by weight, such as about 0.001 to 3% by weight, or about 0.001 to 1% by weight, based on the total content of the slurry (including solvent). It can be included in %.

The slurry may further include an additive, and the additive may be, for example, a chelating agent, a surfactant, a dispersing agent, a pH adjusting agent, or a combination thereof, but is not limited thereto.

The chelating agent may be, for example, oxalic acid, malonic acid, succinic acid, maleic acid, phthalic acid, tartaric acid, aspartic acid, glutamic acid, citric acid, aminocarboxylic acid, phosphoric acid, polyphosphoric acid, nitric acid, phosphonic acid, salts thereof, or combinations thereof. However, it is not limited thereto.

The surfactant may be an ionic or nonionic surfactant, for example, a copolymer of ethylene oxide, a copolymer of propylene oxide, an amine compound, or a combination thereof, but is not limited thereto.

Dispersants are, for example, poly(meth)acrylic acid, poly(meth)acrylic maleic acid, polyacrylonitrile-co-butadiene-acrylic acid, carboxylic acid, sulfonic ester, sulfonic acid, phosphoric ester, cellulose, diol, salts thereof, or It may be selected from a combination of these, but is not limited thereto.

The pH adjusting agent may adjust the pH of the polishing slurry, and may be, for example, an inorganic acid, an organic acid, a salt thereof, or a combination thereof. Inorganic acids may include, for example, nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, bromic acid, iodic acid or salts thereof, and organic acids may include, for example, formic acid, malonic acid, maleic acid, oxalic acid, adipic acid, citric acid, acetic acid, propionic acid, Fumaric acid, lactic acid, salicylic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid or salts thereof may be included, but are not limited thereto.

Each additive may be independently included, for example, in a trace amount of about 1 ppm to 100,000 ppm, but is not limited thereto.

The slurry may further include a solvent capable of dissolving or dispersing the above-described components, and the solvent may be water, for example. The water may be distilled and/or deionized water, for example. The pH of the slurry may be 1 to 12.

The slurry may be supplied on the polishing pad, and chemical mechanical polishing may be performed by bringing the surface of the metal layer 40 into contact with the polishing pad and rotating. In the step of performing the polishing, a predetermined pressure may be applied, for example, a pressure of about 1 psi to 5 psi, about 1.2 psi to 3 psi, about 1.3 psi to 3 psi, about 2 psi to 2 psi, or about 1.3 psi to 2.3 psi may be applied. have.

Chemical mechanical polishing may be carried out, for example, in three steps, the first is to remove the upper portion of the metal layer 40, that is, the bulk metal having a predetermined thickness, and the second is to remove the predetermined thickness remaining on the conductive layer 30. It is a step of removing the metal in detail, and the third is a step of removing the conductive layer 30. The first step may be performed at a relatively high pressure and at a high polishing rate, for example, at a pressure of about 2.5 psi or higher and at a polishing rate of about 6000 Å/min. The second and/or third step may be performed at a relatively low pressure and at a low polishing rate, for example, at a pressure of about 1.5 psi or less and at a polishing rate of about 3000-4000 Å/min.

Referring to FIG. 6, a capping layer 50 is formed on the metal structure 40a and the insulating layer 20. The capping layer 50 may include SiN and/or SiC, but is not limited thereto. The capping layer 50 may be omitted.

The metal structure 40a obtained according to the above-described method may be, for example, a metal wire, and may be a fine metal wire having a fine pitch of about 20 nm or less, about 15 nm or less, or about 10 nm or less, for example, a fine metal having a fine line width without voids. It can be wiring. The above-described method may be used when forming various devices including the metal structure 40a, and, for example, may be effectively used as a method of forming metal wiring when manufacturing a semiconductor device.

Metal wiring may be included in various semiconductor devices. Metal wiring and/or semiconductor devices may be included in various electronic devices, and may be included in semiconductor devices or display devices.

The above-described implementation examples will be described in more detail through the following examples. However, the following examples are for illustrative purposes only and do not limit the scope of the rights.

Synthesis example

Fullerene hydroxide precursor (C ₆₀ (OH) _{6 ~ 12} , Nanom Spectra D100, Frontier Carbon Co., Ltd.) 10g was dispersed in 30% hydrogen peroxide solution and stirred in a flask at 60°C for 48 hours to obtain expensive fullerene hydroxide (C ₆₀ (OH) _24-36 , Peak: C ₆₀ (OH) ₃₁ ) is synthesized. The average particle diameter of fullerene hydroxide measured by the dynamic light scattering method (SUPTEX) is about 1 nm.

Preparation of electrodeposition coating solution

Preparation Example 1 and Comparative Preparation Example 1

Prepare the electrodeposition coating solution as described in Table 1. When preparing the electrodeposition coating solution, fullerene hydroxide obtained in the above synthesis example was used as a nano abrasive. Components except for fullerene hydroxide and H ₂ SO ₄ are first mixed, and then fullerene hydroxide and H ₂ SO ₄ are mixed.

Preparation Example 1 (g/L) Comparative Production Example 1 (g/L) Fullerene hydroxide 20 - Polyacrylic acid One One CuSO ₄ 5H ₂ O 60 60 H ₂ SO ₄ handful 182 NaCl 0.08 0.08 SPS 0.002 0.002 JGB 0.01 0.01

* Polyacrylic acid: Wako Pure Chemical Industries, Ltd.

* CuSO ₄ 5H ₂ O: Kanto Chemical co., Inc.

* SPS: 3,3'-dithiobis (1-propanesulfonic acid) disodium: Tokyo Chemical Industry Co., Ltd.

* JGB: Janus Green B: Tokyo Chemical Industry Co., Ltd.

* pH: 0.0 ~ 2.0 (pH Meter SP-2100, SUPTEX)

Preparation of slurry

Manufacturing Example 2

A slurry was prepared by mixing 0.06% by weight of benzotriazole, 0.04% by weight of ammonium dihydrogenphosphate, 0.5% by weight of triammonium citrate, 1.6% by weight of H ₂ O ₂ and the remaining amount of water. To manufacture.

Manufacturing Example 3

A slurry was prepared by mixing 0.02% by weight of 1,2,4-triazole, 1.0% by weight of H ₂ O ₂ , 0.6% by weight of glycine, and the balance with water.

Manufacturing Example 4

1,2,4-triazole (1,2,4-triazole) 0.02% by weight, H ₂ O ₂ 1.0% by weight, glycine 0.6% by weight, bicine (bicine) 0.2% by weight and the balance by mixing water to prepare a slurry To manufacture.

Manufacturing Example 5

Prepare a slurry containing 0.1% by weight of fullerene hydroxide, 0.06% by weight of benzotriazole, 0.4% by weight of ammonium dihydrogen phosphate, 0.5% by weight of triammonium citrate, 1.6% by weight of H ₂ O ₂ and the balance of water do.

Comparative Production Example 2

Silica (PL-1 with a primary particle diameter of 15 nm, FUSO CHEMICAL) 1% by weight, benzotriazole 0.06% by weight, ammonium dihydrogen phosphate 0.4% by weight, triammonium citrate 0.5% by weight, H ₂ O ₂ 1.6% by weight and the balance To prepare a slurry containing water.

Example

Example 1

As an evaluation sample, an MIT854 patterned silicon wafer in which TEOS and Cu layers were formed was used, and a Ta/TaN conductive layer was formed thereon. Subsequently, in the electrodeposition coating solution according to Preparation Example 1, the Ta/TaN conductive layer of the silicon wafer (cathode) and the counter electrode (anode) were disposed to face each other, and power was connected to the anode and the cathode to obtain various average current densities (0.1A/dm). Electrodeposition is performed for 45 minutes by passing a current at ² to 1.0 A/dm ² ) to form a Cu layer having a thickness of about 1 μm.

Subsequently, a chemical mechanical polishing apparatus (MirraR, Applied Material) was used and the slurry according to Preparation Example 2 was supplied to perform chemical mechanical polishing for 60 seconds under 1.5psi pressure to form a Cu structure.

Example 2

A Cu structure was formed in the same manner as in Example 1, except that the slurry according to Preparation Example 3 was used instead of the slurry according to Preparation Example 2.

Example 3

A Cu structure was formed in the same manner as in Example 1, except that the slurry according to Preparation Example 4 was used instead of the slurry according to Preparation Example 2.

Example 4

A Cu structure was formed in the same manner as in Example 1, except that the slurry according to Preparation Example 5 was used instead of the slurry according to Preparation Example 2.

Comparative Example 1

A Cu structure was formed in the same manner as in Example 1, except that the slurry according to Comparative Preparation Example 2 was used instead of the slurry according to Preparation Example 2.

Comparative Example 2

A Cu structure was formed in the same manner as in Example 1, except that the electrodeposition coating solution according to Comparative Preparation Example 1 was used instead of the electrodeposition coating solution according to Preparation Example 1.

Comparative Example 3

The Cu structure was prepared in the same manner as in Example 1, except that the electrodeposition coating solution according to Comparative Preparation Example 1 was used instead of the electrodeposition coating solution according to Preparation Example 1, and the slurry according to Comparative Preparation Example 2 was used instead of the slurry according to Preparation Example 2. To form.

Comparative Example 4

A Cu structure was formed in the same manner as in Example 1, except that the electrodeposition coating solution according to Comparative Preparation Example 1 was used instead of the electrodeposition coating solution according to Preparation Example 1, and the slurry according to Preparation Example 3 was used instead of the slurry according to Preparation Example 2 do.

Comparative Example 5

A Cu structure was formed in the same manner as in Example 1, except that the electrodeposition coating solution according to Comparative Preparation Example 1 was used instead of the electrodeposition coating solution according to Preparation Example 1, and the slurry according to Preparation Example 4 was used instead of the slurry according to Preparation Example 2 do.

Evaluation I

Electrical properties of the Cu structures obtained in Examples and Comparative Examples were evaluated.

Electrical characteristics are evaluated by resistivity and ampacity. The allowable current capacity is defined as the amount of current at which resistance starts to increase after there is no change in resistance due to current increase, and is the current capacity that increases monotonically while the resistivity (Dr/r0) is greater than 1.

The results are shown in Table 2.

Resistivity (nΩ·m) Allowable current capacity (MA/㎠) Example 1 17 28 Example 2 17 28 Example 3 17 28 Example 4 17 28 Comparative Example 1 17 28 Comparative Example 2 20 6 Comparative Example 3 20 6 Comparative Example 4 20 6 Comparative Example 5 20 6

Referring to Table 2, it can be seen that the Cu structures obtained in Examples 1 to 4 exhibit improved electrical properties compared to the Cu structures obtained in Comparative Examples 2 to 5. From this, it can be seen that the Cu structure obtained by using the electrodeposition coating solution obtained in Preparation Example 1 exhibits improved electrical properties compared to the Cu structure obtained by using the electrodeposition coating solution obtained in Comparative Preparation Example 1.

Evaluation II

The polishing properties of the Cu structures obtained in Examples and Comparative Examples and whether they are damaged after polishing were evaluated.

Polishing properties are evaluated from the material removal rate (MRR).

The polishing rate is calculated by converting the thickness of the tungsten film before and after polishing from the sheet resistance and converting the speed.

Whether the Cu structure is damaged after polishing is evaluated from the degree of scratch, dishing, and erosion of the Cu structure.

The results are shown in Table 3.

Polishing speed (Å/min) Scratch(ea/wf) Indentation (Å) Corrosion (Å) Example 1 4500 0 150 <100 Example 2 5200 0 90 <100 Example 3 5500 0 70 <100 Example 4 4800 3 260 <100 Comparative Example 1 4500 12 660 530 Comparative Example 2 <1000 - - - Comparative Example 3 3800 14 620 470 Comparative Example 4 <1000 - - - Comparative Example 5 <1000 - - -

Referring to Table 3, it can be seen that the Cu structures obtained in Examples 1 to 4 show an equivalent or improved polishing rate with less damage and shape deformation compared to the Cu structures obtained in Comparative Examples 1 to 5.

When summarized in Tables 2 and 3, the Cu structure obtained in the Example has improved electrical properties and an equivalent or improved polishing rate compared to the Cu structure obtained in the Comparative Example, while reducing defects due to damage and shape deformation after polishing. You can see that you can. From this, it can be seen that a void-free fine metal structure with improved performance can be formed according to the electrodeposition coating solution used in the electrodeposition step and the slurry used in the polishing step when forming the metal structure.

Although the embodiments have been described in detail above, the scope of the rights is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept defined in the following claims also belong to the scope of the rights.

10: substrate
20: insulating layer
20a: trench
30: conductive layer
40: metal layer
40a: metal structure
50: capping layer

Claims (20)

Forming a metal layer comprising a metal and a nano-abrasive of less than 5 nm, and
Supplying a slurry to the surface of the metal layer to perform chemical mechanical polishing
Method of manufacturing a metal structure comprising a.
In claim 1,
The slurry is a method of manufacturing a metal structure that does not contain an abrasive having an average particle diameter of 3 nm or more.
In claim 1,
The slurry is an abrasive-free slurry.
In claim 1,
The slurry is a method of manufacturing a metal structure containing an amino acid or a derivative thereof.
In claim 1,
The nano-abrasive is a method of manufacturing a metal structure comprising a carbon abrasive.
In clause 5,
The carbon abrasive is a method of manufacturing a metal structure including fullerene or a derivative thereof, graphene, graphite, carbon nanotubes, carbon dots, or a combination thereof.
In claim 1,
The metal is a method of manufacturing a metal structure comprising copper, silver, gold, aluminum, calcium, zinc, tungsten, iron, tin, platinum, nickel, or a combination thereof.
In claim 1,
The step of forming the metal layer
Preparing an electrodeposition coating solution containing a metal salt, the nano-abrasive and a solvent, and
Disposing a substrate including a conductive layer and an opposite electrode in the electrodeposition coating solution, and performing electrodeposition by flowing a current between the conductive layer and the opposite electrode
Method of manufacturing a metal structure comprising a.
In clause 8,
The metal salt is a method of manufacturing a metal structure comprising a copper salt, a silver salt, a gold salt, an aluminum salt, a calcium salt, a zinc salt, a tungsten salt, an iron salt, a tin salt, a platinum salt, a nickel salt, or a combination thereof.
A method of manufacturing a semiconductor device comprising the step of forming a metal wiring by the manufacturing method according to any one of claims 1 to 9.
A metal structure obtained by the method according to any one of claims 1 to 9.
Metal structures comprising a metal and a nano-abrasive having an average particle diameter of less than 5 nm.
In claim 12,
The metal is a metal structure comprising copper, silver, gold, aluminum, calcium, zinc, tungsten, iron, tin, platinum, nickel, or a combination thereof.
In claim 12,
The nano-abrasive agent is a metal structure comprising fullerene or a derivative thereof, graphene, graphite, carbon nanotubes, carbon dots, or a combination thereof.
In claim 12,
The average particle diameter of the nano-abrasive is a metal structure of 2 nm or less.
In claim 12,
The specific resistance of the metal structure is 0.8 to 1.2 times the specific resistance of the metal.
In claim 12,
The metal structure has a width of 20 nm or less.
Metal wiring comprising the metal structure according to claim 12.
A semiconductor device comprising the metal wiring according to claim 18.
An electronic device comprising the metal wiring according to claim 18 or the semiconductor device according to claim 19.

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