JP2008078577A - Substrate processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method capable of giving a high quality-polished surface where a metal layer is efficiently removed and the generation of defects in polishing such as a metal residue, dishing, and erosion are suppressed in manufacturing a semiconductor device formed of wiring materials such as metals of copper, copper alloy and the like. <P>SOLUTION: The method for processing a semiconductor substrate includes a first processing step for polishing the metal layer on a barrier layer, a second processing step for oxidizing the metal layer left on the insulating layer by supplying an oxidizing processing liquid after the first processing step, and a third processing step for polishing the oxidized metal layer with a chemical/mechanical water system dispersing element after the second processing step. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate processing method for manufacturing a semiconductor device.

  In recent years, with the increase in the density of semiconductor devices, the miniaturization of wirings formed in the semiconductor devices has progressed. As a technique that can achieve further miniaturization of the wiring, a technique called a damascene method is known. This method forms a desired wiring by embedding a wiring material in a groove or the like formed in an insulating layer and then using chemical mechanical polishing to remove excess wiring material deposited other than the groove. It is. Here, when using copper or copper alloy as the wiring material, in order to avoid migration of copper atoms into the insulating layer, tantalum, tantalum nitride, titanium nitride, etc. are usually used at the interface between the copper or copper alloy and the insulating layer. A high-strength, high-dielectric-constant insulating layer (barrier layer) is formed as a material.

  In the manufacture of a semiconductor device using copper or a copper alloy as a wiring material, when the damascene method is adopted, there are various chemical mechanical polishing methods, but a first polishing step for mainly removing copper or a copper alloy, and a barrier mainly. A two-stage chemical mechanical polishing is performed which comprises a second polishing step for removing the layer.

  By the way, in the polishing step, the wiring portion may be concavely shaped due to excessive polishing of the wiring portion. Such a concave wiring shape is called “dishing” or “erosion” and is not preferable because it reduces the yield of semiconductor device manufacturing.

  Various chemical mechanical polishing aqueous dispersions have been proposed in order to suppress the occurrence of “dishing” and “erosion”, improve the surface flatness of the surface to be polished, and increase the yield of semiconductor device manufacturing.

  For example, Patent Document 1 discloses that a chemical mechanical polishing aqueous dispersion containing an abrasive, water, and an iron compound has an effect of suppressing the occurrence of “dishing”.

  In Patent Document 2, an aqueous dispersion for chemical mechanical polishing containing an abrasive, α-alanine, hydrogen peroxide and water has an effect of suppressing the occurrence of “dishing” and “erosion” and has excellent smoothness. It is disclosed that a polished surface can be obtained.

  In Patent Document 3, when a surfactant is further added to the chemical mechanical polishing aqueous dispersion containing an aqueous medium, an abrasive, an oxidizing agent, and an organic acid, a polished surface with excellent smoothness can be obtained. It is disclosed.

  On the other hand, there is a case where metal remains on the surface to be polished, particularly the fine wiring, and the wiring portion has a convex shape so as to suppress the occurrence of “dishing” and “erosion”. Such a convex surface defect is often observed particularly when the wiring material is copper, and is called “copper residue”. If "copper residue" occurs, the yield of semiconductor devices will be greatly reduced, such as leakage current between the wires, and the depth of focus when the layers are multi-layered. It becomes a big problem toward miniaturization.

  In order to suppress the occurrence of this “copper residue”, an oxidizing agent and abrasive grains are generally added to the chemical mechanical polishing aqueous dispersion. The mechanism of chemical mechanical polishing by this chemical mechanical polishing aqueous dispersion is considered to first oxidize the surface of a copper or copper alloy layer with an oxidizing agent and scrape the layer with abrasive grains.

However, in the actual chemical polishing treatment process, “copper residue” tends to occur in the fine wiring portion, and “dishing” and “erosion” tend to easily occur in the wide wiring portion. It is necessary to simultaneously suppress the occurrence of “dishing” and “erosion”.
JP-A-10-163141 JP 2000-160141 A JP 10-44047 A

  An object of the present invention is to efficiently remove a metal layer and suppress the occurrence of polishing defects such as metal residue, dishing, and erosion in the manufacture of a semiconductor device using a metal such as copper or copper alloy as a wiring material. An object of the present invention is to provide a substrate processing method capable of providing a high-quality polished surface.

  A method for treating a semiconductor substrate according to the present invention includes a chemical mechanical polishing aqueous dispersion provided on an insulating layer having a recess via a barrier layer and a target object having a metal layer embedded in the recess. A first treatment step for polishing the metal layer on the barrier layer and supplying an oxidizing treatment liquid to the metal layer on the insulating layer after the first treatment step. And a third treatment step of polishing the oxidized metal layer using a chemical mechanical polishing aqueous dispersion after the second treatment step.

  After the first processing step, the metal layer on the barrier layer may remain entirely on the barrier layer.

  After the first processing step, the metal layer on the barrier layer may partially remain on the barrier layer.

  After the first processing step, the metal layer on the barrier layer may have a thickness of 500 nm or less.

  After the first processing step, the metal layer on the barrier layer may have a thickness of 200 nm or less.

  The metal layer may be a layer made of copper or a copper alloy.

  The oxidizing treatment liquid may contain (A) an oxidizing agent and (B) water.

  The oxidizing agent (A) is at least selected from hydrogen peroxide, organic peroxide, permanganic acid compound, dichromic acid compound, halogen acid compound, nitric acid compound, perhalogen acid compound, persulfate and heteropolyacid. One can be included.

  The concentration of the oxidizing agent may be 0.01 to 10% by mass.

  The chemical mechanical polishing aqueous dispersion may contain (C) abrasive grains, (D) a compound having a heterocyclic ring, (E) a polishing rate improver, and (F) an oxidizing agent.

  The said (C) abrasive grain can contain at least 1 sort (s) chosen from an inorganic particle, an organic particle, and an organic inorganic composite particle.

  The compound (D) having a heterocyclic ring can be an organic compound having at least one heterocyclic ring selected from a heterocyclic 5-membered ring and a heterocyclic 6-membered ring having at least one nitrogen atom.

  The (E) polishing rate improver may include at least one selected from amino acids, aminopolycarboxylic acids, amine compounds, and amino alcohols.

  The (F) oxidizing agent is at least selected from hydrogen peroxide, organic peroxides, permanganic acid compounds, dichromic acid compounds, halogen acid compounds, nitric acid compounds, perhalogen acid compounds, persulfates and heteropolyacids. One can be included.

  The oxidizing agent (A) contained in the oxidizing treatment liquid and the oxidizing agent (F) contained in the chemical mechanical polishing aqueous dispersion may be the same type.

  The substrate processing method according to the present invention includes first to third processing steps. It is the substrate processing according to the present invention that the second processing step of oxidizing the metal layer remaining on the barrier layer with the oxidizing processing liquid is independently provided between the first and third processing steps. Characteristic of the method.

  When the substrate processing method according to the present invention is used, in manufacturing a semiconductor device using a metal such as copper or a copper alloy as a wiring material, the metal layer remaining on the barrier layer is uniformly oxidized by the oxidizing processing liquid. Therefore, the remaining metal layer is efficiently and reliably removed by the third (polishing) treatment step. As a result, according to the substrate processing method of the present invention, it is possible to obtain a high-quality polished surface with no metal residue and suppressed dishing and erosion.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. First Embodiment FIGS. 1A to 1D are cross-sectional views showing a specific example of a semiconductor substrate processing method according to the present invention. The first embodiment will be described below with reference to FIGS. 1A to 1D.

1.1 Object to be processed The object to be processed according to the present invention includes, for example, an object to be processed 100 having a region 22 containing a lot of fine wiring and a region 24 containing a wide wiring as shown in FIG. Can do.

  The target object 100 includes a substrate 10 as shown in FIG. The base 10 has at least a semiconductor substrate (not shown). The base 10 may be composed of, for example, a silicon substrate and a silicon oxide film formed thereon. Furthermore, a functional device such as a transistor may be formed on the semiconductor substrate of the base 10.

  The object to be processed 100 is a barrier provided on the substrate 10 so as to cover the insulating layer 12 in which the wiring recesses 20 such as grooves are formed, the surface of the insulating layer 12, and the bottom and inner wall surfaces of the wiring recesses 20. The metal layer 16 filling the layer 14 and the wiring recess 20 and formed on the barrier layer 14 is sequentially laminated.

  The insulating layer 12 is obtained by, for example, a silicon oxide layer (for example, a PETEOS layer (Plasma Enhanced-TEOS layer), an HDP layer (High Density Plasma Enhanced-TEOS layer)) formed by a vacuum process, or a thermal chemical vapor deposition method. Examples include an insulating layer called silicon oxide layer (FSG), an insulating layer called Fluorine-doped silicate glass (FSG), a boron phosphorus silicate layer (BPSG layer), an insulating layer called SiON (Silicon oxynitride), an insulating layer having a low dielectric constant, and the like. Can do.

  The barrier layer 14 is made of, for example, tantalum, tantalum nitride, titanium, titanium nitride, tantalum-niobium alloy, or the like.

  Examples of the metal layer 16 may include tungsten, aluminum, copper, and alloys containing these. Among these, the effect of the present invention is most effectively exhibited when copper or an alloy containing copper is used as the wiring material. The copper content in the alloy containing copper is preferably 95% by mass.

  As shown in FIG. 1A, the region 22 containing a large amount of fine wiring is likely to be a convex portion when the metal layer 16 forms a layer on the barrier layer 14, and therefore an aqueous dispersion for chemical mechanical polishing is used. Even after polishing, there is a tendency for metal residue to be easily generated. On the other hand, as shown in FIG. 1A, the region 24 including the wide wiring is likely to be a concave portion when the metal layer 16 forms a layer on the barrier layer 14, so that an aqueous dispersion for chemical mechanical polishing is used. Polishing tends to cause dishing and erosion.

1.2 Processing Method 1.2.1 First Step The substrate processing method in the first embodiment (hereinafter also simply referred to as “processing method”) is a method in which a chemical mechanical polishing aqueous dispersion is placed on a polishing platen. A first step of supplying and polishing to a state where the metal layer 16 remains on the barrier layer 14 is included.

  The first step is a step of removing a part of the metal layer 16 deposited on the barrier layer 14.

  In the first embodiment, as shown in FIG. 1B, the metal layer 16 remaining on the barrier layer 14 after the first processing step remains entirely on the barrier layer 14. It is.

  As shown in FIG. 1B, the timing of ending the first step is preferably when the thickness of the metal layer 16 to be removed by chemical mechanical polishing becomes 500 nm or less, more preferably This is when it becomes 200 nm or less. When the metal layer 16 includes a portion having a thickness of 500 nm or more, the surface of the metal layer 16, a part of the metal layer 16 or the entire layer may not be sufficiently oxidized even if the second step is performed. .

  The chemical mechanical polishing aqueous dispersion used in the first step can contain (C) abrasive grains, (D) a compound having a heterocyclic ring, (E) a polishing rate improver, and (F) an oxidizing agent. The chemical mechanical polishing aqueous dispersion is particularly effective in suppressing dishing and erosion, and is preferably used in the present invention. The chemical mechanical polishing dispersion will be described in detail later.

  Polishing in the first step can be performed using a commercially available chemical mechanical polishing apparatus (for example, Mirra (manufactured by Applied Materials)) under known polishing conditions.

  When Mirra (Applied Materials) is used, for example, the following conditions can be used.

  The platen rotational speed is preferably 30 to 150 rpm, more preferably 30 to 130 rpm.

  The head rotation speed is preferably 30 to 150 rpm, more preferably 30 to 130 rpm.

  The polishing pressure is preferably 0.5 to 5 psi (3.4 to 34.5 kPa), and more preferably 1 to 3 psi (6.9 to 20.7 kPa).

  The chemical mechanical polishing aqueous dispersion supply rate is preferably 50 to 300 mL / min, and more preferably 100 to 200 mL / min.

1.2.2 Second Process The processing method according to the first embodiment is a second process in which an oxidizing processing liquid is supplied onto a polishing platen to process a surface to be polished after the first processing process. Process. After the metal layer 16 of the workpiece 100 is polished to a desired thickness in the first step, the second step is performed, whereby a surface or a layer of the metal layer 16 is obtained as shown in FIG. Part or the whole is oxidized, and the metal removal ability is improved in the subsequent polishing step. That is, since metals such as copper or copper alloy are rich in ductility and malleability, polishing treatment is difficult, but when metal such as copper or copper alloy is oxidized, ductility and malleability become small. It becomes easy to polish.

  The oxidizing treatment liquid used in the first embodiment can contain (A) an oxidizing agent and (B) water. Such oxidizing treatment liquid will be described in detail later.

  The second step can be performed using a commercially available chemical mechanical polishing apparatus (for example, Mirra (manufactured by Applied Materials)).

  When Mirra (Applied Materials) is used, for example, the following conditions can be used.

  The platen rotational speed is preferably 0 to 150 rpm, more preferably 30 to 130 rpm.

  The head rotation speed is preferably 0 to 150 rpm, more preferably 30 to 130 rpm.

  The processing pressure is preferably 0 to 1 psi (0 to 6.9 kPa), more preferably 0 to 0.7 psi (0 to 4.8 kPa), and particularly preferably 0 to 0.5 psi (0 to 3. 4 kPa). When the processing pressure is higher than 1 psi (6.9 kPa), planarization of the object to be processed may be impaired, and corrosion of the metal layer 16 may be induced.

  The treatment time is preferably 5 to 60 seconds, more preferably 10 to 30 seconds, and particularly preferably 10 to 20 seconds. When the treatment time is shorter than 5 seconds, the metal layer 16 is not sufficiently oxidized, so that the remaining metal is not sufficiently removed. On the other hand, if the time is longer than 60 seconds, the throughput of the polishing process is lowered.

  The supply flow rate of the oxidizing treatment liquid is preferably 50 to 500 mL / min, more preferably 100 to 300 mL / min, and particularly preferably 150 to 250 mL / min. When the supply flow rate is less than 50 mL / min, the surface of the metal layer 16 is not sufficiently oxidized, and when it is more than 500 mL / min, corrosion of the metal layer 16 may be induced.

1.2.3 Third Step In the treatment method according to the first embodiment, after the second treatment step, the oxidized metal layer 16 and the chemical mechanical polishing aqueous dispersion are placed on a polishing platen. A third step of supplying and polishing is included.

  In the third step, the metal layer 16 to be removed by oxidation treatment is removed by chemical mechanical polishing. That is, the portion of the metal layer 16 that should be the wiring of the object 100 is not polished. In the third step, a part of the barrier layer 14 or the insulating layer 12 can be simultaneously polished as necessary.

  The chemical mechanical polishing aqueous dispersion used in the third step may be the same as or different from the chemical mechanical polishing aqueous dispersion used in the first step. Since the chemical mechanical polishing aqueous dispersion used in the first step is highly effective in suppressing dishing and erosion, it is also preferably used in the third step.

  Polishing in the third step can be performed using a commercially available chemical mechanical polishing apparatus (for example, Mirra (manufactured by Applied Materials)) under known polishing conditions.

  When Mirra (Applied Materials) is used, for example, the following conditions can be used.

  The platen rotational speed is preferably 30 to 150 rpm, more preferably 30 to 130 rpm.

  The head rotation speed is preferably 30 to 150 rpm, more preferably 30 to 130 rpm.

  The polishing pressure is preferably 0.5 to 5 psi (3.4 to 34.5 kPa), and more preferably 1 to 3 psi (6.9 to 20.7 kPa).

  The chemical mechanical polishing aqueous dispersion supply rate is preferably 50 to 300 mL / min, and more preferably 100 to 200 mL / min.

  If the substrate processing method including the first to third steps described above is used, the metal layer 16 remaining on the barrier layer 14 is uniformly oxidized by the oxidizing treatment liquid. Efficient and reliable removal. As a result, according to the substrate processing method of the present invention, as shown in FIG. 1 (D), the object to be processed 100 has no metal residue and is unlikely to produce a metal residue. Since excessive polishing is not required, it is possible to obtain a high-quality polished surface in which even dishing and erosion are suppressed.

  The substrate processing method including the first to third steps described above is not limited to one use, and can be used a plurality of times until a desired surface to be polished is obtained.

1.2.4 Supply Method FIGS. 2A and 2B are schematic views of a liquid supply apparatus used in the semiconductor substrate processing method according to the present invention. Hereinafter, the liquid supply apparatus used in the semiconductor substrate processing method according to the first embodiment will be described with reference to FIGS. 2 (A) and 2 (B).

  In the substrate processing method in the first embodiment, a line 32 for supplying a chemical mechanical polishing aqueous dispersion and a line 34 for supplying an oxidizing treatment liquid are separately provided as shown in FIG. A liquid supply device 30 can be used.

  In the first step, the line 34 can be closed and only the line 32 can be opened to supply the chemical mechanical polishing aqueous dispersion to the polishing platen 50.

  In the second step, the line 32 can be closed and only the line 34 can be opened to supply the oxidizing treatment liquid to the polishing surface plate 50.

  In the third step, the chemical mechanical polishing aqueous dispersion can be supplied to the polishing platen 50 by closing the line 34 and opening only the line 32 as in the first step.

  In the processing method according to the first embodiment, when (A) the oxidizing agent contained in the oxidizing treatment liquid and (F) the oxidizing agent contained in the chemical mechanical polishing aqueous dispersion are the same, The line 32 for supplying the chemical mechanical polishing aqueous dispersion and the line 34 for supplying the oxidizing treatment liquid as shown in FIG. A liquid supply device 40 can be used.

  In the first step, (F) the chemical mechanical polishing aqueous dispersion without oxidizing agent is supplied from line 32, while (A) the oxidizing treatment liquid containing oxidizing agent is supplied from line 34, and the mixing section By mixing at 38, the chemical mechanical polishing aqueous dispersion in which the concentration of the oxidizing agent is controlled can be supplied to the substrate. In general, since the oxidizing agent is easily reduced, the concentration is reduced even if the oxidizing agent is added in advance to the chemical mechanical polishing aqueous dispersion. Therefore, the oxidizing agent is preferably added immediately before using the chemical mechanical polishing aqueous dispersion.

  The liquid supply device 40 can solve this problem, and has the advantage that the number of lines is reduced and simplified.

  Since the liquid supply device 40 can mix two kinds of liquids in advance in the mixing unit 38, the chemical mechanical polishing aqueous dispersion uniformly mixed on the polishing platen 50 can be supplied. The liquid supply device 40 can supply the chemical mechanical polishing aqueous dispersion uniformly mixed in the mixing unit 38 even if the supply flow rates of the lines 32 and 34 are changed. That is, since the liquid supply apparatus 40 can supply the chemical mechanical polishing aqueous dispersion uniformly mixed, chemical mechanical polishing excellent in planarization can be realized.

  In the second step, the line 32 is closed (F), the chemical mechanical polishing aqueous dispersion without oxidizing agent is stopped, and only the line 34 is opened to supply the oxidizing treatment liquid.

  In the 3rd process, it can supply by the same method as the 1st process.

2. Second Embodiment FIGS. 3A to 3D are cross-sectional views showing a specific example of a semiconductor substrate processing method according to the present invention. Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 3 (A) to 3 (D).

2.1 To-be-processed object Since FIG. 3 (A) is the same to-be-processed object 100 as FIG. 1 (A), detailed description is abbreviate | omitted.

2.2 Processing Method 2.2.1 First Step The first step is a step of removing at least a part of the metal layer 16 deposited on the barrier layer 14. FIG. 3B shows a state after completion of the first step in which the chemical mechanical polishing aqueous dispersion is supplied onto the polishing surface plate and polished. In this state, in the object 100, the metal layer 16 on the barrier layer 14 is not completely removed in the region 22 containing a lot of fine wiring, and a partial metal residue 18 is generated. The metal residue 18 needs to be surely removed because it causes leakage current between wirings and affects the depth of focus when the layers are multi-layered.

  The usable chemical mechanical polishing aqueous dispersion, chemical mechanical polishing apparatus, and processing conditions are the same as those in “1.2.1 First step”, and thus detailed description thereof is omitted.

2.2.2 Second Step Oxidizing treatment described in “1.2.2 Second Step” even when a partial metal residue 18 is generated as shown in FIG. The liquid can be supplied onto the polishing surface plate to oxidize the partial metal residue 18 of the workpiece 100 (FIG. 3C).

  The usable oxidizing treatment liquid, chemical mechanical polishing apparatus, and treatment conditions are the same as those in “1.2.2 Second step”, and thus detailed description thereof is omitted.

2.2.3 Third Step As shown in FIG. 3C, the chemical mechanical polishing aqueous dispersion is further polished to a polishing platen even when the remaining metal residue 18 is oxidized in the second step. A third step of supplying and polishing can be performed.

  The usable chemical mechanical polishing aqueous dispersion, chemical mechanical polishing apparatus, and processing conditions are the same as those in “1.2.3 Third step”, and thus detailed description thereof is omitted.

  In the manufacture of a semiconductor device, if a partial metal residue occurs, the metal residue causes a leakage current between wirings as described above, and affects the depth of focus when the layers are multi-layered. Need to be removed. However, excessive removal of the metal residue may cause excessive polishing even in a region where there is no metal residue (for example, a region including a wide wiring), which may cause dishing or erosion.

  If the substrate processing method including the first to third steps described above is used, the partial metal residue 18 on the barrier layer 14 is uniformly oxidized by the oxidizing processing liquid in the region 22 containing a lot of fine wiring. Therefore, it is easily and surely removed without requiring excessive polishing in the third step. As a result, according to the substrate processing method of the present invention, the object to be processed 100 has no partial metal residue as shown in FIG. 3D, and an excessive amount for removing the partial metal residue. Since polishing is not required, a high-quality polished surface in which the occurrence of dishing or erosion is suppressed can be obtained even in the region 24 including the wide wiring.

  The substrate processing method including the first to third steps described above is not limited to one use, and can be used a plurality of times until a desired surface to be polished is obtained.

3. Other target objects The target object of the substrate processing method according to the present invention is not particularly limited to the target object 100 shown in FIGS. 1 (A) and 3 (A). For example, FIG. A workpiece 200 having a structure as shown can be given. In the object 200, the insulating layer is composed of a plurality of layers. Specifically, an insulating layer 26 made of silicon oxide or the like and an insulating layer 28 made of silicon nitride or the like formed under the insulating layer 26 are provided between the base 10 and the insulating layer 12. The same constituent elements as those shown in FIG. 1A are denoted by the same reference numerals.

  As mentioned above, although the to-be-processed object of the substrate processing method concerning this invention was described, this invention is not limited to these. For example, in the example described above, the insulating layer is one layer or three layers, but may be two layers, or may be four layers or more instead. Thus, various aspects can be taken within the scope of the present invention.

4). Oxidizing Treatment Liquid The oxidizing treatment liquid used in the present invention contains (A) an oxidizing agent and (B) water.

4.1 (A) Oxidizing agent (A) As the oxidizing agent, hydrogen peroxide, organic peroxide, permanganic acid compound, dichromic acid compound, halogen acid compound, nitric acid compound, perhalogen acid compound, persulfate And heteropolyacids.

  Examples of the organic peroxide include peracetic acid, perbenzoic acid, tert-butyl hydroperoxide, and the like.

  Examples of the permanganate compound include potassium permanganate.

  Examples of the dichromate compound include potassium dichromate.

  Examples of the halogen acid compound include potassium iodate.

  Examples of the nitrate compound include nitric acid and iron nitrate.

  Examples of the perhalogen acid compound include perchloric acid.

  Examples of the persulfate include ammonium persulfate and potassium persulfate.

  Examples of the heteropolyacid include silicomolybdic acid and silicotungstic acid.

  As the (A) oxidizing agent, it is preferable to use hydrogen peroxide or ammonium persulfate from the viewpoint that the decomposition product is harmless and does not contain a metal atom. Since these oxidizing agents do not contain metal atoms, metal contamination of the object to be treated by the oxidizing agents can be prevented.

  The concentration of the oxidizing agent (A) contained in the oxidizing treatment liquid is preferably 0.01 to 10% by mass, more preferably 0.02 to 8% by mass, and particularly preferably 0.1 to 10% by mass. 5% by mass. When the concentration of the oxidizing agent (A) is lower than 0.01% by mass, the metal layer formed on the surface of the substrate cannot be sufficiently oxidized. May end up. On the other hand, if the concentration of the oxidizing agent (A) is higher than 10% by mass, corrosion of the metal layer formed on the substrate surface may be induced.

4.2 (B) Water (B) Water preferably contains almost no impurities, and distilled water, pure water or ultrapure water can be used.

5. Chemical mechanical polishing aqueous dispersion The chemical mechanical polishing aqueous dispersion used in the present invention comprises (C) abrasive grains, (D) a compound having a heterocyclic ring, (E) a polishing rate improver, and (F) an oxidizing agent. Can be included. The chemical mechanical polishing aqueous dispersion used in the present invention has a particularly high effect of suppressing dishing and erosion, and can be suitably used.

5.1 (C) Abrasive Grain The (C) abrasive grain contains at least one selected from inorganic particles, organic particles, and organic-inorganic composite particles.

  Examples of the inorganic particles include silica, alumina, titania, zirconia, and ceria.

  Examples of the silica include fumed silica, synthetic silica, colloidal silica, and the like. Fumed silica can be obtained by oxidizing silicon tetrachloride in a flame, desalting and purification. Synthetic silica can be obtained by subjecting an alkoxysilicon compound as a raw material to a hydrolysis reaction or a condensation reaction. Colloidal silica can be obtained, for example, by an inorganic colloid method using a raw material purified in advance.

  Examples of the organic particles include polyvinyl chloride, styrene (co) polymer, polyacetal, polyester, polyamide, polycarbonate, olefin (co) polymer, phenoxy resin, and acrylic (co) polymer. Examples of the olefin (co) polymer include polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and the like. Examples of the acrylic (co) polymer include polymethyl methacrylate.

  The organic-inorganic composite particles need only be integrally formed to such an extent that the organic particles and inorganic particles as described above are not easily separated during the chemical mechanical polishing step, and the type and configuration thereof are not particularly limited. . The organic-inorganic composite particles can take, for example, the following configurations (i) to (iii).

  (I) Organic-inorganic composite particles obtained by polycondensation of metal or silicon alkoxide compounds in the presence of organic particles. Here, examples of the metal or silicon alkoxide compound include alkoxysilane, aluminum alkoxide, and titanium alkoxide. In this case, the polycondensate to be purified may be directly bonded to the functional group of the organic particles, or may be bonded via an appropriate coupling agent (for example, a silane coupling agent).

  (Ii) Organic-inorganic composite particles in which organic particles and inorganic particles having zeta potentials with different signs are combined by electrostatic force. In this case, the composite particles may be formed by mixing both in the pH range where the signs of the zeta potential of the organic particles and the inorganic particles are different, and both in the pH range where the signs of the zeta potential of the organic particles and the inorganic particles are the same. After mixing, the composite particles may be formed by changing the liquidity to a pH range where the signs of the zeta potentials of the organic particles and the inorganic particles are different.

  (Iii) Organic-inorganic composite particles obtained by polycondensation of a metal or silicon alkoxide compound in the presence of the composite particles (ii). Here, as the metal or silicon alkoxide compound, the same compounds as in the above (i) can be used.

  As the abrasive grains (C) contained in the chemical mechanical polishing aqueous dispersion used in the present invention, silica or organic-inorganic composite particles are preferable.

  (C) The average dispersed particle diameter of the abrasive grains is preferably 5 to 1000 nm, more preferably 7 to 700 nm, and particularly preferably 10 to 500 nm. The chemical mechanical polishing aqueous dispersion containing abrasive grains in this range can achieve a good balance between the surface to be polished and the polishing rate.

  The concentration of the (C) abrasive grains in the chemical mechanical polishing aqueous dispersion used in the present invention is preferably 0.01 to 10% by mass, more preferably 0.02 to 8% by mass, and particularly preferably. Is 0.1-5 mass%. (C) When the concentration of the abrasive grains exceeds 10% by mass, the chemical mechanical polishing aqueous dispersion may be easily dried, and coarse dry powder may be generated to increase scratches. On the other hand, 0.01% by mass If it is less than this, the polishing rate will be low, and efficient polishing may not be achieved.

5.2 (D) Compound having a heterocyclic ring (D) The compound having a heterocyclic ring is an organic compound having at least one heterocyclic ring selected from a heterocyclic 5-membered ring and a heterocyclic 6-membered ring having at least one nitrogen atom. It can be a compound. Examples of the heterocycle include a hetero five-membered ring such as a pyrrole structure, an imidazole structure, and a triazole structure, or a hetero six-membered ring such as a pyridine structure, a pyrimidine structure, a pyridazine structure, and a pyrazine structure. Such a heterocyclic ring may form a condensed ring. Specific examples include indole structure, isoindole structure, benzimidazole structure, benzotriazole structure, quinoline structure, isoquinoline structure, quinazoline structure, cinnoline structure, phthalazine structure, quinoxaline structure, acridine structure and the like. Of the organic compounds having such a structure, organic compounds having a pyridine structure, a quinoline structure, a benzimidazole structure, or a benzotriazole structure are preferable.

  As the compound having a heterocyclic ring (D) contained in the chemical mechanical polishing aqueous dispersion used in the present invention, quinolinic acid, quinaldic acid, benzimidazole, and benzotriazole are preferable, and quinolinic acid and quinaldic acid are more preferable.

  The concentration of the compound (D) having a heterocyclic ring in the chemical mechanical polishing aqueous dispersion used in the present invention is preferably 0.01 to 10% by mass, more preferably 0.02 to 5% by mass. Especially preferably, it is 0.1-2 mass%. (D) If the concentration of the compound having a heterocyclic ring is less than 0.01% by mass, dishing may increase. On the other hand, if it exceeds 10% by mass, a sufficiently high polishing rate may not be obtained.

5.3 (E) Polishing speed improver (E) The polishing speed improver is selected from, for example, amino acids, aminopolycarboxylic acids, amine compounds, amino alcohols, phosphonic acids, halide ions, thiosulfate ions, and ammonium ions. It can be at least one kind.

  Examples of the amino acid include glycine, alanine, glutamic acid and the like.

  Examples of the aminopolycarboxylic acid include ethylenediaminetetraacetic acid.

  Examples of the amine compound include ethylenediamine, diethylamine, and triethylamine.

  Examples of the amino alcohol include triethanolamine.

  As the polishing rate improver (E) contained in the chemical mechanical polishing aqueous dispersion used in the present invention, ammonium ions, amino acids, amine compounds and aminopolycarboxylic acids are preferred.

  The concentration of the (E) polishing rate improver in the chemical mechanical polishing aqueous dispersion used in the present invention is preferably 0.01 to 5% by mass, more preferably 0.02 to 4% by mass, Especially preferably, it is 0.05-3 mass%. (E) When the concentration of the polishing rate improver is less than 0.01% by mass, the metal may not be polished at a sufficiently high rate. On the other hand, if it exceeds 5% by mass, dishing and corrosion may occur greatly.

5.4 (F) Oxidizing agent (F) As the oxidizing agent, hydrogen peroxide, organic peroxide, permanganic acid compound, dichromic acid compound, halogen acid compound, nitric acid compound, perhalogen acid compound, persulfate And heteropolyacids.

  Examples of the organic peroxide include peracetic acid, perbenzoic acid, tert-butyl hydroperoxide, and the like.

  Examples of the permanganate compound include potassium permanganate.

  Examples of the dichromate compound include potassium dichromate.

  Examples of the halogen acid compound include potassium iodate.

  Examples of the nitrate compound include nitric acid and iron nitrate.

  Examples of the perhalogen acid compound include perchloric acid.

  Examples of the persulfate include ammonium persulfate.

  Examples of the heteropolyacid include silicomolybdic acid and silicotungstic acid.

  The (F) oxidizing agent is preferably hydrogen peroxide or ammonium persulfate from the viewpoint that the decomposition product is harmless and does not contain a metal atom. Since these oxidizing agents do not contain metal atoms, metal contamination of the object to be treated by the oxidizing agents can be prevented.

  The concentration of the (F) oxidizing agent in the chemical mechanical polishing aqueous dispersion used in the present invention is preferably 0.01 to 10% by mass, more preferably 0.02 to 8% by mass, and particularly preferably. Is 0.05-5 mass%. When the concentration of the (F) oxidant is lower than 0.01% by mass, the metal layer formed on the substrate surface cannot be sufficiently oxidized, so that a metal residue is generated even after a subsequent polishing process. May end up. On the other hand, when the concentration of the (F) oxidizing agent is higher than 10% by mass, corrosion of the metal layer formed on the substrate surface may be induced.

5.5 Other Components The chemical mechanical polishing aqueous dispersion used in the present invention may contain an acid, a base, a surfactant, a water-soluble polymer, or the like, if necessary, in addition to the components described above. .

5.5.1 Acid and base Examples of the acid include organic acids and inorganic acids.

  Examples of organic acids include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, isoprenesulfonic acid, gluconic acid, lactic acid, citric acid, tartaric acid, malic acid, glycolic acid, malonic acid, formic acid, oxalic acid, succinic acid, fumaric acid , Maleic acid, phthalic acid and the like.

  Examples of inorganic acids include nitric acid, sulfuric acid, and phosphoric acid.

  Examples of the base include organic bases and inorganic bases.

  Examples of the organic base include tetramethyl hydroxide.

  Examples of the inorganic base include alkali metal hydroxides. Specific examples include sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like.

  The pH of the chemical mechanical polishing aqueous dispersion used in the present invention is preferably 3 to 12, and the acid and base can be used for the purpose of adjusting the pH of the chemical mechanical polishing dispersion.

5.5.2 Surfactant Examples of the surfactant include a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant.

  Examples of the cationic surfactant include aliphatic amine salts and aliphatic ammonium salts.

  Examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester salt, phosphate ester salt and the like. Examples of carboxylates include fatty acid soaps and alkyl ether carboxylates. Examples of the sulfonate include alkyl benzene sulfonate, alkyl naphthalene sulfonate, and α-olefin sulfonate. Examples of sulfate salts include higher alcohol sulfate salts and alkyl ether sulfate salts. Examples of phosphoric acid ester salts include alkyl phosphoric acid esters.

  Examples of the amphoteric surfactant include alkylbetaines, alkylamino fatty acid salts, alkylamine oxides, and the like.

  Examples of the nonionic surfactant include ether type surfactants, ether ester type surfactants, ester type surfactants, and acetylene type surfactants. Examples of ether type surfactants include polyoxyethylene alkyl ethers. Examples of the ether ester type surfactant include polyoxyethylene ether of glycerin ester. Examples of the ester type surfactant include polyethylene glycol fatty acid ester, glycerin ester, sorbitan ester and the like. Examples of acetylene surfactants include acetylene alcohol, acetylene glycol, ethylene oxide adducts of acetylene diol, and the like.

  When the chemical mechanical polishing aqueous dispersion used in the present invention contains a surfactant, the concentration of the surfactant is preferably 0.5% by mass or less, more preferably 0.01 to 0.5. % By mass. The chemical mechanical polishing aqueous dispersion containing the surfactant in this concentration range can polish the surface to be polished more smoothly.

5.5.3 Water-soluble polymer Examples of the water-soluble polymer include polyacrylamide, polyacrylic acid, polyvinyl alcohol, polyvinyl pyrrolidone, and hydroxyethyl cellulose.

  When the chemical mechanical polishing aqueous dispersion used in the present invention contains a water-soluble polymer, the concentration of the water-soluble polymer is preferably 0.01 to 0.5% by mass, more preferably 0.8. It is 02-0.2 mass%.

6). Examples Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to the examples.

6.1 Preparation of Oxidizing Treatment Liquid Ammonium persulfate powder was dissolved in water to prepare a 4% by mass aqueous ammonium persulfate solution.

6.2 Preparation of chemical mechanical polishing aqueous dispersion 6.2.1 Preparation of aqueous dispersion containing fumed silica particles Fumed silica particles (trade name “Aerosil # 90” manufactured by Nippon Aerosil Co., Ltd.) 2 kg Then, it was dispersed in 6.7 kg of ion exchange water using an ultrasonic disperser. By filtering this with a filter having a pore diameter of 5 μm, an aqueous dispersion containing 10% by mass of fumed silica was prepared. The average dispersed particle size of fumed silica contained in this aqueous dispersion was 220 nm.

6.2.2 Preparation of Aqueous Dispersion Containing Colloidal Silica 70 g of ammonia water having a concentration of 25% by mass, 40 g of ion exchange water, 175 g of ethanol and 21 g of tetraethoxysilane are added to a 2 L flask and stirred at a rotation speed of 180 rpm. The temperature was raised to 60 ° C. Stirring was continued for 2 hours while maintaining the temperature at 60 ° C., and then cooled to room temperature. Thus, a colloidal silica / alcohol dispersion having an average particle diameter of 97 nm was obtained.

  Subsequently, the operation of removing the alcohol component while adding ion-exchanged water was repeated several times while maintaining the temperature of the obtained dispersion at 80 ° C. using an evaporator. In this way, the alcohol content in the dispersion was removed, and an aqueous dispersion containing 10% by mass of colloidal silica was prepared. The average dispersed particle size of colloidal silica contained in this aqueous dispersion was 97 nm.

6.2.3 Preparation of aqueous dispersion containing organic-inorganic composite particles 6.2.3a Preparation of aqueous dispersion containing organic particles 90 parts by mass of methyl methacrylate, methoxypolyethylene glycol methacrylate (Shin Nakamura Chemical Co., Ltd.) ), Trade name "NK Ester M-90G # 400") 5 parts by mass, 4-vinylpyridine 5 parts by mass, azo polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd., trade name "V50") 2 parts by mass And 400 parts by mass of ion-exchanged water were added to a 2 L flask, and the temperature was raised to 70 ° C. with stirring in a nitrogen gas atmosphere, followed by polymerization for 6 hours. As a result, an aqueous dispersion containing polymethylmethacrylate particles having an amino group cation and a functional group having a polyethylene glycol chain and having an average dispersion particle diameter of 150 nm was obtained. The polymerization yield was 95%.

6.2.3b Preparation of aqueous dispersion containing composite particles 100 mass of aqueous dispersion containing 10% by mass of polymethyl methacrylate-based particles obtained in the above "6.2.3a Preparation of aqueous dispersion containing organic particles" Was put into a 2 L flask, 1 part by mass of methyltrimethoxysilane was added, and the mixture was stirred at 40 ° C. for 2 hours. Thereafter, the pH was adjusted to 2 with nitric acid to obtain an aqueous dispersion (i). The zeta potential of the polymethyl methacrylate particles contained in the aqueous dispersion (i) was +17 mV.

  On the other hand, the pH of an aqueous dispersion containing 10% by mass of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex O”) was adjusted to 8 with potassium hydroxide to obtain an aqueous dispersion (ii). The zeta potential of the silica particles contained in the aqueous dispersion (ii) was −40 mV.

  Particles in which silica particles are adhered to polymethyl methacrylate particles after gradually adding and mixing 50 parts by mass of water dispersion (ii) to 100 parts by mass of the aqueous dispersion (i) over 2 hours and mixing. An aqueous dispersion containing was obtained. Next, 2 parts by mass of vinyltriethoxysilane was added to the aqueous dispersion and stirred for 1 hour. Thereafter, 1 part by mass of tetraethoxysilane was added to this aqueous dispersion, and stirring was continued for 3 hours while maintaining 60 ° C., followed by cooling to obtain an aqueous dispersion containing organic-inorganic composite particles. The average dispersed particle size of the organic-inorganic composite particles was 180 nm, and silica particles were attached to 80% of the surface of the polymethyl methacrylate particles.

6.3 Example 1
6.3.1 Preparation of aqueous dispersion for chemical mechanical polishing In a polyethylene container, the fumed silica particles prepared in “6.2.1 Preparation of aqueous dispersion containing fumed silica particles” as abrasive grains are added. The aqueous dispersion containing the fumed silica is added in an amount corresponding to 2% by mass with respect to the total amount of the chemical mechanical polishing aqueous dispersion, and then 0.5% by mass of quinaldic acid is added as a compound having a heterocyclic ring. Further, 0.3% by mass of glycine was added as a polishing rate improver, and the mixture was sufficiently stirred. Then, while continuing stirring, 0.1% by weight of ammonium dodecylbenzenesulfonate, ammonium hydroxide was added as a pH adjuster, and 2% by weight of ammonium persulfate was added as an oxidizing agent. Ion exchange water was added so that the total amount of was 100% by mass to obtain a chemical mechanical polishing aqueous dispersion having a pH of 9.0.

6.3.2 Evaluation of remaining copper after oxidation treatment on patterned substrate Chemical polishing machine (Applied Materials, model “Mirra”) and polishing pad (Rohm and Haas Electronic Materials, model “IC1010”) ) And a substrate with a pattern (made by International Semitech, model “SEMATECH # 854”, a test wafer having various wiring patterns, and the deposited thickness of the copper layer is 1100 nm). The chemical mechanical polishing aqueous dispersion prepared in “6.3.1 Preparation of chemical mechanical polishing aqueous dispersion” and the oxidizing treatment liquid prepared in “6.1 Preparation of oxidizing treatment liquid”. Was used to carry out an oxidation treatment.

Using the chemical mechanical polishing aqueous dispersion, polishing was performed under the following condition 1 until the remaining copper layer reached 100 nm. Next, oxidation treatment was performed under the following condition 2 using the oxidizing treatment liquid. Polishing was performed again using the chemical mechanical polishing aqueous dispersion, and after the end point was detected using an optical end point detector, the polishing was terminated when 30 seconds had passed.
I. Condition 1
・ Chemical mechanical polishing aqueous dispersion supply speed: 250 mL / min ・ Surface plate rotation speed: 100 rpm
-Head rotation speed: 80 rpm
Head load: 1.5 psi (10.3 kPa)
Polishing time: end point by optical end point detector + 30 seconds II. Condition 2
・ Oxidizing treatment liquid supply rate: 200 mL / min ・ Surface plate rotation speed: 100 rpm
-Head rotation speed: 80 rpm
Head load: 0 psi (0 kPa)
・ Processing time: 15 seconds ・ Supply method: Supply to the surface plate from an independent line

  About the to-be-processed object after performing the said process process, when the copper residue was observed using the optical microscope, the copper residue was not observed. In the evaluation item “copper residue” in Table 1, the evaluation when the copper residue was observed was “x”, and the evaluation when it was not observed was “◯”.

  Further, when dishing of a portion having a wiring width of 100 μm was measured using a precision step gauge (manufactured by KLA Tencor, model “HRP”), it was as good as 40 nm. Similarly, when the erosion of a portion where a pattern having a wiring width of 9 μm / space width of 1 μm is continued 1250 μm in a direction perpendicular to the wiring was measured, it was as good as 20 nm. In general, dishing and erosion can be determined to be good if they are 50 nm or less.

  Further, when corrosion was observed using an optical microscope, no corrosion was observed. In the evaluation item “corrosion” in Table 1, the evaluation when corrosion was observed was “x”, and the evaluation when it was not observed was “◯”.

6.4 Example 2
A chemical mechanical polishing aqueous dispersion (i) obtained by removing ammonium persulfate as an oxidizing agent from the chemical mechanical polishing aqueous dispersion shown in Example 1 and a 4% aqueous ammonium persulfate solution (ii) were prepared. Using a line as shown in FIG. 2 (B) in which (i) and (ii) are mixed immediately before being supplied to the polishing surface plate, a chemical mechanical polishing aqueous dispersion (i) and an aqueous ammonium persulfate solution (ii) Were simultaneously supplied to the polishing surface plate. The supply amount was adjusted so that the ammonium persulfate, which is an oxidizing agent, had a predetermined concentration at the time of mixing, and polishing was performed under the following condition 3 until the remaining copper layer reached 200 nm. Thereafter, the supply of the chemical mechanical polishing aqueous dispersion (i) was stopped, and only the aqueous ammonium persulfate solution (ii) was supplied as an oxidizing treatment solution, and the treatment was performed under the following condition 4. Polishing was further performed in the same manner, and the polishing was terminated when 30 seconds had elapsed after the end point was detected using an optical end point detector.
III. Condition 3
-Chemical mechanical polishing aqueous dispersion supply rate: 125 mL / min-Oxidizing treatment liquid (ammonium persulfate aqueous solution) supply rate: 125 mL / min-Platen rotation speed: 100 rpm
-Head rotation speed: 80 rpm
Head load: 1.5 psi (10.3 kPa)
Polishing time: end point by optical end point detector + 30 seconds IV. Condition 4
・ Oxidizing treatment liquid supply rate: 200 mL / min ・ Surface plate rotation speed: 100 rpm
-Head rotation speed: 80 rpm
Head load: 0 psi (0 kPa)
・ Processing time: 15 seconds

  About the to-be-processed object after performing the said process process, when the copper residue was observed using the optical microscope, the copper residue was not observed. In the evaluation item “copper residue” in Table 1, the evaluation when the copper residue was observed was “x”, and the evaluation when it was not observed was “◯”.

  Further, when dishing of a portion having a wiring width of 100 μm was measured using a precision step gauge (manufactured by KLA Tencor, model “HRP”), it was as good as 40 nm. Similarly, when the erosion of a portion where a pattern having a wiring width of 9 μm / space width of 1 μm is continued 1250 μm in a direction perpendicular to the wiring was measured, it was as good as 20 nm. In general, dishing and erosion can be determined to be good if they are 50 nm or less.

  Further, when corrosion was observed using an optical microscope, no corrosion was observed. In the evaluation item “corrosion” in Table 1, the evaluation when corrosion was observed was “x”, and the evaluation when it was not observed was “◯”.

6.5 Examples 3 to 7, Comparative Example 1
In Examples 3 to 6 and Comparative Example 2, the chemical mechanical polishing aqueous dispersion is the same as in Example 1, but the type and concentration of the (A) oxidizing agent contained in the oxidizing treatment liquid are the same as in Example 1. And different. The processing method is the same as in the first embodiment.

  In Examples 7 to 9, the oxidizing treatment liquid is the same as in Example 1, but the components and concentrations contained in the chemical mechanical polishing aqueous dispersion are different from those in Example 1. The processing method is the same as in the first embodiment.

  In Examples 10 to 12 and Comparative Example 3, the chemical mechanical polishing aqueous dispersion and the oxidizing treatment liquid are the same as in Example 1, but the thickness of the remaining copper layer that is the surface to be polished is in Example 1. And different.

  In Comparative Example 1, the chemical mechanical polishing aqueous dispersion is the same as that in Example 1, except that the step of supplying the oxidizing treatment liquid is omitted.

  In Examples 3 to 12 and Comparative Examples 1 to 3, oxidation treatment was performed in the same manner as in Example 1. The results are shown in Table 1.

  The evaluation methods for “copper residue”, “dishing”, “erosion”, and “corrosion” are the same as in Examples 1 and 2.

It is sectional drawing which shows one specific example of the processing method of the semiconductor substrate which concerns on this invention. It is the schematic of the liquid supply apparatus used for the processing method of the semiconductor substrate which concerns on this invention. It is sectional drawing which shows one specific example of the processing method of the semiconductor substrate which concerns on this invention. It is sectional drawing which shows one specific example of the to-be-processed object used for the processing method of the semiconductor substrate which concerns on this invention.

Explanation of symbols

10 Substrate 12 Insulating layer (eg, PETEOS layer)
14 Barrier layer 16 Metal layer 18 Partial metal residue 20 Recess 22 Region including a lot of fine wiring 24 Region including a wide wiring 26 Insulating film (for example, silicon nitride)
28 Insulating film (for example, silicon oxide)
Reference Signs List 30 First supply device 32 Line for supplying chemical mechanical polishing aqueous dispersion 34 Line for supplying oxidizing treatment liquid 36 Mixing line 38 Mixing unit 40 Second supply device 50 Polishing surface plate 100, 200 Object to be processed

Claims (15)

An object to be processed, which is provided on an insulating layer having a recess through a barrier layer and has a metal layer embedded in the recess, is formed by using the chemical mechanical polishing aqueous dispersion and the metal on the barrier layer. A first processing step for polishing the layer;
A second treatment step of oxidizing the metal layer on the insulating layer by supplying an oxidizing treatment liquid after the first treatment step;
A third treatment step of polishing the oxidized metal layer using the chemical mechanical polishing aqueous dispersion after the second treatment step;
A substrate processing method. In claim 1,
The substrate processing method, wherein the metal layer on the barrier layer remains entirely on the barrier layer after the first processing step. In claim 1,
The substrate processing method, wherein the metal layer on the barrier layer partially remains on the barrier layer after the first processing step. In any of claims 1 to 3,
The substrate processing method, wherein the metal layer on the barrier layer has a thickness of 500 nm or less after the first processing step. In any of claims 1 to 4,
The substrate processing method, wherein after the first processing step, the metal layer on the barrier layer has a thickness of 200 nm or less. In any of claims 1 to 5,
The substrate processing method, wherein the metal layer is a layer made of copper or a copper alloy. In any one of Claims 1 thru | or 6.
The substrate processing method, wherein the oxidizing treatment liquid contains (A) an oxidizing agent and (B) water. In claim 7,
The oxidizing agent (A) is at least selected from hydrogen peroxide, organic peroxide, permanganic acid compound, dichromic acid compound, halogen acid compound, nitric acid compound, perhalogen acid compound, persulfate and heteropolyacid. A substrate processing method including one type. In claim 7 or 8,
The substrate processing method, wherein the concentration of the oxidizing agent is 0.01 to 10% by mass. In any one of Claim 1 thru | or 9,
The chemical mechanical polishing aqueous dispersion contains (C) abrasive grains, (D) a compound having a heterocyclic ring, (E) a polishing rate improver, and (F) an oxidizing agent. In claim 10,
(C) The substrate processing method, wherein the abrasive grains include at least one selected from inorganic particles, organic particles, and organic-inorganic composite particles. In claim 10 or 11,
(D) The substrate processing method, wherein the compound having a heterocyclic ring is an organic compound having at least one heterocyclic ring selected from a heterocyclic 5-membered ring and a heterocyclic 6-membered ring having at least one nitrogen atom. In any one of claims 10 to 12,
The (E) polishing rate improver includes at least one selected from amino acids, aminopolycarboxylic acids, amine compounds, and amino alcohols. In any one of claims 10 to 13,
The (F) oxidizing agent is at least selected from hydrogen peroxide, organic peroxides, permanganic acid compounds, dichromic acid compounds, halogen acid compounds, nitric acid compounds, perhalogen acid compounds, persulfates and heteropolyacids. A substrate processing method including one type. In any one of Claims 1 thru | or 14.
The substrate processing method, wherein the oxidizing agent (A) contained in the oxidizing treatment liquid and the oxidizing agent (F) contained in the chemical mechanical polishing aqueous dispersion are the same.

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