Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
  • H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
  • H01L21/321—After treatment
  • H01L21/32115—Planarisation
  • H01L21/3212—Planarisation by chemical mechanical polishing [CMP]

Definitions

• This invention relates to polishing compositions and methods for polishing a substrate using the same. More particularly, this invention relates to chemical-mechanical polishing compositions suitable for polishing semiconductor surfaces.
• polishing compositions also known as polishing slurries, CMP slurries, and CMP compositions
• CMP chemical-mechanical polishing
• metal-containing surfaces of semiconductor substrates typically contain an abrasive, various additive compounds, and the like.
• CMP involves the concurrent chemical and mechanical polishing of an overlying first layer to expose a portion of the surface of a non-planar second layer on which the first layer is formed.
• U.S. Patent 4,789,648 discloses a CMP process using a polishing pad and a polishing composition to remove a first layer at a faster rate than a second layer until the surface of the overlying first layer of material becomes coplanar with the upper surface of the covered second layer.
• a more detailed explanation of chemical-mechanical polishing can be found in U.S. Patents 4,671,851, 4,910,155 and 4,944,836.
• conductive materials having low resistivity for conductors in feature definitions formed in materials having low dielectric constants as insulating layers are copper and alloys thereof.
• a conductive material fitting these requirements is copper and alloys thereof.
• Cu copper
• a barrier layer is deposited in feature definitions prior to copper deposition. Barrier materials include, for example, tantalum (Ta), tantalum nitride (TaN), titanium (Ti), and titanium nitride (TiN). Following copper deposition, the excess copper and barrier layer is removed using CMP.
• the removal rates of the metals are then controlled by the use of additives which passivate a metal surface or complex a metal ion.
• This approach requires optimizing the passivation film chemistry to slow down the oxidation of one metal and allow the removal of a second metal on the substrate.
• Many of the known CMP compositions are suitable for limited purposes but also suffer from unacceptable polishing performance. Thus, there remains an ongoing need for new CMP compositions that exhibit useful removal rates for semiconductor materials such as tantalum when present with a second metal.
• the invention provides a chemical-mechanical polishing composition
• a chemical-mechanical polishing composition comprising (a) an abrasive, (b) a first metal polishing rate modifier agent, (c) a second metal polishing rate modifier agent, and (d) a liquid carrier.
• the first metal polishing rate modifier agent has a standard reduction potential less than 0.34 V relative to a standard hydrogen electrode, wherein the first metal polishing rate modifier agent is a quinone, and the second metal polishing rate modifier agent has a standard reduction potential greater than 0.34 V relative to a standard hydrogen electrode.
• the first metal polishing rate modifier agent is an organic oxidizing agent comprising a quinone moiety
• the second metal polishing rate modifier agent is selected from the group consisting of iodide, iodine, l 2 -malonamide 3 , and triiodide.
• the first metal polishing rate modifier agent is an organic oxidizing agent comprising a quinone moiety
• the second metal polishing rate modifier agent is an oxidizing agent present in a concentration below the concentration of the first metal polishing rate modifier agent.
• the first metal polishing rate modifier agent is an organic oxidizing agent comprising a quinone moiety, with the proviso that the first metal polishing rate modifier is not 1 ,2-napthoquinone-4-sulfonic acid, aminoanthraquinone sulfonic acid, or hydroquinone sulfonic acid
• the second metal polishing rate modifier agent is an oxidizing agent, with the proviso that the second metal polishing rate modifier agent is not the same as the first metal polishing rate modifier agent and is not potassium iodate or nitric acid.
• the invention also provides a method of chemically-mechanically polishing a substrate, which method comprises (i) providing a substrate, desirably with at least two metals, (ii) providing one of the aforesaid chemical-mechanical polishing compositions, (iii) contacting the substrate with a polishing pad with the polishing composition therebetween, (iv) moving the polishing pad and polishing composition relative to the substrate, and (iv) abrading at least a portion of the substrate to polish the substrate.
• the invention provides a CMP composition useful for polishing a substrate, preferably a semiconductor substrate that desirably contains at least two metals.
• the CMP composition contains (a) an abrasive, (b) a first metal polishing rate modifier agent, (c) a second metal polishing rate modifier agent, and (d) a liquid carrier.
• the CMP composition desirably provides for even, rapid removal of one or more metals in a substrate relative to conventional CMP compositions.
• the CMP composition can be utilized in a manner in which the selectivity for removal of copper and tantalum, and optionally TiN, can be varied by the user.
• the abrasive can be any suitable abrasive, especially an abrasive suitable for use in CMP of semiconductor materials.
• the abrasive desirably comprises, consists essentially of, or consists of a metal oxide.
• suitable abrasives include, without limitation silica, alumina, titania, ceria, zirconia, or a combination of two or more of the foregoing abrasives.
• the abrasive preferably is silica or alumina, most preferably silica (e.g., amorphous silica, colloidal silica, or colloidal silica doped with aluminum).
• the abrasive can be present in the CMP composition in any suitable amount.
• the abrasive can be present in the CMP composition in an amount of 0.1 wt.% or more, e.g., 0.2 wt.% or more, 0.5 wt.% or more, or 1 wt.% or more.
• the abrasive can be present in the CMP composition in an amount of 20 wt.% or less, e.g., 15 wt.% or less, 12 wt.% or less, 10 wt.% or less, 8 wt.% or less, 5 wt.% or less, 4 wt.% or less, or 3 wt.% or less.
• the abrasive can be present in the CMP composition in an amount of 0.1 wt.% to 20 wt.%, e.g., 0.1 wt.% to 12 wt.%, or 0.1 wt.% to 4 wt.%.
• the abrasive can be in any suitable form.
• the abrasive is in the form of particles, which can be of any suitable size (i.e., the diameter of the smallest sphere encompassing the particle).
• the abrasive can have a mean particle size of 10 nm or more, e.g., 20 nm or more, 30 nm or more, or 50 nm or more.
• the abrasive can have a mean particle size of 500 nm or less, e.g., 300 nm or less, 200 nm or less, or 100 nm or less.
• Particle size can be determined by any suitable method, many of which are well known in the art, such as laser light scattering techniques.
• the abrasive desirably is suspended in the CMP composition, more specifically in the liquid carrier of the CMP composition.
• the abrasive preferably is colloidally stable.
• the term “colloid” refers to the suspension of abrasive particles in the liquid carrier.
• Cold stability refers to the maintenance of that suspension over time.
• an abrasive is considered colloidally stable in a CMP composition if, when the CMP composition is placed into a 100 ml graduated cylinder and allowed to stand without agitation for a time of 2 hours, the difference between the concentration of abrasive in the bottom 50 ml of the graduated cylinder ([B] in terms of g/ml) and the concentration of abrasive in the top 50 ml of the graduated cylinder ([T] in terms of g/ml) divided by the initial concentration of abrasive in the CMP composition ([C] in terms of g/ml) is less than or equal to 0.5 (i.e., ([B] - [T] ⁇ /[C] ⁇ 0.5).
• the value of [B]-[T]/[C] desirably is less than or equal to 0.3, and preferably is less than or equal to 0.1.
• the first and second metal polishing rate modifier agents are selected from the following pairs of first and second metal polishing rate modifier agents: (1) the first metal polishing rate modifier agent has a standard reduction potential less than 0.34 V relative to a standard hydrogen electrode, wherein the first metal polishing rate modifier agent is a quinone, and the second metal polishing rate modifier agent has a standard reduction potential greater than 0.34 V relative to a standard hydrogen electrode, (2) the first metal polishing rate modifier agent is an organic oxidizing agent comprising a quinone moiety, and the second metal polishing rate modifier agent is selected from the group consisting of iodide, iodine, I 2 -malonamide3, and triiodide, (3) the first metal polishing rate modifier agent is an organic oxidizing agent comprising a quinone moiety, and the second metal polishing rate modifier agent is an oxidizing agent present in a concentration below the concentration of the first metal polishing rate modifier agent, and (4) the first metal polishing rate modifier agent is an organic oxidizing agent comprising a
• the first metal polishing rate modifier agent can be any suitable material having a standard reduction potential of 0.34 V (the E 0 value for Cu 2+ — > Cu 0 ) or less relative to a standard hydrogen electrode.
• the second metal polishing rate modifier agent in the first embodiment can be any suitable material having a standard reduction potential greater than 0.34 V relative to a standard hydrogen electrode.
• the first metal polishing rate modifier agent can be any suitable organic oxidizing agent comprising a quinone moiety.
• the second metal polishing rate modifier agent in the second embodiment can be any suitable agent selected from the group consisting of iodide, iodine, k-malonamides, and triiodide.
• the CMP composition of the second embodiment can optionally further comprise a second oxidizing agent.
• the first metal polishing rate modifier agent can be any suitable organic oxidizing agent comprising a quinone moiety.
• the second metal polishing rate modifier agent in the third embodiment can be any suitable oxidizing agent present in a concentration below the concentration of the first metal polishing rate modifier agent.
• the first metal polishing rate modifier agent can be any suitable organic oxidizing agent comprising a quinone moiety, with the proviso that the first metal polishing rate modifier is not 1 ,2-napthoquinone-4-sulfonic acid, aminoanthraquinone sulfonic acid, or hydroquinone sulfonic acid.
• the second metal polishing rate modifier agent in the fourth embodiment can be any suitable oxidizing agent, with the proviso that the second metal polishing rate modifier agent is not the same as the first metal polishing rate modifier agent and is not potassium iodate or nitric acid.
• Suitable organic oxidizing agents include, without limitation, chloranilic acid, organic peroxides, (e.g., £-butyl peroxide), n-methylmorpholine-N-oxide, dichloroindophenol, l2-malonamide3, and quinones, such as dihydroxyquinones, e.g., (2,5-dihydroxybenzoquinone), naphthoquinones (e.g., l,2-na ⁇ hthoquinone-4- sulfonic acid), and anthraquinones with one or more functional groups.
• the functional groups of anthraquinones primarily aid in enhancing the solubility of the anthraquinone in the CMP composition but also can affect the performance of the CMP composition in polishing a substrate.
• Suitable functional groups are, without limitation, sulfonates, phosphates, and amines.
• the anthraquinones can have a mixture of two or more different types of functional groups.
• Preferred functional groups for the anthraquinones are sulfonic acids.
• the organic oxidizing agent preferably is an anthraquinone disulfonic acid, such as 9,10-anthraquinone-l,8-disulfonic acid, 9,10-anthraquinone-l,5-disulfonic acid, 9,10-anthraquinone-2,6-disulfonic acid, and salts thereof.
• anthraquinone disulfonic acid such as 9,10-anthraquinone-l,8-disulfonic acid, 9,10-anthraquinone-l,5-disulfonic acid, 9,10-anthraquinone-2,6-disulfonic acid, and salts thereof.
• the second metal polishing rate modifier agent is an inorganic oxidizer
• it is selected from iodate salts (e.g., potassium iodate), iodine, potassium permanganate, inorganic salts of iron (III) (e.g., ferric nitrate), bromate and chlorate salts, and persulfate salts.
• the inorganic metal polishing rate modifier agent is not nitric acid.
• Iodine can be present as molecular iodine (I 2 ) or as a soluble iodine adduct. Soluble iodine adducts are produced, for example, by combining I 2 with a carbon acid.
• the iodine adduct is Vmalonamidea.
• the first and second metal polishing rate modifier agents can be present in the CMP composition in any suitable amounts.
• each of the first and second metal polishing rate modifier agents can be present in the CMP composition in an amount of 0.001 wt.% or more, e.g., 0.01 wt.% or more, 0.05 wt.% or more, or 0.1 wt.% or more.
• each of the first and second metal polishing rate modifier agents can be present in the CMP composition in an amount of 5 wt.% or less, e.g., 1 wt.% or less, or 0.5 wt.% or less.
• each of the first and second metal polishing rate modifier agents can be present in the CMP composition at a concentration of 1 mM or more, e.g., 2 mM or more, 3 mM or more, or 5 mM or more.
• each of the first and second metal polishing rate modifier agents can be present in the CMP composition in an amount of 60 mM or less, e.g., 40 mM or less, 20 mM or less, or 10 mM or less.
• the second metal polishing rate modifier agent may be present in any concentration; greater than, equal to, or less than the first metal polishing rate modifier agent.
• the concentration of the second metal polishing rate modifier agent in the CMP composition is lower than the concentration of the first metal polishing rate modifier agent in the CMP composition.
• the halide anion can be present in the CMP composition in any suitable concentration.
• the halide ion can be present in the CMP composition in a concentration of 5 ppm or more, e.g., 10 ppm or more, or 25 ppm or more.
• the halide ion can be present in the CMP composition in a concentration of 120 ppm or less, e.g., 100 ppm or less, or 60 ppm or less.
• the liquid carrier can be any suitable liquid carrier.
• suitable liquid carriers include water, or water miscible solvents such as ethanol, methanol, isopropanol, butanol, and combinations thereof.
• the liquid carrier is used to facilitate the application of the abrasive particles, the oxidizers and any other additives to the surface of a suitable substrate.
• the liquid carrier is water.
• the water is deionized water.
• the CMP composition optionally further comprises suitable amounts of one or more other materials.
• Such other materials can be other materials commonly included in CMP compositions.
• such other materials can be corrosion inhibitors, viscosity modifying agents, surfactants,_biocides, and the like.
• the corrosion inhibitor i.e., a film-forming agent
• the corrosion inhibitor can be any suitable corrosion inhibitor.
• the corrosion inhibitor is an organic compound containing a heteroatom- containing functional group.
• the corrosion inhibitor can be a heterocyclic organic compound with at least one 5- or 6-member heterocyclic ring as the active functional group, wherein the heterocyclic ring contains at least one nitrogen atom.
• the corrosion inhibitor is selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, benzotriazole, benzimidazole, benzothiazole, and mixtures thereof.
• the composition ⁇ comprises benzotriazole.
• the CMP composition can comprise any suitable amount of a corrosion inhibitor.
• the biocide can be any suitable biocide.
• a suitable biocide is an isothiazolinone composition such as KATHON® biocide, which is available from Rohm and Haas (Philadelphia, PA).
• the CMP composition can comprise any suitable amount of a biocide, e.g., typically a biocidal amount.
• the CMP composition can have any suitable pH.
• the CMP composition has a pH in the range of 1 to 4, e.g., 2 to 3.
• the CMP composition optionally comprises one or more pH adjusting materials, for example, an acid such as nitric acid, hydrochloric acid, acetic acid, and the like, a base such as ammonia, potassium hydroxide, and the like, or a combination thereof, in addition to the other acidic and basic components of the CMP composition.
• the CMP composition can be prepared by any suitable technique, many of which are known to those skilled in the art.
• the CMP composition can be prepared in a batch or continuous process. Generally, the CMP composition can be prepared by combining the components thereof in any order.
• component includes individual ingredients (e.g., abrasives, acids, bases, metal polishing rate modifier agents, and the like), as well as any combination of ingredients.
• abrasive can be dispersed in water, and the metal polishing rate modifier agent, or the acid or base can be added, and mixed by any method that is capable of incorporating the components into the CMP composition.
• oxidizing agents are added, some or all of the oxidizing agents may be added just prior to the initiation of polishing of the substrate.
• the components can be combined on the polishing platen by two or more delivery systems.
• the invention also provides a method of chemical -mechanical polishing of a substrate, especially a semiconductor substrate.
• the method comprises (i) contacting a surface of a substrate with a polishing pad and a CMP composition as described herein, and (ii) moving the polishing pad relative to the surface of the substrate with the polishing composition therebetween, thereby abrading at least a portion of the surface to polish the substrate.
• the chemical-mechanical polishing method can be used to polish any suitable substrate, and is especially useful for polishing substrates comprising copper, copper-based alloys, tantalum, tantalum nitride, or combinations thereof.
• the invention also provides a method for selecting relative removal rates of these metals in chemical-mechanical polishing of a substrate.
• the method comprises altering the concentration of one or more of the metal polishing rate modifier agents such that the removal rate of a first metal is increased or decreased relative to the removal rate of a second metal.
• increasing the concentration of a metal polishing rate modifier agent in a composition may increase the removal rate of copper and have no effect on the removal rate of tantalum. Therefore, in applications where it is desirable to remove only a small amount of copper relative to tantalum, a lower concentration of the second metal polishing rate modifier agent may be used. Conversely, in applications where it is desirable to remove equal amounts of copper and tantalum, a. high concentration of the second metal polishing rate modifier agent may be used.
• the concentration and combination of the metal polishing rate modifier agents can be altered to effectively polish TiN.
• the CMP method of the invention is particularly suited for use in conjunction with a chemical-mechanical polishing apparatus.
• CMP apparatuses for chemical- mechanical polishing are well known in the art.
• the CMP apparatus comprises a platen, which, when in use, is in motion and has a velocity that results from orbital, linear, and/or circular motion, a polishing pad in contact with the platen and moving with the platen when in motion, and a carrier that holds a substrate to be polished by contacting and moving relative to the surface of the polishing pad.
• the polishing of the substrate takes place by the substrate being placed in contact with the polishing pad and a CMP composition described herein and then moving the polishing pad relative to the substrate, so as to abrade at least a portion of the substrate to polish the substrate.
• a substrate can be planarized or polished with a CMP composition as described herein using any suitable polishing pad (e.g., polishing surface).
• suitable polishing pads include, for example, woven and non-woven polishing pads, grooved or non-grooved pads, porous or non-porous pads, and the like.
• suitable polishing pads can comprise any suitable polymer of varying density, hardness, thickness, compressibility, ability to rebound upon compression, and compression modulus.
• the polishing pad can be a hard or soft pad. Polishing of substrates comprising barrier materials, such as tantalum, on hard pads is often avoided because of the resulting high defectivity due to mechanical factors, such as scratching and de-lamination. However it is often desirable to polish using a hard pad because hard pads last longer, thereby lowering the overall cost of the process.
• the CMP composition of the invention may be used with hard pads and has shown exceptional performance with respect to low defectivity when used with hard pads.
• the CMP composition of the invention may be diluted at the point of use. In other words, the CMP composition of the invention may be diluted at the location of the chemical- mechanical polishing, e.g., at the substrate-polishing pad interface.
• any suitable dilution can be used. Dilution is done by adding an appropriate amount of a suitable liquid carrier, typically an aqueous diluent, with adequate mixing, to a concentrate of the CMP composition.
• the liquid carrier typically is water, preferably distilled or deionized water.
• the CMP composition concentrate can include the various components dispersed or dissolved in the liquid carrier, e.g., an aqueous solvent such as water, in amounts such that, upon dilution of the CMP composition concentrate with an appropriate amount of liquid carrier, e.g., aqueous solvent, each component of the CMP composition will be present in the CMP composition in an amount within the appropriate range for use.
• the term tunable refers to the ability to affect a polishing rate of a substrate component by adjusting the concentration of one or more components of the CMP composition.
• the tantalum polishing rate can be tuned from rates of 0 to 2000 A/min
• the copper polishing rate can be tuned from 0 to 8000 A/min
• the TiN polishing rate can be tuned from 0 to 1500 A/min.
• the CMP composition of the invention is tunable to one, two, or more metals present in a substrate. The tunability of the CMP composition provides greater polishing precision of the substrates and greater flexibility for polishing multiple substrates during manufacturing.
• This example demonstrates the effectiveness of dual metal polishing rate modifier agents, using 9,10-anthraquinone-l,8-disulfonic acid (1,8-AQDSA) as a first metal polishing rate modifier agent and hydrogen peroxide as a second metal polishing rate modifier agent, in polishing substrates containing tantalum and copper.
• polishing compositions contained 4 wt.% colloidal silica and 0.08 wt.% of the potassium salt of 1 ,8- AQDSA and were adjusted to pH 2.2 using nitric acid.
• Polishing Composition IA comparative
• Polishing Compositions IB, 1C, ID, and IE contained 25 ppm, 50 ppm, 100 ppm, and 500 ppm of hydrogen peroxide, respectively.
• This example demonstrates the effectiveness of dual metal polishing rate modifier agents, using 1,8-AQDSA as a first metal polishing rate modifier agent and potassium iodate as a second metal polishing rate modifier agent, in polishing substrates containing tantalum and copper.
• polishing compositions contained 4 wt.% colloidal silica, 0.08 wt.% 1,8- AQDSA, and 500 ppm benzotriazole (BTA), and were adjusted to pH 2.2 with nitric acid.
• Polishing Composition 2A comparative
• Polishing Compositions 2B and 2C contained 25 ppm and 100 ppm of potassium iodate, respectively.
• This example demonstrates the effectiveness of dual metal polishing rate modifier agents, using 1,8-AQDSA as a first metal polishing rate modifier agent (1 st MPRM agent) with either potassium iodate or 2,5-dihydroxybenzoquinone as a second metal polishing rate modifier agent (2 nd MPRM agent), in polishing substrates containing tantalum and copper.
• 1 st MPRM agent 1,8-AQDSA
• 2 nd MPRM agent 2,5-dihydroxybenzoquinone
• Similar substrates comprising tantalum and copper were polished on a MIRRATM polishing tool (Applied Materials) with a Polytex pad from Rodel with different polishing compositions (Polishing Compositions 3A-3C). The tool conditions included a 10.3 kPa (1.5 psi) down force.
• polishing compositions contained 1 wt.% colloidal silica and 0.08 wt.% 1,8-AQDSA, and were adjusted to pH 2.8 with nitric acid.
• Polishing Composition 3 A (comparative) further contained 0.05 wt.% BTA.
• Polishing Composition 3B (invention) contained 0.04 wt.% BTA and 2 mM 2,5-dihydroxybenzoquinone.
• Polishing Composition 3 C contained 0.01 wt.% BTA and 0.01 wt.% (0.47 mM) potassium iodate.
• the removal rates (RR) for copper and tantalum for each of the chemical-mechanical polishing compositions were determined, and the results are summarized in Table 3.
• polishing compositions 4A-4D Similar substrates comprising tantalum and copper were polished on a Logitech tabletop polisher with an IClOlO polishing pad (Rodel) with different polishing compositions (Polishing Compositions 4A-4D). The tool conditions were 102 rpm platen speed, 110 rpm carrier speed, 9.31 kPa (1.35 psi) down force, and 150 mL/min polishing composition flow. [0064] Each of the polishing compositions contained 0.5 wt.% colloidal silica, 0.1 wt.% 1,5- AQDSA, 1000 ppm BTA, and the pH was adjusted to 2.4 using nitric acid.
• Polishing Composition 4A did not contain a second metal polishing rate modifier agent.
• Polishing Compositions 4B, 4C, and 4D contained 125 ppm, 250 ppm, and 500 ppm of potassium iodate, respectively.
• NQSA 4-sulfonic acid
• compositions 5A-5D The tool conditions were 102 rpm platen speed, 110 rpm carrier speed,
• Each polishing composition contained 1 wt.% colloidal silica (50 ran particle size),
• Polishing Composition 5 A comparative
• Polishing Composition 5B, 5C, and 5D comparative
• This example demonstrates the effectiveness of dual metal polishing rate modifier agents, using 1,8-AQDSA as a first metal polishing rate modifier agent and varying amounts of 2,5-dihydroxy-l,4-benzoquinone (DHBQ) as the second metal polishing rate modifier agent, in polishing substrates containing tantalum and copper.
• 1,8-AQDSA 1,8-AQDSA
• DVBQ 2,5-dihydroxy-l,4-benzoquinone
• polishing compositions contained 4 wt.% colloidal silica and 0.08 wt.% 1,8-AQDSA, and the pH adjusted to 2.2 using nitric acid.
• Polishing Composition 6A comparativative
• Polishing Compositions 6B, 6C, and 6D comparative
• polishing composition flow was 103 rpm platen speed, 97 rpm carrier speed, 10.3 kPa (1.5 psi) down force, and 200 mL/min polishing composition flow.
• Each polishing composition contained 4 wt.% colloidal silica, 0.08 wt.% potassium salt of 1,8-AQDSA, and 500 ppm BTA, and the pH was adjusted to 2.2 with nitric acid.
• Polishing Composition 7A comparativative
• Polishing Compositions 7B and 7C contained 450 ppm and 2300 ppm of APS, respectively.
• Polishing Compositions 7D and 7E contained 600 ppm and 1000 ppm of KMnC « 4 , respectively.
• Polishing Compositions 7F and 7G contained 50 ppm and 150 ppm KI 3 , respectively. The KI 3 was made by mixing an equal molar amount of KI and I 2 as a 1% concentrate in water prior to addition to the polishing composition.
• Polishing composition 7H contained 50 ppm malonamide and 20 ppm I 2 . [0080 ⁇ The removal rates (RR) for copper and TEOS for each of the chemical-mechanical polishing compositions were determined, and the results are summarized in Table 7.
• Polihsing Composition 8A further comprised 0.08 wt.% of the potassium salt of 1,8-
• This example demonstrates the effectiveness of dual metal polishing rate modifier agents, using 1,8-AQDSA and iron (III) malonate [Fe(III)(Ma) 3 ], in polishing substrates containing tantalum and copper.
• This example demonstrates the synergistic effect of an organic oxidizer as a first metal polishing rate modifier agent and a halide (iodide) as a second metal polishing rate modifier agent when used in a polishing composition containing two metal polishing rate modifier agents.
• TEOS and copper blanket wafers were polished on a Logitech tabletop polisher with different polishing compositions (Polishing Compositions 10A- 10C).
• This example demonstrates the effectiveness of a polishing composition containing two metal polishing rate modifier agents wherein 1,5-AQDSA is the first metal polishing rate modifier agent and a halide is the second metal polishing rate modifier agent; and of a polishing composition containing two metal polishing rate modifier agents and a halide ion as a third metal polishing rate modifier agent, wherein 1,5-AQDSA is the first metal polishing rate modifier agent, chloronilic acid is the second metal polishing rate modifier agent, and iodide, chloride, and bromide are the halide ions that represent the third metal polishing rate modifier agent, in polishing a substrate containing copper.
• Polishing Composition 1 IF (invention) contained 13 ppm KI and 250 ppm chloranilic acid, respectively.
• Polishing Compositions 1 IH and 111 (invention) contained 20 ppm KI with either 100 ppm or 400 ppm of chloranilic acid, respectively.
• Polishing Compositions IU and 1 IK (invention) contained 40 ppm KI with either 100 or 400 ppm of chloranilic acid, respectively.
• This example demonstrates the effectiveness of two metal polishing rate modifier agents and a halide as a third metal polishing rate modifier agent, using 1 ,5-AQDS A as the first metal polishing rate modifier agent, I 2 as the second metal polishing rate modifier agent, and potassium iodide as the third polishing rate modifier agent, in polishing substrates containing copper.
• polishing Composition 12A (comparative) contained 800 ppm of 1,5-AQDSA.
• Polishing Composition 12B (comparative) contained 40 ppm KI.
• Polishing Composition 12C (comparative) contained 20 ppm I 2 .
• Polishing Composition 12D (comparative) contained 800 ppm 1,5-AQDSA.
• Polishing Composition 12E (invention) contained 40 ppm KI and 20 ppm I 2 .
• Polishing Composition 12F (invention) contained 800 ppm 1,5-AQDSA and 40 ppm KI.
• Polishing Composition 12G (invention) contained 800 ppm 1,5-AQDSA and 20 ppm fe.
• Polishing Composition 12H (invention) contained 800 ppm 1,5-AQDSA, 20 ppm I 2 , and 40 ppm KI. [0105] The removal rates (RR) for copper for each of the chemical-mechanical polishing compositions were determined, and the results are summarized in Table 11.
• the results indicate that there is a synergistic effect of combining KI and another metal polishing rate modifier agent.
• the polishing rate for KI as the sole metal polishing rate modifier agent showed very low removal rates (average 130 A/min).
• the rate for 1,5-AQDSA as the sole metal polishing rate modifier agent also showed very low removal rates (average of 94 A/min).
• the rate for KI in combination with 1,5-AQDSA gave a greater than additive response for the removal rate (average of 261 A/min).
• the results also indicate that there is an increase in the Cu removal rate when I 2 is added as a metal polishing rate modifier agent.
• the removal rate enhancement is very low. Only when I 2 was used in combination with KI were the removal rates significantly enhanced.
• This example further demonstrates the effectiveness of a first metal polishing rate modifier (1 st MPRM) agent and a halide as a second metal polishing rate modifier (2 nd MPRM) agent in polishing substrates containing tantalum and copper.
• Polishing Composition 13E contained 0.15 wt.% 2,6-AQDSA and 60 ppm KI.
• Polishing Compositions 13F and 13G contained 0.2 wt.% 2,6-AQDSA and 40 ppm KI and 100 ppm KI, respectively.
• Polishing Composition 13H contained 0.2 wt.% 1,5-AQDSA and 40 ppm KI.
• Table 12 Co er, Tantalum, and TEOS Removal Rates
• results further indicate an advantage of using a halide as a metal polishing rate modifier agent in conjunction with 2,6-AQDSA as a metal polishing rate modifier agent for the removal rate of Cu and Ta.
• the data indicate that the composition of the invention allows for the independent variation of Cu removal rates versus the Ta or TEOS removal rates.
• polishing Compositions 14A-14Q were polished with Polishing Compositions 14A-14Q. Polishing was conducted on the Logitech tool with the same conditions as used in Example 11. Each wafer type was polished with the various compositions for 60 seconds. [0113] Each of the polishing compositions contained 4 wt.% colloidal silica, 800 ppm 1 ,8-
• This example demonstrates the usefulness of the CMP composition of the invention in reducing defectivities when polishing substrates containing barrier materials with hard pads.
• Two TEOS blanket wafers were polished on a MIRRATM polishing tool (Applied Materials) for 60 seconds with an EPICTM DlOO pad (Cabot Microelectronics, Aurora, Illinois) (i.e., a hard pad) and a Politex pad (i.e., a soft pad) with different polishing compositions (Polishing Compositions 15A- 15C).
• the tool conditions were 103 rpm platen speed, 97 rpm carrier speed, 10.3 kPa (1.5 psi) down force, and 200 mL/min polishing composition flow.
• Polishing Composition 15A contained 4 wt.% silica, 500 ppm BTA, and 800 ppm of 1,5- AQDS A, and the pH was adjusted to 2.2 with nitric acid.
• Polishing Composition 15B (invention) contained 4 wt.% silica, 500 ppm BTA, 800 ppm of 1,5-AQDSA, 17 ppm I 2 , and 34 ppm KI, and the pH was adjusted to 2.2 with nitric acid.
• Polishing Composition 15C was a commercial hydrogen peroxide-based polishing composition having hi gh solids content and high pH (i-CueTM 6678-A12, Cabot Microelectronics Corporation).
• the wafers were inspected for defects using an SPl KLA-Tencor (KLA-Tencor, Inc., San Jose, California) dark field blanket wafer inspection tool.
• the output is a normal and oblique measurement count that is a measure of defectivity; higher defects correlate to higher normal and oblique measurement counts.
• the average normal and oblique counts are reported for each of the two wafers polished per experiment in Table 14.
• polishing composition of the invention exhibits a low number of defects compared with the hydrogen peroxide-based polishing composition on the soft pad.
• the defectivity on the hard pad is higher, as expected, but surprisingly, still within an acceptable range.
• Each of the polishing compositions contains 4 wt.% colloidal silica (Nalco 50 nm diameter) and 500 ppm of BTA.
• Polishing compositions of the invention contained 5.4 mM 1,5- AQDSA as the first metal polishing rate modifier agent and a second metal polishing rate modifier agent as set out in Table 15, and the pH was adjusted to 2.8 with ammonium hydroxide. Comparative polishing compositions that do not contain a first metal polishing rate modifier agent were adjusted to a pH of 2.8 with nitric acid.
• the removal rates (RR) for copper, tantalum, and TiN for each of the chemical- mechanical polishing compositions were determined, and the results are summarized in Table 15.
• Table 15 Co er TiN and Tantalum Removal Rates
• Metal polishing rate modifier agents useful for polishing TiN include AQDSA, H 2 O 2 , iodate, oxone, Vmalonamide, chloranilic acid, perchlorate, J-BuOOH, and bromate.
• Metal polishing rate modifier agents useful for polishing copper include l2-malonamide 3 , persulfate, iodate, oxone, chloranilic acid, and bromate.
• Preferred combinations for polishing compositions requiring tunable Ta, Cu 5 and TiN removal rates include AQDSA and I 2 -malonamide3, iodate, oxone, perchlorate, bromate, and n- methlylmorpholine-N-oxide.
• Polishing Composition 16 contained 4 wt.% colloidal silica, 500 ppm BTA, 5.4 mM 1,5-AQDSA, 0.9 mM I 2 # malonamide 3 , and 185 mM H 2 O 2 .
• the removal rates were 486 A/min for copper, 775 A/min for TiN, and 58 A/min for Ta. Therefore, the presence of another metal polishing rate modifier agent in addition to 1 ,5- AQDSA and I 2 -malonamide 3 significantly increases the polishing rate for the barrier layer TiN.

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