WO2005040459A2 - Electroplating compositions and methods for electroplating - Google Patents
Electroplating compositions and methods for electroplating Download PDFInfo
- Publication number
- WO2005040459A2 WO2005040459A2 PCT/US2004/033229 US2004033229W WO2005040459A2 WO 2005040459 A2 WO2005040459 A2 WO 2005040459A2 US 2004033229 W US2004033229 W US 2004033229W WO 2005040459 A2 WO2005040459 A2 WO 2005040459A2
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- WIPO (PCT)
- Prior art keywords
- copper
- composition
- deposition
- suppressor
- electroplating
- Prior art date
Links
- 239000000203 mixture Substances 0.000 title claims abstract description 243
- 238000009713 electroplating Methods 0.000 title claims abstract description 145
- 238000000034 method Methods 0.000 title claims abstract description 74
- 239000010949 copper Substances 0.000 claims abstract description 180
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 172
- 229910052802 copper Inorganic materials 0.000 claims abstract description 172
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 134
- 238000000151 deposition Methods 0.000 claims abstract description 93
- 238000001465 metallisation Methods 0.000 claims abstract description 13
- 238000007747 plating Methods 0.000 claims description 65
- 239000002253 acid Substances 0.000 claims description 62
- 238000012545 processing Methods 0.000 claims description 29
- 230000008021 deposition Effects 0.000 claims description 27
- 230000008569 process Effects 0.000 claims description 27
- 229910052751 metal Inorganic materials 0.000 claims description 26
- 239000002184 metal Substances 0.000 claims description 26
- 239000012530 fluid Substances 0.000 claims description 10
- 238000005137 deposition process Methods 0.000 claims description 7
- 230000008439 repair process Effects 0.000 claims description 6
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical group [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 5
- 239000005864 Sulphur Substances 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 4
- 238000000137 annealing Methods 0.000 claims description 3
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- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims 5
- 125000003827 glycol group Chemical group 0.000 claims 5
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims 5
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims 5
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- 238000004140 cleaning Methods 0.000 claims 1
- 239000004065 semiconductor Substances 0.000 abstract description 30
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- 239000004020 conductor Substances 0.000 abstract description 4
- 235000012431 wafers Nutrition 0.000 description 22
- 239000007788 liquid Substances 0.000 description 15
- 229910021645 metal ion Inorganic materials 0.000 description 10
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- 229910000881 Cu alloy Inorganic materials 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 4
- 229910000365 copper sulfate Inorganic materials 0.000 description 4
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 4
- 230000005684 electric field Effects 0.000 description 4
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- 230000002829 reductive effect Effects 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 230000000712 assembly Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
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- 229910052736 halogen Inorganic materials 0.000 description 3
- 150000002367 halogens Chemical class 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
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- 238000004070 electrodeposition Methods 0.000 description 2
- -1 halide ions Chemical class 0.000 description 2
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- 229910000838 Al alloy Inorganic materials 0.000 description 1
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 1
- COVZYZSDYWQREU-UHFFFAOYSA-N Busulfan Chemical compound CS(=O)(=O)OCCCCOS(C)(=O)=O COVZYZSDYWQREU-UHFFFAOYSA-N 0.000 description 1
- OCUCCJIRFHNWBP-IYEMJOQQSA-L Copper gluconate Chemical compound [Cu+2].OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C([O-])=O.OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C([O-])=O OCUCCJIRFHNWBP-IYEMJOQQSA-L 0.000 description 1
- 229920005682 EO-PO block copolymer Polymers 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
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- 239000000356 contaminant Substances 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 229940108925 copper gluconate Drugs 0.000 description 1
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 1
- DOBRDRYODQBAMW-UHFFFAOYSA-N copper(i) cyanide Chemical compound [Cu+].N#[C-] DOBRDRYODQBAMW-UHFFFAOYSA-N 0.000 description 1
- ZQLBQWDYEGOYSW-UHFFFAOYSA-L copper;disulfamate Chemical compound [Cu+2].NS([O-])(=O)=O.NS([O-])(=O)=O ZQLBQWDYEGOYSW-UHFFFAOYSA-L 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- PEVJCYPAFCUXEZ-UHFFFAOYSA-J dicopper;phosphonato phosphate Chemical compound [Cu+2].[Cu+2].[O-]P([O-])(=O)OP([O-])([O-])=O PEVJCYPAFCUXEZ-UHFFFAOYSA-J 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- WIYCQLLGDNXIBA-UHFFFAOYSA-L disodium;3-(3-sulfonatopropyldisulfanyl)propane-1-sulfonate Chemical compound [Na+].[Na+].[O-]S(=O)(=O)CCCSSCCCS([O-])(=O)=O WIYCQLLGDNXIBA-UHFFFAOYSA-L 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000003411 electrode reaction Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
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- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- 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
- H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
- H01L21/283—Deposition of conductive or insulating materials for electrodes conducting electric current
- H01L21/288—Deposition of conductive or insulating materials for electrodes conducting electric current from a liquid, e.g. electrolytic deposition
- H01L21/2885—Deposition of conductive or insulating materials for electrodes conducting electric current from a liquid, e.g. electrolytic deposition using an external electrical current, i.e. electro-deposition
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/38—Electroplating: Baths therefor from solutions of copper
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/48—After-treatment of electroplated surfaces
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
- C25D7/12—Semiconductors
- C25D7/123—Semiconductors first coated with a seed layer or a conductive layer
-
- 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
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
- H01L21/76877—Filling of holes, grooves or trenches, e.g. vias, with conductive material
Definitions
- This invention relates generally to electroplating compositions and methods for depositing conductive materials in features, such as trenches and/or contact holes formed on semiconductor workpieces.
- first trenches or canals are formed according to a predetermined pattern in the workpiece surface for the wiring.
- contact holes or vias are also cut into the workpiece to connect one layer of metal to the overlying or underlying metal layer. Those trenches and/or contact holes are then filled with copper or a copper alloy.
- This method eliminates the process of removing unnecessary parts of the conductive layer by etching, requiring only that the surface of the workpiece be polished to remove the overburden of plated metal.
- the shapes of such wiring trenches and/or contact holes in today's device designs have a considerably high aspect ratio (the ratio of depth to width of the trenches and/or contact holes) as the width of the wiring gets smaller.
- Chemical vapor deposition (CVD) has been used for depositing various materials, but it is difficult to prepare an appropriate gas material for copper or a copper alloy.
- Electrolytic plating by immersing a workpiece into a plating solution has since been used to fill the trenches and/or contact holes with the necessary conductive material, typically copper or a copper alloy. Electroplating methods typically require a thin, continuous electrically conductive seed layer be deposited on the workpiece prior to the plating process.
- the seed layer generally is formed of a conductive metal, such as copper. Electroplating the desired metal is then generally accomplished by applying an electrical bias to the seed layer and exposing the workpiece, such as a wafer substrate, to an electroplating solution containing metal ions that will plate over the seed layer in the presence of the electrical bias.
- An electroplating composition comprising copper (e.g., copper sulfate) and an acid or a conductive salt (e.g., sulfuric acid) may be used.
- the acid such as sulfuric acid, is added to the electroplating composition to provide the high ionic conductivity to the plating composition necessary to achieve high throwing power.
- “Throwing power” refers to the ability of an electroplating composition to deposit metal uniformly on a workpiece, such as a wafer substrate.
- the acid does not participate in the electrode reactions, but provides conformal coverage of the plating material over the surface of the workpiece because acid reduces resistivity within the electroplating composition. If the composition has a low concentration of copper and a high concentration of acid, throwing power of the composition is improved.
- a problem encountered with conventional plating solutions is that the deposition process within high aspect ratio trenches and/or contact holes is also influenced by mass transport, i.e., diffusion of the metal into the trenches and/or contact holes affects the kinetics of the deposition reaction in addition to the magnitude of the electric field (as is common on larger feature devices).
- the rate at which plating ions are provided to the surface of the workpiece can limit the plating rate, irrespective of the voltage or current density applied to the plating surface.
- Highly conductive electroplating compositions e.g., high acid concentration compositions
- Voids are often formed when using such compositions for filling relatively small trenches and/or contact holes.
- the deposition process In order to obtain good quality deposition, the deposition process must have high mass- transfer rates and low depletion of the reactant concentration near or within the small trenches and/or contact holes.
- the transport rates are limited by the relatively low metal ion concentration.
- Transport of the metal ion to be plated is directly related to the concentration of the plated metal ion in the electroplating composition.
- a higher metal ion concentration results in a higher rate of transport of the metal into small features and in a higher metal ion concentration within the depletion layer, i.e., the boundary layer at the cathode surface hence, faster and better quality depositions may be achieved.
- the filling capability of the composition is poor.
- the inlets of the trenches and/or contact holes are often blocked before the trenches and/or contact holes are filled, thereby tending to form voids.
- Voids may also be caused by other forces, such as non-uniform nucleation at the seed layer during a plating process, inadequate nucleation, and large grain formation during plating.
- using a typical low acid, high metal plating composition provides inferior throwing power and suppressed additive activity, resulting in unplated areas within features.
- a significant number of voids and/or non-uniform deposition typically result in a detrimentally lowered conductivity as well as poor electromigration resistance.
- the void(s) and/or non-uniformity may be sufficiently large to cause an open circuit and the device fails.
- the plating composition has a low concentration of copper and a high concentration of acid, the plating composition will have high conductivity and good polarization, thereby improving throwing power.
- the plating composition has a high concentration of copper and a low concentration of acid, it is known that the composition will have good transport of the metal ions.
- the concentration of metal ions will be sufficient at bottom of the high aspect ratio trenches and/or contact holes to allow good feature filling.
- Attempts to address the problems introduced using the conventional plating compositions i.e., compositions having a low concentration of copper and a high concentration of acid or visa versa
- various additives have been used, such as particular suppressors, accelerators, and/or levelers in various concentrations.
- Other additives used include halide ions, such as chloride. The additives used depend upon whether the plating composition is a low copper concentration with a high acid concentration or the opposite, as is known to those persons of ordinary skill in the art.
- Certain additives may decrease the deposition rate of metal atoms at a given potential, thereby inhibiting the deposition process, whereas other additives may increase the deposition rate of metal ions at a given potential, thereby accelerating the deposition rate.
- the available plating compositions have not sufficiently resolved the feature filling problems when dealing with the relatively high aspect ratio features in which the transport of metal ions is somewhat limited.
- the electroplating compositions and electroplating methods of this invention provide surprisingly superior fill capabilities and ensure superior copper deposition with bottom-up fill capabilities for high aspect ratio features of submicron size such that the presence of voids is reduced or substantially eliminated altogether.
- the electroplating compositions and methods may be utilized to electroplate a metal into device features, such as high aspect ratio semiconductor device trenches and/or contact holes on a semiconductor workpiece.
- the disclosed compositions and methods are applicable to a wide range of steps used in the manufacture of a metallization layer in a workpiece. For ease of explanation, the compositions and methods are discussed primarily in relation to metallization of features formed in a semiconductor wafer processed to form integrated circuits or other microelectronic components.
- compositions and methods disclosed are not limited to such semiconductor wafers and features but may be used in connection with any semiconductor workpiece wherein metallization is required.
- workpiece is not limited to semiconductor wafers, but rather refers to substrates having generally parallel planar first and second surfaces and that are relatively thin, including semiconductor wafers, ceramic wafers, and other substrates upon which microelectronic circuits or components, data storage elements or layers, and/or micromechanical elements are formed.
- the electroplating compositions include copper and acid at previously avoided relative concentrations.
- the electroplating compositions provide surprisingly superior fill capabilities, particularly copper deposition bottom-up fill capabilities for high aspect ratio features having submicron dimensions (e.g., 0.12 ⁇ m trenches) such that the presence of voids is reduced or substantially eliminated altogether. Additionally, the electroplating compositions are less corrosive toward seed layers, also providing superior fill capabilities.
- the electroplating compositions may comprise an aqueous mixture of copper and sulfuric acid wherein the ratio of copper concentration to sulfuric acid concentration (concentrations in g/L) is equal to from about 0.3 to about 0.8. They may also comprise an aqueous mixture of copper and sulfuric acid wherein the copper concentration is near its solubility limit when the sulfuric acid concentration is from about 65 to about 150 g/L.
- compositions may also include conventional additives, such as accelerators, suppressors, halides and/or levelers.
- the disclosed methods utilize the electroplating compositions for depositing copper onto semiconductor workpieces. The methods further ensure superior copper deposition with bottom-up fill capabilities for high aspect ratio features of submicron size such that the presence of voids is reduced or substantially eliminated altogether.
- Fig. 1 is a graph illustrating the solubility of copper sulfate in sulfuric acid at about 25°C.
- Figs. 2(a)-2(e) are scanning electron microscope (SEM) photographs of copper semiconductor interconnects measuring from about 0.12 ⁇ m to about 0.15 ⁇ m in width at half the height of the interconnect formed by using various embodiments of the electroplating compositions wherein the copper concentration was varied while the acid concentration was about 80 g/L.
- Fig. 2(f) is a pictured leverage plot showing feature fill results when comparing varied acid/copper electroplating compositions, where the copper concentration was increased in successive samples.
- Figs. 1 is a graph illustrating the solubility of copper sulfate in sulfuric acid at about 25°C.
- Figs. 2(a)-2(e) are scanning electron microscope (SEM) photographs of copper semiconductor interconnects measuring from about 0.12 ⁇ m to about 0.15 ⁇ m in width at half the height of the interconnect formed by using various embodiment
- FIG. 3(a)-3(d) are SEM photographs of copper semiconductor interconnects measuring about 0.15 ⁇ m in width at half the height of the interconnect formed using various embodiments of the electroplating compositions wherein the acid concentration was varied while the copper concentration was about 20 g/L (in Figs. 3(a)-(b)) and about 50 g/L (in Figs. 3(c)-(d)).
- Fig. 3(e) is an SEM photograph of an interconnect trench measuring about 0.023 ⁇ m in width at half the height of the interconnect trench prior to electroplating.
- Fig. 3(f) is a pictured leverage plot showing the feature fill results when comparing varied acid/copper electroplating compositions, wherein the acid concentration was increased in successive samples.
- FIG. 4(a)-4(c) are SEM photographs of copper semiconductor interconnects measuring about 0.25 ⁇ m in width at half the interconnect height formed using a prior art electroplating composition wherein the copper concentration was about 50 g/L while the acid concentration was about 10 g/L.
- Figs. 4(d)-4(f) are SEM photographs of copper semiconductor interconnects measuring about 0.25 ⁇ m in width at half the interconnect height formed using an embodiment of the electroplating compositions of this invention wherein the copper concentration was about 50 g/L while the acid concentration was about 80g/L.
- FIG. 5(a) is an SEM photograph of copper semiconductor interconnects measuring about 0.2 ⁇ m in width at half the height of the interconnect formed using a prior art electroplating composition wherein the copper concentration was about 20 g/L while the acid concentration was about 180 g/L
- Fig. 5(b) is an SEM photo of copper semiconductor interconnects measuring about 0.2 ⁇ m in width at half the height of the interconnect formed using an embodiment of the electroplating compositions of this invention wherein the copper concentration was about 50 g/L while the acid concentration was about 80g/L.
- FIG. 6(a) is an SEM photograph of a copper semiconductor via measuring about 0.16 ⁇ m in width at half the height of the via formed using a prior art electroplating composition wherein the copper concentration was about 20 g/L while the acid concentration was about 180 g/L.
- Fig. 6(b) is an SEM photograph of a copper semiconductor via measuring about 0.16 ⁇ m in width at half the height of the via formed using an embodiment of the electroplating compositions of this embodiment of this invention wherein the copper concentration was about 40 g/L while the acid concentration was about 100 g/L.
- Fig. 7(a) is a cross-sectional view of a representative electroprocessing station having a processing chamber or reactor for use in a processing tool with which the electrochemical compositions may be utilized. Fig.
- FIG. 7(b) is a cross-sectional view of a portion of a representative processing chamber or reactor with which the electrochemical compositions may be utilized.
- Figs. 8(a)-8(d) are representative process flow charts illustrating a few of many possible manners of implementing metallization of a semiconductor workpiece utilizing the electrochemical compositions and methods of this invention.
- Figs. 9(a) and 9(b) illustrate two representative processing tools with which the electroplating compositions may be utilized.
- electroplating compositions of copper and acid such as sulfuric acid
- copper and acid such as sulfuric acid
- the electroplating compositions of this invention do not follow such conventional wisdom. Instead, they include copper concentrations more equivalent to the acid concentrations.
- the electroplating compositions formulated in accordance with this invention comprise an aqueous mixture of copper and sulfuric acid wherein the ratio of the copper concentration to the sulfuric acid concentration (all concentrations listed in g/L are grams per liter of solution) is equal to from about 0.3 to about 0.8 g/L.
- the electroplating compositions comprise a mixture of copper and sulfuric acid wherein the ratio of the copper concentration to the sulfuric acid concentration is equal to from about 0.4 to about 0.7 g/L. In yet other embodiments the electroplating compositions comprise a mixture of copper and sulfuric acid wherein the ratio of the copper concentration to the sulfuric acid concentration is equal to from about 0.5 to about 0.6 g/L. In other embodiments the electroplating compositions comprise an aqueous mixture of copper and sulfuric acid wherein the copper concentration in the composition is within about 60% to about 90% of its solubility limit when the sulfuric acid concentration is from about 65 to about 150 g/L.
- the electroplating compositions comprise an aqueous mixture of copper and sulfuric acid wherein the copper concentration in the composition is within about 60 % to about 90 % of its solubility limit when the sulfuric acid concentration is from about 70 to about 120 g/L.
- the compositions comprise an aqueous mixture of copper at a concentration of from about 35 to about 60 g/L and sulfuric acid at a concentration of from about 65 to about 150 g/L.
- the compositions comprise an aqueous mixture of copper at a concentration of from about 45 to about 55 g/L and sulfuric acid at a concentration of from about 75 to about 120 g/L.
- electroplating compositions comprising an aqueous mixture of about 40 g/L copper and about 100 g/L sulfuric acid or about 50 g/L copper and about 80 g/L sulfuric acid.
- Other exemplary embodiments comprise aqueous mixtures of about 60 g/L copper and about 65 g/L sulfuric acid or about 47 g/L copper and about 70 g/L sulfuric acid.
- the copper source used in the electroplating compositions of this invention may be, for example, a copper salt such as copper sulfate, copper fluoborate, copper gluconate, copper sulfamate, copper sulfonate, copper pyrophosphate, copper chloride, copper cyanide, combinations thereof, and the like.
- a copper salt such as copper sulfate, copper fluoborate, copper gluconate, copper sulfamate, copper sulfonate, copper pyrophosphate, copper chloride, copper cyanide, combinations thereof, and the like.
- copper sulfate is primarily mentioned herein, it is to be understood that copper from any suitable source may be used in the disclosed compositions.
- the electroplating compositions may contain other mineral acids in combination with or in place of sulfuric acid, such as fluoboric acid and the like, organic acids, such as methane sulfonic (MSA), amidosulfuric, aminoacetic, and combinations thereof, and the like, combinations of mineral acids and organic acids.
- the electroplating compositions may include further additives such as suppressors, accelerators, and levelers to assist in filling small features.
- the electroplating compositions may also contain additives such as halide ions, for example chloride, bromide, iodide, combinations thereof, and the like.
- chloride is added in combination with certain suppressing additives (e.g., polyethers) in an amount sufficient to interact and suppress deposition of copper at constant voltage, or to increase the over potential for a given applied current density.
- certain suppressing additives e.g., polyethers
- the concentrations of halides added are typically determined by the operating parameters chosen for the particular hardware.
- the halogen concentration is from about 10 ppm to about 100 ppm.
- about 50 ppm HC1 may be added to an electroplating composition comprising about 50 g/L copper and about 80 g/L sulfuric acid.
- about 20 ppm HC1 is added to an electroplating composition comprising about 40 g/L copper and about 100 g/L sulfuric acid.
- Other suitable additives used to aid the suppressor in decreasing the deposition rate and/or to aid the accelerator in increasing the deposition rate may be added.
- Suppressors generally increase cathodic polarization and adsorb on the substrate surface to inhibit or reduce copper deposition in the adsorbed areas.
- Suppressors added to the plating composition may include, e.g., two-element polyethylene glycol based suppressors, such as suppressors made of random/block copolymers of ethylene oxide and propylene oxide mixed in a wide range of ratios.
- CTJBATH ViaForm Suppressor (DF75), available from Enthone, Inc. of West Haven, CT, or Shipley C- 3100 suppressor, available from Shipley Company of Marlborough, MA, may be used.
- Embodiments of the electroplating compositions may include any suitable suppressor type and concentration.
- CUBATH ViaForm DF75 suppressor at a concentration of from about 2 ml/L to about 30 ml/L, or about 2 to about 10 may be used.
- Shipley C-3100 suppressor at a concentration of from about 5 ml/L to about 25 ml/L, or about 10 to about 20 may be used.
- about 2 ml/L of the CUBATH suppressor is used in an electroplating composition comprising about 50 g/L copper and about 80 g/L sulfuric acid.
- about 17.5 ml/L of Shipley C-3100 suppressor, available from Shipley Company of Marlborough, MA is used in an electroplating composition comprising about 40 g/L copper and about 100 g/L sulfuric acid.
- Accelerators reduce cathodic polarization and compete with suppressers for adsorption sites to accelerate copper growth in the adsorbed areas.
- the accelerators used in the plating composition may include, e.g., sulphur containing compounds, such as bis(sodium sulfopropyl)disulfide (SPS).
- Embodiments of the electroplating compositions may include, for example, an accelerator such as the CUBATH ViaForm DF74.
- an accelerator such as the CUBATH ViaForm DF74.
- Such an accelerator may be used in any suitable concentration of from about 2 ml/L to about 30 ml/L, from about 2 to about 8 ml/L.
- about 5 ml/L may be used in an electroplating composition comprising about 50 g/L copper and about 80 g/L sulfuric acid.
- the accelerator For seed layers with superior coverage such as CVD, about 8 ml/L of this accelerator may be used. For seed layers with poor bottom coverage (e.g., bottom voids), about 2 ml L of the DF74 or a like accelerator may be used. In another embodiment, about 10 ml/L of Shipley B-3100 accelerator (available from Shipley) is used in an electroplating composition comprising about 40 g/L copper and about 100 g/L sulfuric acid. Suppressors and accelerators heavily populate around the features and since the suppressors inhibit the copper growth, a small overhang of the seed layer can close the mouth of the feature leading to a void in the feature.
- Shipley B-3100 accelerator available from Shipley
- an electroplating composition where the suppression is mostly active on the top of the topographical features and the accelerators dominate the suppressors in activity inside features so as to achieve bottom up growth may be particularly useful.
- concentrations of such components may vary to be optimized for particular hardware and/or operating conditions as desired.
- Suitable concentration ranges for additives (e.g., halides, accelerators, suppressors, optional levelers) to the electroplating compositions may vary depending upon the specific operating conditions for a particular chosen process and or tool (e.g., temperature, spin speed, flow rate, current density) as is known to those persons of ordinary skill in the art.
- Continued acceleration after filling the features may result in excess growth of copper over the features creating surface protrusions.
- a leveler such as CUBATH ViaForm Leveler DF79, available from Enthone, or Shipley U-3100 leveler (available from Shipley) may be added to the electroplating compositions disclosed herein.
- Other suitable levelers may be used to suppress the current at the protrusions to provide a leveled surface.
- Specific embodiments of the electroplating compositions include a leveler concentration of from about 0.5 ml/L to about 3 ml/L, or from about 1.0 to about 3.0 ml/L.
- about 2.5 ml L of the DF79 leveler may be used in an electroplating composition comprising about 50 g/L copper and about 80 g/L sulfuric acid.
- about 2 ml/L of Shipley U-3100 leveler may be used in an electroplating composition comprising about 40 g/L copper and about 100 g/L sulfuric acid.
- the operating temperatures of electroplating compositions of this invention may range from about 15°C to about 30°C or from about 22°C to about 27°C.
- an operating temperature of an electroplating composition comprising about 50 g/L copper and about 80 g/L sulfuric acid of about 25°C has been found useful.
- the plating methods using electroplating compositions of this invention may be carried out, for example, in a fountain style plating reactor of the type currently marketed by Semitool, Inc.
- Figure 7(a) illustrates a partial schematic, cross-sectional view of a representative plating station 110.
- a support member 140 includes a spin motor 144 and a rotor 142 coupled to the spin motor 144.
- the rotor 142 supports a contact assembly 160.
- the rotor 142 may include a backing plate 145 and a seal 141.
- the backing plate 145 moves transverse to a workpiece 101 (arrow T) between a first position (shown in solid lines in Figure 7(a)) in which the backing plate 145 contacts a backside of the workpiece 101 and a second position (shown in broken lines in Figure 7(a)) in which it is spaced apart from the backside of the workpiece 101.
- the contact assembly 160 may include a carrier 162, a plurality of contacts 164 carried by the carrier 162, and a plurality of shafts 166 extending between the carrier 162 and the rotor 142.
- the contacts 164 can be ring-type spring contacts or other types of contacts that are configured to engage a portion of the seed-layer on the workpiece 101.
- Commercially available support members 140 and contact assemblies 160 can be used.
- the plating station 110 may include a reactor vessel 130 having an outer housing or chamber 131 and an inner chamber 132 (both shown schematically in Figure 7(a)) disposed within the outer chamber 131.
- the inner chamber 132 carries at least one electrode (not shown in Figure 7(a)) and directs a flow of processing liquid, such as an embodiment of the electroplating compositions of this invention, to the workpiece 101.
- the processing liquid flows over a weir (as indicated by arrow F) and into the outer chamber 131, which captures the processing liquid for recirculation, recycling or disposal.
- the support member 140 holds the workpiece 101 at a workpiece- processing site (such as a workpiece plane) of the reactor vessel 130 so that at least a plating surface of the workpiece 101 engages the processing liquid.
- An electrical field is established in the processing liquid by applying an electrical potential between the plating surface of the workpiece 101 and one or more electrodes (described in greater detail below with reference to Figure 7(b)) positioned in the inner vessel 132.
- the contact assembly 160 is biased with a negative potential with respect to the electrode(s) in the inner chamber 132 to plate conductive materials onto the workpiece 101.
- one of the electrodes (a "thieving" electrode) is also biased with a negative potential with respect to the other electrodes to control the uniformity with which materials are applied to the workpiece 101.
- Figure 7(b) is a schematic illustration of an embodiment of the reactor vessel 130 having multiple electrodes, including a thieving electrode.
- the reactor vessel 130 includes a helical drain channel 134 between the inner chamber 132 and the outer chamber 131.
- the drain channel 134 receives processing liquid, such as an embodiment of the electroplating compositions of this invention, overflowing the inner chamber 132 and guides the processing liquid toward a liquid outlet 135.
- Liquid enters the inner chamber 132 through a primary inlet 136a and a secondary inlet 136b.
- the primary inlet 136a is coupled to a primary flow channel 137 that directs a portion of the processing liquid within the inner chamber 132 to a primary flow guide 170.
- the primary flow guide 170 includes apertures 171 that direct the flow toward a central axis 139 of the inner chamber 132.
- the secondary inlet 136b may be coupled to a distributor 189 that directs a secondary liquid, for example the same or a different embodiment of the electroplating compositions of this invention, to a plurality of electrodes.
- the inner chamber 132 includes four concentric electrodes 180.
- a controller 183 is operatively coupled to the electrodes 180a-d to individually control the current applied to each electrode, and accordingly control the corresponding conductive paths between the electrodes and the workpiece feature.
- the electrodes 180 are housed in a field shaping unit 176 having a corresponding plurality of electrode compartments 177 (shown as compartments 177a- 177d) separated by partitions 178.
- the distributor 189 directs the secondary liquid into each compartment 177 via a corresponding plurality of distributor channels 179 (shown as distributor channels 179a-179d). Accordingly, the secondary liquid proceeds through the distributor 189, past the electrodes 180, and upwardly toward the workpiece feature.
- the effect of the field shaping unit 176 on the electrical field produced by the electrodes 180 is as if the electrodes 180 were positioned at the exits of each compartment 177, as shown by virtual electrode positions 181 a- 181 d.
- the primary flow guide 170 forms an inwardly facing vessel wall 138 (indicated in dashed lines in Figure 7(b)) that extends upwardly and outwardly from the primary fluid inlet 136a.
- a shield 184 having an aperture 182 can be positioned between the electrodes 180 and the workpiece 101 feature to control the interaction between the workpiece feature and the fluid flow and electrical field within the reactor vessel 130.
- each compartment 177 has one or more apertures 174 (e.g., holes and/or slots) through which liquid and gas bubbles pass. Accordingly, gas bubbles trapped in each compartment 177 proceed radially outwardly through the apertures 177 of each compartment until they exit the inner chamber 132.
- Each compartment 177 may include an interface member 175.
- the interface members 175 may include a filter or other element configured to trap air bubbles and other particulates, while allowing the secondary liquid to pass toward the workpiece feature.
- the interface members 175 include ion membranes that allow ions to pass toward the workpiece feature, while preventing or substantially preventing the secondary fluid from passing toward the feature. Instead, the secondary fluid passes through the apertures 174 and out of the inner chamber 132 via the helical drain channel 134. The first fluid can be collected at a separate drain (not shown).
- the ion membrane allows the fluid as well as ions to pass through.
- the system of Fig. 9(a) includes a plurality of processing stations 210. These processing stations include one or more rinsing/drying stations and one or more electroplating stations. (Other suitable immersion-chemical processing tools may be used with the electroplating compositions.)
- the system includes thermal processing stations, such as at 215, which include at least one thermal reactor that is adapted for rapid thermal processing (RTP).
- the workpieces are transferred between processing stations 210 and the RTP station 215 using one or more robotic transfer mechanisms 220 that are disposed for linear movement along a central track 225.
- One or more of the stations 210 may also incorporate structures that are adapted for executing an in-situ rinse.
- Fig. 9(b) illustrates another representative processing tool in which the electroplating compositions of this invention may be used.
- the processing tool shown in Fig. 9(b) includes an RTP station 235 located in portion 230 that includes at least one thermal reactor, may be integrated into a tool set.
- at least one thermal reactor is serviced by a dedicated robotic mechanism 240.
- the dedicated robotic mechanism 240 accepts workpieces that are transferred to it by the robotic transfer mechanisms 220. Transfer may take place through an intermediate staging door/area 245.
- an annealing station may be implemented as a separate module that is attached to upgrade an existing tool set.
- the electroplating compositions of this invention may be utilized with any of a myriad of workpiece metallization processing methods for forming interconnects and vias in a workpiece.
- Figs. 8(a)-8(d) illustrate several possible electrochemical deposition metallization process flows wherein the disclosed electroplating compositions may be used to form interconnects, vias or other such features.
- a typical Damascene process flow is illustrated in Fig. 8(a).
- the workpiece is first provided with a metallic seed layer and a barrier/adhesion layer that are disposed over a dielectric layer into which trenches (or other device features) are formed.
- the seed layer is used to conduct electrical current during a subsequent metal electroplating step.
- the seed layer is a very thin layer of metal that can be applied using one of several methods.
- the seed layer of metal can be laid down using physical vapor deposition or chemical vapor deposition methods to produce a layer on the order of about 500 A thick.
- the seed layer can also be formed of copper, gold, nickel, palladium, and most or all other metals.
- the seed layer is formed over a surface that is convoluted by the presence of the trenches, or other device features, which are recessed into the dielectric substrate.
- an electrochemical (electroless or electrolytic) seed layer repair or enhancement step is performed (not shown in Fig. 8(a)).
- a seed layer such as an ultra-thin seed layer, may be repaired if needed to render the seed layer suitable for a subsequent metal deposition, or enhanced by depositing additional metal on the existing seed layer, in a separate deposition step to provide an "enhanced" seed layer.
- the enhanced seed layer typically has a thickness at all points on sidewalls of substantially all recessed features distributed within the workpiece that is equal to or greater than about 10% of the nominal seed layer thickness over an exteriorly disposed surface of the workpiece.
- a seed layer enhancement process may be performed as disclosed in U.S. Patent Nos. 6,290,833 and 6,565, 729, which are incorporated herein by reference.
- a seed layer enhancement process may be followed by a rinsing step.
- a copper layer is electroplated onto the seed layer in the form of a blanket layer.
- the blanket layer is plated to an extent which forms an overlying layer, to provide a copper layer that fills the trenches (or other device features) used to form the interconnect wiring.
- the copper layer may optionally then be rinsed, typically in Dl water and (optionally) dried.
- the rinsing/drying, if performed, may occur in the chamber in which the electrochemical plating occurs or in separate chambers depending upon the plating tool used. Subsequently, excess copper is removed by transferring the workpiece to a stripping unit to, e.g., bevel-etch the excess copper.
- excess copper is selectively removed from, for example, a backside of the workpiece and/or a peripheral edge of a process side of a workpiece, using methods such as those disclosed in U.S. Patent No. 6,413,436, which is incorporated herein by reference.
- the bevel etched and back side cleaned workpiece may then be rinsed.
- the backside clean and initial Dl rinse can occur simultaneously.
- Each of the plating, rinsing and etching steps can be performed in the same chamber or can be performed in separate chambers.
- the etched workpiece is subsequently annealed.
- the workpiece may be rinsed with, e.g., Dl water, prior to annealing.
- the workpiece may be annealed using any suitable method.
- the workpiece may be annealed using conventional furnace methods or may be annealed at temperatures below 100°C, or even at ambient room temperature, using methods such as those disclosed in U.S. Patent No. 6,508,920, which patent is incorporated herein by reference.
- the workpiece may then be chemically mechanically polished to, for example, remove copper that is deposited in excess of what is desired for the device features.
- an alternative process utilizing the electroplating compositions of this invention may include a preclean or pre-wet step prior to copper plating so as to limit surface defects and remove waste materials therefrom.
- the preclean or pre-wet step, copper plating, backside clean and/ or bevel etch and Dl rinsing steps may all take place in the plating tool.
- the anneal and CMP steps may then follow outside the plating tool.
- a seed layer repair or enhancement step may be performed prior to copper plating (Fig. 8c)).
- the seed layer repair step may comprise electrochemically depositing a second seed layer followed by a Dl rinse.
- the second seed layer deposition may be performed by any suitable means, such as discussed above. As shown in Fig.
- the seed repair, copper plating, backside clean and or bevel etch and Dl rinsing steps may all take place in the plating tool.
- the anneal and CMP steps may then follow outside the plating tool.
- the copper plating, back side clean/bevel etch, Dl rinsing and anneal steps may all take place in the plating tool.
- CMP may then be performed outside the plating tool.
- the electroplating compositions of this invention may be used in a number of electroplating tools using any of a variety of workpiece metallization processing methods.
- a number of process parameters may be used for the metallization process using the electroplating compositions disclosed herein.
- the process parameters utilized depend upon the features to be filled, the tool being used and other such variables as know to those persons skilled in the art.
- One possible process is set forth below as a representative example only.
- a workpiece loading bias for example, from about 0.1 V to about 1.0 V may be applied to the workpiece plating surface while the workpiece is being immersed in an embodiment of the disclosed electroplating composition.
- a loading bias of about 0.4 V or greater for 200 mm workpieces have been found to provide a void free fill of the features.
- the wafer may be rotated upon immersion into the electroplating composition between about 40 ⁇ m and about 200 ⁇ m. Upon plating, the wafer is rotated between about 10 ⁇ m and about 150 ⁇ m.
- Exemplary embodiments of the plating methods rotate the wafer upon immersion at about 75 ⁇ m and upon plating at about, 75 ⁇ m at 1.0 amp for 5 seconds, 40 ⁇ m at 1.0 amp for 25 seconds, and 40 ⁇ m at 4.5 amps for the remaining time necessary to deposit the desired thickness.
- the rotation speeds, biases, and time periods utilized depend upon the plating tool used and the device to be formed.
- the wafer was rotated upon immersion into the plating composition at between about 40 ⁇ m and about 200 ⁇ m. Upon plating the wafer is rotated between about 10 ⁇ m and about 150 ⁇ m.
- Exemplary embodiments of the plating methods rotate the wafer upon immersion at about 75 ⁇ m and upon plating at about, 75 ⁇ m at 1.0 amp for 5 seconds, 40 ⁇ m at 1.0 amp for 5 seconds, 40 ⁇ m at 2.0 amp for 39 seconds, and 60 ⁇ m at 8.22 amp until the desired thickness is achieved.
- a 1 ⁇ m copper deposition may be deposited on 200 mm wafer having a copper seed layer of about 400 A.
- the wafer may be rotated at about 150 ⁇ m.
- the current density may be from about 2 mAmps/cm 2 to about 70 mAmps/cm 2 .
- the current density may be from about 3 mAmps/cm 2 to about 25 mAmps/cm 2 for a time period in which the desired thickness is achieved.
- the current density utilized can be varied during the plating process, typically but not exclusively starting at a low current density and finishing with a higher current density.
- Example 1 and Comparative Data A representative embodiment of the electroplating composition of this invention is shown in Table 1.
- FIG. 4(f) show some voiding, the number and size of the voids in the interconnects are significantly fewer and smaller as compared to the resulting voiding in interconnects formed using the prior art high copper/low acid electroplating composition, as can be seen in the microphotograph of Fig. 4(c).
- another prior art electroplating composition i.e., a conventional low copper/high acid composition
- a prior art electroplating composition comprising 20 g/L Cu and 180 g/L sulfuric acid produced seam voids in metallized trenches.
- an embodiment of the electrochemical plating compositions of this invention specifically a composition comprising 80 g/L sulfuric acid and 50 g/L Cu, produced void free features in the identical size trenches (as shown in Fig. 5(b)).
- Example 2 and Comparative Data Another embodiment of the electroplating composition of this invention is shown in Table 2.
- Table 2 Component Concentration g/L Cu 40 H 2 SO 4 100 Accelerator (B-3100) 10.0 Suppressor (C-3100) 17.5 Leveler (U-3100) 3.0 ⁇ _-_ * HCL 20 * Halogen concentration in ppm.
- suitable current densities such as those set forth above, void free filling of a via was achieved with this embodiment of the electroplating composition of this invention as is illustrated in Fig. 6(b).
- a prior art electroplating composition was tested under the same conditions with identical additives (at identical concentrations) as was Example 2.
- a via fill having voids as can be seen in Fig.
- the prior art electroplating composition compared had the conventional high acid and low copper combination (i.e., 20 g/L Cu and 180 g/L sulfuric acid) producing a via having visible voids, as shown in Fig. 6(a) while the embodiments of the electroplating compositions of this invention showed surprisingly superior results, a void-free via filling was achieved, as shown in Fig. 6(b).
- Example 3 As shown in Figs. 2(a) through 2(e), copper semiconductor interconnect trenches measuring about 0.12 to about 0.15 ⁇ m in width at half the height of the interconnect were filled using various embodiments of the electroplating compositions wherein the copper concentration was varied while the acid concentration was about 80 g/L and were compared to various prior art compositions. Specifically, as shown in Figs. 2(a) and 2(c), interconnect trenches were filled utilizing a prior art electroplating composition comprising 20 g/L copper and 80 g/L acid. As can be seen in the micrographs of these figures, the prior art low copper/high acid compositions result in devices having visible voids. In comparison, however, as shown in Figs.
- the electroplating compositions of this invention having copper and acid concentrations near the copper solubility limit resulted in devices having a relatively low number of voids formed.
- interconnect trenches were filled utilizing an electroplating composition comprising 35 g/L copper and 80 g/L acid providing superior results.
- Example 4 As the Fig. 2(f) tabulated results show a number of example electroplating compositions tested wherein the copper concentration was increased step-wise and the acid concentrations were kept relatively low. This increase in copper concentration relative to the low acid concentration (contrary to conventional wisdom) again gave su ⁇ risingly superior results. Specifically, the additive concentrations and halide concentrations were held constant while the acid and copper concentrations were varied from 1 Og/1 to 150g/l and from 20g/l to 50g/l, respectively. After plating, the plated wafers were cross-sectioned and examined for the presence of voids. For each example of electroplating compositions tested, five filled features at each of three sizes (0.12, 0.15, 0.20 ⁇ ms) were examined.
- Example 5 and Comparative Data As shown in Figs. 3(a)-3(d), copper semiconductor interconnect trenches measuring about 0.15 ⁇ m in width at half the height of the interconnect were filled using electroplating compositions wherein the sulfuric acid concentration was varied while the copper concentration was 20 g/L or 50 g/L (20 g/L Cu and 80 and 150 g/L acid, respectively in Figs. 3(a)-(b)) and 50 g/L Cu with 10 and 80 g/L acid, respectively in Figs. 3(c)-(d)). As shown in Fig. 3(a), an interconnect trench was filled utilizing an electroplating composition comprising 20 g/L copper and 80 g/L acid.
- an interconnect trench was filled utilizing an electroplating composition comprising 20 g/L copper and 150 g/L sulfuric acid - like the typical conventional high acid/low copper compositions. Again, inferior results are achieved with such a composition.
- an interconnect trench was filled utilizing an electrochemical composition comprising 50 g/L copper and 10 g/L sulfuric acid. Results are shown in Fig. 3(c). (The results shown in Fig. 3(d) show the superior results achieved with the electroplating composition of this invention as described above in Example 1.)
- Example 6 As the Fig. 3(f) tabulated results further demonstrate, increasing the acid concentration while increasing the copper concentration so that it is at or near its solubility limit provides a statistically significant improvement in feature fill.
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- 2004-10-08 WO PCT/US2004/033229 patent/WO2005040459A2/en active Application Filing
- 2004-10-08 CN CN200480029839.2A patent/CN1867703A/en active Pending
- 2004-10-08 JP JP2006535564A patent/JP2007508461A/en active Pending
- 2004-10-08 EP EP04794546A patent/EP1680535A4/en not_active Withdrawn
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CN105696034A (en) * | 2014-12-12 | 2016-06-22 | 英飞凌科技股份有限公司 | Electrolyte, method of forming a copper layer and method of forming a chip |
US10648096B2 (en) | 2014-12-12 | 2020-05-12 | Infineon Technologies Ag | Electrolyte, method of forming a copper layer and method of forming a chip |
Also Published As
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EP1680535A4 (en) | 2008-05-07 |
CN1867703A (en) | 2006-11-22 |
JP2007508461A (en) | 2007-04-05 |
WO2005040459A3 (en) | 2006-01-12 |
TW200516176A (en) | 2005-05-16 |
EP1680535A2 (en) | 2006-07-19 |
US20050081744A1 (en) | 2005-04-21 |
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