US20060223320A1 - Polishing technique to minimize abrasive removal of material and composition therefor - Google Patents
Polishing technique to minimize abrasive removal of material and composition therefor Download PDFInfo
- Publication number
- US20060223320A1 US20060223320A1 US11/093,578 US9357805A US2006223320A1 US 20060223320 A1 US20060223320 A1 US 20060223320A1 US 9357805 A US9357805 A US 9357805A US 2006223320 A1 US2006223320 A1 US 2006223320A1
- Authority
- US
- United States
- Prior art keywords
- composition
- recited
- corrosion inhibitor
- complexing agent
- polishing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000000203 mixture Substances 0.000 title claims abstract description 66
- 239000000463 material Substances 0.000 title claims abstract description 26
- 238000005498 polishing Methods 0.000 title claims description 59
- 238000000034 method Methods 0.000 title claims description 28
- 238000004090 dissolution Methods 0.000 claims abstract description 9
- 239000002002 slurry Substances 0.000 claims description 25
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 21
- 229910052751 metal Inorganic materials 0.000 claims description 21
- 239000002184 metal Substances 0.000 claims description 21
- 239000003112 inhibitor Substances 0.000 claims description 20
- 230000007797 corrosion Effects 0.000 claims description 19
- 238000005260 corrosion Methods 0.000 claims description 19
- 239000008139 complexing agent Substances 0.000 claims description 14
- 230000007935 neutral effect Effects 0.000 claims description 12
- YXVFQADLFFNVDS-UHFFFAOYSA-N diammonium citrate Chemical compound [NH4+].[NH4+].[O-]C(=O)CC(O)(C(=O)O)CC([O-])=O YXVFQADLFFNVDS-UHFFFAOYSA-N 0.000 claims description 10
- 239000002245 particle Substances 0.000 claims description 9
- 239000012964 benzotriazole Substances 0.000 claims description 8
- 239000000758 substrate Substances 0.000 claims description 7
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 claims description 6
- 239000004065 semiconductor Substances 0.000 claims description 6
- 150000003852 triazoles Chemical class 0.000 claims description 6
- QRUDEWIWKLJBPS-UHFFFAOYSA-N benzotriazole Chemical compound C1=CC=C2N[N][N]C2=C1 QRUDEWIWKLJBPS-UHFFFAOYSA-N 0.000 claims description 5
- 239000003989 dielectric material Substances 0.000 claims description 5
- 239000004020 conductor Substances 0.000 claims description 4
- 239000007800 oxidant agent Substances 0.000 claims description 4
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- ROFVEXUMMXZLPA-UHFFFAOYSA-N Bipyridyl Chemical group N1=CC=CC=C1C1=CC=CC=N1 ROFVEXUMMXZLPA-UHFFFAOYSA-N 0.000 claims description 2
- 239000002253 acid Substances 0.000 claims description 2
- 150000007513 acids Chemical class 0.000 claims description 2
- 150000003863 ammonium salts Chemical class 0.000 claims description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims description 2
- 229920002006 poly(N-vinylimidazole) polymer Polymers 0.000 claims description 2
- 150000003536 tetrazoles Chemical class 0.000 claims description 2
- 125000003354 benzotriazolyl group Chemical group N1N=NC2=C1C=CC=C2* 0.000 claims 2
- WTKZEGDFNFYCGP-UHFFFAOYSA-N Pyrazole Chemical compound C=1C=NNC=1 WTKZEGDFNFYCGP-UHFFFAOYSA-N 0.000 claims 1
- 125000003396 thiol group Chemical class [H]S* 0.000 claims 1
- 238000007517 polishing process Methods 0.000 abstract 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 12
- 229910052802 copper Inorganic materials 0.000 description 12
- 239000010949 copper Substances 0.000 description 12
- 230000008569 process Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000003082 abrasive agent Substances 0.000 description 3
- 230000010354 integration Effects 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- NSPMIYGKQJPBQR-UHFFFAOYSA-N 4H-1,2,4-triazole Chemical compound C=1N=CNN=1 NSPMIYGKQJPBQR-UHFFFAOYSA-N 0.000 description 2
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 238000000231 atomic layer deposition Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- -1 i.e. Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005240 physical vapour deposition Methods 0.000 description 2
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 238000003486 chemical etching Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000004070 electrodeposition Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 150000003217 pyrazoles Chemical class 0.000 description 1
- 238000009790 rate-determining step (RDS) Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- PXQLVRUNWNTZOS-UHFFFAOYSA-N sulfanyl Chemical class [SH] PXQLVRUNWNTZOS-UHFFFAOYSA-N 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
Images
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 at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System 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]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
- B24B37/042—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor
- B24B37/044—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor characterised by the composition of the lapping agent
-
- 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
- C09G—POLISHING COMPOSITIONS; SKI WAXES
- C09G1/00—Polishing compositions
- C09G1/04—Aqueous dispersions
Definitions
- the field of invention relates generally to the fabrication of integrated circuits. More particularly, the invention relates to compositions and methods for using polishing layers of material in furtherance of fabricating semiconductor circuits.
- the fabrication of modern semiconductor devices includes forming multiple layers of conductive and dielectric materials on substrates. To that end two various processes are employed to deposit and to remove material associated with the layer. Exemplary deposition techniques include electrochemical deposition, chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), physical vapor deposition (PVD) and the like. Exemplary removal techniques include etching, such as chemical or plasma etching, as well as polishing.
- CVD chemical vapor deposition
- PECVD plasma enhanced CVD
- ALD atomic layer deposition
- PVD physical vapor deposition
- Exemplary removal techniques include etching, such as chemical or plasma etching, as well as polishing.
- CMP Chemical-mechanical polishing
- polishing slurries are well known and widely used techniques for polishing layers to provide the same with a smooth, if not planar, shape.
- the surface being polished has regions with differing materials present, e.g., materials with differing mechanical properties and chemical reactivity.
- the removal rate over the surface is not uniform, which makes obtaining the desired planarization of the surface difficult, while minimizing roughness over the area thereof.
- minimization of dishing is difficult. Dishing results from one of the regions, e.g., the metal region, being removed at a greater rate than the rate at which the other regions of the surface are removed.
- polishing slurries for use in CMP contain fine, suspended abrasive particles to facilitate mechanical polishing of the surface, as well as acidic or basic chemical components to facilitate chemical polishing of the surface.
- the rate at which polishing occurs for a given material and operating conditions is related to the quantity of abrasive particles in the slurry.
- the damage to the surface being polished is also related to the size of the particles in the slurry.
- Chemical component selection may also dramatically affect polish rate and quality for a given material and operating conditions.
- FIG. 1 is a cross-sectional view of a chemical-mechanical polishing machine known in the art but which can be used in practicing the present invention
- FIG. 2 is a schematic cross-sectional view of a chemical-mechanical polishing machine known in the art but which can be used in practicing the present invention
- FIG. 3 is a cross-sectional view showing an exemplary structure to undergo polishing in accordance with the present invention
- FIG. 4 is a cross-sectional view showing a slurry composition in accordance with the present invention, being disposed between the exemplary structure of FIG. 3 and a polishing pad of the polishing machine shown in FIG. 1 in accordance with the present invention;
- FIG. 5 is a cross-sectional view showing the exemplary structure of FIG. 3 having a surface undergoing polishing
- FIG. 6 is a cross-sectional view showing the exemplary structure of FIG. 3 after polishing in accordance with the present invention.
- Polishing machine 10 has a platen 12 , a wafer carrier 14 , a polishing pad 16 , and a slurry 18 on polishing pad 16 .
- An under-pad 20 is typically attached to the upper surface 22 of platen 12 , and polishing pad 16 is positioned on under-pad 20 .
- a drive assembly 24 rotates platen 12 as indicated by arrow A.
- drive assembly 24 may cause platen 12 to reciprocate as indicated by arrow B.
- Wafer carrier 14 has a lower surface 26 to which a wafer 28 may be attached, or wafer 28 may be attached to a resilient pad 30 positioned between wafer 28 and lower surface 26 .
- Wafer carrier 14 may be a weighted, free-floating wafer carrier, or an actuator assembly 32 may be attached to wafer carrier 14 to impart axial and rotational motion, as indicated by arrows C and D, respectively.
- Polishing pad 16 may be embodied as a conventional polishing pad, a web-type polishing pad, a belt-type polishing pad, or any other polishing pad format known in the art. Polishing pad 16 may also be employed as a fixed-abrasive polishing pad. Such a fixed-abrasive polishing pad 16 may be impregnated with particulate abrasives including, but not limited to, alumina, titanium dioxide, silicon dioxide, and cerium dioxide. The abrasives in a fixed-abrasive polishing pad 16 are typically leached therefrom during polishing of wafer 28 .
- an exemplary wafer 28 that undergoes polishing in accordance with the present invention includes a substrate 40 having a recess 42 disposed within a surface 44 .
- substrate 40 includes a dielectric layer and recess 42 is formed within the dielectric layer.
- a metal layer 48 such as copper, is disposed on surface 44 and substantially fills recess 42 .
- a liner 50 is disposed between substrate 40 and metal layer 48 , and is located on surface 44 and surfaces 46 of recess 42 .
- Wafer 28 may comprise various other layers adjacent to recess 42 , surface 44 , liner 50 , and/or metal layer 48 , but for the purposes of simplicity of discussion, no other such structures are depicted.
- polishing pad 16 is placed in close proximity to metal layer 48 . Subsequently, polishing pad 16 is brought in frictional contact with metal layer 48 and, in combination with slurry 18 , removes portions of metal layer 48 . To attenuate, if not prevent, “dishing,” portions 52 of metal layer 48 are removed before portions 54 of metal layer 48 , which are more distant from polishing pad 16 . Once metal layer 48 is substantially removed outside the trench region, liner 50 is subsequently removed from surface 44 outside the trench region by continued polishing with slurry 18 and polishing pad 16 .
- a new surface 144 is defined having first and second regions 146 and 148 .
- First region 146 is comprised of metal from the remaining portions of metal layer 48 , with second region 148 comprising substrate 40 and liner 50 .
- surface 144 has varying material properties across an area thereof, with region 146 typically being harder than region 148 , e.g. when region 148 is a dielectric material.
- the polish rate of region 146 may be greater than the polish rate of region 148 . This may present as “dishing” in which region 146 has a concave shape.
- the present invention significantly attenuates dishing by changing the rate limiting step of the polishing operation.
- metal removal is controlled more by dissolution rather than kinetics during polishing of metal layer 48 .
- dishing may be avoided while at the same time minimizing roughness.
- the polishing operation can be understood to have two principle operating mechanisms or steps, dissolution and kinetics.
- the kinetic step of removal can be defined as the reaction to form soluble metal oxides
- dissolution can be defined as the removal of the metal oxide by dissolving the same in a solvent.
- copper itself does not dissolve in solvents but copper oxide does.
- the removal process is principally governed or controlled by the removal of the oxides from the surface by dissolution, and not by kinetics at the metal interface.
- Kinetic removal of material from surface 144 in accordance with the invention has less of an influence in the polishing rate in large part as a result of providing a neutral pH environment.
- this is accomplished using a reactive liquid (RL) slurry having a neutral pH.
- RL slurries are generally characterized by containing little or no abrasives, i.e., particles. Removal of materials is achieved primarily through chemical reaction of the material being polished with the RL slurry components.
- a composition in accordance with an embodiment of the present invention is provided with a pH that is generally in the range of 5 to 8. Optimal results were achieved using a pH of approximately 7.5. If present at all, particles in the slurry are generally no greater than 250 parts per million of the slurry composition or 0.0025 weight percent. Also included in the composition is a corrosion inhibitor that further minimizes kinetic removal of material from surface 144 during polishing. Other components of the composition may include an oxidizing agent, as well as a complexing agent that controls the rate of dissolution of the material from surface 144 . An exemplary material from which region 146 is formed is copper. As a result, it is desired that the RL composition facilitate removal of copper.
- An exemplary corrosion inhibitor for the slurry composition may be a triazole-based compound, such as 1,2,4-triazole, C 2 H 3 N 3 , and benzotriazole.
- Other suitable inhibitors may include imidazole, polyvinylimidazole, theophiline, bipyridyl, mercapto benzothizole,phenyl marcapto tetrazole, or pyrazole compounds.
- An exemplary oxidizing agent may be hydrogen peroxide, H 2 O 2 .
- An exemplary complexing agent may be dibasic ammonium citrate, (NH 4 ) 2 HC 6 H 5 O 7 , or more generally ammonium salts of citric, oxalic, tartaric, succinic, or actetic acids.
- a first embodiment of the present invention may be as follows: COMPOSIITON 1 hydrogen peroxide dibasic ammonium citrate 1,2,4-triazole water Hydrogen peroxide consists of approximately 0.1% to 3%, and more preferably 1% to 3%, by weight of COMPOSITION 1, and dibasic ammonium citrate consists of approximately 0.1% to 12% by weight of COMPOSITION 1. 1,2,4-Triazole consists of approximately 1% to 6% by weight of COMPOSITION 1, with the remaining portion of the COMPOSITION 1 consisting of a carrier including water.
- a second embodiment of the present invention may be as follows: COMPOSITION 2 hydrogen peroxide dibasic ammonium citrate benzotriazole water Hydrogen peroxide consists of approximately 0.1% to 3%, and more preferably 1% to 3%, by weight of COMPOSITION 2, and dibasic ammonium citrate consists of approximately 0.1% to 12% by weight of COMPOSITION 2. Benzotriazole consists of approximately 0.0001% to 3% by weight of COMPOSITION 2, with the remaining portion of COMPOSITION 2 consisting of a carrier including water.
- a neutral pH RL slurry of the present invention offers many advantages over conventional slurries, including improved planarity. Specifically, copper is passivated when exposed to neutral pH compositions. It is believed that the passivation of copper during polishing provides improved planarization. Additionally, the neutral pH slurry of the present invention reduces the corrosion of the copper during polishing, thereby minimizing the formation of micro-trenches and minimizing roughness. As a result, the present neutral pH RL slurry provides wider process windows, lower defects, and ease of integration into present copper low-K dielectric layers.
- COMPOSITIONS 1 and 2 are selected to facilitate planarization of surfaces having copper-containing materials and dielectric-containing materials.
- other components may be employed dependent upon the materials contained in the layer being polished. Therefore, this invention is not limited to the particular forms illustrated above. Nor is the invention limited or restricted to the particular theories, advantages, or perceived properties disclosed above. Rather, the invention should be defined as set forth in the appended claims and will cover all modifications that do not depart from the scope of this invention.
Abstract
Description
- The field of invention relates generally to the fabrication of integrated circuits. More particularly, the invention relates to compositions and methods for using polishing layers of material in furtherance of fabricating semiconductor circuits.
- The fabrication of modern semiconductor devices includes forming multiple layers of conductive and dielectric materials on substrates. To that end two various processes are employed to deposit and to remove material associated with the layer. Exemplary deposition techniques include electrochemical deposition, chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), physical vapor deposition (PVD) and the like. Exemplary removal techniques include etching, such as chemical or plasma etching, as well as polishing.
- Chemical-mechanical polishing (CMP) methods and polishing slurries are well known and widely used techniques for polishing layers to provide the same with a smooth, if not planar, shape. Often, however, the surface being polished has regions with differing materials present, e.g., materials with differing mechanical properties and chemical reactivity. As a result, the removal rate over the surface is not uniform, which makes obtaining the desired planarization of the surface difficult, while minimizing roughness over the area thereof. For example when polishing a surface having a metal region surrounded by dielectric, minimization of dishing is difficult. Dishing results from one of the regions, e.g., the metal region, being removed at a greater rate than the rate at which the other regions of the surface are removed. This results in a concave region in the metal area, which is often undesirable when a planar shape is desired. To avoid the deleterious effects of CMP of surfaces having regions of differing material properties, various CMP slurries have been developed to obtain desirable CMP characteristics: low polish induced damage, high polishing rate, process predictability, high polished surface uniformity, low polished surface roughness, and the use of non-hazardous, low-cost polish materials.
- Historically, polishing slurries for use in CMP contain fine, suspended abrasive particles to facilitate mechanical polishing of the surface, as well as acidic or basic chemical components to facilitate chemical polishing of the surface. The rate at which polishing occurs for a given material and operating conditions is related to the quantity of abrasive particles in the slurry. However, the damage to the surface being polished is also related to the size of the particles in the slurry. Chemical component selection may also dramatically affect polish rate and quality for a given material and operating conditions.
- Additionally, advanced integration schemes, e.g., stacks with ultra low dielectric (ULK) and air gap integration schemes, are often structurally compromised by CMP processes through interfacial stress created during the CMP process, erosion, as well as absorption of CMP slurry chemicals.
- Therefore, a need exists to provide improved techniques for polishing layers in furtherance of producing semiconductor circuits.
-
FIG. 1 is a cross-sectional view of a chemical-mechanical polishing machine known in the art but which can be used in practicing the present invention; -
FIG. 2 is a schematic cross-sectional view of a chemical-mechanical polishing machine known in the art but which can be used in practicing the present invention; -
FIG. 3 is a cross-sectional view showing an exemplary structure to undergo polishing in accordance with the present invention; -
FIG. 4 is a cross-sectional view showing a slurry composition in accordance with the present invention, being disposed between the exemplary structure ofFIG. 3 and a polishing pad of the polishing machine shown inFIG. 1 in accordance with the present invention; -
FIG. 5 is a cross-sectional view showing the exemplary structure ofFIG. 3 having a surface undergoing polishing; -
FIG. 6 is a cross-sectional view showing the exemplary structure ofFIG. 3 after polishing in accordance with the present invention; and - Referring to
FIGS. 1 and 2 , a brief overview of apolishing machine 10 is depicted that may be employed in accordance with the present invention.Polishing machine 10 has aplaten 12, awafer carrier 14, apolishing pad 16, and aslurry 18 onpolishing pad 16. An under-pad 20 is typically attached to theupper surface 22 ofplaten 12, andpolishing pad 16 is positioned on under-pad 20. Adrive assembly 24 rotatesplaten 12 as indicated by arrow A. In addition,drive assembly 24 may causeplaten 12 to reciprocate as indicated by arrow B. The motion ofplaten 12 is imparted to polishingpad 16 through under-pad 20 becausepolishing pad 16 frictionally engages under-pad 20.Wafer carrier 14 has alower surface 26 to which awafer 28 may be attached, orwafer 28 may be attached to aresilient pad 30 positioned betweenwafer 28 andlower surface 26. -
Wafer carrier 14 may be a weighted, free-floating wafer carrier, or anactuator assembly 32 may be attached towafer carrier 14 to impart axial and rotational motion, as indicated by arrows C and D, respectively.Polishing pad 16 may be embodied as a conventional polishing pad, a web-type polishing pad, a belt-type polishing pad, or any other polishing pad format known in the art.Polishing pad 16 may also be employed as a fixed-abrasive polishing pad. Such a fixed-abrasive polishing pad 16 may be impregnated with particulate abrasives including, but not limited to, alumina, titanium dioxide, silicon dioxide, and cerium dioxide. The abrasives in a fixed-abrasive polishing pad 16 are typically leached therefrom during polishing ofwafer 28. - Referring to
FIGS. 1 and 3 , anexemplary wafer 28 that undergoes polishing in accordance with the present invention includes asubstrate 40 having arecess 42 disposed within asurface 44. In a preferred embodiment,substrate 40 includes a dielectric layer andrecess 42 is formed within the dielectric layer. Ametal layer 48, such as copper, is disposed onsurface 44 and substantially fillsrecess 42. Aliner 50 is disposed betweensubstrate 40 andmetal layer 48, and is located onsurface 44 andsurfaces 46 ofrecess 42.Wafer 28 may comprise various other layers adjacent torecess 42,surface 44,liner 50, and/ormetal layer 48, but for the purposes of simplicity of discussion, no other such structures are depicted. - Referring to
FIGS. 4 and 5 , topolish metal layer 48 in accordance with the present invention,slurry 18 is disposed betweenmetal layer 48 andpolishing pad 16.Polishing pad 16 is placed in close proximity tometal layer 48. Subsequently,polishing pad 16 is brought in frictional contact withmetal layer 48 and, in combination withslurry 18, removes portions ofmetal layer 48. To attenuate, if not prevent, “dishing,”portions 52 ofmetal layer 48 are removed beforeportions 54 ofmetal layer 48, which are more distant frompolishing pad 16. Oncemetal layer 48 is substantially removed outside the trench region,liner 50 is subsequently removed fromsurface 44 outside the trench region by continued polishing withslurry 18 andpolishing pad 16. - Referring to
FIG. 6 , upon removal ofmetal layer 48 andliner 50 from outside the trench region, anew surface 144 is defined having first andsecond regions First region 146 is comprised of metal from the remaining portions ofmetal layer 48, withsecond region 148 comprisingsubstrate 40 andliner 50. As a result,surface 144 has varying material properties across an area thereof, withregion 146 typically being harder thanregion 148, e.g. whenregion 148 is a dielectric material. As a result, were polishingpad 16 to impart a uniform force againstsurface 144 for a given slurry composition, the polish rate ofregion 146 may be greater than the polish rate ofregion 148. This may present as “dishing” in whichregion 146 has a concave shape. - The present invention, however, significantly attenuates dishing by changing the rate limiting step of the polishing operation. In the present invention, metal removal is controlled more by dissolution rather than kinetics during polishing of
metal layer 48. Specifically, it was recognized that by controlling or limiting the removal rate by dissolution fromsurface 144, dishing may be avoided while at the same time minimizing roughness. For purposes of understanding the present invention, the polishing operation can be understood to have two principle operating mechanisms or steps, dissolution and kinetics. The kinetic step of removal can be defined as the reaction to form soluble metal oxides, while dissolution can be defined as the removal of the metal oxide by dissolving the same in a solvent. In the context of polishing copper, copper itself does not dissolve in solvents but copper oxide does. Thus, to effectively remove copper using solvent containing slurries, one has to first react the copper to form copper oxide. In the present invention, the removal process is principally governed or controlled by the removal of the oxides from the surface by dissolution, and not by kinetics at the metal interface. - Kinetic removal of material from
surface 144 in accordance with the invention has less of an influence in the polishing rate in large part as a result of providing a neutral pH environment. In a preferred embodiment, this is accomplished using a reactive liquid (RL) slurry having a neutral pH. RL slurries are generally characterized by containing little or no abrasives, i.e., particles. Removal of materials is achieved primarily through chemical reaction of the material being polished with the RL slurry components. - More specifically, a composition in accordance with an embodiment of the present invention is provided with a pH that is generally in the range of 5 to 8. Optimal results were achieved using a pH of approximately 7.5. If present at all, particles in the slurry are generally no greater than 250 parts per million of the slurry composition or 0.0025 weight percent. Also included in the composition is a corrosion inhibitor that further minimizes kinetic removal of material from
surface 144 during polishing. Other components of the composition may include an oxidizing agent, as well as a complexing agent that controls the rate of dissolution of the material fromsurface 144. An exemplary material from whichregion 146 is formed is copper. As a result, it is desired that the RL composition facilitate removal of copper. An exemplary corrosion inhibitor for the slurry composition may be a triazole-based compound, such as 1,2,4-triazole, C2H3N3, and benzotriazole. Other suitable inhibitors may include imidazole, polyvinylimidazole, theophiline, bipyridyl, mercapto benzothizole,phenyl marcapto tetrazole, or pyrazole compounds. An exemplary oxidizing agent may be hydrogen peroxide, H2O2. An exemplary complexing agent may be dibasic ammonium citrate, (NH4)2HC6H5O7, or more generally ammonium salts of citric, oxalic, tartaric, succinic, or actetic acids. - A first embodiment of the present invention may be as follows:
COMPOSIITON 1 hydrogen peroxide dibasic ammonium citrate 1,2,4-triazole water
Hydrogen peroxide consists of approximately 0.1% to 3%, and more preferably 1% to 3%, by weight of COMPOSITION 1, and dibasic ammonium citrate consists of approximately 0.1% to 12% by weight of COMPOSITION 1. 1,2,4-Triazole consists of approximately 1% to 6% by weight of COMPOSITION 1, with the remaining portion of the COMPOSITION 1 consisting of a carrier including water. - A second embodiment of the present invention may be as follows:
COMPOSITION 2 hydrogen peroxide dibasic ammonium citrate benzotriazole water
Hydrogen peroxide consists of approximately 0.1% to 3%, and more preferably 1% to 3%, by weight of COMPOSITION 2, and dibasic ammonium citrate consists of approximately 0.1% to 12% by weight of COMPOSITION 2. Benzotriazole consists of approximately 0.0001% to 3% by weight of COMPOSITION 2, with the remaining portion of COMPOSITION 2 consisting of a carrier including water. - A neutral pH RL slurry of the present invention offers many advantages over conventional slurries, including improved planarity. Specifically, copper is passivated when exposed to neutral pH compositions. It is believed that the passivation of copper during polishing provides improved planarization. Additionally, the neutral pH slurry of the present invention reduces the corrosion of the copper during polishing, thereby minimizing the formation of micro-trenches and minimizing roughness. As a result, the present neutral pH RL slurry provides wider process windows, lower defects, and ease of integration into present copper low-K dielectric layers.
- The embodiments of the present invention described above are exemplary. Many changes and modifications may be made to the disclosure recited above, while remaining within the scope of the invention. For example, the components of COMPOSITIONS 1 and 2 are selected to facilitate planarization of surfaces having copper-containing materials and dielectric-containing materials. However, other components may be employed dependent upon the materials contained in the layer being polished. Therefore, this invention is not limited to the particular forms illustrated above. Nor is the invention limited or restricted to the particular theories, advantages, or perceived properties disclosed above. Rather, the invention should be defined as set forth in the appended claims and will cover all modifications that do not depart from the scope of this invention.
Claims (33)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/093,578 US20060223320A1 (en) | 2005-03-30 | 2005-03-30 | Polishing technique to minimize abrasive removal of material and composition therefor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/093,578 US20060223320A1 (en) | 2005-03-30 | 2005-03-30 | Polishing technique to minimize abrasive removal of material and composition therefor |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060223320A1 true US20060223320A1 (en) | 2006-10-05 |
Family
ID=37071132
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/093,578 Abandoned US20060223320A1 (en) | 2005-03-30 | 2005-03-30 | Polishing technique to minimize abrasive removal of material and composition therefor |
Country Status (1)
Country | Link |
---|---|
US (1) | US20060223320A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160079084A1 (en) * | 2003-01-03 | 2016-03-17 | Air Products And Chemicals, Inc. | Composition and Method Used for Chemical Mechanical Planarization of Metals |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5897375A (en) * | 1997-10-20 | 1999-04-27 | Motorola, Inc. | Chemical mechanical polishing (CMP) slurry for copper and method of use in integrated circuit manufacture |
US6117783A (en) * | 1996-07-25 | 2000-09-12 | Ekc Technology, Inc. | Chemical mechanical polishing composition and process |
US6274478B1 (en) * | 1999-07-13 | 2001-08-14 | Motorola, Inc. | Method for forming a copper interconnect using a multi-platen chemical mechanical polishing (CMP) process |
US6276996B1 (en) * | 1998-11-10 | 2001-08-21 | Micron Technology, Inc. | Copper chemical-mechanical polishing process using a fixed abrasive polishing pad and a copper layer chemical-mechanical polishing solution specifically adapted for chemical-mechanical polishing with a fixed abrasive pad |
US20020132560A1 (en) * | 2001-01-12 | 2002-09-19 | Qiuliang Luo | Polishing method for selective chemical mechanical polishing of semiconductor substrates |
US20020182982A1 (en) * | 2001-06-04 | 2002-12-05 | Applied Materials, Inc. | Additives for pressure sensitive polishing compositions |
US20020193051A1 (en) * | 1999-04-27 | 2002-12-19 | Hitachi, Ltd. | Apparatus and method for producing substrate with electrical wire thereon |
US6561883B1 (en) * | 1999-04-13 | 2003-05-13 | Hitachi, Ltd. | Method of polishing |
US6562719B2 (en) * | 2000-08-04 | 2003-05-13 | Hitachi, Ltd. | Methods of polishing, interconnect-fabrication, and producing semiconductor devices |
US6565422B1 (en) * | 1999-02-19 | 2003-05-20 | Hitachi, Ltd. | Polishing apparatus using substantially abrasive-free liquid with mixture unit near polishing unit, and plant using the polishing apparatus |
US20040134873A1 (en) * | 1996-07-25 | 2004-07-15 | Li Yao | Abrasive-free chemical mechanical polishing composition and polishing process containing same |
US6800218B2 (en) * | 2001-08-23 | 2004-10-05 | Advanced Technology Materials, Inc. | Abrasive free formulations for chemical mechanical polishing of copper and associated materials and method of using same |
US20040248412A1 (en) * | 2003-06-06 | 2004-12-09 | Liu Feng Q. | Method and composition for fine copper slurry for low dishing in ECMP |
US20060169597A1 (en) * | 2001-03-14 | 2006-08-03 | Applied Materials, Inc. | Method and composition for polishing a substrate |
-
2005
- 2005-03-30 US US11/093,578 patent/US20060223320A1/en not_active Abandoned
Patent Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6635186B1 (en) * | 1996-07-25 | 2003-10-21 | Ekc Technology, Inc. | Chemical mechanical polishing composition and process |
US6313039B1 (en) * | 1996-07-25 | 2001-11-06 | Ekc Technology, Inc. | Chemical mechanical polishing composition and process |
US6117783A (en) * | 1996-07-25 | 2000-09-12 | Ekc Technology, Inc. | Chemical mechanical polishing composition and process |
US20040134873A1 (en) * | 1996-07-25 | 2004-07-15 | Li Yao | Abrasive-free chemical mechanical polishing composition and polishing process containing same |
US5897375A (en) * | 1997-10-20 | 1999-04-27 | Motorola, Inc. | Chemical mechanical polishing (CMP) slurry for copper and method of use in integrated circuit manufacture |
US6276996B1 (en) * | 1998-11-10 | 2001-08-21 | Micron Technology, Inc. | Copper chemical-mechanical polishing process using a fixed abrasive polishing pad and a copper layer chemical-mechanical polishing solution specifically adapted for chemical-mechanical polishing with a fixed abrasive pad |
US6565422B1 (en) * | 1999-02-19 | 2003-05-20 | Hitachi, Ltd. | Polishing apparatus using substantially abrasive-free liquid with mixture unit near polishing unit, and plant using the polishing apparatus |
US6561883B1 (en) * | 1999-04-13 | 2003-05-13 | Hitachi, Ltd. | Method of polishing |
US20020193051A1 (en) * | 1999-04-27 | 2002-12-19 | Hitachi, Ltd. | Apparatus and method for producing substrate with electrical wire thereon |
US6274478B1 (en) * | 1999-07-13 | 2001-08-14 | Motorola, Inc. | Method for forming a copper interconnect using a multi-platen chemical mechanical polishing (CMP) process |
US6562719B2 (en) * | 2000-08-04 | 2003-05-13 | Hitachi, Ltd. | Methods of polishing, interconnect-fabrication, and producing semiconductor devices |
US20030186497A1 (en) * | 2000-08-04 | 2003-10-02 | Hitachi, Ltd. | Methods of polishing, interconnect-fabrication, and producing semiconductor devices |
US20020132560A1 (en) * | 2001-01-12 | 2002-09-19 | Qiuliang Luo | Polishing method for selective chemical mechanical polishing of semiconductor substrates |
US20060169597A1 (en) * | 2001-03-14 | 2006-08-03 | Applied Materials, Inc. | Method and composition for polishing a substrate |
US6783432B2 (en) * | 2001-06-04 | 2004-08-31 | Applied Materials Inc. | Additives for pressure sensitive polishing compositions |
US20020182982A1 (en) * | 2001-06-04 | 2002-12-05 | Applied Materials, Inc. | Additives for pressure sensitive polishing compositions |
US6800218B2 (en) * | 2001-08-23 | 2004-10-05 | Advanced Technology Materials, Inc. | Abrasive free formulations for chemical mechanical polishing of copper and associated materials and method of using same |
US20050026437A1 (en) * | 2001-08-23 | 2005-02-03 | Ying Ma | Abrasive free formulations for chemical mechanical polishing of copper and associated materials and method of using same |
US20040248412A1 (en) * | 2003-06-06 | 2004-12-09 | Liu Feng Q. | Method and composition for fine copper slurry for low dishing in ECMP |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160079084A1 (en) * | 2003-01-03 | 2016-03-17 | Air Products And Chemicals, Inc. | Composition and Method Used for Chemical Mechanical Planarization of Metals |
US10373842B2 (en) * | 2003-01-03 | 2019-08-06 | Versum Materials Us, Llc | Composition and method used for chemical mechanical planarization of metals |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6099604A (en) | Slurry with chelating agent for chemical-mechanical polishing of a semiconductor wafer and methods related thereto | |
KR100653797B1 (en) | Method for manufacturing semiconductor device | |
US6267909B1 (en) | Planarization composition for removing metal films | |
EP1490897B1 (en) | Tantalum barrier removal solution | |
TWI583754B (en) | Chemical-mechanical planarization of substrates containing copper, ruthenium, and tantalum layers | |
WO2013112490A1 (en) | Slurry for cobalt applications | |
KR102459037B1 (en) | Chemical mechanical polishing method for tungsten | |
CN108250977B (en) | Chemical mechanical polishing solution for barrier layer planarization | |
TWI294456B (en) | ||
US20060261041A1 (en) | Method for manufacturing metal line contact plug of semiconductor device | |
WO2018120808A1 (en) | Chem-mechanical polishing liquid for barrier layer | |
TW483061B (en) | Chemical-mechanical polishing apparatus, polishing pad, and method for manufacturing semiconductor device | |
WO2008022277A2 (en) | Selective chemistry for fixed abrasive cmp | |
US7465668B2 (en) | Method of manufacturing semiconductor device | |
KR102459544B1 (en) | Chemical mechanical polishing method for tungsten using polyglycols and polyglycol derivatives | |
US20060223320A1 (en) | Polishing technique to minimize abrasive removal of material and composition therefor | |
JP3917593B2 (en) | Manufacturing method of semiconductor device | |
US10640682B2 (en) | Chemical mechanical polishing method for tungsten | |
US6670272B2 (en) | Method for reducing dishing in chemical mechanical polishing | |
US20060138087A1 (en) | Copper containing abrasive particles to modify reactivity and performance of copper CMP slurries | |
Shinn et al. | Chemical-mechanical polish | |
CN111378382B (en) | Chemical mechanical polishing solution and application thereof | |
CN104745085B (en) | A kind of chemical mechanical polishing liquid for cobalt barrier polishing | |
CN108250972B (en) | Chemical mechanical polishing solution for barrier layer planarization | |
WO2002100963A1 (en) | Use of a gettering agent in a chemical mechanical polishing and rinsing operation and apparatus therefor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: FREESCALE SEMICONDUCTOR, INC., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:COOPER, KEVIN E.;COOPER, JENNIFER;FARKAS, JANOS;AND OTHERS;REEL/FRAME:016442/0088;SIGNING DATES FROM 20050228 TO 20050321 Owner name: ADVANCED MICRO DEVICES, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:COOPER, KEVIN E.;COOPER, JENNIFER;FARKAS, JANOS;AND OTHERS;REEL/FRAME:016442/0088;SIGNING DATES FROM 20050228 TO 20050321 |
|
AS | Assignment |
Owner name: CITIBANK, N.A. AS COLLATERAL AGENT, NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNORS:FREESCALE SEMICONDUCTOR, INC.;FREESCALE ACQUISITION CORPORATION;FREESCALE ACQUISITION HOLDINGS CORP.;AND OTHERS;REEL/FRAME:018855/0129 Effective date: 20061201 Owner name: CITIBANK, N.A. AS COLLATERAL AGENT,NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNORS:FREESCALE SEMICONDUCTOR, INC.;FREESCALE ACQUISITION CORPORATION;FREESCALE ACQUISITION HOLDINGS CORP.;AND OTHERS;REEL/FRAME:018855/0129 Effective date: 20061201 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: FREESCALE SEMICONDUCTOR, INC., TEXAS Free format text: PATENT RELEASE;ASSIGNOR:CITIBANK, N.A., AS COLLATERAL AGENT;REEL/FRAME:037354/0225 Effective date: 20151207 |