WO1996025270A1 - Abrasive-free selective chemo-mechanical polish for tungsten - Google Patents

Abrasive-free selective chemo-mechanical polish for tungsten Download PDF

Info

Publication number
WO1996025270A1
WO1996025270A1 PCT/US1996/000154 US9600154W WO9625270A1 WO 1996025270 A1 WO1996025270 A1 WO 1996025270A1 US 9600154 W US9600154 W US 9600154W WO 9625270 A1 WO9625270 A1 WO 9625270A1
Authority
WO
WIPO (PCT)
Prior art keywords
tungsten
polishing
reactant
tungsten portion
applying
Prior art date
Application number
PCT/US1996/000154
Other languages
French (fr)
Inventor
Roger L. Alvis
Liliana Thompson
Paul R. Besser
Original Assignee
Advanced Micro Devices, Inc.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Advanced Micro Devices, Inc. filed Critical Advanced Micro Devices, Inc.
Publication of WO1996025270A1 publication Critical patent/WO1996025270A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F3/00—Brightening metals by chemical means
    • C23F3/04—Heavy metals
    • 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

Definitions

  • This invention relates to polishing processes and systems and, particularly, to tungsten polishing processes and systems.
  • Integrated circuit manufacturing processes often create topographic features (i.e. , rotrusions and depressions) on the surface in integrated circuit structures that reduce the accuracy of subsequent lithographic processes.
  • topographic features i.e. , rotrusions and depressions
  • a process used to manufacture integrated circuits having tungsten structures results in the formation of the undesirable topographic features because the upper surface of the tungsten structure is lower than the surrounding structure.
  • Figures 1A-1C show the formation of a tungsten via for use with a multiple metal layer interconnect structure 100, using a plasma etchbac process. Like reference numbers are used for like structures between drawings.
  • Figure 1A shows a structure 100 including a tungsten layer 110 deposited over an etchstop or barrier layer 120.
  • Barrier layer 120 is typically made of Titanium ("Ti") or Titanium Nitride (“TiN”) or both.
  • Part of tungsten layer 110 forms a tungsten via 130 in a recess 140 in an insulating layer 150.
  • Tungsten via 130 can be used to interconnect a layer 160 with a conductive layer, typically Aluminum (“Al”), subsequently deposited over tungsten via 130 and barrier layer 120 (after the plasma etchback process) .
  • Figure IB shows tungsten via 130 and islands 170 and 180 formed over barrier layer 120 by a plasma etchback process.
  • the plasma etch process removes the upper portion of tungsten layer 110 (i.e., the portion of tungsten layer 110 above the top surface 122 of barrier layer 120) .
  • a top surface 132 of tungsten via 130 is approximately level with a top surface 122 of barrier layer 120.
  • Islands 170 and 180 are undesired residual islands of tungsten leftover from tungsten layer 110 due to the initial roughness of the tungsten film which causes the etch rate to be greater in the opening of recess 140.
  • the plasma etchback process is allowed to continue (i.e., overetch) to remove islands 170 and 180 as shown in Figure 1C.
  • the top surface 132 of tungsten via 130 becomes lower than the top surface of 122 of barrier layer 120, thereby forming undesirable topographic features 190 in structure 100.
  • Topographic features 190 will have a more pronounced detrimental effect as device sizes become smaller in the next generation process technologies.
  • Figure 2 shows a chemo-mechanical system 200 having an abrasive slurry 210 for forming tungsten structures on a wafer 220.
  • abrasive slurry 210 is placed onto the surface of a pad 230, which is kept in contact with a surface 222 of wafer 220 by holder 240.
  • Wafer 220 is held against pad 230 with a pressure in the range of 3-9 psi.
  • Pad 230 is mounted on a table 250, and table 250 (and consequently, pad 230) is rotated by a motor (not shown) to polish the surface 222 of wafer 220.
  • Slurry 210 flows between surface 222 and pad 230 during the polishing process to aid in removing tungsten from surface 222 of wafer 220.
  • the sizes of any topographic features are reduced; however, the abrasive slurry polishing process of system 200 is not selective to the barrier, and therefore degrades the integrity of a barrier layer surrounding the upper surface of the remaining tungsten.
  • the abrasive slurry polishing process is continued into insulating layer 150, whereby portions of barrier layer 120 and insulating layer 150 are removed as illustrated in Figure 3A.
  • top surface 132 of tungsten via 130 is substantially level with a top surface 152 of insulating layer 150.
  • tungsten via 130 is typically used to interconnect layer 160 with an Al layer deposited over tungsten via 130.
  • a barrier layer 310 is deposited on top of insulating layer 150 and tungsten via 130, as illustrated in Figure 3B, to improve the conductive and electromigration properties of the subsequently deposited Al layer.
  • an additional deposition is required after the abrasive slurry polishing process.
  • wafer 220 must be thoroughly cleaned to remove the abrasive particles and slurry medium from abrasive slurry 210 left behind on wafer 220.
  • abrasive slurry 210 must be stirred during the polishing process to ensure homogeneity of slurry 210.
  • the slurry manufacturer must process slurry 210 to remove contaminants and ensure uniform particle size, increasing the cost of slurry 210.
  • an abrasive-free, selective chemo-mechanical process for polishing tungsten comprises the steps of applying hydrogen peroxide ("H 2 0 2 ") to a polishing pad, and polishing the tungsten with the polishing pad and H 2 0 2 .
  • This embodiment is used advantageously in applications such as polishing a structure with a tungsten layer deposited over a Ti/TiN barrier layer having recesses. The process is performed at room temperature using an approximately 30% H 2 0 2 solution. The tungsten layer is polished to remove the upper portion of the tungsten layer so that the upper surfaces of the tungsten remaining in the recesses are substantially level with the upper surface of the
  • H 2 0 2 is highly selective for reacting with tungsten relative to the Ti and TiN, this process selectively removes tungsten while leaving the Ti/TiN barrier layer intact. Thus, no additional barrier layer deposition is necessary. Further, no abrasive particles are left behind on the structure after polishing. Still further, H 2 0 2 is relatively inexpensive compared to an abrasive slurry and need not be stirred during use.
  • Figures 1A-1C illustrate steps of a plasma etchback process for forming a tungsten via.
  • Figure 2 shows a chemo-mechanical polishing system using an abrasive slurry.
  • Figure 3A-3B illustrate steps of forming a tungsten via using the abrasive slurry polishing system of Figure 2.
  • Figure 4 shows an abrasive-free chemo-mechanical polishing system according to one embodiment of the present invention.
  • Figure 5 shows an abrasive-free chemo-mechanical polishing system according to another embodiment of the present invention.
  • Figure 6 illustrates a tungsten via resulting from a polishing process according to one embodiment of the present invention.
  • FIG. 4 shows an abrasive-free polishing system 400 according to one embodiment of the present invention, adapted for die polishing.
  • System 400 is used to polish a die 410 having tungsten structures on the surface of die 410.
  • die 410 can include a tungsten layer, a barrier layer, and a tungsten via similar to tungsten layer 110, barrier layer 120, and tungsten via 130 shown in Figure 1A.
  • System 400 includes a motorized polishing wheel 420 with a polishing pad 422, such as models Poly et I or Ecomet I made by Bhueler, located at 41 Waukegan
  • a 30% H 2 0 2 solution is applied to polishing pad 422. Although a 30% H 2 0 2 solution is used in this embodiment, any concentration within the range 10-60% is suitable.
  • the H 2 0 2 reacts with the tungsten to form soluble tungsten oxides.
  • Die 410 is fixed to a platen 430 and pyrex specimen mount centering ring 440 available from Gatan Inc., 780 Commonwealth Drive, Warrendale PA 15806.
  • An adhesive such as crystal wax, also available from Gatan Inc., is used to fix die 410 to platen 430.
  • Polishing wheel 420 rotates at approximately 200 rpm, although any speed in the range of 0-300 rpm is suitable.
  • the operator places platen 430 and centering ring 440 onto pad 422.
  • the operator applies the surface of wafer 410 to pad 422 by pressing down on an end 432 of platen 430 with a light pressure to polish a surface 412 of die 410.
  • the operator moves platen 430 and centering ring 440 along the surface of pad 422 in the opposite direction of the rotation of pad 422 for more uniform polishing.
  • Die 410 is polished until the Ti/TiN barrier is visible over the entire surface (except, of course, the upper surface of the tungsten vias) of die 410.
  • This process is performed at room temperature; however, any temperature in the range of 10-60°C is suitable. Generally, the polishing process is faster with higher temperature. At room temperature, this process takes approximately 5-240 seconds and results in a structure having the upper surface of the tungsten substantially level with the upper surface of the barrier layer. Because the H 2 0 2 solution contains no abrasive particles, there are no abrasive particles to clean from the surface of polished die 410, as is necessary in system 200 ( Figure 2) . Further, because the H 2 0 2 solution is highly selective for tungsten relative to Ti and TiN, the Ti/TiN barrier layer of die 410 remains intact, thereby eliminating the need to redeposit the barrier layer as may be necessary when a plasma etchback system is used.
  • FIG. 5 shows an abrasive-free polishing system 500 according to another embodiment of the present invention, adapted for wafer polishing.
  • System 500 is used to polish a wafer 510 that includes a plurality of dice, each die being similar to die 410 shown in Figure 4.
  • System 500 is similar to a conventional chemo- mechanical polishing system, except that system 500 includes a H 2 0 2 solution 520 and does not include an abrasive slurry.
  • system 500 can include a polisher such as Model 6ds-sp made by Strausbaugh, located in San Luis Obispo, CA.
  • H 2 0 2 solution 520 is stored in a dispenser 522 and applied onto the surface of a pad 530.
  • Dispenser 522 controls the flow of H 2 0 2 520 onto pad 530 to be approximately 100-200 ml/minute.
  • Pad 530 is kept in contact with a surface 512 of wafer 510 by a holder 540.
  • Wafer 510 is held against pad 530 and rotated by an overarm mechanism (not shown) coupled to holder 540 with a pad-to-wafer pressure of approximately 3-9 psi.
  • Pad 530 is mounted on a table 550.
  • Table 550 is rotated at approximately 30-40 rpm, in the same direction that wafer 410 is rotated, to polish the surface 512 of wafer 510.
  • H 2 0 2 solution 520 "floods" pad 530, whereby H 2 0 2 can selectively remove tungsten, aided by the mechanical contact of pad 530 on surface 512 of wafer 510. Wafer 510 is kept in contact with pad 530 until the upper surface of the tungsten is polished to the desired level.
  • Figure 6 illustrates a structure 600 having a tungsten via 610, resulting from the abrasive-free chemo-mechanical polishing processes described in conjunction with Figure 4, after being applied to a structure similar to structure 100 ( Figure 1A) .
  • tungsten via 610 is formed in a recess 620 defined by a barrier layer 630.
  • An upper surface 612 of tungsten via 610 is substantially level with an upper surface 632 of barrier layer 630, thereby reducing topographical features in the surface of structure 600.
  • barrier layer 630 remains intact and is suitable as an underlayer for a subsequent metal layer deposition.
  • H 2 0 2 concentration, pad-to-wafer (or pad- to-die) interface pressure, pad rotation rate, and H 2 0 2 solution temperature can be altered to achieve tungsten removal at different rates and/or efficiency.
  • polishing tools or fixtures different from those describe above can be used to obtain substantially similar results.
  • other embodiments may be adapted for applications other than the formation of tungsten vias with barrier layers.
  • solutions with reactants other than H 2 0 2 can be used, provided the reactant is selective to react with tungsten relative to the barrier layer and other structures used in the application.

Abstract

According to one embodiment of the present invention, an abrasive-free, selective chemo-mechanical process for polishing tungsten comprises the steps of applying H2O2 to a polishing device, and polishing the tungsten with H2O2. This embodiment is used advantageously in applications such as polishing a structure with a tungsten layer deposited over a Ti/TiN barrier layer having recesses. The tungsten layer is polished so that the upper surfaces of the tungsten remaining in recesses formed in the barrier layer are substantially level with the upper surface of the Ti/TiN layer, thereby substantially reducing the size of topographic features on the structure. Because the H2O2 is highly selective for reacting with tungsten relative to the Ti and TiN, this process selectively removes tungsten while leaving the Ti/TiN barrier layer intact.

Description

ABRASIVE-FREE SELECTIVE CHEMO-MECHANICAL POLISH FOR TUNGSTEN
FTELD OF THE INVENTION
This invention relates to polishing processes and systems and, particularly, to tungsten polishing processes and systems.
BACKGROUND
Integrated circuit manufacturing processes often create topographic features (i.e. , rotrusions and depressions) on the surface in integrated circuit structures that reduce the accuracy of subsequent lithographic processes. For example, a process used to manufacture integrated circuits having tungsten structures results in the formation of the undesirable topographic features because the upper surface of the tungsten structure is lower than the surrounding structure.
Figures 1A-1C (prior art) show the formation of a tungsten via for use with a multiple metal layer interconnect structure 100, using a plasma etchbac process. Like reference numbers are used for like structures between drawings.
Figure 1A shows a structure 100 including a tungsten layer 110 deposited over an etchstop or barrier layer 120. Barrier layer 120 is typically made of Titanium ("Ti") or Titanium Nitride ("TiN") or both. Part of tungsten layer 110 forms a tungsten via 130 in a recess 140 in an insulating layer 150. Tungsten via 130 can be used to interconnect a layer 160 with a conductive layer, typically Aluminum ("Al"), subsequently deposited over tungsten via 130 and barrier layer 120 (after the plasma etchback process) . Figure IB shows tungsten via 130 and islands 170 and 180 formed over barrier layer 120 by a plasma etchback process. The plasma etch process removes the upper portion of tungsten layer 110 (i.e., the portion of tungsten layer 110 above the top surface 122 of barrier layer 120) . A top surface 132 of tungsten via 130 is approximately level with a top surface 122 of barrier layer 120. Islands 170 and 180 are undesired residual islands of tungsten leftover from tungsten layer 110 due to the initial roughness of the tungsten film which causes the etch rate to be greater in the opening of recess 140.
The plasma etchback process is allowed to continue (i.e., overetch) to remove islands 170 and 180 as shown in Figure 1C. However, due to continued exposure of tungsten via 130 to the etch chemistry, the top surface 132 of tungsten via 130 becomes lower than the top surface of 122 of barrier layer 120, thereby forming undesirable topographic features 190 in structure 100. Topographic features 190 will have a more pronounced detrimental effect as device sizes become smaller in the next generation process technologies.
Figure 2 (prior art) shows a chemo-mechanical system 200 having an abrasive slurry 210 for forming tungsten structures on a wafer 220. In system 200, abrasive slurry 210 is placed onto the surface of a pad 230, which is kept in contact with a surface 222 of wafer 220 by holder 240. Wafer 220 is held against pad 230 with a pressure in the range of 3-9 psi. Pad 230 is mounted on a table 250, and table 250 (and consequently, pad 230) is rotated by a motor (not shown) to polish the surface 222 of wafer 220. Slurry 210 flows between surface 222 and pad 230 during the polishing process to aid in removing tungsten from surface 222 of wafer 220. After polishing surface 222 of wafer 220 using system 200, the sizes of any topographic features are reduced; however, the abrasive slurry polishing process of system 200 is not selective to the barrier, and therefore degrades the integrity of a barrier layer surrounding the upper surface of the remaining tungsten. Thus, the abrasive slurry polishing process is continued into insulating layer 150, whereby portions of barrier layer 120 and insulating layer 150 are removed as illustrated in Figure 3A. As a result, top surface 132 of tungsten via 130 is substantially level with a top surface 152 of insulating layer 150. However, there is no barrier layer above insulating layer 150.
As stated above, tungsten via 130 is typically used to interconnect layer 160 with an Al layer deposited over tungsten via 130. However, a barrier layer 310 is deposited on top of insulating layer 150 and tungsten via 130, as illustrated in Figure 3B, to improve the conductive and electromigration properties of the subsequently deposited Al layer. Thus, an additional deposition is required after the abrasive slurry polishing process.
Further, (referring back to Figure 2) wafer 220 must be thoroughly cleaned to remove the abrasive particles and slurry medium from abrasive slurry 210 left behind on wafer 220. In addition, abrasive slurry 210 must be stirred during the polishing process to ensure homogeneity of slurry 210. Also, the slurry manufacturer must process slurry 210 to remove contaminants and ensure uniform particle size, increasing the cost of slurry 210.
SUMMARY
According to one embodiment of the present invention, an abrasive-free, selective chemo-mechanical process for polishing tungsten comprises the steps of applying hydrogen peroxide ("H202") to a polishing pad, and polishing the tungsten with the polishing pad and H202. This embodiment is used advantageously in applications such as polishing a structure with a tungsten layer deposited over a Ti/TiN barrier layer having recesses. The process is performed at room temperature using an approximately 30% H202 solution. The tungsten layer is polished to remove the upper portion of the tungsten layer so that the upper surfaces of the tungsten remaining in the recesses are substantially level with the upper surface of the
Ti/TiN layer, thereby substantially reducing the size of topographic features on the structure. Because the H202 is highly selective for reacting with tungsten relative to the Ti and TiN, this process selectively removes tungsten while leaving the Ti/TiN barrier layer intact. Thus, no additional barrier layer deposition is necessary. Further, no abrasive particles are left behind on the structure after polishing. Still further, H202 is relatively inexpensive compared to an abrasive slurry and need not be stirred during use.
BRIEF DESCRIPTION OF THE DRAWINGS
Figures 1A-1C (prior art) illustrate steps of a plasma etchback process for forming a tungsten via. Figure 2 (prior art) shows a chemo-mechanical polishing system using an abrasive slurry.
Figure 3A-3B (prior art) illustrate steps of forming a tungsten via using the abrasive slurry polishing system of Figure 2. Figure 4 shows an abrasive-free chemo-mechanical polishing system according to one embodiment of the present invention.
Figure 5 shows an abrasive-free chemo-mechanical polishing system according to another embodiment of the present invention.
Figure 6 illustrates a tungsten via resulting from a polishing process according to one embodiment of the present invention.
DETAILED DESCRIPTION Figure 4 shows an abrasive-free polishing system 400 according to one embodiment of the present invention, adapted for die polishing. System 400 is used to polish a die 410 having tungsten structures on the surface of die 410. For example, die 410 can include a tungsten layer, a barrier layer, and a tungsten via similar to tungsten layer 110, barrier layer 120, and tungsten via 130 shown in Figure 1A.
System 400 includes a motorized polishing wheel 420 with a polishing pad 422, such as models Poly et I or Ecomet I made by Bhueler, located at 41 Waukegan
Road, Lale Bluff, 111., 60044. A 30% H202 solution is applied to polishing pad 422. Although a 30% H202 solution is used in this embodiment, any concentration within the range 10-60% is suitable. The H202 reacts with the tungsten to form soluble tungsten oxides. Die 410 is fixed to a platen 430 and pyrex specimen mount centering ring 440 available from Gatan Inc., 780 Commonwealth Drive, Warrendale PA 15806. An adhesive such as crystal wax, also available from Gatan Inc., is used to fix die 410 to platen 430.
Polishing wheel 420 rotates at approximately 200 rpm, although any speed in the range of 0-300 rpm is suitable. The operator places platen 430 and centering ring 440 onto pad 422. The operator applies the surface of wafer 410 to pad 422 by pressing down on an end 432 of platen 430 with a light pressure to polish a surface 412 of die 410. The operator moves platen 430 and centering ring 440 along the surface of pad 422 in the opposite direction of the rotation of pad 422 for more uniform polishing. Die 410 is polished until the Ti/TiN barrier is visible over the entire surface (except, of course, the upper surface of the tungsten vias) of die 410. This process is performed at room temperature; however, any temperature in the range of 10-60°C is suitable. Generally, the polishing process is faster with higher temperature. At room temperature, this process takes approximately 5-240 seconds and results in a structure having the upper surface of the tungsten substantially level with the upper surface of the barrier layer. Because the H202 solution contains no abrasive particles, there are no abrasive particles to clean from the surface of polished die 410, as is necessary in system 200 (Figure 2) . Further, because the H202 solution is highly selective for tungsten relative to Ti and TiN, the Ti/TiN barrier layer of die 410 remains intact, thereby eliminating the need to redeposit the barrier layer as may be necessary when a plasma etchback system is used. Although a H202 solution is described, other solutions that are reactive with tungsten can be used, provided all of the reactants the solutions are relatively non-reactive with Ti and TiN. Figure 5 shows an abrasive-free polishing system 500 according to another embodiment of the present invention, adapted for wafer polishing. System 500 is used to polish a wafer 510 that includes a plurality of dice, each die being similar to die 410 shown in Figure 4. System 500 is similar to a conventional chemo- mechanical polishing system, except that system 500 includes a H202 solution 520 and does not include an abrasive slurry. For example, system 500 can include a polisher such as Model 6ds-sp made by Strausbaugh, located in San Luis Obispo, CA.
H202 solution 520 is stored in a dispenser 522 and applied onto the surface of a pad 530. Dispenser 522 controls the flow of H202 520 onto pad 530 to be approximately 100-200 ml/minute. Pad 530 is kept in contact with a surface 512 of wafer 510 by a holder 540. Wafer 510 is held against pad 530 and rotated by an overarm mechanism (not shown) coupled to holder 540 with a pad-to-wafer pressure of approximately 3-9 psi. Pad 530 is mounted on a table 550. Table 550 is rotated at approximately 30-40 rpm, in the same direction that wafer 410 is rotated, to polish the surface 512 of wafer 510. Although a rotation speed of 30-40 rpm is described, any speed in the range 0-100 rpm is suitable. H202 solution 520 "floods" pad 530, whereby H202 can selectively remove tungsten, aided by the mechanical contact of pad 530 on surface 512 of wafer 510. Wafer 510 is kept in contact with pad 530 until the upper surface of the tungsten is polished to the desired level.
Figure 6 illustrates a structure 600 having a tungsten via 610, resulting from the abrasive-free chemo-mechanical polishing processes described in conjunction with Figure 4, after being applied to a structure similar to structure 100 (Figure 1A) .
Although system 400 was used to form structure 600, system 500 could be used to form a structure substantially identical to structure 600. As shown in Figure 6, tungsten via 610 is formed in a recess 620 defined by a barrier layer 630. An upper surface 612 of tungsten via 610 is substantially level with an upper surface 632 of barrier layer 630, thereby reducing topographical features in the surface of structure 600. Further, barrier layer 630 remains intact and is suitable as an underlayer for a subsequent metal layer deposition.
The foregoing has described the principles and preferred embodiments of the present invention. However, the invention should not be construed as being limited to the particular embodiments described. For example, the H202 concentration, pad-to-wafer (or pad- to-die) interface pressure, pad rotation rate, and H202 solution temperature can be altered to achieve tungsten removal at different rates and/or efficiency. Further, polishing tools or fixtures different from those describe above can be used to obtain substantially similar results. Still further, other embodiments may be adapted for applications other than the formation of tungsten vias with barrier layers. In addition, solutions with reactants other than H202 can be used, provided the reactant is selective to react with tungsten relative to the barrier layer and other structures used in the application. Thus, above- described embodiments should be regarded as illustrative rather than restrictive. Variations can be made to those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.

Claims

Ql___ We claim:
1. A method for polishing tungsten in a structure having a tungsten portion and a non-tungsten portion, said method comprising the steps of: applying an abrasive-free reactant to a surface of said structure, said reactant being relatively reactive with said tungsten portion and relatively non-reactive with said non-tungsten portion; and polishing said surface of said structure with a polishing device and said reactant.
2. The method of Claim 1 wherein said step of applying a reactant further comprises the step of providing a reactant comprising hydrogen peroxide.
3. The method of Claim 2 wherein said step of providing a reactant further comprised the step of providing said hydrogen peroxide at a concentration in the range of 10-60%.
4. The method of Claim 2 wherein said step of providing a reactant further comprises the step of providing said reactant at a temperature in the range of 10 to 60 °C.
5. The method of Claim 2 wherein said step of applying further comprises the steps of: applying said reactant to a polishing surface of said polishing device; and arranging the position of said wafer and said polishing device so that said polishing surface of said polishing device is in contact with said surface of said structure.
6. The method of Claim 2 wherein said step of polishing further comprises the step of removing an upper portion of said tungsten portion while leaving said non-tungsten portion substantially intact.
7. The method of Claim 6 wherein said step of polishing further comprises the step of polishing said structure until a top surface of a remaining portion of said tungsten portion is substantially level with a top surface of said non-tungsten portion.
8. A structure polished in accordance with the method of Claim 7.
9. A system for polishing tungsten in a structure having a tungsten portion and a non-tungsten portion, said system comprising: means for applying a reactant to a surface of said structure, said reactant being relatively reactive with said tungsten portion and relatively non-reactive with said non-tungsten portion; and a polishing device for polishing said surface of said structure at least in part with said reactant.
10. The system of Claim 9 wherein said reactant comprises hydrogen peroxide.
11. The system of Claim 10 wherein said reactant further comprises hydrogen peroxide at a concentration in the range of 10-60%.
12. The system of Claim 10 wherein said means for applying further comprises means for providing said reactant at a temperature in the range of 10 to 60 °C.
13. The system of Claim 10 wherein said means for applying further comprises: means for applying said reactant to a polishing surface of said polishing device; and means for arranging the position of said wafer and said polishing device so that said polishing surface of said polishing device is in contact with said surface of said structure.
14. The system of Claim 10 wherein said polishing device is capable of removing an upper portion of said tungsten portion while leaving said non-tungsten portion substantially intact.
15. The system of Claim 14 wherein said polishing device polishes said structure so that a top surface of a remaining portion of said tungsten portion is substantially level with a top surface of said non- tungsten portion.
16. A system for polishing tungsten in a structure having a tungsten portion and a non-tungsten portion, said system comprising: a dispenser for storing and applying hydrogen peroxide to a surface of said structure; a polishing device for chemo-mechanically polishing said surface of said structure with said hydrogen peroxide, wherein said polishing device is capable of removing an upper portion of said tungsten portion while leaving said non-tungsten portion substantially intact so that a top surface of a remaining portion of said tungsten portion is substantially level with a top surface of said non-tungsten portion.
17. The system of Claim 16 wherein said polishing device further comprises a pad for receiving hydrogen peroxide from said dispenser and for applying said hydrogen peroxide to surface of said structure.
PCT/US1996/000154 1995-02-15 1996-01-11 Abrasive-free selective chemo-mechanical polish for tungsten WO1996025270A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US38886095A 1995-02-15 1995-02-15
US08/388,860 1995-02-15

Publications (1)

Publication Number Publication Date
WO1996025270A1 true WO1996025270A1 (en) 1996-08-22

Family

ID=23535835

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1996/000154 WO1996025270A1 (en) 1995-02-15 1996-01-11 Abrasive-free selective chemo-mechanical polish for tungsten

Country Status (1)

Country Link
WO (1) WO1996025270A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998049723A1 (en) * 1997-04-30 1998-11-05 Minnesota Mining And Manufacturing Company Method of planarizing the upper surface of a semiconductor wafer
US6194317B1 (en) * 1998-04-30 2001-02-27 3M Innovative Properties Company Method of planarizing the upper surface of a semiconductor wafer
WO2001053039A1 (en) * 2000-01-18 2001-07-26 Rodel Holdings, Inc. Dissolution of metal particles produced by polishing
US6602436B2 (en) 2000-08-11 2003-08-05 Rodel Holdings, Inc Chemical mechanical planarization of metal substrates

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3436286A (en) * 1963-03-28 1969-04-01 Siemens Ag Polishing method for the removal of material from monocrystalline semiconductor bodies
US5192715A (en) * 1989-07-25 1993-03-09 Advanced Micro Devices, Inc. Process for avoiding spin-on-glass cracking in high aspect ratio cavities
US5209816A (en) * 1992-06-04 1993-05-11 Micron Technology, Inc. Method of chemical mechanical polishing aluminum containing metal layers and slurry for chemical mechanical polishing

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3436286A (en) * 1963-03-28 1969-04-01 Siemens Ag Polishing method for the removal of material from monocrystalline semiconductor bodies
US5192715A (en) * 1989-07-25 1993-03-09 Advanced Micro Devices, Inc. Process for avoiding spin-on-glass cracking in high aspect ratio cavities
US5209816A (en) * 1992-06-04 1993-05-11 Micron Technology, Inc. Method of chemical mechanical polishing aluminum containing metal layers and slurry for chemical mechanical polishing

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998049723A1 (en) * 1997-04-30 1998-11-05 Minnesota Mining And Manufacturing Company Method of planarizing the upper surface of a semiconductor wafer
US6194317B1 (en) * 1998-04-30 2001-02-27 3M Innovative Properties Company Method of planarizing the upper surface of a semiconductor wafer
WO2001053039A1 (en) * 2000-01-18 2001-07-26 Rodel Holdings, Inc. Dissolution of metal particles produced by polishing
US6602112B2 (en) 2000-01-18 2003-08-05 Rodel Holdings, Inc. Dissolution of metal particles produced by polishing
US6602436B2 (en) 2000-08-11 2003-08-05 Rodel Holdings, Inc Chemical mechanical planarization of metal substrates

Similar Documents

Publication Publication Date Title
US6423640B1 (en) Headless CMP process for oxide planarization
US5913712A (en) Scratch reduction in semiconductor circuit fabrication using chemical-mechanical polishing
US6497784B1 (en) Semiconductor wafer edge bead removal method and tool
US7104869B2 (en) Barrier removal at low polish pressure
JP3645528B2 (en) Polishing method and semiconductor device manufacturing method
US6261158B1 (en) Multi-step chemical mechanical polishing
EP1057591A2 (en) Selective damascene chemical mechanical polishing
JP2000301454A (en) Chemical-mechanical polishing process and constituting element thereof
US6468135B1 (en) Method and apparatus for multiphase chemical mechanical polishing
KR20010052820A (en) A technique for chemical mechanical polishing silicon
JPH11111656A (en) Manufacture of semiconductor device
JP3172008B2 (en) Method for manufacturing semiconductor device
US6218306B1 (en) Method of chemical mechanical polishing a metal layer
JPH09186116A (en) Manufacture of semiconductor device and semiconductor manufacture device
US20020173221A1 (en) Method and apparatus for two-step polishing
JPH11256141A (en) Grinding slurry and grinding
US5906949A (en) Chemical-mechanical polishing process
WO1996025270A1 (en) Abrasive-free selective chemo-mechanical polish for tungsten
US6634930B1 (en) Method and apparatus for preventing metal corrosion during chemical mechanical polishing
US6686284B2 (en) Chemical mechanical polisher equipped with chilled retaining ring and method of using
US20040009653A1 (en) Method for forming wiring structure
US6319095B1 (en) Colloidal suspension of abrasive particles containing magnesium as CMP slurry
US6362101B2 (en) Chemical mechanical polishing methods using low pH slurry mixtures
JPH08323614A (en) Chemical and mechanical abrasion method and device
US6537135B1 (en) Curvilinear chemical mechanical planarization device and method

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP KR

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase