Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
  • B08B7/0021—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by liquid gases or supercritical fluids
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
  • C11D7/04—Water-soluble compounds
  • C11D7/10—Salts
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/32—Organic compounds containing nitrogen
  • C11D7/3209—Amines or imines with one to four nitrogen atoms; Quaternized amines
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/32—Organic compounds containing nitrogen
  • C11D7/3281—Heterocyclic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/50—Solvents
  • C11D7/5004—Organic solvents
  • C11D7/5022—Organic solvents containing oxygen
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/20—Dry etching; Plasma etching; Reactive-ion etching
  • H10P50/28—Dry etching; Plasma etching; Reactive-ion etching of insulating materials
  • H10P50/282—Dry etching; Plasma etching; Reactive-ion etching of insulating materials of inorganic materials
  • H10P50/283—Dry etching; Plasma etching; Reactive-ion etching of insulating materials of inorganic materials by chemical means
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P70/00—Cleaning of wafers, substrates or parts of devices
  • H10P70/20—Cleaning during device manufacture
  • H10P70/23—Cleaning during device manufacture during, before or after processing of insulating materials
  • H10P70/234—Cleaning during device manufacture during, before or after processing of insulating materials the processing being the formation of vias or contact holes
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
  • C11D2111/10—Objects to be cleaned
  • C11D2111/14—Hard surfaces
  • C11D2111/22—Electronic devices, e.g. PCBs or semiconductors

Definitions

• the present invention relates to supercritical carbon dioxide-based compositions useful in semiconductor manufacturing for the removal of particle contamination from patterned silicon/silicon dioxide substrates having such particle contamination thereon, and to methods of using such compositions for removal of particle contamination from semiconductor substrates.
• the problems attendant the removal of contaminant particles from semiconductor substrates include the fact that surface contamination may be organic and/or inorganic in character, thereby complicating the cleaning process from the perspective of selecting compatible cleaning agents.
• surface contamination may be organic and/or inorganic in character, thereby complicating the cleaning process from the perspective of selecting compatible cleaning agents.
• not all surfaces to be cleaned are smooth and may possess varying degrees of roughness due to previous etching and/or deposition processes, thereby complicating the cleaning procedure.
• there exist several forces of adhesion such as Van der Waals force of attraction, electrostatic interactions, gravity and chemical interactions, which impact the removal of contaminant particles. Accordingly, flow characteristics, chemistry and physical aspects are all involved, and complicate the removal of particulate contamination.
• the present invention relates to supercritical carbon dioxide-based compositions useful in semiconductor manufacturing for the removal of contaminant particles from substrates having such particles thereon, and methods of using such compositions for removal of contaminant particles from semiconductor substrates.
• the invention relates to a particle contamination cleaning composition, comprising SCC02, alcohol, fluorine source and, optionally, hydroxyl additive.
• the invention relates to a particle contamination cleaning composition, comprising SCC02, methanol, ammonium fluoride, fluorinated surfactant, and boric acid, wherein methanol is present at a concentration of from about 5 to about 20 wt.%, fluoride is present at a concentration of from about 0.01 to about 2.0 wt.%, and boric acid is present at a concentration of from about 0.01 to about 2.0 wt.%, based on the total weight of the cleaning composition.
• a further aspect of the invention relates to a method of removing particle contamination from a substrate having same thereon, said method comprising contacting the particle contamination with a cleaning composition comprising SCC02, alcohol, fluorine source and, optionally, hydroxyl additive, for sufficient time and under sufficient contacting conditions to remove the particle cont-raiination from the substrate.
• Figure 1 is an optical microscope photograph of a wafer comprising a patterned silicon dioxide layer and silicon layer, showing contaminant particles of SiN thereon, subsequent to cleaning thereof with SCC02/methanol solution.
• Figure 2 is an optical microscope photograph of a wafer of the type shown in Figure 1, after cleaning with a cleaning composition containing SCC02, methanol and ammonium fluoride and boric acid.
• Figure 3 is an optical microscope photograph of a wafer of the type shown in Figure 1, after cleaning with a cleaning composition containing SCC02, methanol and a fluorinated surfactant.
• Figure 4 is an optical microscope photograph of a wafer of the type shown in Figure 1 , after cleaning with a cleaning composition containing SCC02, methanol, ammonium fluoride, boric acid and a fluorinated surfactant.
• the present invention is based on the discovery of a supercritical carbon dioxide-based cleaning composition that is highly efficacious for the removal of contaminant particles from semiconductor substrates on which same are present.
• the compositions and methods of the invention are effective for removal of surface particles, including particles of organic and/or inorganic composition, from silicon and silicon dioxide regions of both blanket and patterned wafers.
• Supercritical carbon dioxide SCC02
• SCC02 Supercritical carbon dioxide
• a gas Like a gas, it diffuses rapidly, has low viscosity, near-zero surface tension, and penetrates easily into deep trenches and vias.
• a liquid Like a liquid, it has bulk flow capability as a "wash" medium.
• the present invention contemplates a particle contamination cleaning composition including SCC02, alcohol, fluorine source and, optionally, hydroxyl additive.
• SCC02 SCC02
• alcohol fluorine source
• hydroxyl additive SCC02
• fluorine source fluorine source
• hydroxyl additive hydroxyl additive
• the fluorine source aids in the removal of silicon impurities that reside on the Si/Si0 2 surface.
• the fluorine source may be of any suitable type, e.g., a fluorine- containing compound or other fluoro species.
• Illustrative fluorine source components include hydrogen fluoride (HF), trietliylamine trihdyrogen fluoride or other amine friliydrogen fluoride compound of the formula NR 3 (HF) 3 wherein each R is independently selected from hydrogen and lower alkyl (C C 8 alkyl), hydrogen fluoride-pyridine (pyr-HF), and ammonium fluorides of the formula R 4 NF, wherein each R is independently selected from hydrogen and lower (C ⁇ -C 8 alkyl), etc.
• Ammonium fluoride (NH 4 F) is a presently preferred fluorine source in compositions of the invention, although any other suitable fluoro source component(s) may be employed with equal success.
• the composition may also include fluorinated surfactant(s), which provide additional fluorine and fluoride in the composition.
• the optional hydroxyl additive functions to protect the wafer from additional oxidation.
• Boric acid is a presently preferred hydroxyl additive, although other hydroxyl agents may also be advantageously employed for such purpose, e.g., 3-hydroxy-2-naphthoic acid.
• the hydroxyl additive may also be a fluorine source, e.g., 2-fluorophenol, etc.
• the alcohol used to form the SCC02/alcohol solution as the solvent phase of the cleaning composition may be of any suitable type. In one embodiment of the invention, such alcohol comprises a C r C 4 alcohol (i.e., methanol, ethanol, propanol, or butanol), or a mixture of two or more of such alcohol species.
• the alcohol is methanol.
• the presence of the alcoholic co- solvent with the SCC02 serves to increase the solubility of the composition for inorganic salts and polar organic compounds present in the particulate contamination.
• the specific proportions and amounts of SCC02 and alcohol in relation to each other may be suitably varied to provide the desired solubilizing (solvating) action of the SCC02/alcohol solution for the particulate contamination, as readily dete ⁇ ninable within the skill of the art without undue effort.
• the concentration of the alcohol may be in a range of from about 5 to about 20 wt.%, based on the total weight of the composition.
• the cleaning composition of the invention includes SCC02, alcohol, ammonium fluoride, fluorinated surfactant, and boric acid.
• ammonium fluoride is present at a concentration of from about 0.01 to about 1.0 wt.%), and boric acid is present at a concentration of from about 0.01 to about 1.0 wt.%, based on the total weight of the cleaning composition.
• the cleaning composition can be employed to contact a substrate having particulate contamination thereon at a pressure in a range of from about 1000 to about 7500 psi for sufficient time to effect the desired removal of the particulate contamination from the substrate, e.g., for a contacting time in a range of from about 5 to about 30 minutes and a temperature of from about 35 to about 100°C, although greater or lesser contacting durations and temperatures may be advantageously employed in the broad practice of the present invention, where warranted.
• the cleaning process in a particularly preferred embodiment includes sequential processing steps including dynamic flow of the cleaning composition over the substrate having the particulate contamination thereon, followed by a static soak of the substrate in the cleaning composition, with the respective dynamic flow and static soak steps being carried out alternatingly and repetitively, in a cycle of such alternating steps.
• the dynamic flow/static soak steps may be carried out for three successive cycles in the aforementioned illustrative embodiment of contacting time of 30 minutes, as including a sequence of 10 minutes dynamic flow, 10 minutes static soak, and 10 minutes dynamic flow.
• the substrate thereafter preferably is washed with copious amounts of
• SCC02/alcohol solution (not containing any other components), e.g., a 20%> methanol solution, in a first washing step, to remove any residual precipitated chemical additives from the substrate region in which removal of particulate contamination has been effected, and finally with copious amounts of pure SCC02, in a second washing step, to remove any residual alcohol co-solvent and/or precipitated chemical additives from the substrate region.
• the sample wafers examined in this study included silicon nitride particles residing on a patterned silicon dioxide layer and silicon layer.
• the samples were first processed using pure SCC02 at 50°C and 4400 psi, and although the velocity of the flowrate (10 mL/mm) removed some of the particles, it was ineffective at completely removing all of the contaminate particles.
• Figure 1 is an optical microscope photograph of this wafer comprising a patterned silicon dioxide layer and silicon layer, showing contaminant particles of SIN thereon, subsequent to cleaning thereof with SCC02/methanol solution.
• Various chemical additives/surfactants then were added to the SCC02/methanol solution and their particle removal efficiency was examined.
• Figure 2 shows tlie optical image of the wafer cleaned with a SCC02/methanol/boric acid/NI F solution at 50°C and clearly shows that the SiN particles are removed from the Si0 2 surface, however, this cleaning solution was not effective toward removing the particles from the silicon regions.
• the boric acid was used both to protect the Si0 2 surface from attack by the fluoride ions, as well as to hydrogen bond to tlie silicon oxide surface to assist in lift-off of tlie particles which are most likely held via Van der Waals forces.
• the fluoride source was used to aid in particle removal by chemically reacting with the SiN particles, thus aiding in their removal from the wafer surface.
• a covalent fluoride source that does not generate HF upon exposure to moisture, is generally desired for particle removal from silicon surfaces.
• Figure 3 is an optical microscope photograph of a wafer of the type shown in Figure 1, after cleaning with a cleaning composition containing SCC02, methanol and a fluorinated surfactant.
• the SCC02/methanol/F-surfactant solution did not remove particles from the Si0 2 surface.
• Figure 4 is an optical microscope photograph of a wafer of the type shown in Figure 1, after cleaning with a cleaning composition containing SCC02, methanol, ammonium fluoride, boric acid and a fluorinated surfactant, showing that such composition successfully removed surface particles from the entire patterned wafer.
• the cleaning compositions of the present invention are readily formulated by simple mixing of ingredients, e.g., in a mixing vessel under gentle agitation.
• cleaning compositions are applied to the substrate for contacting with the residue thereon, at suitable elevated pressures, e.g., in a pressurized contacting chamber to which the cleaning composition is supplied at suitable volumetric rate and amount to effect the desired contacting operation for removal of tlie post etch residue removal.
• suitable elevated pressures e.g., in a pressurized contacting chamber to which the cleaning composition is supplied at suitable volumetric rate and amount to effect the desired contacting operation for removal of tlie post etch residue removal.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Cleaning Or Drying Semiconductors (AREA)
• Detergent Compositions (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

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Cited By (1)

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• 2002
  • 2002-10-31 US US10/284,861 patent/US6943139B2/en not_active Expired - Fee Related
• 2003
  • 2003-10-13 TW TW092128267A patent/TW200408699A/zh unknown
  • 2003-10-29 JP JP2004550192A patent/JP2006505139A/ja active Pending
  • 2003-10-29 WO PCT/US2003/034332 patent/WO2004042794A2/en not_active Ceased
  • 2003-10-29 AU AU2003288966A patent/AU2003288966A1/en not_active Abandoned
  • 2003-10-29 CN CNB2003801021202A patent/CN100346887C/zh not_active Expired - Fee Related
  • 2003-10-29 EP EP03781458A patent/EP1559132A4/en not_active Withdrawn
  • 2003-10-29 KR KR1020057007090A patent/KR20050075758A/ko not_active Ceased
  • 2003-10-29 CN CNA2007101547063A patent/CN101215493A/zh active Pending

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