Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
  • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
  • C09K3/1463—Aqueous liquid suspensions
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
  • H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
  • H01L21/30625—With simultaneous mechanical treatment, e.g. mechanico-chemical polishing

Definitions

• the present invention relates to a polishing composition for use in polishing an edge of an object such as semiconductor substrates, and to a method for polishing an edge of an object such as semiconductor substrates using such a polishing composition.
• Polishing compositions for use in polishing edges of semiconductor substrates that is, a polishing composition for polishing edges are disclosed in Japanese Laid-Open Patent Publications No. 11-349925 and No. 2004-128069.
• a polishing composition for polishing edges are disclosed in Japanese Laid-Open Patent Publications No. 11-349925 and No. 2004-128069.
• the polishing compositions disclosed in the above publications No. 11-349925 and No. 2004-128069 have been improved to respond to such requirements.
• the polishing composition of the above publications does not sufficiently satisfy the requirements and there is yet room for improvements in the polishing composition.
• a polishing composition for use in polishing an edge of an object includes an abrasive, at least one kind of compound selected from imidazole and an imidazole derivative, and water.
• the present invention also provides a method including polishing an edge of an object using the above polishing composition.
• the present invention also provides a method for manufacturing a polished product.
• the method includes: preparing the above polishing composition; and polishing an edge of a semi-finished product of the polished product using the prepared polishing composition.
• a polishing composition according to this embodiment contains an abrasive, imidazole or an imidazole derivative, and water.
• the abrasive plays the role of mechanically polishing an object.
• the abrasive preferably contains silicon dioxide, and more preferably is silicon dioxide. Silicon dioxide has superior performance in polishing the object smoothly. Silicon dioxide may be any of colloidal silica, fumed silica, and precipitated silica, and preferably is colloidal silica.
• the object polished using a polishing composition containing colloidal silica has less surface defects such as scratches as compared to the object polished using a polishing composition containing silicon dioxide other than colloidal silica.
• the average particle size of the abrasive in the polishing composition obtained from the specific surface area of the abrasive measured through a BET method is preferably 10 nm or more, and more preferably 30 nm or more, and most preferably 50 nm or more. Meanwhile, when an abrasive has too large an average particle size, there is a risk of generating scratches on the object.
• the average particle size of the abrasive in the polishing composition obtained from the specific surface area of the abrasive measured through the BET method is preferably 200 nm or less, and more preferably 120 nm or less, and most preferably 80 nm or less.
• a polishing composition containing too small an amount of an abrasive is not so high in polishing ability.
• the content of the abrasive in the polishing composition is preferably 0.1% by mass or more, and more preferably 1.0% by mass or more, and most preferably 10.0% by mass or more.
• the content of the abrasive in the polishing composition is preferably 50.0% by mass or less.
• the imidazole and the imidazole derivative in the polishing composition contribute to an improvement of the polishing ability of the polishing composition.
• the reason why the imidazole and the imidazole derivative contribute to an improvement of the polishing ability is considered to be that the unshared electron pair of the nitrogen atom at the 1-position of the imidazole ring directly acts on the object.
• the imidazole and the imidazole derivative have a small risk of corroding the object unlike other amines such as monoethanolamine, or 1,8-diazabicyclo(5,4,0)-undecene-7 (abbrev. DBU), and 1,5-diazabicyclo(4,3,0)-nonene-5 (abbrev. DBN).
• the imidazole derivative may be one in which, for example, at least one of hydrogen atoms bonded to the nitrogen atom at the 1-position, the carbon atom at the 2-position, the carbon atom at the 4-position, and the carbon atom at the 5-position of the imidazole ring is substituted by an alkyl group such as a methyl group and an ethyl group, a hydroxy group, a carboxy group, or an amino group.
• a polishing composition containing too small an amount of imidazole or an imidazole derivative is not so high in polishing ability.
• the content of the imidazole or the imidazole derivative in the polishing composition is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more, and most preferably 1.0% by mass or more.
• the polishing composition contains a large amount of imidazole or an imidazole derivative, there is a risk of roughening the surface of the polished object, since chemical corrosion of the polishing composition becomes too strong.
• the content of the imidazole or the imidazole derivative in the polishing composition is preferably 20.0% by mass or less, and more preferably 15.0% by mass or less, and most preferably 10.0% by mass or less.
• the water serves as a medium for dispersing or dissolving components other than water in the polishing composition.
• Water may be industrial water, tap water, distilled water, or one obtained by filtering any of these, and preferably contains as little impurities as possible.
• the polishing composition according to this embodiment is for use in, for example, polishing the edges of semiconductor substrates such as silicon wafers.
• the polishing composition is for use in, for example, polishing the edges of semi-finished products to obtain semiconductor substrates as polished products.
• the edge of the object is polished using the polishing composition, for example, by placing a polishing member such as a polishing pad in contact with the edge of the object, and sliding either the object or the polishing member while feeding the polishing composition into the contact portion.
• the preferred embodiment provides the following advantages.
• a polishing composition according to this embodiment contains imidazole or an imidazole derivative that contribute to an improvement of polishing ability of the polishing composition.
• the polishing composition of this embodiment compared to the conventional polishing compositions, has greater polishing ability, and promptly polishes the edge of the object, or more specifically, the edges of the semiconductor substrates.
• the polishing composition of this embodiment is hence very useful in polishing edges of semiconductor substrates.
• the imidazole and the imidazole derivative have less risk of corroding the object unlike other amines such as monoethanolamine, DBU, and DBN. Therefore, the object polished using the polishing composition of this embodiment is less corroded as compared to the object polished using the polishing composition containing other amines such as monoethanolamine, DBU, and DBN.
• the electric characteristic of the semiconductor device decreases.
• the semiconductor substrate that is polished using the polishing composition of this embodiment is not or hardly corroded. Therefore, a semiconductor device the electric characteristic of which is suppressed from decreasing is manufactured from the semiconductor substrate.
• the polishing composition of this embodiment When an oxidizing agent is added to the polishing composition of this embodiment, depending on the amount of the oxidizing agent that is added, there is a risk of forming a passivation layer on the surface of the object being polished. When the passivation layer is formed on the surface of the object, there is a risk of decreasing polishing ability of the polishing composition since polishing of the object through chemical polishing operation of the polishing composition is hindered. However, the polishing composition of this embodiment avoids a negative effect caused by an oxidizing agent since the polishing composition does not contain the oxidizing agent.
• the preferred embodiment may be modified as follows.
• the polishing composition of this embodiment may further contain an alkali compound.
• the alkali compound plays the role of chemically polishing an object, and contributes to an improvement of polishing ability of the polishing composition.
• the alkali compound may contain any of tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, potassium hydrogen carbonate, potassium carbonate, sodium hydrogen carbonate, sodium carbonate, ammonia, ammonium hydrogen carbonate, and ammonium carbonate, and preferably includes at least one kind selected from the group consisting of tetramethylammonium hydroxide, potassium hydroxide, and sodium hydroxide, and more preferably includes tetramethylammonium hydroxide. Tetramethylammonium hydroxide, potassium hydroxide, and sodium hydroxide have high ability of polishing the object, and tetramethylammonium hydroxide has particularly high ability of polishing the object.
• the polishing ability of the polishing composition does not improve much.
• the content of the alkali compound in the polishing composition is preferably 0.05% by mass or more, and more preferably 0.25% by mass or more, and most preferably 0.5% by mass or more.
• the content of the alkali compound in the polishing composition is preferably 6.0% by mass or less, and more preferably 5.0% by mass or less, and most preferably 2.0% by mass or less.
• the polishing composition of this embodiment may further contain a water-soluble polymer.
• the water-soluble polymer acts to improve the wettability of the object. When the object has a high wettability, even if the abrasive adheres to the object, the adhered abrasive is easily removed by simply washing.
• the water-soluble polymer may include any of hydroxyethyl cellulose, polyvinyl alcohol, polyethylene oxide, and polyethylene glycol, and preferably includes hydroxyethyl cellulose. Hydroxyethyl cellulose has particularly high ability of improving the wettability of the object.
• the molecular weight of hydroxyethyl cellulose is preferably 300,000 or more, and more preferably 600,000 or more, and most preferably 900,000 or more.
• the molecular weight of polyvinyl alcohol is preferably 1,000 or more, and more preferably 5,000 or more, and most preferably 10,000 or more
• the molecular weight of polyethylene oxide is preferably 20,000 or more
• the molecular weight of polyethylene glycol is preferably 100 or more, and more preferably 300 or more, and most preferably 1,000 or more.
• the molecular weight of a water-soluble polymer is excessively high, there is a risk of excessively increasing the viscosity of the polishing composition.
• the molecular weight of hydroxyethyl cellulose is preferably 3,000,000 or less, and more preferably 2,000,000 or less, and most preferably 1,500,000 or less.
• the molecular weight of polyvinyl alcohol is preferably 1,000,000 or less, and more preferably 500,000 or less, and most preferably 300,000 or less
• the molecular weight of polyethylene oxide is preferably 50,000,000 or less, and more preferably 30,000,000 or less, and most preferably 10,000,000 or less
• the molecular weight of polyethylene glycol is preferably 20,000 or less.
• the content of the water-soluble polymer in the polishing composition is preferably 0.0001% by mass or more, and more preferably 0.001% by mass or more, and most preferably 0.005% by mass or more.
• the content of the water-soluble polymer in the polishing composition is preferably 0.5% by mass or less, and more preferably 0.3% by mass or less, and most preferably 0.15% by mass or less.
• the polishing composition according to this embodiment may further contain a chelating agent.
• the chelating agent suppresses contamination of the object with metal impurities by forming a complex ion with metal impurities in the polishing composition thereby capturing the metal impurities.
• the metal impurities in this specification refer to iron, nickel, copper, calcium, magnesium, and hydroxide or oxide of the same.
• the chelating agent may be any of nitrilotriacetic acid, ethylenediaminetetraacetic acid, hydroxyethylenediaminetetraacetic acid, propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, ethylenediaminetetraethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, ethylenediaminetetrakismethylenephosphonic acid, diethylenetriaminepentaethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, triethylenetetraminehexaethylenephosphonic acid, triethylenetetraminehexamethylenephosphonic acid, and propanediaminetetraethylenephosphonic acid propanediaminetetramethylenephosphonic acid, and the acid of the same, which are ammonium salt, potassium salt, sodium salt, and lithium salt.
• the polishing composition containing a large amount of a chelating agent easily gelates.
• the content of the chelating agent in the polishing composition is preferably 6% by mass or less, and more preferably 3% by mass or less, and most preferably 1% by mass or less.
• the polishing composition of this embodiment may contain a small amount of an oxidizing agent.
• the polishing composition contains a large amount of the oxidizing agent (for example, when the content of the oxidizing agent in the polishing composition is 1% by mass or more), there is a risk of decreasing the polishing ability of the polishing composition since the passivation layer is formed on the surface of the object as described above.
• the content of the oxidizing agent is small, the passivation layer is not formed, or only a thin passivation layer is formed that is easily removed by mechanical polishing operation of the abrasive.
• the content of the oxidizing agent in the polishing composition is preferably 0.1% by mass or less, and more preferably 0.01% by mass or less.
• the polishing composition according to this embodiment may contain both the imidazole and the imidazole derivative.
• the polishing composition according to this embodiment may be prepared by diluting liquid concentrate with water.
• the polishing composition according to this embodiment may be used for polishing an edge of an object other than semiconductor substrates.
• Examples 1 to 17 an abrasive, imidazole, and water were mixed, and to the mixture was added an alkali compound, a water-soluble polymer, or a chelating agent, if necessary, to prepare liquid concentrates of polishing compositions.
• an abrasive and water were mixed, and to the mixture was added imidazole or its alternate compound, an alkali compound, a water-soluble polymer, a chelating agent, or an oxidizing agent, if necessary, to prepare liquid concentrates of polishing compositions.
• An edge of a silicon wafer was polished using each polishing composition of Examples 1 to 17 and Comparative Examples 1 to 10 under a first polishing condition shown in Table 3.
• the difference in the weight of each silicon wafer before and after polishing, that is, the reduced weight of each silicon wafer was measured.
• the polishing rate obtained by dividing the measured weight reduction amount of each silicon wafer by polishing time is shown in the column entitled “Polishing rate” of Tables 1 and 2.
• An edge of a silicon wafer was polished using each polishing composition of Examples 1 to 17 and Comparative Examples 1 to 10 under a second polishing condition shown in Table 3.
• the edge of the polished wafer was observed with a microscope. Based on how much of scratches located on the edge of the wafer before polishing has been removed, the polishing compositions were evaluated according to a five rank scale: excellent (1), good (2), acceptable (3), slightly poor (4), and poor (5).
• the polishing composition when the entire surface of the wafer was maintained in a mirror-finished state, the polishing composition was ranked excellent; when large part of the surface of the wafer was maintained in a mirror-finished state, the polishing composition was ranked good; when most of the surface of the wafer is maintained in the mirror-finished state, the polishing composition was ranked acceptable; when large part of the surface of the wafer was not maintained in the mirror-finished state, the polishing composition was ranked slightly poor; and when the entire surface of the wafer was not maintained in the mirror-finished state, the polishing composition was ranked poor.
• the evaluation results are shown in the column entitled “Corrosiveness” in Tables 1 and 2.
• colloidal silica* 1 NaOH HEC* 1 TTHA — 1.03 5 5 35.0% 0.5% 0.008% 0.08% C.
• colloidal silica* 1 piperazine HEC* 1 TTHA — 1.20 5 4 35.0% 5.0% 0.008% 0.08% C.
• colloidal silica* 1 DBU HEC* 1 TTHA — 1.50 1 4 35.0% 2.5% 0.008% 0.08% C.
• polishing pad “DRP-II” manufactured by Inclination angle of unit: 45 degrees SPEEDFAM Co., Ltd.
• Vertical speed of drum 72 mm/minute Inclination angle of unit: 45 degrees Rotation time of lower chuck: 60 seconds
• Vertical speed of drum 72 mm/minute Number of polishing: 4 times (forward/backward ⁇ Rotation time of lower chuck: 60 seconds front/rear)
• Number of polishing 4 times (forward/backward ⁇ Total polishing time: 240 seconds front/rear)
• Chamfering angle 22 degrees Total polishing time: 240 seconds
• Feed rate of polishing composition 200
• Chamfering angle 22 degrees mL/minute Feed rate of polishing composition: 200 Temperature of polishing composition: 20-25° C. mL/minute Temperature of polishing composition: 20-25° C.
• colloidal silica * 1 represents colloidal silica having the average particle size of 55 nm, which is obtained from the specific surface area measured through the BET method
• colloidal silica * 2 represents colloidal silica having the average particle size of 35 nm, which is also obtained from the specific surface area measured through the BET method.
• TMAH represents tetramethylammonium hydroxide
• KOH represents potassium hydroxide
• NaOH represents sodium hydroxide.
• HEC * 1 represents hydroxyethyl cellulose having an average molecular weight of 1,200,000
• HEC * 2 represents hydroxyethyl cellulose having an average molecular weight of 300,000
• HEC * 3 represents hydroxyethyl cellulose having an average molecular weight of 1,600,000.
• TTHA represents triethylenetetraminehexaacetic acid
• DTPA represents diethylenetriaminepentaacetic acid.
• H 2 O 2 represents hydrogen peroxide.
• the polishing rate measured using any of the polishing compositions of Examples 1 to 17 was generally greater than the polishing rate measured using the polishing composition of any of Comparative Examples 1 to 10. Any of the evaluations on scratches when using the polishing compositions of Examples 1 to 17 was either excellent or good. The results suggest that any polishing composition of Examples 1 to 17 has high polishing ability.
• the polishing rate measured using any of the polishing compositions of Examples 1 to 3 containing an alkali compound was greater than the polishing rate measured using the polishing composition of any of Examples 5 to 7 containing no alkali compound.
• the results suggest that polishing ability of a polishing composition is enhanced by addition of an alkali compound.
• the evaluation for the corrosiveness of the polishing composition of Example 5 containing no alkali compound is superior than the evaluation for the corrosiveness of the polishing composition of Example 1 containing tetramethylammonium hydroxide as an alkali compound. Furthermore, the evaluation for the corrosiveness of the polishing composition of Example 1 is superior than the evaluation for the corrosiveness of the polishing compositions of Examples 8 and 9 containing potassium hydroxide or sodium hydroxide as an alkali compound.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)

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• 2004
  • 2004-10-15 JP JP2004300873A patent/JP5026665B2/ja active Active
• 2005
  • 2005-10-12 GB GB0520729A patent/GB2420122B/en not_active Expired - Fee Related
  • 2005-10-13 TW TW094135700A patent/TW200621960A/zh unknown
  • 2005-10-13 US US11/250,103 patent/US20060080896A1/en not_active Abandoned
  • 2005-10-14 KR KR1020050096823A patent/KR101362837B1/ko active IP Right Grant
  • 2005-10-14 DE DE102005049202A patent/DE102005049202A1/de not_active Ceased
  • 2005-10-14 CN CN2005101134555A patent/CN1760307B/zh not_active Expired - Fee Related
• 2007
  • 2007-06-28 US US11/823,606 patent/US7597729B2/en active Active
• 2013
  • 2013-12-12 KR KR1020130154509A patent/KR20130142982A/ko not_active Application Discontinuation

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