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
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
  • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
  • C23C18/1204—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material inorganic material, e.g. non-oxide and non-metallic such as sulfides, nitrides based compounds
  • C23C18/1208—Oxides, e.g. ceramics
  • C23C18/1212—Zeolites, glasses

Definitions

• This invention relates to a coating fluid for forming an oxide coating which is thermally stable and has good coating properties and a method for forming an oxide coating using the same.
• the present invention provides:
• a coating fluid for forming an oxide coating on a substrate which comprises a reaction product obtained by subjecting
• the present invention also provides a process for forming a coating oxide on a substrate which comprises a step of coating a coating fluid on a substrate, said coating fluid comprising a reaction product obtained by subjecting (A) a silane compound expressed by the formula RmSi(OR) 4-m wherein R represents an alkyl group of 1 to 4 carbon atoms or an aryl group and m represents an integer of 0 to 2 and (B) an organic metal compound expressed by the formula M(OR′) n wherein M represents a metal atom of magnesium, boron, phosphorus, zirconium, yttrium, titanium or barium, R′ represents an alkyl group of 1 to 4 carbon atoms or an aryl group and n represents a valence of the metal atom, to hydrolysis and condensation by the use of a catalyst in the presence of a solvent; a step of drying said coated substrate at a temperature of 50-200°C; and a step of calcining said dried coated substrate at a temperature of 400-
• the silane compound used in the present invention is expressed by the formula RmSi(OR) 4-m and its concrete examples are tetrafunctional silanes such as Si(OCH3)4, Si(OC2H5)4, Si(OC3H7), etc., trifunctional silanes such as CH3Si(OCH3)3, CH3Si(OC2H5)3, CH3Si(OC3H7)3, C2H5Si(OCH3)3, C6H5Si(OCH3)3, CH3Si(OC6H5)3, etc.
• tetrafunctional silanes such as Si(OCH3)4, Si(OC2H5)4, Si(OC3H7), etc.
• trifunctional silanes such as CH3Si(OCH3)3, CH3Si(OC2H5)3, CH3Si(OC3H7)3, C2H5Si(OCH3)3, C6H5Si(OCH3)3, CH3Si(OC6H5)3, etc.
• alkoxysilanes such as (CH3)2Si(OCH3)2, (CH3)2Si(OC2H5)2, (CH3)2Si(OC3H7)2, (C2H5)2Si(OCH3)2, (C6H5)2Si(OCH3)2, (CH3)2Si(OC6H5)2, etc.
• alkoxysilanes may be used singly or in admixture of two or more members thereof.
• the organic metal compound used in the present invention is expressed by the formula M(OR′) n and its concrete examples are B(O i-C3H7)3, Mg(OC3H7)2, P(O i-C3H7)3, Ti(O i-C3H7)4, Ti(OC6H5), etc. These metal compounds may be used singly or in admixture of two or more members thereof. Further, the above-mentioned R and R′ may be the same or different.
• the proportions of the silane compound and the organic metal compound used in the present invention it is preferred in the aspects of coating properties, carbon residue, etc. that the proportion of the silane compound be in the range of 70 to 90% by mol and that of the organic metal compound be in the range of 10 to 30% by mol.
• the silane compound is preferred to be a tetrafunctional silane Si(OR)4 singly or a mixture of 20 to 40% by mol of a tetrafunctional silane Si(OR)4, 20 to 60% by mol of a trifunctional silane RSi(OR)3 and 0 to 40% by mol of a bifunctional silane R2Si(OR)2.
• amide solvents such as N,N-dimethylformamides which do not react with alkyl groups or aryl groups, alcohol solvents which have the same carbon atoms as those of the alkyl or aryl group in the silane compound, etc. are preferably used in the aspect of coating properties. These solvents may be used in admixture.
• reaction catalyst used in the present invention are inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, hydrofluoric acid, etc., oxides such as phosphorus pentoxide, boron oxide and organic acids such as oxalic acid, etc.
• the quantity of the catalyst added is preferably in the range of 0.1 to 5% by weight based on the total weight of the silane and the organic metal compound.
• the coating fluid of the present invention is obtained by subjecting the silane compound and the organic metal compound to hydrolysis and condensation by the use of a catalyst as described above in the presence of a solvent. Further, the thermal expansion coefficient of the oxide coating obtained using the resulting solution can be optinally varied by selecting the kind and quantity of the organic metal compound.
• the coating fluid is coated on the surface of a substrate such as silicon, glass, ceramics, aluminium, etc. by means of spinner, brush, spray, etc., followed by drying usually at 50 to 200°C, preferably 100 to 150°C and then calcining usually at 400 to 800°C, preferably 400 to 500°C.
• the oxide coating obtained using the coating fluid of the present invention is smaller in the carbon content than oxide coatings obtained using conventional silanol condensates, and an oxide of e.g. Mg, P, Zr, Y, Ti or Ba is contained there-n as a second component to form a reaction product with SiO2, whereby the resulting coating is thermally stable and good coating properties is obtained.
• an oxide of e.g. Mg, P, Zr, Y, Ti or Ba is contained there-n as a second component to form a reaction product with SiO2, whereby the resulting coating is thermally stable and good coating properties is obtained.
• Si(OCH3)4 (51g), CH3Si(OCH3)3 (45g), (CH3)2Si(OCH3)2 (12g), B(O i-C3H7)3 (31g) and Mg(OC3H7)2 (10g) were dissolved in a mixed solvent of N,N-dimethylformamide (160g) and methanol (40g), followed by adding to the solution, a solution (55g) of oxalic acid (0.6g) in water and subjecting the mixture to hydrolysis and condensation to prepare a solution of the reaction product.
• This solution was coated on a Si wafer by means of a spinner at 3,000 rpm, followed by drying at 150°C for one hour and then calcining in an electric oven at 400°C for one hour to obtain a colorless, transparent silica coating without any crack.
• the coating thickness of the silica coating was measured by means of a surface roughness meter (TALYSTEP, trademark of product made by RANK TAYLOR HOBSON Co. LTD.) to give 0.7 ⁇ m. Further, when the inflared absorption spectra of the coating was measured by means of an inflared spectrophotometer, absorptions cf Mg-O and B-O bonds were observed besides Si-O-Si absorption; thus it was confirmed that the coating was a complete oxide coating. Further, when the oxide coating was treated by means of a barrel type oxygen plasma ashing device (PR-501A, tradename of product made by Yamato Kagaku Co. LTD.) at 400W for 20 minutes, no crack was observed in the coating.
• PR-501A barrel type oxygen plasma ashing device
• thermophysical tester TMA 8,150 type, tradename of product made by Rigaku Denki Co. LTD.
• Si(OC2H5)4 (145g), P(OC3H7)3 (41g) and Mg(OC3H7)2 (14g) were dissolved in ethyl alcohol (300g), followed by adding to the solution, a solution (66g) of oxalic acid (0.8g) in water and subjecting the mixture to hydrolysis and condensation to prepare a solution of the reaction product.
• Example 2 When the solution was coated onto a Si wafer, followed by drying and calcining under the same conditions as in Example 1 to obtain a colorless, transparent silica coating having a coating thickness of 0.5 ⁇ m and no crack. Further, when coating of the above solution was carried out on a Si wafer having an aluminum pattern deposited thereon under the same conditions as in Example 1, a colorless, transparent oxide coating without any crack was obtained.
• Si(OC2H5)4(69g), CH3Si(OC2H5)3 (59g), (CH3)2Si(OC2H5)2 (31g) and B(O i-C3H7)3 (31g) were dissolved in a mixed solvent of ethanol (26g) and N,N-dimethylformamide (105g), followed by adding to the solution, a solution of oxalic acid (0.6g) in water (56g) and subjecting the mixture to hydrolysis and condensation to prepare a solution of the reaction product.
• Si(OCH3)4 (51g), CH3Si(OCH3)3 (30g), C6H5Si(OCH3)3 (22g), (CH3)2Si(OCH3)2 (12g), B(O i-C3H7)3 (31g) and Mg(OC3H7)2 (10g) were dissolved in diethylene glycol diethyl ether (200g), followed by adding to the solution, a solution (55g) of phosphoric acid (0.5g) in water and subjecting the mixture to hydrolysis and condensation to prepare a solution of the reaction product.
• This solution was coated on a Si wafer and a Si wafer having an aluminum pattern deposited thereon, followed by drying and calcining under the same conditions as in Example 1 to obtain a colorless, transparent oxide coating having a coating thickness of 0.8 ⁇ m without any crack.
• Si(OC2H5)4 35g was dissolved in a mixed solvent of ethanol (64g) and ethyl acetate (26g), followed by adding to the solution, a solution of oxalic acid (0.5g) in water (12g), followed by subjecting the mixture to hydrolysis and condensation to prepare a silanol oligomer solution.
• Si(OCH3)4 (17g), CH3Si(OCH3)3 (25g) and (CH3)2Si(OCH3)2 (5g) were dissolved in a mixed solvent of N,N-dimethylformamide (48g) and methanol (6g), followed by adding to the solution, a solution of phosphoric acid (0.5g) in water (20g) and subjecting the mixture to hydrolysis and condensation to prepare a silanol oligomer solution.
• the coating fluid for forming an oxide coating of the present invention is thermally stable and superior in the coating properties; hence cracks do not occur in the oxide coating of even about 1.5 ⁇ m or more formed on the surface of a substrate using the coating fluid.
• the coating fluid for forming an oxide coating of the present invention is effective for coating electronic parts, particularly coating for step-covering on multilevel inter connection of semi­conductors, planarizing the element surface of magnetic bubble domain memory, etc.
• the present invention aims to provide a coating fluid for forming an oxide coating having overcome the above-mentioned drawbacks of the prior art and having a good thermal stability and superior coating properties.
• the inventors of the present Invention have made extensive research in order to achieve the above-mentioned aims and as a result have noted that in order to form an oxide coating without any cracks on a substrate such as silicon, aluminum, etc. and further without any occurrence of cracks even at the time of the subsequent oxidizing step such as oxygen plasma treatment, it is necessary to use a coating fluid satisfying conditions of (1) reducing the strain of curing shrinkage at the time of calcination, (2) bringing the thermal expan­sion coefficient of the coating close to that of the substrate, and (3) making the carbon content in the coating very low or nil and such a coating fluid is obtained by subjecting a specified compound to hydrolysis and condensation by the use of a catalyst in the presence of a solvent; thus we have achieved the present invention.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Inorganic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
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• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Polymers With Sulfur, Phosphorus Or Metals In The Main Chain (AREA)
• Silicon Polymers (AREA)
• Local Oxidation Of Silicon (AREA)
• Structures Or Materials For Encapsulating Or Coating Semiconductor Devices Or Solid State Devices (AREA)
• Formation Of Insulating Films (AREA)

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• 1989
  • 1989-01-31 EP EP19890300927 patent/EP0327311B1/fr not_active Expired - Lifetime
  • 1989-01-31 JP JP1022041A patent/JPH021778A/ja active Granted
  • 1989-01-31 DE DE1989618124 patent/DE68918124T2/de not_active Expired - Fee Related

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