PRECURSOR COMPOSITION FOR POROUS THIN FILM, METHOD FOR PREPARATION OF THE PRECURSOR COMPOSITION, POROUS THIN FILM, METHOD FOR PREPARATION OF THE POROUS THIN FILM, AND SEMICONDUCTOR DEVICE

• US 20090186210A1
• Filed: 05/16/2007
• Published: 07/23/2009
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: Ulvac Incorporated
• Original Assignee: Ulvac Incorporated
• Inventors: Tanaka, Hirofumi, Kohmura, Kazuo, Nakayama, Takahiro, Fujii, Nobutoshi
• Granted Patent: US 8,394,457 B2
• Time in Patent Office: Days
• US Class Current: 428/304.400
• CPC Class Codes: C08G 77/04 Polysiloxanes
• CPC Class Codes: C08G 77/56 Boron-containing linkages C08G77/485 takes precedence
• CPC Class Codes: C08G 77/58 Metal-containing linkages C08G77/485 takes precedence
• CPC Class Codes: C09D 183/04 Polysiloxanes
• CPC Class Codes: C09D 183/14 in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms C09D183/10 takes precedence
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/31695 Deposition of porous oxides or porous glassy oxides or oxide based porous glass
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]

Abstract

Disclosed is a precursor composition comprising: a compound selected from a compound represented by the formula: Si(OR¹)₄ and a compound represented by the formula R_a(Si) (OR²)_4-a (in the formulas represents a monovalent organic group; R represents a hydrogen atom, a fluorine atom or a monovalent organic group; R² represents a monovalent organic group; and a is an integer ranging from 1 to 3, provided that R, R¹ and R² may be the same or different from one another) a thermally degradable organic compound; an element having a catalyst activity; urea; and the like. A porous thin film produced from the precursor composition is irradiated with ultraviolet ray, and then subjected to gas-phase reaction with a hydrophobic compound. A porous thin film thus prepared can be used for the manufacture of a semiconductor device.

Claims

1. A precursor composition for forming a porous thin film comprising at least one member selected from the group consisting of compounds (A) represented by the following general formula (1) and compounds (B) represented by the following general formula (2):

Si(OR¹)₄  

 

(1)

R_a(Si)(OR²)_4-a  

 

(2)

(In the foregoing formulas (1) and (2), R¹ represents a monovalent organic group;

R represents a hydrogen atom, a fluorine atom or a monovalent organic group;

R² represents a monovalent organic group;

a is an integer ranging from 1 to 3, provided that R, R¹and R² may be the same or different from one another);

a heat decomposable organic compound (C) which undergoes heat decomposition at a temperature of not less than 250°

C.;

at least one element (D) selected from the group consisting of amphoteric elements having an electronegativity of not higher than 2.5, elements having an ionic radius of not less than 1.6 Å and

elements having an atomic weight of not less than 130; and

further a compound (E) which is thermally decomposed at a temperature ranging from 90 to 200°

C. and can form an amine through the thermal decomposition and whose aqueous solution and/or solution in an alcohol/water mixed solvent have a pH value falling within the range of from 6.5 to 8, at a temperature of not higher than the heat-decomposition temperature thereof.

2. The precursor composition for forming a porous thin film as set forth in claim 1, wherein the heat-decomposable organic compound (C) comprises at least one surfactant having a molecular weight ranging from 200 to 5000.

3. The precursor composition for forming a porous thin film as set forth in claim 1, wherein the content of metallic ion impurities other than the element (D) included in the precursor composition is not higher than 10 ppb.

4. The precursor composition for forming a porous thin film as set forth in claim 1, wherein the element (D) is at least one member selected from the group consisting of B, Al, P, Zn, Ga, Ge, As, Se, In, Sn, Sb, Te, Rb, Cs, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At and lanthanum series.

5. The precursor composition for forming a porous thin film as set forth in claim 1, wherein the compound (E) is included in the precursor composition in a concentration ranging from 0.03 to 0.13 mole per mole of the Si atoms present in the precursor composition.

6. The precursor composition for forming a porous thin film as set forth in claim 1, wherein the compound (E) is urea and the urea is included in the precursor composition in a concentration ranging from 0.03 to 0.13 mole per mole of the Si atoms present in the precursor composition.

19. A method for the preparation of a porous thin film comprising the steps of applying onto a surface of a substrate a solution of a precursor composition for forming a porous thin film prepared according to the method as set forth in claim 1;

drying a resulting coated layer of the solution by heating the same at a temperature ranging from 100 to 400°

C.;

irradiating a porous thin film formed on the substrate surface with ultraviolet rays having a wavelength ranging from 157 to 344 nm; and

then reacting the porous thin film with a hydrophobic compound having a hydrophobic group and at least one group selected from polymerizable groups through a gas-phase reaction carried out at a temperature ranging from 100 to 600°

C. to thus form a hydrophobic porous thin film.

20. The method for the preparation of a porous thin film as set forth in claim 19, wherein the hydrophobic compound is a compound which has at least one hydrophobic group selected from alkyl groups each having 1 to 6 carbon atoms and C₆H₅ group and at least one polymerizable group selected from a hydrogen atom, an OH group and a halogen atom.

21. The method for the preparation of a porous thin film as set forth in claim 19, wherein the hydrophobic compound is an organic silicon atom-containing compound having at least one kind of binding unit represented by the formula:

Si—

X—

Si (wherein X represents an oxygen atom, an NR³ group, a C_nH_2n group or a C₆H₄ group, R³ represents a C_mH_2m+1 group or a C₆H₅ group, n is 1 or 2 and m is an integer ranging from 1 to

     6) and at least two kinds of binding units represented by the formula;

Si-A (wherein A represents a hydrogen atom, an OH group, a OC_bH_2b+1 group or a halogen atom, provided that a plurality of substituents A present in the same molecule may be the same or different, and b is an integer ranging from 1 to

     6).

22. A method for the preparation of a porous thin film comprising the step of repeating the method as set forth in claim 19 to thus form a porous thin film having an improved mechanical strength.

23. A porous thin film prepared according to the method as set forth in claim 19.

24. A semiconductor device produced using a porous thin film=prepared according to the method as set forth in claim 19.

7. A method for the preparation of a precursor composition for forming a porous thin film comprising the steps of blending, in an organic solvent, at least one member selected from the group consisting of compounds (A) represented by the following general formula (1) and compounds (B) represented by the following general formula (2):

Si(OR¹)₄  

 

(1)

R_a(Si)(OR²)_4-a  

 

(2)

(In the foregoing formulas (1) and (2), R¹ represents a monovalent organic group;

R represents a hydrogen atom, a fluorine atom or a monovalent organic group;

R² represents a monovalent organic group; and

a is an integer ranging from 1 to 3, provided that R, R¹and R² may be the same or different from one another);

a heat decomposable organic compound (C) which undergoes heat decomposition at a temperature of not less than 250°

C.; and

at least one element (D) selected from the group consisting of amphoteric elements having an electronegativity of not higher than 2.5, elements having an ionic radius of not less than 1.6 Å and

elements having an atomic weight of not less than 130, or at least one compound containing the element (D); and

then mixing the resulting mixed solution with a compound (E) which is thermally decomposed at a temperature ranging from 90 to 200°

C. and can generate an amine through the thermal decomposition and whose aqueous solution and/or solution in an alcohol/water mixed solvent have a pH value falling within the range of from 6.5 to 8, at a temperature of not higher than the heat-decomposition temperature thereof.

8. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 7, wherein the heat-decomposable organic compound (C) comprises at least one surfactant having a molecular weight ranging from 200 to 5000.

9. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 7, wherein the content of metallic ion impurities other than the element (D) included in the precursor composition is not higher than 10 ppb.

10. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 7, wherein the element (D) is at least one member selected from the group consisting of B, Al, P, Zn, Ga, Ge, As, Se, In, Sn, Sb, Te, Rb, Cs, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At and lanthanum series.

11. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 7, wherein the compound (E) is included in the precursor composition in a concentration ranging from 0.03 to 0.13 mole per mole of the Si atoms present in the precursor composition.

12. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 7, wherein the compound (E) is urea and the urea is included in the precursor composition in a concentration ranging from 0.03 to 0.13 mole per mole of the Si atoms present in the precursor composition.

13. A method for the preparation of a precursor composition for forming a porous thin film comprising the steps of blending, in an organic solvent, at least one member selected from the group consisting of compounds (A) represented by the following general formula (1) and compounds (B) represented by the following general formula (2):

Si(OR¹)₄  

 

(1)

R_a(Si)(OR²)_4-a  

 

(2)

(In the foregoing formulas (1) and (2), R¹ represents a monovalent organic group;

R represents a hydrogen atom, a fluorine atom or a monovalent organic group;

R² represents a monovalent organic group; and

a is an integer ranging from 1 to 3, provided that R, R¹and R² may be the same or different from one another), with a heat decomposable compound (C) which undergoes heat decomposition at a temperature of not less than 250°

C., to give a mixed solution;

adding, to the resulting mixed solution, at least one element (D) selected from the group consisting of amphoteric elements having an electronegativity of not higher than 2.5, elements having an ionic radius of not less than 1.6 Å and

elements having an atomic weight of not less than 130, or at least one compound containing the element (D), and then mixing them to give a solution; and

blending the resulting solution with a compound (E) which is thermally decomposed at a temperature ranging from 90 to 200°

C. and can form an amine through the thermal decomposition and whose aqueous solution and/or solution in an alcohol/water mixed solvent have a pH value falling within the range of from 6.5 to 8, at a temperature of not higher than the heat-decomposition temperature thereof.

14. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 13, wherein the heat-decomposable organic compound (C) comprises at least one surfactant having a molecular weight ranging from 200 to 5000.

15. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 13, wherein the content of metallic ion impurities other than the element (D) included in the precursor composition is not higher than 10 ppb.

16. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 13, wherein the element (D) is at least one member selected from the group consisting of B, Al, P, Zn, Ga, Ge, As, Se, In, Sn, Sb, Te, Rb, Cs, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At and lanthanum series.

17. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 13, wherein the compound (E) is included in the precursor composition in a concentration ranging from 0.03 to 0.13 mole per mole of the Si atoms present in the precursor composition.

18. The method for the preparation of a precursor composition for forming a porous thin film as set forth in claim 13, wherein the compound (E) is urea and the urea is included in the precursor composition in a concentration ranging from 0.03 to 0.13 mole per mole of the Si atoms present in the precursor composition.