Insulation film forming material, insulation film, method for forming the insulation film, and semiconductor device

• US 6,727,515 B2
• Filed: 03/22/2002
• Issued: 04/27/2004
• Est. Priority Date: 11/02/2001
• Status: Expired due to Term

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited
• Inventors: Nakata, Yoshihiro, Suzuki, Katsumi, Sugiura, Iwao, Yano, Ei
• Primary Examiner(s): Tran, Minh Loan
• Assistant Examiner(s): Forde, Remmon R.
• Application Number:
  US10/102,723
• Publication Number:
  US 20030089903A1
• Time in Patent Office: 767 Days
• Field of Search: 257/40, 257/65, 257/758, 257/759, 257/632, 257/642, 257/643, 257/651, 438/1, 438/99, 438/780, 438/781, 438/783
• US Class Current: 257/40
• 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: C09D 183/16 in which all the silicon atoms are connected by linkages other than oxygen atoms
• 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/31695 Deposition of porous oxides or porous glassy oxides or oxide based porous glass
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 2221/1047 the air gaps being formed by pores in the dielectric
• CPC Class Codes: H01L 23/5222 Capacitive arrangements or effects of, or between wiring layers other capacitive arrangements H01L23/642
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/53295 Stacked insulating layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Porous insulation films 28, 40, 50 are formed of an insulation forming material including a silicon compound having a skeleton containing C—C bonds, a pore forming compound which is decomposed or evaporated by a heat treatment, and a solvent which dissolves the silicon compound with the pore forming compound, whereby the porous insulation film can have good mechanical strength and low dielectric constant.

Claims

1. An insulation film forming material comprising:

a silicon compound having a skeleton of C—

C bonds;

a porous forming compound which is decomposed or evaporated by a heat treatment; and

a solvent which dissolves the silicon compound with the porous forming material.

2. An insulation film forming material according to claim 1, wherein

the silicon compound has a structure expressed by the following general formula

(Either of R₁ and R₂ is hydrogen, and the other is hydrocarbon having 1-3 carbon atoms or a phenyl group. R₃ is hydrocarbon having 1-3 carbon atoms or a phenylene group, or oxygen. o is an integer of 20-1000.)

3. An insulation film forming material according to claim 1, wherein the silicon compound has side chains containing hydrogen.

4. An insulation film forming material according to claim 1, wherein

the silicon compound is one of poly(dimethylcarbosiloxane), poly(hydromethylcarbosilane), poly(diethylcarbosilane), poly(hydroethylcarbosilane), poly(carbosilastyrene), poly(phenylmethylcarbosilane), poly(diphenylcarbosilane), poly(dimethylsilphenylenesiloxane), poly(methylsilphenylene siloxane), poly(diethylsilphenylenesiloxane), poly(ethylsilphenylene siloxane), poly(dipropylsilphenylenesiloxane) poly(propylsilphenylenesiloxane), poly(phenylsilphenylenesiloxane), poly(phenysilphenylenesiloxane), poly(phenylmethylsilphenylenesiloxane), poly(phenylethylsilphenlenesiloxane), poly(phenylpropylsilphenylenesiloxane), poly(ethylmethylsilphenylenesiloxane), poly(methylpropylsilphenylenesiloxane), and poly(ethylpropylsilphenylenesiloxane).

5. An insulation film forming material according to claim 1, wherein

the pore forming compound is an amine compound having 4 or more carbon atoms.

6. An insulation film forming material according to claim 5, wherein

the amine compound is one of aminobutane, diaminobutane, cyclohexylamine, dicyclohexylamine, tetramethylammoniun hydride, hexamethylammonium hydride, and hexadisilylammonium hydride.

11. A method for forming an insulation film comprising the steps of:

applying to a substrate an insulation film forming material according to claim 1 including a silicon compound having a skeleton containing C—

C bonds, a pore forming compound which is decomposed or evaporated by a heat treatment and a solvent which dissolves the silicon compound and the pore forming compound;

drying the insulation film forming material applied to the substrate to form a film containing the silicon compound and the pore forming compound; and

decomposing or evaporating the pore forming compound by subjecting the substrate to the heat treatment to eliminate the pore forming compound from the film to form pores in the film.

12. A method for forming an insulation film according to claim 11, wherein the silicon compound has a structure expressed by the following general formula

(Either of R₁ and R₂ is hydrogen, and the other is hydrocarbon having 1-3 carbon atoms or a phenyl group. R₃ is hydrocarbon having 1-3 carbon atoms or a phenylene group, or oxygen. o is an integer of 20-1000.)

13. A method forming an insulation film according to claim 11, wherein the silicon compound is one of poly(dimethylcarbosiloxane), poly(hydromethylcarbosilane), poly(diethylcarbosilane), poly(hydroethylcarbosilane), poly(carbosilastyrene), poly(phenylmethylcarbosilane), poly(diphenylcarbosilane), poly(dimethylsilphenylenesiloxane), poly(methylsilphenylene siloxane), poly(diethylsilphenylenesiloxane), poly(ethylsilphenylene siloxane), poly(dipropylsilphenylenesiloxane), poly(propylsilphenylenesiloxane) poly(phenylsilphenylenesiloxane), poly(phenysilphenylenesiloxane), poly(phenylmethylsilphenylenesiloxane), poly(phenylethylsilphenylenesiloxane), poly(phenylpropylsilphenylenesiloxane), poly(ethylmethylsilphenylenesiloxane), poly(methylpropylsilphenylenesiloxane), and poly(ethylpropylsilphenylenesiloxane).

14. A method for forming an insulation film according to claim 11, wherein

a concentration of the pore forming compound in the insulation film forming material is adjusted to thereby control a porosity of the film.

15. An insulation film forming method according to claim 11, wherein

the pore forming compound is an amine compound containing 4 or more carbon atoms, and

the substrate with the film formed on is subjected to a heat treatment in an atmosphere of a below 5% oxygen concentration at 300-500°

C. to form the pores in the film.

7. An insulation film comprising a film of a silicon compound having a skeleton containing C—

C bonds, wherein pores of below 10 nm-size are formed in the film.

8. An insulation film according to claim 7, wherein the silicon compound has a structure expressed by the following general formula

(Either of R₁ and R₂ is hydrogen, and the other is hydrocarbon having 1-3 carbon atoms or a phenyl group. R₃ is hydrocarbon having 1-3 carbon atoms or a phenylene group, or oxygen. o is an integer of 20-1000.)

9. An insulation film according to claim 7, wherein

the silicon compound is one of poly(dimethylcarbosiloxane), poly(hydromethylcarbosilane), poly(diethylcarbosilane), poly(hydroethylcarbosilane), poly(carbosilastyrene), poly(phenylmethylcarbosilane), poly(diphenylcarbosilane), poly(dimethylsilphenylenesiloxane), poly(methylsilphenylene siloxane), poly(diethylsilphenylenesiloxane), poly(ethylsilphenylene siloxane), poly(dipropylsilphenylenesiloxane), poly(propylsilphenylenesiloxane), poly(phenylsilphenylenesiloxane), poly(phenysilphenylenesiloxane), poly(phenylmethylsilphenylenesiloxane), poly(phenylethylsilphenylenesiloxane), poly(phenylpropylsilphenylenesiloxane), poly(ethylmethylsilphenylnesiloxane), poly(methylpropylsilphenylenesiloxane), and poly(ethylpropylsilphenylenesiloxane).

10. An insulation film according to claim 7, wherein a ratio of oxygen atom to silicon atom in the skeleton of the film is in the range of 1 silicon atom to 0-0.5 oxygen atom.

16. A semiconductor device comprising a porous insulation film comprising a film of a silicon compound having a skeleton containing C—

C bonds formed on a semiconductor substrate, wherein pores of below 10 nm-size are formed in the film.

17. A semiconductor device according to claim 16, further comprising

a buried interconnection layer buried in the porous insulation film.

18. A semiconductor device according to claim 16, further comprising

a first interconnection layer formed above the semiconductor substrate, the porous insulation film formed on the first interconnection layer, and

a second interconnection layer formed on the porous insulation film.

19. A semiconductor device according to claim 16, wherein the silicon compound has a structure expressed by the following general fomula

(Either of R₁ and R2 is hydrogen, and the other is hydrocarbon having 1-3 carbon atoms or a phenyl group. R₃ is hydrocarbon having 1-3 carbon atoms or a phenylene group, or oxygen. o is an integer of 20-1000.)

20. A semiconductor device according to claim 16, wherein the silicon compound is one of poly(dimethylcarbosiloxane), poly(hydromethylcarbosilane), poly(diethylcarbosilane), poly(hydroethylcarbosilane), poly(carbosilastyrene), poly(phenylmethylcarbosilane), poly(diphenylcarbosilane), poly(dimethylsilphenylenesiloxane), poly(methylsilphenylene siloxane), poly(diethylsilphenylenesiloxane), poly(ethylsilphenylene siloxane), poly(dipropylsilphenylenesiloxane), poly(propylsilphenylenesiloxane), poly(phenylsilphenylenesiloxane), poly(phenysilphenylenesiloxane), poly(phenylmethylsilphenylenesiloxane), poly(phenylethylsilphenylenesiloxane), poly(phenylpropylsilphenylenesiloxane), poly(ethylmethylsilphenylenesiloxane), poly(methylpropylsilphenylenesiloxane), and poly(ethylpropylsilphenylenesiloxane).

21. A semiconductor device according to claim 16, wherein a ratio of oxygen atom to silicon atom in the skeleton of the film of the porous insulation film is in the range of 1 silicon atom to 0-0.5 oxygen atom.