Compositions for preparing low dielectric materials containing solvents
Silica-based materials and films having a dielectric constant of 3.7 or below and compositions and methods for making and using same are disclosed herein. In one aspect, there is provided a composition for preparing a silica-based material comprising an at least one silica source, a solvent, an at least one porogen, optionally a catalyst, and optionally a flow additive wherein the solvent boils at a temperature ranging from 90° C. to 170° C. and is selected from the group of compounds represented by the following formulas: HO—CHR 8 —CHR 9 —CH 2 —CHR 10 R 11 where R 8 , R 9 , R 10 and R 11 can independently be an alkyl group ranging from 1 to 4 carbon atoms or a hydrogen atom; and R 12 —CO—R 13 where R 12 is a hydrocarbon group having from 3 to 6 carbon atoms; R 13 is a hydrocarbon group having from 1 to 3 carbon atoms; and mixtures thereof.
1 . A composition for producing a silica-based material having a dielectric constant of about 3.7 or less, the composition comprising: an at least one silica source, a solvent, an at least one porogen, optionally a catalyst, and optionally a flow additive wherein the solvent boils at a temperature ranging from 90° C. to 170° C. and is selected from the group of compounds represented by the following formulas:
a. HO—CHR 8 —CHR 9 —CH 2 —CHR 10 R 11 where R 8 , R 9 , R 10 and R 11 can independently be an alkyl group ranging from 1 to 4 carbon atoms or a hydrogen atom; and
b. R 12 —CO—R 13 where R 12 is a hydrocarbon group having from 3 to 6 carbon atoms; R 12 is a hydrocarbon group having from 1 to 3 carbon atoms; and mixtures thereof.
2 . The composition of claim 1 further comprising an ionic additive.
3 . The composition of claim 1 wherein the at least one silica source is selected from the group represented by the following formulas:
a. R a Si(OR 1 ) 4-a , wherein R independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group; R 1 represents a monovalent organic group; and a is an integer selected from 1 and 2;
b. Si(OR 2 ) 4 , where R 2 represents a monovalent organic group;
c. R 3 b (R 4 O) 3-b Si—R 7 —Si(OR 5 ) 3-c R 6 c , wherein R 4 and R 5 may be the same or different and each represents a monovalent organic group; R 3 and R 6 may be the same or different; b and c may be the same or different and each independently is a number ranging from 0 to 3; R 7 represents an oxygen atom, a phenylene group, or a group represented by —(CH 2 ) n —, wherein n is an integer ranging from 1 to 6; and mixtures thereof.
4 . The composition of claim 1 wherein the composition contains 20 to 80 mole percent Si—C bonds relative to the total number of Si atoms within the composition.
5 . The composition of claim 1 wherein the solvent is selected from alcohol isomers having from 4 to 6 carbon atoms, ketone isomers having from 4 to 8 carbon atoms, and mixtures thereof.
6 . The composition of claim 5 wherein the solvent is selected from 1-pentanol, 2-pentanol, 2-methyl-1-butanol, 2-methyl-1-pentanol, 2-heptanone, 4-heptanone, 1-tert-butoxy-2-ethoxyethane, 2-methoxyethylacetate, 2,3-dimethyl-3-pentanol, 1-methoxy-2-butanol, 4-methyl-2-pentanol, 1-tert-butoxy-2-methoxyethane, 3-methyl-1-butanol, 2-methyl-1-butanol, 3-methyl-2-pentanol, 1,2-diethoxyethane, 1-butanol, 3-methyl-2-butanol, 5-methyl-2-hexanol, and mixtures thereof.
7 . The composition of claim 1 wherein the solvent has a total metal content of less than 1 ppm.
8 . The process of claim 1 wherein the solvent has a total solubility parameter ranging from 15 and 25 (J/m 3 ) 1/2 .
9 . The process of claim 1 wherein the solvent has a surface tension ranging from 20 to 50 dyne/cm.
10 . The process claim 1 wherein the solvent has a viscosity ranging from 0.5 to 7 centipoise as measured by parallel plate methodology.
11 . The composition of claim 1 wherein the composition has a total metal content of less than 1 ppm.
12 . The composition of claim 1 wherein a weight ratio of weight of porogen to weight of porogen and weight of SiO 2 within the composition ranges from 0.9 to 0.1.
13 . The composition of claim 1 comprising the catalyst and wherein the catalyst is an acid catalyst.
14 . The composition of claim 1 that exhibits Newtonian behavior.
15 . The composition of claim 1 comprising a flow additive.
16 . The composition of claim 15 wherein the amount of flow additive in the composition is one percent by weight or less.
17 . The composition of claim 15 wherein the flow additive boils at a temperature of 100° C. or greater.
18 . The composition of claim 15 wherein the flow additive comprises poly-dimethylsiloxane.
19 . The composition of claim 15 wherein the flow additive comprises polyether modified dimethylsiloxane.
20 . The composition of claim 1 wherein the at least one silica source hydrolyzes and condenses and the product of hydrolysis and condensation has a radius of gyration of 5 nanometers or less.
21 . A composition for forming a silica-based film having a dielectric constant of about 3.7 or less comprising: an at least one silica source, a solvent, optionally at least one porogen, optionally a catalyst, and a flow additive.
22 . The composition of claim 21 wherein the amount of flow additive in the composition is one percent by weight or less.
23 . The composition of claim 21 wherein the flow additive boils at a temperature of 100° C. or greater.
24 . The composition of claim 21 wherein the flow additive comprises poly-dimethylsiloxane.
25 . The composition of claim 21 wherein the flow additive comprises polyether modified dimethylsiloxane.
26 . A process for forming a silica-based film with a dielectric constant of 3.7 or less, the process comprising:
providing a composition comprising: an at least one silica source, a solvent, optionally an at least one porogen, optionally an at least one catalyst, and optionally a flow additive wherein the solvent wherein the solvent boils at a temperature ranging from 90° C. to 170° C.;
depositing the composition onto a substrate using a bowl configuration selected from an open spinning bowl configuration and a semi-closed spinning bowl configuration to form a coated substrate; and
curing the coated substrate to form the silica-based film.
27 . The process of claim 26 wherein the depositing is conducted using the open spinning bowl configuration.
28 . The process of claim 26 wherein the depositing is conducted using the semi-closed spinning bowl configuration.
29 . The process of claim 26 wherein the solvent comprises one or more functionalities selected from hydroxyl, carbonyl, ester, and combinations thereof.
30 . The process of claim 26 wherein the solvent boils at a temperature ranging from 120 to 170° C.
31 . The process of claim 26 wherein the solvent has a total solubility parameter ranging from 15 and 25 (J/m 3 ) 1/2 .
32 . The process of claim 26 wherein the solvent has a surface tension ranging from 20 to 50 dyne/cm.
33 . The process claim 26 wherein the solvent has a viscosity ranging from 0.5 to 7 centipoise as measured by parallel plate methodology.
34 . The process of claim 26 wherein the solvent is selected from the group of compounds represented by the following formulas:
a. HO—CHR 8 —CHR 9 —CH 2 —CHR 10 R 11 where R 8 , R 9 , R 10 and R 11 can independently be an alkyl group ranging from 1 to 4 carbon atoms or a hydrogen atom; and
b. R 12 —CO—R 13 where R 12 is a hydrocarbon group having from 3 to 6 carbon atoms; R 13 is a hydrocarbon group having from 1 to 3 carbon atoms; and mixtures thereof.
35 . The process of claim 34 wherein the solvent is selected from alcohol isomers having from 4 to 6 carbon atoms, ketone isomers having from 4 to 8 carbon atoms, linear or branched hydrocarbon acetates wherein the hydrocarbon has from 4 to 6 carbon atoms, ethylene glycol ethers, propylene glycol ethers, ethylene glycol ether acetates, propylene glycol ether acetates, and mixtures thereof.
36 . The process of claim 35 wherein the solvent is selected from 1-pentanol, 2-pentanol, 2-methyl- 1 -butanol, 2-methyl-1-pentanol, 2-ethoxyethanol, 2-propoxyethanol, 1-propoxy-2-propanol, 2-heptanone, 4-heptanone, 1-tert-butoxy-2-ethoxyethane, 2-methoxyethylacetate, propylene glycol methyl ether acetate, pentyl acetate, 1-tert-butoxy-2-propanol, 2,3-dimethyl-3-pentanol, 1-methoxy-2-butanol, 4-methyl-2-pentanol, 1-tert-butoxy-2-methoxyethane, 3-methyl-1-butanol, 2-methyl-1-butanol, 2-methoxyethanol, 3-methyl-2-pentanol, 1,2-diethoxyethane, 1-methoxy-2 propanol, 1-butanol, 3-methyl-2-butanol, 5-methyl-2-hexanol, and mixtures thereof.
37 . The process of claim 35 wherein the solvent is selected from ethylene glycol ethers, propylene glycol ethers, ethylene glycol ether acetates, propylene glycol ether acetates, and mixtures thereof.
38 . The process of claim 26 wherein the at least one silica source hydrolyzes and condenses and the product of hydrolysis and condensation has a radius of gyration of 5 nanometers or less.
39 . A silica-based film formed by the process of claim 26 .
40 . The silica-based film of claim 39 comprising 20 to 80 mole percent Si—C bonds to the total number of Si atoms.
41 . The silica-based film of claim 39 comprising 500 ppm or less of an amine or a hydroxide.
42 . The silica-based film of claim 39 comprising pores.
43 . The silica-based film of claim 39 wherein the film exhibits a film uniformity of 5% or less.
44 . A process for forming a silica-based film having a dielectric constant of 3.7 or less, the process comprising:
providing a composition comprising: an at least one silica source wherein the at least one silica source partially hydrolyzes to provide a low boiling solvent, an at least one solvent, water, and a catalyst wherein the solvent boils at a temperature ranging from 90° C. to 170° C. and is selected from the group of compounds represented by the following formulas:
a. HO—CHR 8 —CHR 9 —CH 2 —CHR 10 R 11 where R 8 , R 9 , R 10 and R 11 can independently be an alkyl group ranging from 1 to 4 carbon atoms or a hydrogen atom; and
b. R 12 —CO—R 13 where R 12 is a hydrocarbon group having from 3 to 6 carbon atoms; R 13 is a hydrocarbon group having from 1 to 3 carbon atoms; and mixtures thereof.
removing from the composition from about 20 to about 75% of the total number of moles of low boiling solvents and from 20 to 80% of the total number of moles of water to provide a reduced composition;
depositing the reduced composition onto a substrate using a bowl configuration selected from an open spinning bowl configuration and a semi-closed spinning bowl configuration to form a coated substrate; and
curing the coated substrate to form the silica-based film.
45 . The process of claim 44 further comprising adding to the reduced composition solvent prior to depositing.
46 . The process of claim 44 where the removing is conducted by heating the composition to a temperature ranging from 30 and 100° C.
47 . The process of claim 44 where the removing is conducted by vacuum distillation.
48 . The process of claim 44 wherein the composition further comprises at least one porogen.
49 . The process of claim 44 wherein the depositing is conducted using the open spinning bowl configuration.
50 . The process of claim 44 wherein the depositing is conducted using the semi-closed spinning bowl configuration.
51 . The process of claim 44 wherein the composition comprises 1 ppm or less of metals.
52 . The process of claim 44 wherein the composition further comprises an ionic additive.
53 . The process of claim 44 wherein the reduced composition has an ambient temperature storage stability, of 10 days or greater.
54 . The process of claim 44 wherein the at least one silica source hydrolyzes and condenses and the product of hydrolysis and condensation has a radius of gyration of 5 nanometers or less.
55 . A silica-based film formed by the process of claim 44 .
56 . The silica-based film of claim 55 wherein the film exhibits a film uniformity of 5% or less.
57 . A process for forming a silica-based film with a dielectric constant of 3.7 or less, the process comprising:
providing a composition comprising an at least one silica source, a solvent, optionally at least one porogen, optionally a catalyst, and a flow additive;
depositing 3 milliliters or less of the composition onto a substrate to form a coated substrate wherein the depositing is conducted in a continuous stream; and
curing the coated substrate to one or more temperatures for a time sufficient to form the silica-based film.
58 . The process of claim 57 wherein the substrate comprises a 300 mm wafer and the amount of composition to square area of substrate ranges from 0.00141 to 0.0170 cc/cm 2 .
59 . The process of claim 57 wherein the substrate comprises a 200 mm wafer and the amount of composition to square area of substrate ranges from 0.00159 to 0.0255 cc/cm 2 .