Mechanical enhancement of dense and porous organosilicate materials by UV exposure
View Patent ↗Low dielectric materials and films comprising same have been identified for improved performance when used as interlevel dielectrics in integrated circuits as well as methods for making same. In one aspect of the present invention, an organosilicate glass film is exposed to an ultraviolet light source wherein the film after exposure has an at least 10% or greater improvement in its mechanical properties (i.e., material hardness and elastic modulus) compared to the as-deposited film.
1. A mixture for depositing an organosilicate film comprising a dielectric constant of 3.5 or below, the mixture comprising at least one structure-former precursor selected from the group consisting of an organosilane and an organosiloxane and a pore-former precursor that is distinct from the at least one structure-former precursor, wherein the pore-former precursor is a hydrocarbon compound consisting of from 1 to 13 carbon atoms and less than or equal to 2n+2 hydrogen atoms wherein n is the number of carbon atoms, and wherein at least one of the precursors and/or the organosilicate film exhibits an absorbance in the 200 to 400 nm wavelength range.
2. The mixture of claim 1 wherein the hydrocarbon is selected from the group consisting of alpha-terpinene, limonene, cyclohexane, gamma-terpinene, dimethylhexadiene, ethylbenzene, norbornadiene, 1,2,4-trimethylcyclohexane, 1,5-dimethyl-1,5-cyclooctadiene, camphene, adamantane, 1,3-butadiene, alpha-pinene, beta-pinene, and decahydronaphthelene.
3. The mixture of claim 1 wherein the porogen is removable by ultraviolet radiation.
4. The mixture of claim 1 wherein the organosilicate film is represented by the formula Si v O w C x H y F z , where v+w+x+y+z=100%, v is from 10 to 35 atomic %, w is from 10 to 65 atomic %, x is from 5 to 30 atomic %, y is from 10 to 50 atomic %, and z is from 0 to 15 atomic %.
5. The mixture of claim 1 wherein the at least one structure-former precursor comprises an organosilane.
6. The mixture of claim 5 wherein the organosilane is selected from the group consisting of: methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, phenylsilane, methylphenylsilane, cyclohexylsilane, tert-butylsilane, ethylsilane, diethylsilane, tetraethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, dimethylethoxysilane, methyldiethoxysilane, triethoxysilane, methyltriethoxysilane, trimethylphenoxysilane, phenoxysilane, ditertbutylsilane, diethoxysilane, diacetoxymethylsilane, and mixtures thereof.
7. The mixture of claim 1 wherein the at least one structure-former precursor comprises an organosiloxane.
8. The mixture of claim 7 wherein the organosiloxane is selected from the group consisting of: 1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, hexamethyldisiloxane, 1,1,2,2-tetramethyldisiloxane, octamethyltrisiloxane, and mixtures thereof.
9. The mixture of claim 1 wherein the organosilane comprises diethoxymethylsilane.
10. The mixture of claim 9 wherein the hydrocarbon is selected from the group consisting of alpha-terpinene, limonene, cyclohexane, gamma-terpinene, dimethylhexadiene, ethylbenzene, norbornadiene, 1,2,4-trimethylcyclohexane, 1,5-dimethyl-1,5-cyclooctadiene, camphene, adamantane, 1,3-butadiene, alpha-pinene, beta-pinene, and decahydronaphthelene.
11. A mixture for depositing an organosilicate film, the mixture comprising: from 5 to 95% by weight of a structure-former precursor selected from the group consisting of an organosilane and an organosiloxane and from 5 to 95% by weight of a pore-former precursor that is distinct from the at least one structure-former precursor, wherein the pore-former precursor is a hydrocarbon compound consisting of from 1 to 13 carbon atoms and less than or equal to 2n+2 hydrogen atoms wherein n is the number of carbon atoms, and wherein the at least one of the precursors and/or the organosilicate film exhibits an absorbance in the 200 to 400 nm wavelength range.
12. The mixture of claim 11 wherein the hydrocarbon is selected from the group consisting of alpha-terpinene, limonene, cyclohexane, gamma-terpinene, dimethylhexadiene, ethylbenzene, norbornadiene, 1,2,4-trimethylcyclohexane, 1,5-dimethyl-1,5-cyclooctadiene, camphene, adamantane, 1,3-butadiene, alpha-pinene, beta-pinene, and decahydronaphthelene.
13. The mixture of claim 11 wherein the porogen is removable by ultraviolet radiation.
14. The mixture of claim 11 wherein the organosilicate film is represented by the formula Si v O w C x H y F z , where v+w+x+y+z=100%, v is from 10 to 35 atomic %, w is from 10 to 65 atomic %, x is from 5 to 30 atomic %, y is from 10 to 50 atomic %, and z is from 0 to 15 atomic %.
15. The mixture of claim 11 wherein the at least one structure-former precursor comprises an organosilane.
16. The mixture of claim 15 wherein the organosilane is selected from the group consisting of: methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, phenylsilane, methylphenylsilane, cyclohexylsilane, tert-butylsilane, ethylsilane, diethylsilane, tetraethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, dimethylethoxysilane, methyldiethoxysilane, triethoxysilane, methyltriethoxysilane, trimethylphenoxysilane, phenoxysilane, ditertbutylsilane, diethoxysilane, diacetoxymethylsilane, and mixtures thereof.
17. The mixture of claim 11 wherein the at least one structure-former precursor comprises an organosiloxane.
18. The mixture of claim 17 wherein the organosiloxane is selected from the group consisting of: 1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, hexamethyldisiloxane, 1,1,2,2-tetramethyidisiloxane, octamethyltrisiloxane, and mixtures thereof.
19. The mixture of claim 11 wherein the organosilane comprises diethoxymethylsilane.
20. The mixture of claim 19 wherein the hydrocarbon is selected from the group consisting of alpha-terpinene, limonene, cyclohexane, gamma-terpinene, dimethylhexadiene, ethylbenzene, norbornadiene, 1,2,4-trimethylcyclohexane, 1,5-dimethyl-1,5-cyclooctadiene, camphene, adamantane, 1,3-butadiene, alpha-pinene, beta-pinene, and decahydronaphthelene.