Low k precursors providing superior integration attributes

1. A chemical vapor deposition method for producing a porous organosilica glass film, said method comprising:

providing a substrate within a vacuum chamber;

introducing into the vacuum chamber, gaseous reagents including at least one precursor selected from the group consisting of one or more silicon-containing precursor; and a porogen precursor, that is distinct from the silicon-containing precursor;

wherein the porogen precursor is aromatic in nature, and represented by the formula:

where R1-R6 are independently selected from the group consisting of: H, OH, C 1 to C 6 linear hydrocarbon, C 3 to C 6 branched, saturated, singly or multiply unsaturated hydrocarbon, C 4 to C 6 cyclic hydrocarbon, C 1 to C 6 alcohol, C 4 to C 6 branched, saturated or multiple unsaturated, cyclic ether, C 2 to C 6 epoxide or ketone;

wherein the one or more silicon containing precursors are selected from the formulas:

(i) R 1 n (OR 2 ) p (O(O)CR 4 ) 3-n-p Si—R 7 —SiR 3 m (O(O)CR 5 ) q (OR 6 ) 3-m-q where R 1 and R 3 are independently selected from the group consisting of H or C 1 to C 4 linear hydrocarbon, C 3 to C 4 branched or saturated hydrocarbon, C 2 to C 4 singly unsaturated hydrocarbon, C 3 to C 4 multiply unsaturated hydrocarbon, C 4 cyclic hydrocarbon, C 1 to C 4 partially or fully fluorinated hydrocarbon; R 2 , R 6 and R 7 are independently selected from the group consisting of C 1 to C 6 linear hydrocarbon, C 3 to C 6 branched, saturated or multiply unsaturated hydrocarbon, C 2 to C 6 singularly unsaturated hydrocarbon, C 4 to C 6 cyclic or, aromatic hydrocarbon, C 1 to C 6 partially or fully fluorinated hydrocarbon; R 4 and R 5 are independently selected from the group consisting of: H, C 1 to C 6 linear hydrocarbon, C 3 to C 6 branched, saturated or multiply unsaturated hydrocarbon, C 2 to C 6 singularly unsaturated hydrocarbon, C 4 to C 6 cyclic or, aromatic hydrocarbon, C 1 to C 6 partially or fully fluorinated hydrocarbon; n is 0 to 3; m is 0 to 3; q is 0 to 3 and p is 0 to 3; provided that n+m≧1, n+p≦3, and m+q≦3;

(ii) R 1 n (OR 2 ) p (O(O)CR 3 ) 4−(n+p) Si where R 1 is independently selected from the group consisting of: H or C 1 to C 4 linear hydrocarbon, C 3 to C 4 branched, saturated, or multiply unsaturated hydrocarbon, C 2 to C 4 singularly unsaturated hydrocarbon, C 4 cyclic hydrocarbon, C 1 to C 4 partially or fully fluorinated hydrocarbon; R 2 is independently selected from the group consisting of C 1 to C 6 linear hydrocarbon, C 3 to C 6 branched, saturated, singly or multiply unsaturated hydrocarbon, C 2 to C 6 singularly unsaturated hydrocarbon, C 4 to C 6 cyclic or aromatic hydrocarbon, C 1 to C 6 partially or fully fluorinated hydrocarbon, R 3 is independently selected from the group consisting of H, C 1 to C 6 linear hydrocarbon, C 3 to C 6 branched, saturated, or multiply unsaturated hydrocarbon, C 2 to C 4 singularly unsaturated hydrocarbon, C 4 to C 6 cyclic or aromatic hydrocarbon, C 1 to C 6 partially or fully fluorinated hydrocarbon; n is 1 to 3; and, p is 0 to 3;

(iii) Methyltriethoxysilane; and,

(iv) Methyltrimethoxysilane;

applying energy to the gaseous reagents in the vacuum chamber to induce reaction of the gaseous reagents to deposit a preliminary film on the substrate, wherein the preliminary film contains the porogen; and

using UV radiation to remove from the preliminary film a portion of organic material originating from the porogen precursor to provide the porous organosilica glass film having a dielectric constant of from 2.1 to 2.6 and a carbon content (XPS) of from 33% to 45%.

2. The method of claim 1 wherein the porous organosilica glass 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 %, y is from 10 to 50 atomic % and z is from 0 to 15 atomic %.

3. The method of claim 2 wherein w is from 20 to 45 atomic %, and z is 0.

4. The method of claim 1 wherein an oxidant is added.

5. The method of claim 4 wherein the oxidant is selected from the group consisting of O 2 , ozone, H 2 O 2 , and N 2 O.

6. The method of claim 4 wherein the ratio of added oxidant is <50% compared to the total precursor vapor flow.

7. The method of claim 4 wherein the ratio of added oxidant is <20% compared to the total precursor vapor flow.

8. The method of claim 1 wherein the method takes place in the absence of added oxidant.

9. The method of claim 1 wherein a silicon precursor having formula R 1 x R 2 y Si is added to the deposition method, where R 1 and R 2 can be independently alkoxy or hydrogen groups, and x+y=4.

10. The method of claim 1 wherein TEOS is added to the deposition method.

11. The method of claim 1 wherein TES (triethoxysilane) is added to the deposition method.

12. The method of claim 1 wherein DES (diethoxysilane) is added to the deposition method.

13. The method of claim 1 wherein most of the hydrogen in the porous organosilica glass film is bonded to carbon.

14. The method of claim 1 wherein the porous organosilica glass film has a density less than 1.5 g/ml.

15. The method of claim 1 wherein the porous organosilica glass film has pores which have an equivalent spherical diameter less than or equal to 5 nm.

16. The method of claim 1 wherein the porous organosilica glass film has an average weight loss of less than 1.0 wt %/hr isothermal at 425° C. under N 2 .

17. The method of claim 1 wherein the porous organosilica glass film has an average weight loss of less than 1.0 wt %/hr isothermal at 425° C. under air.

18. The method of claim 1 wherein the porogen is selected from the group consisting of: toluene, benzene, cymene, xylene, phenol, mesitylene, ethyl benzene, styrene, ethoxybenzene, methoxybenzene, benzaldehyde and mixtures thereof.

19. The method of claim 1 wherein the porogen is cymene.

20. The method of claim 1 wherein the porogen is toluene.

21. The method of claim 1 , wherein the silicon-containing precursor is diethoxymethylsilane (DEMS).