Using polydentate ligands for sealing pores in low-k dielectrics
View Patent ↗In preferred embodiments, a polydentate pore-sealing ligand is used to seal or repair pores damaged by plasma processing. The polydentate ligand includes bidentate ligands corresponding to the general formula X—CH 2 —(CH 2 ) n —CH 2 —X or X—Si(CH 3 ) 2 —(CH 2 ) n —Si(CH 3 ) 2 —X. The polydentate ligand also includes tridendate ligands corresponding to the general formula X—CH 2 —(CH 2 ) m (CXH)(CH 2 ) o —CH 2 —X or X—Si(CH 3 ) 2 —(CH 2 ) m (CXH)(CH 2 ) o —Si(CH 3 ) 2 —X. Alternative embodiments may include single or multiply branched polydentate ligands. Other embodiments include ligands that are cross-linked after attachment to the dielectric. Still other embodiments include a derivatization reaction wherein silanol groups formed by plasma damage are removed and favorable dielectric properties are restored.
1. A method for forming a carbon-containing, porous low-k dielectric layer on a semiconductor substrate, the method comprising:
providing a carbon containing, porous, low-k dielectric layer on said semiconductor substrate; and
treating the pores of said low-k, porous dielectric layer with a polydentate pore-sealing ligand.
2. The method of claim 1 , wherein the polydentate pore-sealing ligand is a bidentate ligand.
3. The method of claim 2 , wherein the bidentate ligand corresponds to the general formula X—CH 2 —(CH 2 ) n —CH 2 —X; wherein n=0–2; and wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
4. The method of claim 2 , wherein the bidentate ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) n —Si(CH 3 ) 2 —X; wherein n=0–2; and wherein X is H, NH 2 , Cl, Br, I, —OCH 3 , —SO 2 F or triflate.
5. The method of claim 2 , wherein the bidentate ligand is a branched ligand.
6. The method of claim 5 , wherein the branched ligand corresponds to the general formula X—CH 2 —(CH 2 ) m (CR 1 R 2 )(CH 2 ) o —CH 2 —X; wherein 2+m+o+1=n/2; wherein R 1 and R 2 are independently H, Alkyl, or Aryl; and wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
7. The method of claim 1 , wherein the polydentate pore-sealing ligand is a tridentate ligand.
8. The method of claim 7 , wherein the tridentate ligand corresponds to the general formula X—CH 2 —(CH 2 ) m (CXH)(CH 2 ) o —CH 2 —X; wherein m≈o≈n; and wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
9. The method of claim 7 , wherein the tridentate ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (CXH)(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈n; and wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
10. The method of claim 7 , wherein the tridentate ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (SiXCH 3 )(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈n; and wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
11. The method of claim 1 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—CH 2 —(CH 2 ) m (CH(CH 2 ) p —X)(CH 2 ) o —CH 2 —X; wherein m≈o≈p≈n/2; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
12. The method of claim 1 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (CH(CH 2 ) p —X)(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈p≈n/2; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
13. The method of claim 1 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (CH(CH 2 ) p SiX(CH 3 ) 2 )(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈p≈n/2; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
14. The method of claim 1 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—CH 2 —(CH 2 ) n —Y; wherein n=0–3; wherein X is H, NH 2 , Cl, Br, OCH 3 , —SO 2 F or triflate; and wherein Y is O—H, —NH 2 , amide, or imide.
15. The method of claim 1 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) n —Y; wherein n=0–3; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate; and wherein Y is O—H, —NH 2 , amide, or imide.
16. The method of claim 1 , wherein reacting the plurality of open pores with a polydentate pore-sealing ligand comprises the steps of reacting the polydentate pore-sealing ligand with the carbon-containing, porous, low-k insulator and then cross-linking the polydentate pore-sealing ligand.
17. The method of claim 1 , wherein the carbon-containing, porous, low-k dielectric layer comprises a carbon-doped oxide.
18. The method of claim 1 , wherein the carbon-containing, porous, low-k dielectric layer comprises porous silica.
19. The method of claim 1 , wherein the carbon-containing, porous, low-k dielectric layer comprises OSG.
20. The method of claim 1 further comprising:
forming a silicon halide by reacting a silanol in the carbon-containing, porous, low-k dielectric layer with a halogenating agent; and
performing a derivatizing reaction with the silicon halide.
21. The method of claim 20 , wherein the halogenating agent is selected from the group consisting essentially of thionyl chloride, sulfuryl chloride and carboxydichloride.
22. The method of claim 20 , wherein the derivatizing reaction includes using an organometallic compound.
23. The method of claim 22 , wherein the organometallic compound is selected from the group consisting essentially of a Grignard reagent, lithium dialkylcopper, trimethyl aluminum, and methyl lithium.
24. A method of fabricating a semiconductor device comprising:
forming an active device on a substrate;
depositing a carbon-containing, porous, low-k insulator over the active device;
exposing the insulator to a plasma;
sealing a plurality of open pores in the carbon-containing, porous, low-k insulator by reacting the plurality of open pores with a polydentate pore-sealing ligand.
25. The method of claim 24 , wherein the polydentate pore-sealing ligand is a bidentate ligand.
26. The method of claim 25 , wherein the bidentate ligand corresponds to the general formula X—CH 2 —(CH 2 ) n —CH 2 —X; wherein n=0–2; and wherein X is NH 2 , Cl, Br, I, —OCH 3 , —SO 2 F or triflate.
27. The method of claim 25 , wherein the bidentate ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) n —Si(CH 3 ) 2 —X; wherein n=0–2; and wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
28. The method of claim 25 , wherein the bidentate ligand is a branched ligand.
29. The method of claim 28 , wherein the branched ligand corresponds to the general formula X—CH 2 —(CH 2 ) m (CR 1 R 2 )(CH 2 ) o —CH 2 —X; wherein 2+m+o+1=n/2; wherein R 1 and R 2 are independently H, Alkyl, or Aryl; and wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
30. The method of claim 24 , wherein the polydentate pore-sealing ligand is a tridentate ligand.
31. The method of claim 30 , wherein the tridentate ligand corresponds to the general formula X—CH 2 —(CH 2 ) m (CXH)(CH 2 ) o —CH 2 —X; wherein m, o≈n; and wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
32. The method of claim 30 , wherein the tridentate ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (CXH)(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈n; and wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
33. The method of claim 30 , wherein the tridentate ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (SiXCH 3 )(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o ≈n; and wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
34. The method of claim 24 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—CH 2 —(CH 2 ) m (CH(CH 2 ) p —X)(CH 2 ) o —CH 2 —X; wherein m≈o≈p≈n/2; wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
35. The method of claim 24 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (CH(CH 2 ) p —X)(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈p≈n/2; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
36. The method of claim 24 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) m (CH(CH 2 ) p SiX(CH 3 ) 2 )(CH 2 ) o —Si(CH 3 ) 2 —X; wherein m≈o≈p≈n/2; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate.
37. The method of claim 24 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—CH 2 —(CH 2 ) n —Y; wherein n=0–3; wherein X is NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate; and wherein Y is —O—H, —NH 2 , amide, or imide.
38. The method of claim 24 , wherein the polydentate pore-sealing ligand corresponds to the general formula X—Si(CH 3 ) 2 —(CH 2 ) n —Y; wherein n=0–3; wherein X is H, NH 2 , Cl, Br, I, OCH 3 , —SO 2 F or triflate; and wherein Y is —O—H, —NH 2 , amide, or imide.
39. The method of claim 24 , wherein reacting the plurality of open pores with a polydentate pore-sealing ligand comprises the steps of reacting the polydentate pore-sealing ligand with the carbon-containing, porous, low-k insulator and then cross-linking the polydentate pore-sealing ligand.
40. The method of claim 24 , wherein the carbon-containing, porous, low-k insulator comprises a carbon-doped oxide.
41. The method of claim 24 , wherein the carbon-containing, porous, low-k insulator comprises porous silica.
42. The method of claim 24 , wherein the carbon-containing, porous, low-k insulator comprises OSG.
43. The method of claim 24 further comprising:
forming a silicon halide by reacting a silanol in the carbon-containing, porous, low-k insulator with a halogenating agent; and
performing a derivatizing reaction with the silicon halide.
44. The method of claim 43 , wherein the halogenating agent is selected from the group consisting essentially of thionyl chloride, sulfuryl chloride and carboxydichloride.
45. The method of claim 43 , wherein the derivatizing reaction includes using an organometallic compound.
46. The method of claim 43 , wherein the organometallic compound is selected from the group consisting essentially of a Grignard reagent, lithium dialkylcopper, trimethyl aluminum, and methyl lithium.