Method of depositing dielectric materials in damascene applications

• US 20030129827A1
• Filed: 07/15/2002
• Published: 07/10/2003
• Est. Priority Date: 12/14/2001
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Xia, Li-Qun, Venkataraman, Shankar, Nemani, Srinivas D., Xu, Ping, Han, Fei, Yieh, Ellie, Zheng, Yi, Lee, Ju-Hyung, Moghadam, Farhad K., Sinha, Ashok K., Yim, Kangsub
• Granted Patent: US 6,890,850 B2
• Time in Patent Office: Days
• US Class Current: 438/629
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• 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 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/3127 Layers comprising fluoro (hydro)carbon compounds, e.g. polytetrafluoroethylene
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76828 thermal treatment
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence

Abstract

Methods are provided for depositing an oxygen-doped dielectric layer. The oxygen-doped dielectric layer may be used for a barrier layer or a hardmask. In one aspect, a method is provided for processing a substrate including positioning the substrate in a processing chamber, introducing a processing gas comprising an oxygen-containing organosilicon compound, carbon dioxide, or combinations thereof, and an oxygen-free organosilicon compound to the processing chamber, and reacting the processing gas to deposit an oxygen-doped dielectric material on the substrate, wherein the dielectric material has an oxygen content of about 15 atomic percent or less. The oxygen-doped dielectric material may be used as a barrier layer in damascene or dual damascene applications.

Claims

1. A method for processing a substrate, comprising:

introducing a processing gas consisting essentially of a compound comprising oxygen and carbon and an oxygen-free organosilicon compound to the processing chamber; and

reacting the processing gas to deposit a dielectric material on the substrate, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content of about 15 atomic percent or less.

2. The method of claim 1, wherein the oxygen-free organosilicon compound comprises an organosilane compound selected from the group of methylsilane, dimethylsilane, trimethylsilane, ethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilanopropane, 1,3,5-trisilano-2,4,6-trimethylene, and combinations thereof.

3. The method of claim 2, wherein the compound comprising oxygen and carbon is an oxygen-containing organosilicon compound selected from the group of dimethyldimethoxysilane, 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), hexamethyldisiloxane (HMDS), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, and combinations thereof.

4. The method of claim 3, wherein the ratio of the oxygen-containing organosilicon compound to the oxygen-free organosilicon compound is between about 1:

4 and about 1;

1.

5. The method of claim 1, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content between about 3 atomic % and about 10 atomic % of oxygen.

6. The method of claim 1, wherein the processing gas further comprises an inert gas selected from the group of argon, helium, neon, xenon, or krypton, and combinations thereof.

7. The method of claim 3, wherein the oxygen-containing organosilicon compound comprises 1,3,5,7-tetramethylcyclotetrasiloxane and the oxygen-free organosilicon compound comprises trimethylsilane.

8. The method of claim 1, wherein reacting the processing gas comprises generating a plasma by applying a power density between about 0.03 watts/cm² and about 1500 watts/cm².

9. The method of claim 1, wherein the oxygen-free organosilicon precursor comprises Si—

H bonds.

10. The method of claim 2, wherein the compound comprising oxygen and carbon has the formula C_XH_YO_Z, with x being between 0 and 2, Y being between 0 and 2, and Z being between 1 and 3, wherein X+Y is at least 1 and X+Y+Z is 3 or less.

11. The method of claim 2, wherein the compound comprising oxygen and carbon has the formula has the formula C_XH_YO_Z, with x being between 0 and 2, Y being between 0 and 2, and Z being between 1 and 3, wherein X+Y is at least 1 and X+Y+Z is 3 or less.

12. The method of claim 11, wherein the compound comprising oxygen and carbon is selected from the group of carbon dioxide, carbon monoxide, water, and combinations thereof.

13. The method of claim 6, wherein the compound comprising oxygen and carbon is carbon dioxide, the oxygen-free organosilicon compound is trimethylsilane, and the inert gas is helium.

14. A method of processing a substrate, comprising:

depositing a barrier layer on the substrate by reacting a processing gas comprising an oxygen-containing organosilicon compound and an oxygen-free organosilicon compound, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content of about 15 atomic percent or less; and

depositing an intermetal dielectric layer on the barrier layer.

15. The method of claim 14, wherein the oxygen-free organosilicon precursor comprises Si—

H bonds.

16. The method of claim 15, wherein the oxygen-free organosilicon compound comprises an organosilane compound selected from the group of methylsilane, dimethylsilane, trimethylsilane, ethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilanopropane, 1,3,5-trisilano-2,4,6-trimethylene, and combinations thereof.

17. The method of claim 14, wherein the oxygen-containing organosilicon compound comprises an organosiloxane compound selected from the group of dimethyldimethoxysilane, 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), hexamethyldisiloxane (HMDS), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, and combinations thereof.

18. The method of claim 14, wherein the oxygen-containing organosilicon compound comprises an organosiloxane compound comprising silicon-hydrogen bonds and is selected from the group of 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, and combinations thereof.

19. The method of claim 14, wherein the ratio of the oxygen-containing organosilicon compound to the oxygen-free organosilicon compound is between about 1:

4 and about 1;

1.

20. The method of claim 14, wherein the oxygen-containing organosilicon compound comprises 1,3,5,7-tetramethylcyclotetrasiloxane and the oxygen-free organosilicon compound comprises trimethylsilane.

21. The method of claim 14, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content between about 3 atomic % and about 10 atomic %.

22. The method of claim 14, wherein the processing gas further comprises an inert gas selected from the group of argon, helium, neon, xenon, or krypton, and combinations thereof.

23. The method of claim 14, wherein reacting the processing gas comprises generating a plasma by applying a power density between about 0.03 watts/cm² and about 1500 watts/cm².

24. The method of claim 14, wherein the intermetal dielectric layer is deposited by a method comprising:

depositing a photoresist material on a blanket dielectric layer;

patterning the photoresist layer;

etching the blanket dielectric layer and the barrier layer to define an interconnect opening therethrough; and

depositing one or more conductive materials to fill the interconnect opening.

25. A method for processing a substrate, comprising:

depositing at least one dielectric layer on a substrate surface;

forming an hardmask layer on the at least one dielectric layer, wherein the hardmask layer is deposited by reacting a processing gas comprising an oxygen-containing organosilicon compound in a plasma to deposit a material containing silicon, carbon, and an oxygen content of about 15 atomic percent or less;

defining a pattern in at least one region of the hardmask layer;

forming a feature definition in the at least one dielectric layer by the pattern formed in the at least one region of the hardmask layer;

depositing a conductive material in the feature definition;

polishing the conductive material, wherein the polishing process has a removal rate ratio between the conductive material and the hardmask layer of about 4;

1 or greater.

26. The method of claim 25, wherein at least one of the at least one dielectric layers comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less.

27. The method of claim 25, wherein the oxygen-containing organosilicon compound comprises an organosiloxane compound selected from the group of dimethyldimethoxysilane, 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), hexamethyldisiloxane (HMDS), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, and combinations thereof.

28. The method of claim 25, wherein the removal rate ratio between the conductive material and the hardmask layer is greater than about 4.5:

1.

29. The method of claim 25, wherein the processing gas further comprises an oxygen-free organosilicon compound.

30. The method of claim 29, wherein the oxygen-free organosilicon compound comprises an organosilane compound selected from the group of methylsilane, dimethylsilane, trimethylsilane, ethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilanopropane, 1,3,5-trisilano-2,4,6-trimethylene, and combinations thereof.

31. The method of claim 29, wherein the ratio of the oxygen-containing organosilicon compound to the oxygen-free organosilicon compound is between about 1:

4 and about 1;

1.

32. The method of claim 29, wherein the oxygen-containing organosilicon compound comprises 1,3,5,7-tetramethylcyclotetrasiloxane and the oxygen-free organosilicon compound comprises trimethylsilane.

33. The method of claim 25, wherein the hardmask layer comprises silicon, oxygen, and carbon, and has an oxygen content between about 3 atomic % and about 10 atomic %.

34. The method of claim 25, wherein the processing gas further comprises an inert gas selected from the group of argon, helium, neon, xenon, or krypton, and combinations thereof.

35. The method of claim 25, wherein reacting a processing gas comprising an oxygen-containing organosilicon compound in a plasma comprises introducing the oxygen-containing organosilicon compound into the processing chamber at a flow rate of about 3000 sccm or less, introducing an inert gas into the processing chamber at a flow rate of about 5000 sccm or less maintaining the processing chamber at a pressure of between about 1 Torr and about 12 Torr, maintaining the substrate temperature between about 200°

C. and about 450°

C., and generating the plasma by supplying a power level for a 200 mm substrate between about 200 watts and about 1000 watts to the processing chamber.

36. The method of claim 25, wherein reacting the processing gas comprises generating a plasma by applying a power density between about 0.03 watts/cm² and about 1500 watts/cm².

37. The method of claim 25, wherein the oxygen-containing organosilicon compound comprises an organosiloxane compound having silicon-hydrogen bonds and is selected from the group of 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), 1,3-bis(silanomethylene)disiloxane, bis(1 -methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, and combinations thereof.

38. A method of processing a substrate, comprising:

depositing a barrier layer on the substrate by reacting a processing gas consisting essentially of carbon dioxide and an oxygen-free organosilicon compound in a plasma generated at a power density between about 0.03 watts/cm² and about 1500 watts/cm², wherein oxygen-free organosilicon compound comprises silicon-hydrogen bonds and the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content of about 15 atomic percent or less; and

depositing an intermetal dielectric layer on the barrier layer.

39. The method of claim 38, wherein the oxygen-free organosilicon compound comprises an organosilane compound selected from the group of methylsilane, dimethylsilane, trimethylsilane, ethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilanopropane, 1,3,5-trisilano-2,4,6-trimethylene, and combinations thereof.

40. The method of claim 38, wherein the ratio of the carbon dioxide to the oxygen-free organosilicon compound in the processing gas is between about 1:

3 and about 1;

1.

41. The method of claim 38, wherein the oxygen-free organosilicon compound comprises trimethylsilane.

42. The method of claim 38, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content between about 3 atomic % and about 10 atomic %.

43. The method of claim 38, wherein the processing gas further comprises an inert gas selected from the group of argon, helium, neon, xenon, or krypton, and combinations thereof.

44. The method of claim 38, wherein the intermetal dielectric layer is deposited by a method comprising:

depositing a photoresist material on a blanket dielectric layer;

patterning the photoresist layer;

etching the blanket dielectric layer and the barrier layer to define an interconnect opening therethrough; and

depositing one or more conductive materials to fill the interconnect opening.

45. The method of claim 38, wherein the processing gas further comprises an oxygen-containing organosilicon compound.

46. The method of claim 45, wherein the oxygen-containing organosilicon compound comprises an organosiloxane compound selected from the group of dimethyldimethoxysilane, 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), hexamethyldisiloxane (HMDS), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, hexamethylcyclotrisiloxane, and combinations thereof.

47. The method of claim 45, wherein the oxygen-containing organosilicon compound comprises an organosiloxane compound having silicon-hydrogen bonds and is selected from the group of 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, and combinations thereof.

48. The method of claim 45, wherein the ratio of the oxygen-containing organosilicon compound to the oxygen-free organosilicon compound is between about 1:

4 and about 1;

1.

49. The method of claim 47, wherein the oxygen-containing organosilicon compound comprises 1,3,5,7-tetramethylcyclotetrasiloxane and the oxygen-free organosilicon compound comprises trimethylsilane.

50. The method of claim 49, wherein the compound comprising oxygen and carbon is an organosiloxane compound having silicon-hydrogen bonds and is selected from the group of 1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane (TMDSO), 1,3-bis(silanomethylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)propane, hexamethoxydisiloxane (HMDOS), 1,3,5-trisilano-2,4,6-trimethylene, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, and combinations thereof.