Method of improving moisture resistance of low dielectric constant films

• US 6,743,737 B2
• Filed: 08/22/2002
• Issued: 06/01/2004
• Est. Priority Date: 11/04/1998
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chopra, Nasreen Gazala, Mandal, Robert, Lu, Yung-Cheng, Cheung, David, Yau, Wai-Fan, Moghadam, Farhad
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Luk, Olivia T
• Application Number:
  US10/226,717
• Publication Number:
  US 20030054667A1
• Time in Patent Office: 649 Days
• Field of Search: 438/758, 438/780, 438/781, 438/789, 438/790, 438/579, 427/489, 427/503
• US Class Current: 438/758
• 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 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• 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 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/02343 treatment by exposure to a liquid
• CPC Class Codes: H01L 21/02359 treatment to change the surface groups of the insulating layer
• CPC Class Codes: H01L 21/3125 layers comprising silazane compounds
• 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

Abstract

A method and apparatus for depositing a low dielectric constant film includes depositing a silicon oxide based film, preferably by reaction of an organosilicon compound and an oxidizing gas at a low RF power level from about 10 W to about 500 W, exposing the silicon oxide based film to water or a hydrophobic-imparting surfactant such as hexamethyldisilazane, and curing the silicon oxide based film at an elevated temperature. Dissociation of the oxidizing gas can be increased in a separate microwave chamber to assist in controlling the carbon content of the deposited film. The moisture resistance of the silicon oxide based films is enhanced.

Claims

1. A method for depositing a low dielectric constant material on a substrate, comprising:

depositing a silicon oxide based material comprising carbon-silicon bonds and a carbon content of between about 1% and about 50% by atomic weight on a substrate, wherein the silicon oxide based material is located between conductive interconnects or conductive contacts/vias;

exposing the silicon oxide based material to a surface modifying surfactant; and

planarizing the silicon oxide based material.

2. The method of claim 1, wherein the silicon oxide based material is deposited by reacting one or more silicon compounds that contain carbon with an oxidizing gas at an RF power level from about 10 W to about 500 W.

3. The method of claim 2, wherein the silicon compounds are selected from a group consisting of methylsilane, dimethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilano-propane, 1,3,5-trisilano-2,4,6-trimethylene, 1,3-dimethyidisiloxane, 1,3-bis(silano-methylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)-propane, 2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, fluorinated carbon derivatives thereof, and combinations thereof.

4. The method of claim 1, further comprising curing the silicon oxide based material at a temperature between about 100°

C. to about 450°

C.

5. The method of claim 1, wherein the surface modifying surfactant selected from a group consisting of hexamethyldisilazane, trimethyl-silyldiethylamine, phenyidimethylsilyldimethylamine, trimethoxysilyldimethylamine, tris(trifluoromethyl)-silyi dimethylamine, bis(trimethylsilyl)hydrazine, 1-phenyldimethyl-silyl-2-methyl-hydrazine, 1-trimethoxysilyl-2-methylhydrazine, 1-tris(trifluoromethyl-silyl)-2-methyl-hydrazine, and trimethylchlorosilane.

6. The method of claim 1, wherein planarizing the silicon oxide material is performed by a chemical mechanical polishing technique.

7. The method of claim 1, wherein the silicon oxide based material has a carbon content between about 5% and about 30% by atomic weight.

8. The method of claim 1, wherein the silicon oxide-based material is exposed to the hydrophobic-imparting surfactant and heated to a temperature between about 10°

C. and about 100°

C.

9. The method of claim 2, wherein the oxidizing gas is N₂O or O₂.

10. The method of claim 1, wherein the silicon oxide based material has a dielectric constant of about 3 or less.

11. A method for depositing a low dielectric constant material, comprising:

depositing a silicon oxide based material comprising carbon-silicon bonds and a carbon content of between about 1% and about 50% by atomic weight on a substrate by reacting one or more silicon compounds that contain carbon with an oxidizing gas at an RF power level between about 10 W and about 250 W, wherein the silicon oxide based material is located between conductive interconnects or conductive contacts/vias;

exposing the silicon oxide-based material to a surface modifying surfactant at a temperature from about 10°

C. to about 100°

C.; and

chemical mechanical polishing the silicon oxide based material.

12. The method of claim 11, wherein the silicon compounds are selected from a group consisting of methylsilane, dimethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilanopropane, 1,3,5-trisilano-2,4,6-trimethylene, 1,3-dimethyldisiloxane, 1,3-bis(silanomethylene)disiloxane, bis(1-methyldi-siloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)-propane, 2,4,6,8-tetramethylcyclotetra-siloxane, 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, fluorinated carbon derivatives thereof, and combinations thereof.

13. The method process of claim 11, wherein the surface modifying surfactant is selected from a group consisting of hexamethyldisilazane, trimethylsilyldiethylamine, phenyldimethylsilyldimethylamine, trimethoxysilyldimethylamine, tris(trifluoromethyl)-silyldimethylamine, bis(trimethyl-silyl)hydrazine, 1-phenyldimethylsilyl-2-methyl-hydrazine, 1-trimethoxysilyl-2-methyl-hydrazine, 1-tris(trifluoromethylsilyl)-2-methyl-hydrazine, and trimethylchlorosilane.

14. The method of claim 11, wherein the surface modifying surfactant comprises hexamethyldisilazane.

15. The method of claim 11, wherein the silicon oxide based material has a carbon content between about 5% and 30% by atomic weight.

16. The method of claim 11, wherein the oxidizing gas is N₂O or O₂.

17. The method of claim 11, wherein the silicon oxide based material has a dielectric constant of about 3 or less.

18. A method for processing a substrate, comprising:

depositing a first material;

depositing a low dielectric constant material adjacent the first material, wherein the low dielectric constant material is a silicon oxide based material comprising carbon-silicon bonds and a carbon content of between about 1% and about 50% by atomic weight on a substrate;

exposing the silicon oxide based material to a surface modifying surfactant; and

planarizing the silicon oxide based material; and

then

depositing a second material adjacent the low dielectric constant material.

19. The method of claim 18, wherein the first material comprises a dielectric material and the second material comprises a photo resist material or one or more conductive materials.

20. The method of claim 18, wherein the first material comprises a first dielectric layer, the low dielectric constant material comprises a second dielectric material and the second material comprises a barrier layer, a metal fill layer, or both.

21. The method of claim 18, further comprising etching the first dielectric layer to define one or more vertical interconnects and etching the silicon oxide based material to define one or more horizontal interconnects prior to depositing the second material.

22. The method of claim 18, wherein the low dielectric constant material is deposited by reacting one or more silicon compounds that contain carbon with an oxidizing gas at an RF power level from about 10 W to about 500 W.

23. The method of claim 22, wherein the one or more silicon compounds are selected from a group consisting of methylsilane, dimethylsilane, trimethylsilane, disilanomethane, bis(methylsilano)methane, 1,2-disilanoethane, 1,2-bis(methylsilano)ethane, 2,2-disilano-propane, 1,3,5-trisilano-2,4,6-trimethylene, 1,3-dimethyidisiloxane, 1,3-bis(silano-methylene)disiloxane, bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyldisiloxanyl)-propane, 2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,6,8,10-pentamethylcyclopentasiloxane, 1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimethylene, fluorinated carbon derivatives thereof, and combinations thereof.

24. The method of claim 18, wherein the surface modifying surfactant is selected from a group consisting of hexamethyldisilazane, trimethyl-silyldiethylamine, phenyldimethylsilyldimethylamine, trimethoxysilyldimethylamine, tris(trifluoromethyl)-silyldimethylamine, bis(trimethylsilyl)hydrazine, 1-phenyldimethyl-silyl-2-methyl-hydrazine, 1-trimethoxysilyl-2-methylhydrazine, 1-tris(trifluoromethyl-silyl)-2-methyl-hydrazine, and trimethylchlorosilane.

25. The method of claim 18, wherein the low dielectric constant material has a carbon content between about 5% and about 30% by atomic weight.

26. The method of claim 18, wherein the low dielectric constant material is exposed to the surface modifying surfactant at a temperature between about 10°

C. and about 100°

C.

27. The method of claim 22, wherein the oxidizing gas is N₂O or O₂.

28. The method of claim 18, wherein the low dielectric constant material has a dielectric constant of about 3 or less.

29. The method of claim 18, further comprising curing the silicon oxide based material at a temperature from about 100°

C. to about 400°

C.