Nitrogen-free dielectric anti-reflective coating and hardmask

• US 7,105,460 B2
• Filed: 07/11/2002
• Issued: 09/12/2006
• Est. Priority Date: 07/11/2002
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials (Holdings) (Applied Materials Incorporated)
• Inventors: Rathi, Sudha, Bencher, Christopher D., Kim, Bok Hoen, M'Saad, Hichem, Silvetti, Mario D., Ahn, Sang H., Wang, Yuxiang May
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Berry, Renee R.
• Application Number:
  US10/193,489
• Publication Number:
  US 20040009676A1
• Time in Patent Office: 1,524 Days
• Field of Search: 438/710, 438/725, 438/763, 438/778, 438/780, 438/790, 438/789
• US Class Current: 438/778
• CPC Class Codes: C23C 16/401 containing silicon
• 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 21/31144 using masks
• CPC Class Codes: H01L 21/314 Inorganic layers H01L21/3105, H01L21/32 take precedence
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• 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 a dielectric material. The dielectric material may be used for an anti-reflective coating or as a hardmask. In one aspect, a method is provided for processing a substrate including introducing a processing gas comprising a silane-based compound and an organosilicon compound to the processing chamber and reacting the processing gas to deposit a nitrogen-free dielectric material on the substrate. The dielectric material comprises silicon and oxygen.

Claims

1. A method for processing a substrate, comprising:

introducing a processing gas comprising an oxygen-free silane-based compound and an oxygen-containing organosilicon compound to the processing chamber, wherein the oxygen-free silane-based compound has the formula Si_xH_2x+2 or Si_XCl_2x+2 and X is 1 to 4; and

reacting the processing gas to deposit a nitrogen-free dielectric material on the substrate, wherein the dielectric material comprises silicon and oxygen.

2. The method of claim 1, wherein the oxygen-free silane-based compound is selected from the group of silane, disilane, chlorosilane, dichlorodisilane, and combinations thereof.

3. The method of claim 1, wherein the oxygen-containing organosilicon compound is selected from the group of tetraethoxysilane (TEOS), triethoxyfluorosilane (TEFS), 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), dimethyldiethoxy (DMDE) silane, and combinations thereof.

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

20 mgm and about 6 sccm;

5 mgm.

5. The method of claim 1, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content between about 15 atomic % and about 50 atomic % of oxygen.

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

7. The method of claim 1, wherein the deposited nitrogen-free dielectric material has an index of refraction between about 1.5 and about 2.2 and an extinction coefficient of between about 0.3 and about 0.9.

8. The method of claim 1, further comprising exposing the deposited nitrogen-free dielectric material to an annealing process or to a plasma treatment process.

9. The method of claim 8, wherein the nitrogen-free dielectric layer is a hardmask layer having a selectivity of oxide to hardmask of about 4:

1 or greater.

10. The method of claim 1, wherein the reacting the processing gas comprises generating a plasma with a RF power source having a high frequency RF power capacity, a low frequency capacity, or both.

28. The method of claim 1, wherein reacting the processing gas comprises supplying silane to a plasma processing chamber at a flow rate between about 100 sccm and about 700 sccm, supplying tetraethoxysilane to the plasma processing chamber at a flow rate of about 2000 mgm or greater, supplying helium at a flow rate between about 500sccm and about 10,000sccm, maintaining a substrate temperature between about 250°

C. and about 450°

C., maintaining a chamber pressure between about 3 Torr and about 10 Torr, supplying an RF power of between about 100 watts and about 1000 watts for a 200 mm substrate, and spacing the substrate from the source of processing gas at a distance between about 300 mils and about 500 mils.

11. A method of processing a substrate, comprising:

forming a dielectric layer on a surface of a substrate;

depositing an anti-reflective coating on a dielectric layer by reacting a processing gas comprising an oxygen-free silane-based compound and an oxygen-containing organosilicon compound to deposit a nitrogen-free dielectric material on the substrate, wherein the anti-reflective coating comprises silicon and oxygen and the oxygen-free silane-based compound has the formula Si_XH_2X+2 or Si_XCl_2X+2 and X is 1 to 4;

depositing a photoresist material on the anti-reflective coating; and

patterning the photoresist layer.

12. The method of claim 11, further comprising:

etching the anti-reflective coating and any underlying dielectric material to define an interconnect opening therethrough; and

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

13. The method of claim 11, wherein the oxygen-free silane-based compound is selected from the group of silane, disilane, chlorosilane, dichlorodisilane, and combinations thereof.

14. The method of claim 11, wherein the oxygen-containing organosilicon compound is selected from the group of tetraethoxysilane (TEOS), triethoxyfluorosilane (TEFS), 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), dimethyldiethoxy (DMDE) silane, and combinations thereof.

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

20 mgm and about 6 sccm;

5 mgm.

16. The method of claim 11, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content between about 15 atomic % and about 50 atomic % of oxygen.

17. The method of claim 11, wherein the processing gas further comprises an inert gas, an oxygen and carbon source, or combinations thereof, wherein the inert gas is selected from the group consisting of argon, helium, neon, xenon, krypton, and combinations thereof, and the oxygen and carbon source is selected from the group consisting of carbon monoxide, carbon dioxide, and combinations thereof.

18. The method of claim 11, wherein the deposited nitrogen-free dielectric material has an index of refraction between about 1.5 and about 2.2 and an extinction coefficient of between about 0.3 and about 0.9.

19. The method of claim 11, further comprising exposing the deposited nitrogen-free dielectric material to an annealing process or to a plasma treatment process.

20. The method of claim 11, wherein the reacting the processing gas comprises generating a plasma with a RF power source having a high frequency RF power capacity, a low frequency capacity or both.

29. The method of claim 11, wherein reacting the processing gas comprises supplying silane to a plasma processing chamber at a flow rate between about 100 sccm and about 700 sccm, supplying tetraethoxysilane to the plasma processing chamber at a flow rate of about 2000 mgm or greater, supplying helium at a flow rate between about 500sccm and 10,000sccm, maintaining a substrate temperature between about 250°

C. and about 450°

C., maintaining a chamber pressure between about 3 Torr and about 10 Torr, supplying an RF power of between about 100 watts and about 1000 watts for a 200 mm substrate, and spacing the substrate from the source of processing gas at a distance between about 300 mils and about 500 mils.

30. The method of claim 11, wherein the dielectric layer comprises a silicon oxycarbide material.

31. The method of claim 11, wherein the dielectric layer is deposited on a barrier layer material.

32. The method of claim 31, wherein the barrier layer material comprises an oxygen-doped silicon carbide material.

21. A method for processing a substrate, comprising:

depositing at least one organic or inorganic dielectric layer on a substrate surface;

forming a hardmask layer on the at least one organic or inorganic dielectric layer, wherein the hardmask layer is deposited by a process comprising reacting a processing gas comprising an oxygen-free silane-based compound and an oxygen-containing organosilicon compound to deposit a nitrogen-free dielectric material on the substrate, wherein the hardmask layer comprises silicon and oxygen, the oxygen-free silane-based compound has the formula Si_XH_2X+2 or Si_XCl_2X+2 and X is 1 to 4, and has a selectivity of oxide to hardmask of about 4;

1 or greater;

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

forming a feature definition in the at least one organic or inorganic dielectric layer by the pattern formed in the at least one region of the hardmask layer.

22. The method of claim 21, wherein the oxygen-free silane-containing compound is selected from the group of silane, disilane, chlorosilane, dichlorodisilane, and combinations thereof.

23. The method of claim 21, wherein the organosilicon compound is selected from the group of tetraethoxysilane (TEOS), triethoxyfluorosilane (TEFS), 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), dimethyldiethoxy (DMDE) silane, and combinations thereof.

24. The method of claim 21, wherein the ratio of the oxygen-free silane-containing compound to the oxygen-containing organosilicon compound is between about 1 sccm:

20 mgm and about 6 sccm;

5 mgm.

25. The method of claim 21, wherein the dielectric material comprises silicon, oxygen, and carbon, and has an oxygen content between about 15 atomic % and about 50 atomic % of oxygen.

26. The method of claim 21, wherein the processing gas further comprises an inert gas, an oxygen and carbon source, or combinations thereof, wherein the inert gas is selected from the group of argon, helium, neon, xenon, krypton, and combinations thereof, and combinations thereof, and the oxygen and carbon source is selected from the group consisting of carbon monoxide, carbon dioxide, and combinations thereof.

27. The method of claim 21, wherein the reacting the processing gas comprises generating a plasma at a RF power source having a high frequency RF power capacity, a low frequency capacity, or both.

33. The method of claim 21, further comprising exposing the deposited nitrogen-free dielectric material to an annealing process or to a plasma treatment process.

34. The method of claim 21, wherein reacting the processing gas comprises supplying silane to a plasma processing chamber at a flow rate between about 100 sccm and about 700 sccm, supplying tetrahoxysilane to the plasma processing chamber at a flow rate of about 2000 mgm or greater, supplying helium at a flow rate between about 500 sccm and about 10,000 sccm, maintaining a substrate temperature between about 250°

C. and about 450°

C., maintaining a chamber pressure between about 3 Torr and about 10 Torr, supplying an RF power of between about 100 watts and about 1000 watts for a 200 mm substrate, and spacing the substrate from the source of processing gas at a distance between about 300 mils and about 500 mils.

35. The method of claim 21, wherein the at least one organic or inorganic dielectric layer comprises a silicon oxycarbide material.

36. The method of claim 21, wherein the dielectric layer is deposited on a barrier layer material.

37. The method of claim 36, wherein the barrier layer material comprises an oxygen-doped silicon carbide material.