Method of depositing dielectric materials in damascene applications

• US 6,890,850 B2
• Filed: 07/15/2002
• Issued: 05/10/2005
• Est. Priority Date: 12/14/2001
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Brewster, William M.
• Application Number:
  US10/196,498
• Publication Number:
  US 20030129827A1
• Time in Patent Office: 1,030 Days
• Field of Search: 438/631, 438/634, 438/638, 438/789
• US Class Current: 438/631
• 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 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• 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:

depositing a first barrier layer by a process comprising;

introducing a processing gas consisting essentially carbon dioxide, an inert gas, and an oxygen-free organosilicon compound to the processing chamber; and

reacting the processing gas to deposit an oxygen-doped silicon carbide on a surface of the substrate, wherein the oxygen-doped silicon carbide has an oxygen content of about 15 atomic percent or less;

depositing a first dielectric layer on the first barrier layer;

depositing a second barrier layer on the first dielectric layer; and

then

etching feature definitions in the second barrier layer to expose the first dielectric layer.

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 1, further comprising depositing a second dielectric layer on the second barrier layer.

4. The method of claim 1, further comprising:

depositing a photoresist material on the second dielectric layer;

patterning the photoresist layer;

etching the second dielectric layer, the first dielectric layer, and the first barrier layer to define an interconnect feature definition therethrough; and

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

5. The method of claim 1, wherein the oxygen-doped silicon carbide has an oxygen content between about 3 atomic % and about 10 atomic % of oxygen.

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

7. The method of claim 1, wherein the second barrier layer is deposited by a process comprising:

introducing a processing gas consisting essentially carbon dioxide, an inert gas, and an oxygen-free organosilicon compound to the processing chamber; and

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

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 1, wherein the reacting the processing gas to deposit the oxygen-doped silicon carbide comprises supplying trimethylsilane to a plasma processing chamber at a flow rate between about 50 milligrams/minute (mgm) and about 1000 mgm, supplying carbon dioxide at a flow rate between about 50 milligrams/minute (mgm) and about 1000 mgm, supplying helium at a flow rate between about 100 sccm and about 2000 sccm, maintaining a substrate temperature between about 200°

C. and about 450°

C., maintaining a chamber pressure between 2 Torr and 10 Torr, and an RF power of between about 10 watts and about 1000 watts.

11. The method of claim 1, further comprising exposing the oxygen-doped silicon carbide to an annealing process, a plasma treatment process or both.

12. The method of claim 1, further comprising depositing a silicon carbide cap layer on the substrate surface prior to deposition of the oxygen-doped silicon carbide.

13. The method of claim 1, wherein the oxygen-free organosilicon compound is trimethylsilane and the inert gas is helium.

14. The method of claim 1, wherein substrate surface comprises a dielectric material, a metal material, or combinations thereof.

15. The method of claim 1, wherein the metal material comprises copper.

16. A method for processing a substrate, comprising:

depositing at least one dielectric layer on a substrate surface;

forming an hardmask layer having an oxygen content of about 15 atomic percent or less on the at least one dielectric layer, wherein the hardmask layer is deposited by a process comprising;

introducing a processing gas consisting essentially carbon dioxide, an inert gas, and an oxygen-free organosilicon compound to a processing chamber; and

reacting the processing gas in a plasma to deposit an oxygen-doped silicon carbide material;

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.

17. The method of claim 16, 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.

18. The method of claim 16, wherein the at least one dielectric layer comprises depositing a first barrier layer by a process comprising:

introducing a processing gas consisting essentially carbon dioxide, an inert gas, and an oxygen-free organosilicon compound to the processing chamber; and

reacting the processing gas to deposit an oxygen-doped silicon carbide on a surface of the substrate, wherein the oxygen-doped silicon carbide has an oxygen content of about 15 atomic percent or less;

depositing a first dielectric layer on the first barrier layer; and

depositing a second barrier layer on the first dielectric layer.

19. The method of claim 16, wherein the removal rate ratio between the conductive material and the hardmask layer is greater than about 4.5:

1.

20. The method of claim 17, wherein the removal rate ratio between the at least one dielectric layer and the hardmask layer is greater than about 6:

1.

21. The method of claim 16, 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.

22. The method of claim 16, further comprising exposing the oxygen-doped silicon carbide to an annealing process, a plasma treatment process or both.

23. The method of claim 16, wherein the oxygen-free organosilicon compound is trimethylsilane and the inert gas is helium.

24. The method of claim 16, wherein the hardmask layer has an oxygen content between about 3 atomic % and about 10 atomic %.

25. The method of claim 16, wherein the inert gas is selected from the group of argon, helium, neon, xenon, or krypton, and combinations thereof.

26. The method of claim 16, wherein the reacting the processing gas to deposit an oxygen-doped silicon carbide comprises supplying trimethylsilane to a plasma processing chamber at a flow rate between about 50 milligrams/minute (mgm) and about 1000 mgm, supplying carbon dioxide at a flow rate between about 50 milligrams/minute (mgm) and about 1000 mgm, supplying helium at a flow rate between about 100 sccm and about 2000 sccm, maintaining a substrate temperature between about 200°

C. and about 450°

C., maintaining a chamber pressure between 2 Torr and 10 Torr and an RF power of between about 10 watts and about 1000 watts.

27. The method of claim 16, 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.