Removable amorphous carbon CMP stop

• US 6,541,397 B1
• Filed: 03/29/2002
• Issued: 04/01/2003
• Est. Priority Date: 03/29/2002
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Bencher, Christopher Dennis
• Primary Examiner(s): GHYKA, ALEXANDER G
• Application Number:
  US10/112,012
• Time in Patent Office: 368 Days
• Field of Search: 438/710, 438/725, 438/763, 438/778, 438/780, 438/787, 438/790, 427/534, 427/536, 427/577, 427/249.1, 134/1.1
• US Class Current: 438/780
• CPC Class Codes: H01L 21/02115 the material being carbon, e.g. alpha-C, diamond or hydrogen doped carbon
• 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 21/022 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 21/02274 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 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/3146 Carbon layers, e.g. diamond-like layers
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• 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 21/7684 Smoothing; Planarisation

Abstract

A method is provided for processing a substrate including removing amorphous carbon material disposed on a low k dielectric material with minimal or reduced defect formation and minimal dielectric constant change of the low k dielectric material. In one aspect, the invention provides a method for processing a substrate including depositing at least one dielectric layer on a substrate surface, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less, forming amorphous carbon material on the at least one dielectric layer, and removing the one or more amorphous carbon layers by exposing the one or more amorphous carbon layers to a plasma of a hydrogen-containing gas.

Claims

1. A method for processing a substrate in a chamber, comprising:

depositing at least one dielectric layer on a substrate surface, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less;

forming one or more amorphous carbon layers on the at least one dielectric layer; and

removing the one or more amorphous carbon layers by exposing the one or more amorphous carbon layers to a plasma of a hydrogen-containing gas.

2. The method of claim 1, wherein the forming one or more amorphous carbon layers comprises reacting one or more hydrocarbon compounds having the general formula C_xH_y, wherein x has a range of 2 to 4 and y has a range of 2 to 10.

3. The method of claim 2, wherein the one or more hydrocarbon compounds are selected from the group consisting of propylene (C₃H₆), propyne (C₃H₄), propane (C₃H₈), butane (C₄H₁₀), butylene (C₄H₈), butadiene (C₄H₆), acetelyne (C₂H₂), and combinations thereof.

4. The method of claim 2, further comprising generating a plasma when reacting the one or more hydrocarbon compounds.

5. The method of claim 1, wherein the hydrogen-containing gas comprises a gas selected from the group of hydrogen, ammonia, water vapor, and combinations thereof.

6. The method of claim 1, wherein the plasma is generated by applying a power level between about 0.15 watts/cm² and about 5 watts/cm² to the chamber.

7. The method of claim 6, wherein the one or more amorphous carbon layers are exposed to the plasma for between about 10 seconds and about 120 seconds.

8. The method of claim 1, wherein removing the one or more amorphous carbon layers comprises introducing a hydrogen-containing gas selected from the group of hydrogen, ammonia, water vapor, and combinations thereof, into the chamber at a flow rate of about 5000 sccm or less, maintaining the chamber at a pressure of between about 1 Torr and about 10 Torr, maintaining the substrate temperature between about 100°

C. and about 300°

C., generating the plasma by supplying a power level between about 50 watts and about 1500 watts to the processing chamber for a 200 mm substrate, and maintaining the plasma between about 10 seconds and about 120 seconds.

9. A method for processing a substrate, comprising:

depositing at least one dielectric layer on a substrate surface, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less;

forming one or more amorphous carbon layers on the at least one dielectric layer by providing a gas mixture to the deposition chamber and generating a plasma of the gas mixture to disassociate the one or more hydrocarbon compounds in the gas mixture, wherein the gas mixture comprises an inert gas and one or more hydrocarbon compounds have the general formula C_xH_y, wherein x has a range of 2 to 4 and y has a range of 2 to 10; and

removing the one or more amorphous carbon layers by exposing the one or more amorphous carbon layers to a hydrogen-containing plasma for between about 10 seconds and about 120 seconds.

10. The method of claim 9, wherein the hydrogen containing plasma comprises a hydrogen-containing gas selected from the group of hydrogen, ammonia, water vapor, and combinations thereof.

11. The method of claim 10, wherein the one or more hydrocarbon compounds are selected from the group consisting of propylene (C₃H₆), propyne (C₃H₄), propane (C₃H₈), butane (C₄H₁₀), butylene (C₄H₈), butadiene (C₄H₆), acetelyne (C₂H₂), and combinations thereof.

12. The method of claim 11, wherein the one or more hydrocarbon compounds further comprises one or more fluorinated derivatives of the one or more hydrocarbon compounds.

13. The method of claim 9, wherein removing the one or more amorphous carbon layers comprises introducing a hydrogen-containing gas selected from the group of hydrogen, ammonia, water vapor, and combinations thereof, into the chamber at a flow rate of about 5000 sccm or less, maintaining the chamber at a pressure of between about 1 Torr and about 10 Torr, maintaining the substrate temperature between about 100°

C. and about 300°

C., generating the plasma by supplying a power level between about 50 watts and about 1500 watts to the processing chamber for a 200 mm substrate, and maintaining the plasma between about 10 seconds and about 120 seconds.

14. A method for processing a substrate, comprising:

depositing at least one dielectric layer on a substrate surface, wherein the dielectric layer comprises silicon, oxygen, and carbon and has a dielectric constant of about 3 or less;

forming one or more amorphous carbon layers on the at least one dielectric layer;

defining a pattern in at least one region of the one or more amorphous carbon layers;

forming feature definitions in the at least one dielectric layer by the pattern formed in the at least one region of the one or more amorphous carbon layers;

depositing one or more conductive materials in the feature definitions;

polishing the one or more conductive materials and stopping on the one or more amorphous carbon layers; and

removing the one or more amorphous carbon layers by exposing the one or more amorphous carbon layers to a plasma of a hydrogen-containing gas.

15. The method of claim 14, wherein the forming one or more amorphous carbon layers comprises reacting one or more hydrocarbon compounds having the general formula C_xH_y, wherein x has a range of 2 to 4 and y has a range of 2 to 10.

16. The method of claim 15, wherein the one or more hydrocarbon compounds are selected from the group consisting of propylene (C₃H₆), propyne (C₃H₄), propane (C₃H₈), butane (C₄H₁₀), butylene (C₄H₈), butadiene (C₄H₆), acetelyne (C₂H₂), and combinations thereof.

17. The method of claim 15, wherein the one or more hydrocarbon compounds further comprises one or more fluorinated derivatives of the one or more hydrocarbon compounds.

18. The method of claim 15, further comprising generating a plasma when reacting the one or more hydrocarbon compounds.

19. The method of claim 14, wherein the hydrogen-containing gas comprises a gas selected from the group of hydrogen, ammonia, water vapor, and combinations thereof.

20. The method of claim 17, wherein the plasma is generated by applying a power level between about 0.15 watts/cm² and about 5 watts/cm² to the chamber for between about 10 seconds and about 120 seconds.

21. The method of claim 14, wherein removing the one or more amorphous carbon layers comprises introducing a hydrogen-containing gas selected from the group of hydrogen, ammonia, water vapor, and combinations thereof, into the chamber at a flow rate of about 5000 sccm or less, maintaining the chamber at a pressure of between about 1 Torr and about 10 Torr, maintaining the substrate temperature between about 100°

C. and about 300°

C., generating the plasma by supplying a power level between about 50 watts and about 1500 watts to the processing chamber for a 200 mm substrate, and maintaining the plasma between about 10 seconds and about 120 seconds.

22. The method of claim 14, wherein the one or more conductive materials and the one or more amorphous carbon layers are removed at a ratio of conductive materials to amorphous carbon of greater than about 1:

1.