Interface with dielectric layer and method of making

• US 20020102856A1
• Filed: 01/31/2001
• Published: 08/01/2002
• Est. Priority Date: 01/31/2001
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Xia, Li-Qun, Maydan, Dan, Yieh, Ellie, Nguyen, Huong Thanh
• Granted Patent: US 6,514,850 B2
• Time in Patent Office: Days
• US Class Current: 438/710
• 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 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/3144 on silicon
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• 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

Abstract

Methods of forming an interface in a dielectric material to act as an indicator for terminating an etching process, and products produced thereby.

Claims

1. A method of forming an interface to serve as an endpoint for an etching procedure, said method comprising the steps of:

providing a substrate formed of a carbon containing material; and

transforming a surface layer of the substrate to remove carbon atoms so that the surface layer indicates a signature under FTIR that is different from a signature indicated by a remainder of the substrate.

2. The method of claim 1, wherein said transforming comprises creating a plasma from at least one gas selected from the group consisting of nitrogen, oxygen, helium and argon;

and bombarding the surface layer with ions created in the plasma.

3. The method of claim 1, wherein said transforming comprises replacing carbon atoms in the surface layer of the substrate with nitrogen atoms or bonding nitrogen with carbon to form an amine, amide or nitride.

4. The method of claim 1, wherein the substrate is a C-doped silicon material and said transforming changes the surface layer from a Si—

C—

O material to a material comprising Si—

N—

O,

5. The method of claim 1, wherein the surface layer which is transformed is less than or equal to about 200Å

thick.

6. The method of claim 1, wherein the surface layer which is transformed is about 500Å

thick.

7. The method of claim 2, wherein said transforming comprises subjecting the substrate to a nitrogen plasma treatment in a chamber during which about 700 Watts of RF₁ (13.56 Khz) or RF₂ (356 KHz) energy is applied and helium and nitrogen are inputted.

8. The method of claim 7, wherein helium is inputted at about 2000 sccm and nitrogen is inputted at about 500 sccm.

9. The method of claim 7, wherein said transforming is conducted at about 1.5 Torr pressure for about 120 seconds, and a chuck temperature in the chamber is maintained at about 400°

C.

10. The method of claim 2, wherein said transforming comprises subjecting the substrate to an oxygen plasma treatment in a chamber during which about 100 to 700 Watts of RF₁ (13.56 Khz) or RF2 (356 KHz) energy is applied and helium and oxygen are inputted.

11. The method of claim 10, wherein helium is inputted at about 2000 sccm and oxygen is inputted at about 600 sccm.

12. The method of claim 10, wherein said transforming is conducted at about 1.5 Torr pressure for up to 120 seconds, and a chuck temperature in the chamber is maintained at about 400°

C.

13. The method of claim 2, wherein said transforming comprises subjecting the substrate to a helium plasma treatment in a chamber during which about 600 to 750 Watts of RF₁ (13.56 Khz) or RF2 (356 KHz) energy is applied and helium is inputted.

14. The method of claim 13, wherein helium is inputted at about 2600 sccm.

15. The method of claim 13, wherein said transforming is conducted at about 8.7 Torr pressure for up to 120 seconds, and a chuck temperature in the chamber is maintained at about 400°

C.

17. The method of claim 16, wherein the surface layer is less than or equal to about 500Å

thick.

18. The method of claim 17, wherein the surface layer is about 200Å

thick.

19. The method of claim 16, further comprising:

etching a via through the additional low k material, the transformed surface layer and the low k material layer, and ending at an interface with the etch stop layer.

20. The method of claim 19, further comprising:

etching a trench through the additional low k material and ending at an interface with the transformed surface layer.

21. The method of claim 16, further comprising:

etching a trench through the additional low k material and ending at an interface with the transformed surface layer.

22. The method of claim 21, further comprising:

etching a via through the trench, the transformed surface layer and the low k material layer, and ending at an interface with the etch stop layer.

23. The method of claim 16, wherein said transforming comprises subjecting the substrate to a plasma treatment, wherein the plasma is generated from at least one of the gases selected from the group consisting of nitrogen, oxygen, helium and argon.

24. The method of claim 23, wherein said plasma treatment is a nitrogen plasma treatment which comprises, flowing He and N₂ into a plasma treatment chamber at predefined flow rates, and inputting RF₁, or RF₂ energy at a predefined power and for a predefined time period.

25. The method of claim 16, wherein said low-k material comprises a C-doped silicon material.

26. The method of claim 25, wherein said C-doped silicon material comprises Black Diamond™

.

27. The method of claim 16, wherein the etch stop layer is deposited on an oxide layer.

28. The method of claim 27, wherein the oxide layer is deposited on a substrate.

29. The method of claim 16, further comprising depositing a second etch stop layer over the additional amount of low k material.

16. A method of dual damascene processing, comprising the steps of:

depositing a low k material layer on an etch stop layer;

transforming a surface layer of the low k material layer to alter the chemical composition thereof;

and depositing an additional amount of the low k material over the transformed surface layer.

30. A low k material product adapted to be etched, said product comprising:

a first layer of said low k material, said low k material layer having a transformed surface layer having a chemical formula different from a remainder of said first layer; and

a second layer of said low k material layer deposited over said transformed surface layer.

31. The low k material product of claim 30, further comprising an etch stop layer, said first layer of said low k material having been deposited on said etch stop layer.

32. The product of claim 31, wherein said etch stop layer comprises a nitride.

33. The product of claim 31, wherein said etch stop layer comprises SiC.

34. The product of claim 31, wherein said etch stop layer comprises BLOk.

35. The product of claim 30, wherein said low k material comprises a C-doped material.

36. The product of claim 30, wherein said low k material comprises Black Diamond™

.

37. The product of claim 30, wherein said transformed surface layer has a thickness less than or equal to about 500Å

.

38. The product of claim 37, wherein said transformed surface layer has a thickness less than or equal to about 200Å

.

39. The product of claim 30, wherein said transformed surface layer does not substantially effect the k value of said low k material.

40. The product of claim 30, said transformed surface layer having been transformed by plasma treatment by subjecting said surface layer to a plasma generated by at least one of the gases selected from the group consisting of nitrogen, oxygen, helium and argon.

41. The product of claim 40, said transformed surface layer having been transformed by nitrogen plasma treatment.

42. A stacked layer structure produced according to dual damascene procedures, said structure comprising:

an etch stop layer;

a low k material layer deposited on said etch stop layer, said low k material layer having a transformed surface layer having a chemical formula different from a remainder of said low k material layer;

an additional low k material layer deposited over said transformed surface layer;

a via passing through said additional low k material layer, said transformed surface layer and said low k material layer and terminating at an interface with said etch stop layer; and

a trench passing through said additional low k material layer and terminating at an interface with said transformed surface layer.