Advanced seed layery for metallic interconnects

• US 7,105,434 B2
• Filed: 12/28/2004
• Issued: 09/12/2006
• Est. Priority Date: 10/02/1999
• Status: Expired due to Term

• Current Assignee: Uri Cohen
• Original Assignee: Uri Cohen
• Inventors: Cohen, Uri
• Primary Examiner(s): Wilson, Christian D.
• Application Number:
  US11/023,833
• Publication Number:
  US 20050124153A1
• Time in Patent Office: 623 Days
• Field of Search: 438/625, 438627-629, 438/637, 438641-643
• US Class Current: 438/629
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 2221/1089 Stacks of seed layers
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• CPC Class Codes: H01L 23/53209 based on metals, e.g. alloys, metal silicides H01L23/53285 takes precedence
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53252 Additional layers associated with noble-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

One embodiment of the present invention is a method for making metallic interconnects, which method is utilized at a stage of processing a substrate having a patterned insulating layer which includes at least one opening and a field surrounding the at least one opening, the field and the at least one opening being ready for depositing one or more seed layers, which method includes steps of: (a) depositing by an ALD technique at least an initial portion of a substantially conformal seed layer on the field and inside surfaces of the at least one opening, wherein said at least one opening has a width of less than about 0.13 μm; (b) depositing by a PVD technique a substantially non-conformal seed layer over the substantially conformal seed layer, said substantially non-conformal seed layer being thicker than said substantially conformal seed layer over the field; and (c) electroplating a metallic layer over the substantially non-conformal seed layer, wherein the electroplated metallic layer consists of a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

Claims

1. A method for making metallic interconnects, which method is utilized at a stage of processing a substrate having a patterned insulating layer which includes at least one opening and a field surrounding the at least one opening, the field and the at least one opening being ready for depositing one or more seed layers, which method comprises steps of:

depositing by a CVD technique a substantially conformal seed layer over the field and inside surfaces of the at least one opening, wherein said at least one opening has a width of less than about 0.13 μ

m;

depositing by a PVD technique a second seed layer over the substantially conformal seed layer, wherein the substantially conformal and the second seed layers do not seal the at least one opening; and

electroplating a metallic layer over the second seed layer, wherein the electroplated metallic layer comprises a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

2. The method of claim 1 wherein at least one of said the substantially conformal seed layer and the second seed layer comprises one or more materials selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

3. The method of claim 1 wherein at least an initial stage of the depositing by a CVD technique utilizes one or more precursors comprising one or more inorganic copper compounds which do not contain oxygen or carbon atoms.

4. The method of claim 3 wherein the one or more inorganic copper compounds comprise copper halide compounds.

5. The method of claim 1 further comprising a step of depositing a barrier layer on the field and inside surfaces of the at least one opening prior to the step of depositing the substantially conformal seed layer.

6. The method of claim 1 wherein the PVD technique comprises one or more sputtering techniques selected from a group consisting of collimated sputtering, Hollow Cathode Magnetron (HCM) sputtering, Self Ionized Plasma (SIP) sputtering, and Ionized Metal Plasma (IMP) sputtering techniques.

7. The method of claim 1 wherein the substantially conformal seed layer has a thickness in a range of about 20 Å

to about 300 Å

over the field and the second seed layer has a thickness in a range of about 100 Å

to about 2000 Å

over the field.

8. The method of claim 1 wherein said at least one opening has a width of less than about 0.10 μ

m.

12. The method of claim 1 wherein the one or more inorganic copper compounds comprise copper halide compounds.

9. A method for making metallic interconnects, which method is utilized at a stage of processing a substrate having a patterned insulating layer which includes at least one opening and a field surrounding the at least one opening, the field and the at least one opening being ready for depositing one or more seed layers, which method comprises steps of:

depositing by a PVD technique a first seed layer over the substrate, said first seed layer has a thickness greater than about 250 Å

over the field, and wherein said at least one opening has a width of less than about 0.13 μ

m;

depositing by a CVD technique a substantially conformal seed layer over the first seed layer, said wherein the substantially conformal and the first seed layers do not seal the at least one opening; and

electroplating a metallic layer over the substantially conformal seed layer, wherein the electroplated metallic layer comprises a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

10. The method of claim 9 wherein at least one of said first seed layer and the substantially conformal seed layer comprises one or more materials selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

11. The method of claim 9 wherein at least an initial stage of the depositing by a CVD technique utilizes one or more precursors comprising one or more inorganic copper compounds which do not contain oxygen or carbon atoms.

13. The method of claim 9 wherein the PVD technique comprises one or more sputtering techniques selected from a group consisting of collimated sputtering, Hollow Cathode Magnetron (HCM) sputtering, Self Ionized Plasma (SIP) sputtering, and Ionized Metal Plasma (IMP) sputtering techniques.

14. The method or claim 9 wherein the first seed layer has a thickness in a range of about 250 Å

to about 2,000 Å

over the field and the substantially conformal seed layer has a thickness in a range of about 20 Å

to about 300 Å

over the field.

15. The method of claim 9 wherein said at least one opening has a width of less than about 0.10 μ

m.

16. A method for making metallic interconnects, which method is utilized at a stage of processing a substrate having a patterned insulating layer which includes at least one opening and a field surrounding the at least one opening, the field and the at least one opening being ready for depositing one or more seed layers, which method comprises steps of:

depositing three or more seed layers over the field and inside surfaces of the at least one opening, wherein at least one seed layer is deposited by a CVD technique and at least one seed layer is deposited by a PVD technique, said three or more seed layers do not seal the at least one opening; and

electroplating a metallic layer over the three or more seed layer, wherein the electroplated metallic layer comprises a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

17. The method of claim 16 wherein at least one of the three or more seed layers comprises one or more materials selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

18. The method of claim 16 further comprising a step of depositing a barrier layer on the field and inside surfaces of the at least one opening prior to the steps of depositing the three or more seed layers.

19. The method of claim 16 wherein:

a first seed layer is deposited by a PVD technique over the substrate;

a second seed layer is deposited by a CVD technique over the first seed layer; and

a third seed layer is deposited by a PVD technique over the second seed layer, wherein the third seed layer being thicker than the first or second seed layers over the field, the three seed layers do not seal the at least one opening, and the at least one opening has a width of less than about 0.13 μ

m.

20. The method of claim 16 wherein at least two of the three or more seed layers are deposited by one or more CVD techniques.

21. The method of claim 19 wherein said first seed layer has a thickness in a range from about 50 Å

to about 500 Å

over the field, said second seed layer a thickness in a range from about 20 Å

to about 300 Å

over the field, and said third seed layer has a thickness in a range from about 300 Å

to about 2,000 Å

over the field.