Seed layers for metallic interconnects

• US 20050148172A1
• Filed: 02/14/2005
• Published: 07/07/2005
• Est. Priority Date: 10/02/1999
• Status: Active Grant

• Current Assignee: Uri Cohen
• Original Assignee: Uri Cohen
• Inventors: Cohen, Uri
• Granted Patent: US 7,199,052 B2
• Time in Patent Office: Days
• US Class Current: 438/643
• 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

Abstract

One embodiment of the present invention is a method for making copper or a copper alloy interconnects, which method includes: (a) forming a patterned insulating layer over a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening; (b) depositing a barrier layer over the patterned insulating layer including over the field and inside surfaces of the at least one opening, the barrier layer consists of a refractory metal or an alloy of a refractory metal; (c) physical vapor depositing a substantially non-conformal seed layer consisting of copper or a copper alloy over the barrier layer, wherein said substantially non-conformal seed layer is thicker than about 500 Å over the field; (d) chemical vapor depositing a substantially conformal seed layer consisting of copper or a copper alloy over the substantially non-conformal seed layer; and (e) filling the at least one opening by electroplating a metallic layer consisting of copper or a copper alloy over the substantially conformal seed layer.

Claims

1. A method for making copper or a copper alloy interconnects, said method comprising:

forming a patterned insulating layer over a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

depositing a barrier layer over the patterned insulating layer including over the field and inside surfaces of the at least one opening, the barrier layer comprising a refractory metal or an alloy comprising a refractory metal;

physical vapor depositing a substantially non-conformal seed layer comprising copper or a copper alloy over the barrier layer, wherein said substantially non-conformal seed layer is thicker than about 500 Å

over the field;

chemical vapor depositing a substantially conformal seed layer comprising copper or a copper alloy over the substantially non-conformal seed layer; and

filling the at least one opening by electroplating a metallic layer comprising copper or a copper alloy over the substantially conformal seed layer.

2. A method for making copper or a copper alloy interconnects, said method comprising:

forming a patterned insulating layer on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

depositing a barrier layer over the field and inside surfaces of the at least one opening;

depositing two seed layers comprising copper or a copper alloy over the barrier layer using two different deposition techniques, wherein one of said two seed layers comprises a substantially conformal seed layer and the other seed layer comprises a substantially non-conformal seed layer, wherein the substantially conformal seed layer is deposited by a chemical vapor deposition technique and the substantially non-conformal seed layer is deposited by a physical vapor deposition technique, and wherein the seed layer deposited by the physical vapor deposition technique is thicker than about 500 Å

over the field; and

filling the at least one opening by electroplating a metallic layer comprising copper or a copper alloy over the two seed layers.

3. The method of claim 2 wherein the physical vapor deposition technique comprises a biased substrate sputtering technique.