Methods for the electrochemical deposition of copper onto a barrier layer of a work piece

• US 7,405,157 B1
• Filed: 03/02/2005
• Issued: 07/29/2008
• Est. Priority Date: 11/10/2003
• Status: Expired due to Fees

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Reid, Jon, Park, Seyang
• Primary Examiner(s): Whitehead, Jr.; Carl
• Assistant Examiner(s): SNOW, COLLEEN ERIN
• Application Number:
  US11/071,135
• Time in Patent Office: 1,245 Days
• Field of Search: 438/652, 438/674, 438/677, 205/183, 205/186, 205/187, 205/291
• US Class Current: 438/677
• CPC Class Codes: C25D 5/18 Electroplating using modulated, pulsed or reversing current
• CPC Class Codes: C25D 5/34 Pretreatment of metallic surfaces to be electroplated
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76861 Post-treatment or after-treatment not introducing additional chemical elements into the layer
• CPC Class Codes: H01L 21/76864 Thermal treatment
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material

Abstract

Methods are provided for electrochemically depositing copper on a work piece. One method includes the step of depositing overlying the work piece a barrier layer having a surface and subjecting the barrier layer surface to a surface treatment adapted to facilitate deposition of copper on the barrier layer. Copper then is electrochemically deposited overlying the barrier layer.

Claims

1. A method for depositing copper overlying a work piece, the method comprising the steps of:

depositing overlying the work piece a barrier layer having a surface;

annealing said surface of said barrier layer in an oxygen-free environment to form an annealed thin film;

after the step of annealing, exposing said surface of said barrier layer to a halide acid solution adapted to facilitate deposition of copper on said barrier layer; and

electrochemically depositing copper overlying said barrier layer.

2. The method of claim 1, wherein the step of depositing overlying a work piece a barrier layer comprises depositing overlying the work piece a layer of material selected from the group comprising ruthenium, cobalt, molybdenum, tungsten, rhodium, palladium, osmium, rhenium, iridium, and platinum.

3. The method of claim 1, wherein the step of exposing said surface of said barrier layer to a halide acid solution comprises the step of exposing said surface of said barrier layer to a halide acid solution having an acidic concentration of between about five percent (5%) to about sixty percent (60%) by weight.

4. The method of claim 3, wherein the step of exposing said surface of said barrier layer to a halide acid solution comprises the step of exposing said surface of said barrier layer to a halide acid solution having an acidic concentration of between about forty-five percent (45%) to about forty-seven percent (47%) by weight.

5. The method of claim 1, wherein the step of exposing said surface of said barrier layer to a halide acid solution comprises the step of exposing said surface of said barrier layer to a halide acid solution for between about one (1) and one hundred (100) seconds.

6. The method of claim 1, wherein the step of exposing said surface of said barrier layer to a halide acid solution comprises the step of exposing said surface of said barrier layer to a halide acid solution for between about five (5) and ten (10) seconds.

7. The method of claim 1, wherein the step of exposing said surface of said barrier layer to a halide acid solution comprises the step of exposing said surface of said barrier layer to a halide acid solution at a temperature of between about 0°

and about 100°

C.

8. The method of claim 7, wherein the step of exposing said surface of said barrier layer to a halide acid solution comprises the step of exposing said surface of said barrier layer to a halide acid solution at a temperature in the range of about 18°

C. and 25°

C.

9. The method of claim 1, further comprising:

rinsing the halide acid solution from the barrier layer using at least one of distilled water and deionized water.

10. The method of claim 1, wherein the step of electrochemically depositing comprises at least one of depositing by electroplating and depositing by electrochemical deposition.

11. The method of claim 1, wherein the step of annealing comprises annealing said annealed thin film in an oxygen-free environment at a temperature in a range of about 100°

C. to about 500°

C. for a time period in a range of about 10 seconds to about 1000 seconds.

12. A method for electrochemically depositing a copper layer onto a ruthenium layer of a work piece, the method comprising the steps of:

depositing on the work piece a ruthenium layer having a surface;

annealing said surface of said ruthenium layer in an oxygen-free environment to form an annealed ruthenium-containing thin film;

after the step of annealing, exposing said surface of said ruthenium layer to a halide acid solution adapted to facilitate deposition of copper on said ruthenium layer; and

electrochemically depositing a layer of copper overlying said ruthenium layer.

13. The method of claim 12, wherein the step of exposing said surface of said ruthenium layer to a halide acid solution comprises the step of exposing said surface of said ruthenium layer to a halide acid solution having an acidic concentration of about five percent (5%) to about sixty percent (60%) by weight.

14. The method of claim 12, further comprising annealing said surface of said ruthenium layer in an oxygen-free environment to form an annealed thin film, before the step of exposing.

15. The method of claim 14, wherein the step of annealing comprises annealing said annealed thin film in an oxygen-free environment at a temperature in a range of about 100°

C. to about 500°

C. for a time period in a range of about 10 seconds to about 1000 seconds.