Electric contact element for electrochemical deposition system

• US 20010000396A1
• Filed: 12/05/2000
• Published: 04/26/2001
• Est. Priority Date: 11/30/1998
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Dordi, Yezdi N., Stevens, Joseph J.
• Granted Patent: US 6,613,214 B2
• Time in Patent Office: Days
• US Class Current: 204/212
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 17/12 Shape or form C25D17/14 takes precedence
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H05K 3/241 characterised by the electroplating method; means therefor, e.g. baths or apparatus

Abstract

An apparatus and associated method for deposition of metal ions contained in an electrolyte solution to form a metal film primarily on a seed layer formed on at least a first side of a substrate. The substrate has a second side that is opposed the first side and an edge joining the first side and the second side. The apparatus comprises a substrate holder system and an electric contact element. The electric contact element physically contacts one of the second side or the edge of the substrate. In one aspect, the substrate is rotated about its vertical axis when the seed layer of substrate is immersed in the electrolyte solution during the metal film deposition. In another aspect, the substrate is not rotated about its vertical axis when the seed layer on the substrate is immersed in the electrolyte solution during the metal film deposition. In different embodiments, the electric contact element contacts the seed layer on the second side of the substrate, a diffusion barrier layer on the second side of the substrate, or the seed layer on the edge of the substrate.

Claims

1. An apparatus for depositing a metal film onto a substrate having seed layer on at least a first side, a second side that is opposed to the first side, and an edge, the apparatus comprising:

a substrate holder system disposed to supports the substrate at a position wherein at least a portion of the seed layer on the substrate is disposed in contact with an electrolyte solution; and

an electric contact element disposed to contact one or more of the second side or the edge of the substrate.

2. The apparatus of

claim 1

, further comprising a seal disposed between the substrate holder system and the first side of the substrate.

3. The apparatus of

claim 2

, wherein the seal limits passage of fluid between the electrolyte cell and the second side of the substrate.

4. The apparatus of

claim 2

, wherein the seal comprises at least two peripherally circumferentially spaced seals.

5. The apparatus of

claim 1

, wherein the electric contact element contacts a diffusion barrier layer disposed on the second side of the substrate.

6. The apparatus of

claim 1

, wherein the seed layer extends over the edge and the electric contact element is disposedcontact the seed layer on the edge of the substrate.

9. The apparatus of

claim 1

, further comprising a rotatable head assembly disposed to rotate the substrate.

10. The apparatus of

claim 1

, wherein the substrate is not rotated about its vertical axis when the seed layer of substrate is immersed in the electrolyte solution.

8. The apparatus of

claim 8

, wherein the electric contact element is disposed to contact a peripheral edge plating surface on the edge of the substrate.

7. The apparatus of

claim 8

, wherein the electric contact element is disposed to contact a bevel plating surface on the edge of the substrate.

11. A method for depositing a metal film onto a substrate having a metal film onto a first side, the substrate comprises a second side that is opposed the first side and an edge, the method comprising:

supporting the substrate in a seed layer facing down position at a position wherein at least a portion on the seed layer of the first side of the substrate is disposed in contact with an electrolyte solution; and

contacting the second side or the edge of the substrate with an electric contact element.

12. The method of

claim 11

, further comprising limiting the passage of fluid between within the electrolyte cell and the second side of the substrate.

13. The method of

claim 11

, wherein the seed layer extends over to the second side of the substrate.

14. The method of

claim 11

, wherein the electric contact element contacts the diffusion barrier layer on the second side of the substrate, wherein the portion of the diffusion barrier layer that the electric contact element contacts is electrically coupled to the seed layer.

15. The method of

claim 11

, wherein the electric contact element contacts the seed layer on the edge of the substrate.

16. The method of

claim 15

, wherein the electric contact element contacts a bevel plating surface on the edge of the substrate.

17. The method of

claim 15

, wherein the electric contact element contacts a peripheral edge plating surface on the edge of the substrate.

18. The method of

claim 11

, further comprising rotating the substrate about the vertical axis of the.

19. An apparatus for deposition a metal film on at least of first side of a substrate having a seed layer, the substrate also having a second side that is opposed the first side, and an edge, the apparatus comprising:

a substrate holder system disposed to support the substrate at a position wherein at least a portion of the seed layer on the substrate is disposed in contact with an electrolyte solution, the substrate holder system comprising;

a substrate holder assembly that supports the substrate,

a head rotation portion that provides rotation to the substrate holder assembly, and

a head lift portion that can vertically displace the substrate holder assembly; and

an electric contact element contained in the substrate holder assembly, the electric contact element disposed to contact one or more of the second side or the edge of the substrate.

20. An apparatus for depositing a metal film onto a seed layer on a first side of a substrate, the substrate having a second side that is opposed the first side, and an edge, the apparatus comprising:

support means for supporting the substrate in a seed layer facing down position; and

contact means for contacting one or more of the second side or the edge of the substrate with an electric contact element.

21. The apparatus of

claim 20

, further comprising rotation means for controllably rotating the substrate.

22. A method for increasing uniformity of electric current density within a seed layer disposed on a front side of a substrate, the substrate having the front side, a second side that is opposed the first side, and an edge, the method comprising:

supporting the substrate in a front side facing down position wherein at least a portion of the seed layer of the substrate is disposed in electrolyte solution; and

contacting one of the second side or the edge of the substrate with an electric contact element.

23. A computer readable medium containing a computer instruction routine that, when executed, causes a general purpose processor to control an electric current density applied across a seed layer on a substrate, the method comprising:

supporting the substrate in a seed layer facing down position at a position wherein at least a portion on the seed layer of the first side of the substrate is disposed in contact with an electrolyte solution; and

contacting the second side or the edge of the substrate with an electric contact element.