METHOD AND APPARATUS FOR REMOTE PLASMA TREATMENT FOR REDUCING METAL OXIDES ON A METAL SEED LAYER

• US 20180350670A1
• Filed: 11/30/2017
• Published: 12/06/2018
• Est. Priority Date: 03/06/2013
• Status: Abandoned Application

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Spurlin, Tighe A., Antonelli, George Andrew, Doubina, Natalia V., Duncan, James E., Reid, Jonathan David, Porter, David W.
• Application Number:
  US15/828,286
• Publication Number:
  US 20180350670A1
• Time in Patent Office: Days
• CPC Class Codes: C23C 18/1619 Apparatus for electroless plating
• CPC Class Codes: C23C 18/1675 Process conditions
• CPC Class Codes: C23C 18/1851 of surfaces of non-metallic or semiconducting in organic material
• CPC Class Codes: C23C 18/1865 Heat
• CPC Class Codes: C23C 18/1868 Radiation, e.g. UV, laser
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 5/34 Pretreatment of metallic surfaces to be electroplated
• CPC Class Codes: C25D 5/40 Nickel; Chromium
• CPC Class Codes: C25D 5/42 of light metals
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• 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 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/68742 characterised by a lifting arrangement, e.g. lift pins
• CPC Class Codes: H01L 21/76861 Post-treatment or after-treatment not introducing additional chemical elements into the layer
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76874 for electroless plating

Abstract

Method and apparatus for reducing metal oxide surfaces to modified metal surfaces and cooling the metal surfaces are disclosed. By exposing a metal oxide surface to remote plasma, the metal oxide surface on a substrate can be reduced to pure metal. A remote plasma apparatus can treat the metal oxide surface as well as actively cool, load/unload, and move the substrate within a single standalone apparatus. The remote plasma apparatus can be configured to actively cool the substrate during and/or after reducing the metal oxide to pure metal using an active cooling system. The active cooling system can include one or more of an actively cooled pedestal, an actively cooled showerhead, and one or more cooling gas inlets for delivering cooling gas to cool the substrate.

Claims

1. A remote plasma apparatus comprising:

a processing chamber;

a substrate support for holding a substrate with a metal seed layer in the processing chamber, wherein a portion of the metal seed layer of the substrate has been converted to oxide of the metal;

a remote plasma source over the substrate support;

a showerhead comprising a plurality of through-holes and positioned between the remote plasma source and the substrate support; and

a controller configured with instructions for performing the following operations;

form a remote plasma of a reducing gas species in the remote plasma source;

expose the metal seed layer of the substrate to the remote plasma in the processing chamber under conditions that reduce the oxide of the metal; and

move the substrate away from the substrate support and towards the showerhead to position the substrate closer to the showerhead, wherein the showerhead is actively cooled to a temperature below about 30°

C. so that a temperature of the substrate is lower when closer to the actively cooled showerhead than when further away from the actively cooled showerhead.

2. The remote plasma apparatus of claim 1, further comprising one or more cooling gas inlets for delivering cooling gas into the processing chamber, wherein the one or more cooling gas inlets are positioned above the substrate support.

3. The remote plasma apparatus of claim 2, wherein the controller is further configured with instructions for flowing the cooling gas from the one or more cooling gas inlets to cool the substrate after completion of exposing the metal seed layer to the remote plasma, wherein flowing the cooling gas cools the substrate to a temperature of about 30°

C. or less.

4. The remote plasma apparatus of claim 2, wherein the cooling gas includes at least one of argon, helium, or nitrogen.

5. The remote plasma apparatus of claim 2, wherein a temperature of the cooling gas is between about −

270°

C. and about 30°

C.

6. The remote plasma apparatus of claim 1, further comprising:

one or more movable members in the processing chamber configured to move the substrate to a plurality of positions between the showerhead and the substrate support, wherein a distance between the showerhead and the substrate support for the plurality of positions is between about 0.05 inches and about 0.75 inches.

7. The remote plasma apparatus of claim 1, wherein the showerhead is actively cooled during exposure of the metal seed layer to the remote plasma.

8. The remote plasma apparatus of claim 1, wherein the showerhead is actively cooled after completion of exposing the metal seed layer to the remote plasma.

9. The remote plasma apparatus of claim 1, wherein the controller is further configured with instructions for transferring the substrate to an electroplating apparatus after cooling the substrate.

10. The remote plasma apparatus of claim 9, wherein the remote plasma apparatus is part of the electroplating apparatus.

11. The remote plasma apparatus of claim 1, wherein the substrate support includes a pedestal with one or more fluid channels to actively cool or actively heat the pedestal.

12. The remote plasma apparatus of claim 11, wherein the controller is further configured with instructions for maintaining a temperature of the pedestal between about −

10°

C. and about 150°

C.

13. A remote plasma apparatus comprising:

a processing chamber;

a substrate support for holding a substrate with a metal seed layer in the processing chamber, wherein a portion of the metal seed layer of the substrate has been converted to oxide of the metal;

a remote plasma source over the substrate support;

one or more cooling gas inlets above the substrate support in the processing chamber;

a showerhead comprising a plurality of through-holes and positioned between the remote plasma source and the substrate support; and

a controller configured with instructions for performing the following operations;

form a remote plasma of a reducing gas species in the remote plasma source;

expose the metal seed layer of the substrate to the remote plasma in the processing chamber under conditions that reduce the oxide of the metal; and

cool the substrate actively to a temperature of about 30°

C. or less by flowing a cooling gas onto the substrate using the one or more cooling gas inlets after completion of exposing the metal seed layer to the remote plasma.

14. The remote plasma apparatus of claim 13, wherein a temperature of the cooling gas is between about −

270°

C. and about 30°

C., the temperature of the substrate being actively cooled by the cooling gas to 30°

C. or less in a span of about 100 seconds or less.

15. The remote plasma apparatus of claim 13, wherein the one or more cooling gas inlets are positioned to provide the cooling gas through the showerhead and/or from an area peripheral to the substrate support.

16. The remote plasma apparatus of claim 13, wherein the controller is further configured with instructions for:

maintaining a temperature of the showerhead below about 30°

C. so that a temperature of the substrate is lower when closer to the showerhead than when further away from the showerhead; and

moving the substrate towards the showerhead to further cool the substrate after completion of exposing the metal seed layer to the remote plasma.

17. The remote plasma apparatus of claim 13, wherein the controller is further configured with instructions for transferring the substrate to an electroplating apparatus after cooling the substrate.

18. The remote plasma apparatus of claim 17, wherein the remote plasma apparatus is part of the electroplating apparatus.

19. The remote plasma apparatus of claim 13, wherein the substrate support includes a pedestal with one or more fluid channels to actively cool or actively heat the pedestal.

20. The remote plasma apparatus of claim 19, wherein the controller is further configured with instructions for maintaining a temperature of the pedestal between about −

10°

C. and about 150°

C.