Remote Plasma Source for Pre-Treatment of Substrates Prior to Deposition

• US 20090017227A1
• Filed: 07/11/2007
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: YU, Jick M., FU, Xinyu
• Granted Patent: US 8,021,514 B2
• Time in Patent Office: Days
• US Class Current: 427/569
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream

Abstract

A plasma processing chamber particularly useful for pre-treating low-k dielectric films and refractory metal films subject to oxidation prior to deposition of other layers. A remote plasma source (RPS) excites a processing gas into a plasma and delivers it through a supply tube to a manifold in back of a showerhead faceplate. The chamber is configured for oxidizing and reducing plasmas in the same or different processes when oxygen and hydrogen are selectively supplied to the RPS. The supply tube and showerhead may be formed of dielectric oxides which may be passivated by a water vapor plasma from the remote plasma source. In one novel process, a protective hydroxide coating is formed on refractory metals by alternating neutral plasmas of hydrogen and oxygen.

Claims

1. A plasma processing chamber, comprising:

a vacuum chamber;

a pedestal disposed in the vacuum chamber for supporting a substrate to be processed;

a showerhead in opposition to the pedestal and including a gas manifold and a plurality of apertures through a face plate between the gas manifold and an interior of the vacuum chamber;

a plasma generating unit;

an inlet tube connected between an output of the plasma generating unit and the manifold;

a source of oxygen gas selectively connectable to the plasma generating unit; and

a source of hydrogen gas selectively connectable to the plasma generating unit.

2. The chamber of claim 1, further comprising a source of water vapor selectively connectable to the plasma generating unit.

3. The chamber of claim 1, wherein the source of water vapor comprises an ampoule containing water mounted on the vacuum chamber.

4. The chamber of claim 2, wherein the inlet tube is lined with an oxide material.

5. The chamber of claim 4, wherein the oxide material comprises alumina.

6. The chamber of claim 2, wherein a wall of the manifold comprises an oxide material.

7. The chamber of claim 6, wherein the oxide material comprises quartz.

8. The chamber of claim 7, wherein the faceplate comprises quartz.

9. The chamber of claim 1, further comprising an ion filter operatively associated with the inlet tube.

10. A process for processing a substrate disposed in a vacuum processing chamber, comprising the steps of:

a first step of remotely generating a first plasma of oxygen and admitting it to the chamber; and

a second step of remotely generating a second plasma of hydrogen and admitting it to the chamber.

11. The process of claim 10, wherein the first and second steps are performed sequentially.

12. The process of claim 10, wherein the first and second steps are performed concurrently.

13. The process of claim 10, wherein the substrate contains an exposed layer of a metal.

14. The process of claim 13, wherein the metal comprises tantalum.

15. The process of claim 14, wherein the layer of a metal is partially overlaid by a copper layer.

16. The process of claim 10, wherein the substrate comprises:

a dielectric layer with a hole formed therein;

a barrier layer comprising tantalum formed on sidewalls of the hole; and

a seed layer comprising copper formed over the barrier layer on the sidewalls.