Methods and systems for low interfacial oxide contact between barrier and copper metallization
The present invention relates to methods and systems for the metallization of semiconductor devices. One aspect of the present invention is a method of depositing a copper layer onto a barrier layer so as to produce a substantially oxygen free interface therebetween. In one embodiment, the method includes providing a substantially oxide free surface of the barrier layer. The method also includes depositing an amount of atomic layer deposition (ALD) copper on the oxide free surface of the barrier layer effective to prevent oxidation of the barrier layer. The method further includes depositing a gapfill copper layer over the ALD copper. Another aspect of the present invention is a system for depositing a copper layer onto barrier layer so as to produce a substantially oxygen-free interface therebetween. In one embodiment, the integrated system includes at least one barrier deposition module. The system also includes an ALD copper deposition module configured to deposit copper by atomic layer deposition. The system further includes a copper gapfill module and at least one transfer module coupled to the at least one barrier deposition module and to the ALD copper deposition module. The transfer module is configured so that the substrate can be transferred between the modules substantially without exposure to an oxide-forming environment.
1. A method of manufacturing a semiconductor device having copper metallization and a transition metal barrier layer or transition metal compound barrier layer so as to produce a substantially oxygen free interface between the barrier layer and the copper metallization, the method comprising:
(a) providing the barrier layer, treating the barrier layer in a hydrogen containing plasma to provide a substantially oxide free surface of the barrier layer;
(b) depositing an amount of pure ALD copper onto the oxide free surface of the barrier layer effective for preventing oxidation of the barrier layer; and
(c) electroplating a gapfill copper layer onto the amount of copper.
2. The method of claim 1 , further comprising electroless deposition of a copper seed layer onto the ALD copper, prior to electroplating the gapfill copper.
3. The method of claim 1 , further comprising a least one of:
1. storing the substrate with the ALD copper for an amount of time and
2. transporting the substrate with the ALD copper.
4. The method of claim 1 , wherein depositing the ALD copper excludes oxygen compounds or oxygen.
5. The method of claim 3 , wherein storing the substrate with the ALD copper for an amount of time and transporting the substrate with the ALD copper occur in an oxygen-containing environment.
6. The method of claim 3 , wherein storing the substrate with the ALD copper for an amount of time and transporting the substrate with the ALD copper occur in a substantially non-oxygen containing environment.
7. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer includes atomic layer deposition of the barrier layer.
8. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer includes atomic layer deposition of tantalum or tantalum nitride.
9. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer includes atomic layer deposition of tantalum nitride and depositing the amount of ALD copper is accomplished with copper(I) 1,3-diketiminates,
(N,N′-diisopropylacetamidinato)copper(1), or
(N,N′-di-sec-butylacetamidinato)copper(1).
10. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer is accomplished by atomic layer deposition of tantalum nitride for the barrier layer and treatment of the barrier layer surface in a hydrogen containing plasma.
11. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer is accomplished by atomic layer deposition of tantalum nitride for the barrier layer and treatment of the barrier layer surface in a hydrogen containing plasma; the method further comprising electroless deposition of a copper seed layer onto the ALD copper.
12. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer includes enriching the surface of the barrier layer with a transition metal.
13. The method of claim 1 , wherein providing the substantially oxide free surface of the barrier layer includes enriching the surface of the barrier layer with tantalum.
14. The method of claim 1 , wherein the barrier layer comprises tantalum or tantalum nitride.