In situ deposition of a low κ dielectric layer, barrier layer, etch stop, and anti-reflective coating for damascene application
The present invention provides a SiC material, formed according to certain process regimes, useful as a barrier layer, etch stop, and/or an ARC, in multiple levels, including the pre-metal dielectric (PMD) level, in IC applications and provides a dielectric layer deposited in situ with the SiC material for the barrier layers, and etch stops, and ARCs. The invention may also utilize a plasma containing a reducing agent, such as ammonia, to reduce any oxides that may occur, particularly on metal surfaces such as copper filled features. This particular SiC material is useful in complex structures, such as a damascene structure and is conducive to in situ deposition, especially when used in multiple capacities for the different layers, such as the barrier layer, the etch stop, and the ARC and can include in situ deposition of the associated dielectric layer(s).
1. A method of forming a silicon carbide layer on a substrate, comprising:
depositing a silicon carbide material by generating a plasma of a silicon source, a carbon source, and a noble gas by applying a first RF power at a first frequency and applying a second RF power at a second frequency less than the first frequency;
depositing a first dielectric layer in situ on the silicon carbide layer; and
depositing a silicon carbide etch stop in situ on the first dielectric layer;
depositing a second dielectric layer in situ on the silicon carbide etch stop;
patterning and etching the substrate to form a damascene structure;
forming a conductive material in the damascene structure; and
removing a contaminant on the substrate surface by:
introducing a reducing agent comprising nitrogen and hydrogen into a chamber;
initiating a reducing plasma in the chamber; and
exposing an oxide on the substrate layer to the reducing agent.
2. The method of claim 1 , wherein the patterning and etching the substrate to form a damascene structure comprises depositing a silicon carbide anti-reflective coating in situ on the second dielectric layer.
3. The method of claim 1 , wherein the patterning and etching the substrate to form a damascene structure comprises depositing a photoresist layer on the second dielectric layer.
4. The method of claim 2 , further comprising depositing a photoresist layer on the silicon carbide anti-reflective coating.
5. The method of claim 1 , wherein the first dielectric layer comprises a silicon-oxygen-carbon based material deposited from the plasma enhanced chemical vapor deposition of an organosiloxane, a disilano compound, or combinations thereof.
6. The method of claim 1 , wherein the silicon and carbon are derived from a common organosilane, independent of other carbon sources.
7. The method of claim 1 , wherein the silicon and carbon are derived from a common source, and reacting the silicon and the carbon in the presence of the plasma to form silicon carbide occurs independent of the presence of a separate hydrogen source.
8. The method of claim 1 , wherein the silicon and carbon are derived from a common source and reacting the silicon and the carbon in the presence of the plasma to form silicon carbide occurs independent of the presence of a separate carbon source.
9. The method of claim 1 , further comprising selecting an anti-reflective coating that has a single selected thickness to produce a reflectivity of about 7 percent or less when an underlying dielectric layer below the anti-reflective coating has a thickness from about 5000 Å to about 10000 Å.
10. The method of claim 1 , wherein the first RF frequency comprises 13.56 MHz and the second RF frequency comprises 360 kHz.