Claims
- 1. A method used to fabricate a device on a substrate, which method is utilized at a stage of processing wherein a metal gate stack is disposed or formed over a gate oxide, which metal stack includes a refractory metal layer disposed or formed over a refractory metal barrier/adhesion layer, which method comprises steps of:
etching the refractory metal layer and stopping on or in the refractory metal barrier/adhesion layer; and etching the refractory metal barrier/adhesion layer using a passivation etching chemistry without oxygen.
- 2. The method of claim 1 wherein the step of etching the refractory metal layer utilizes a main etch chemistry that includes CF4.
- 3. The method of claim 2 wherein the main etch chemistry further includes NF3.
- 4. The method of claim 3 wherein the main etch chemistry utilizes a flow rate of CF4 in a range from about 70 to about 120 sccm; and a flow rate of NF3 in a range from about 10 sccm to about 50 sccm.
- 5. The method of claim 3 wherein the main etch chemistry utilizes a ratio of flow rates for CF4/NF3 in a range from about 1.5:1 to about 8:1.
- 6. The method of claim 1 wherein etching the refractory metal barrier/adhesion layer using a passivation etching chemistry without oxygen utilizes an overetch chemistry that includes HBr.
- 7. The method of claim 6 wherein the overetch chemistry utilizes a flow rate of HBr in a range from about 20 to about 400 sccm; and a flow rate of Cl2 in a range from about 0 to about 50 sccm.
- 8. The method of claim 6 wherein the overetch chemistry utilizes a flow ratio for Cl2/HBr of<about 2.0.
- 9. The method of claim 6 wherein the refractory metal layer is a Ta layer, and the refractory metal barrier/adhesion layer is a TaNx layer.
Parent Case Info
[0001] This application claims the benefit of U.S. Provisional Application No. 60/365,144, filed on Mar. 14, 2002, which application is incorporated by reference herein.
Provisional Applications (1)
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Number |
Date |
Country |
|
60365144 |
Mar 2002 |
US |