Methods of processing substrates having metal materials
Methods of processing substrates having metal layers are provided herein. In some embodiments, a method of processing a substrate comprising a metal layer having a patterned mask layer disposed above the metal layer, the method may include etching the metal layer through the patterned mask layer; and removing the patterned mask layer using a first plasma formed from a first process gas comprising oxygen (O 2 ) and a carbohydrate. In some embodiments, a two step method with an additional second process gas comprising chlorine (Cl 2 ) or a sulfur (S) containing gas, may provide an efficient way to remove patterned mask residue.
1. A method of processing a substrate comprising a metal layer having a patterned mask layer disposed above the metal layer, the method comprising:
etching the metal layer through the patterned mask layer;
removing a first portion of the patterned mask layer using a second plasma formed from a second process gas comprising oxygen (O 2 ), ethylene (C 2 H 4 ), and one of a chlorine (Cl 2 )containing gas or a sulfur (S) containing gas; and
removing a remaining portion of the patterned mask layer using a first plasma formed from a first process gas comprising oxygen (O 2 ) and ethylene (C 2 H 4 ).
2. The method of claim 1 , wherein the patterned mask layer comprises a tri-layer resist comprising a first antireflective layer, a second antireflective layer disposed over the first antireflective layer, and a patterned photoresist layer defining a pattern to be etched into the metal hard mask layer.
3. The method of claim 2 , wherein the first antireflective layer is an organic antireflective layer.
4. The method of claim 2 , wherein the second antireflective layer comprises a silicon-based antireflective layer.
5. The method of claim 1 , wherein the patterned mask layer comprises a photoresist.
6. The method of claim 1 , wherein the patterned mask layer comprises at least one of a silicon based antireflective layer, a carbon-rich antireflective layer, a bottom antireflective layer, a dielectric antireflective layer, or an amorphous carbon layer.
7. The method of claim 1 , wherein the metal layer comprises titanium (Ti), tantalum (Ta), aluminum (Al), tungsten (W), copper (Cu), chromium (Cr), gold (Au), titanium nitride (TiN), tantalum nitride (TaN), tungsten nitride (WN), boron nitride (BN), germanium-antimony-tellurium (GeSbTe), or a metal-containing dielectric material having a dielectric constant greater than about 3.9.
8. The method of claim 1 , wherein etching the metal layer through the patterned mask layer comprises:
etching a pattern defined by the patterned mask layer into the metal layer using a plasma formed from a process gas comprising chlorine (Cl 2 ) and ethylene (C 2 H 4 ).
9. The method of claim 1 , wherein the first process gas is provided at a flow rate of about 10 to about 1000 sccm.
10. The method of claim 1 , wherein the first process gas has a flow rate ratio of oxygen (O 2 ) to ethylene (C 2 H 4 ) of about 1000:1 to about 1:1.
11. The method of claim 10 , wherein the flow rate ratio of oxygen (O 2 ) to ethylene (C 2 H 4 ) is adjusted to facilitate control over a critical dimension of features formed by the patterned mask layer.
12. The method of claim 1 , wherein forming the first plasma from the first process gas comprises:
applying a plasma power source of up to about 3000 W at a frequency from about 50 kHz to about 60 MHz to ignite the first process gas to form the first plasma.
13. The method of claim 1 , wherein the second process gas is provided at a flow rate of about 10 sccm to about 1000 sccm.
14. The method of claim 1 , wherein an amount of ethylene (C 2 H 4 ) in the second process gas may be adjusted to control a critical dimension of features formed by the patterned mask layer.
15. The method of claim 1 , wherein the second process gas comprises either:
oxygen (O 2 ), ethylene (C 2 H 4 ), and the sulfur (S) containing gas having a flow rate ratio of oxygen (O 2 ) to ethylene (C 2 H 4 ) to the sulfur (S) containing gas of about 1:0.001:0.1 to about 1:1:10; or
oxygen (O 2 ), ethylene (C 2 H 4 ), and the chlorine (Cl 2 ) containing gas having a flow rate ratio of oxygen (O 2 ) to ethylene (C 2 H 4 ) to the chlorine (Cl 2 ) containing gas to of about 1:0.001:0.01 to about 1:1:10.
16. The method of claim 1 , wherein forming the second plasma from the second process gas comprises:
applying a plasma power source of up to about 3000 W at a frequency from about 50 kHz to about 60 MHz to ignite the second process gas to form the second plasma.
17. The method of claim 1 , wherein the second process gas further comprises an inert gas.
18. The method of claim 1 , wherein the method is performed in a single process chamber.