Method for removing polymer as etching residue
A method for removing polymer as an etching residue is described. A substrate with polymer as an etching residue thereon is provided, and a hydrogen-containing plasma is used to treat the substrate. A wet clean step is then performed to remove the polymer from the substrate. The treatment using hydrogen-containing plasma can change the chemical property of the polymer, so that the polymer can be removed more easily in the subsequent wet clean step.
1. A method for removing polymer as an etching residue, comprising:
providing a substrate formed with a patterned metal hard-mask layer and polymer as an etching residue thereon;
using hydrogen-containing plasma to treat the substrate; and
performing a wet clean step to remove the polymer from the substrate.
2. The method of claim 1 , wherein the hydrogen-containing plasma treatment is conducted in situ in an etching chamber of a dry etching step in which the etching residue was produced.
3. The method of claim 1 , wherein gases for producing the hydrogen-containing plasma comprise H 2 and N 2 .
4. The method of claim 1 , wherein the polymer is formed on a sidewall of an opening in a dielectric layer formed over the substrate, the opening being defined by the patterned metal hard-mask layer.
5. The method of claim 1 , wherein the polymer contains fluorine.
6. The method of claim 1 , wherein the wet clean step uses an aqueous solution containing quarternaly ammonium salt to remove the polymer from the substrate.
7. The method of claim 1 , wherein gases for producing the hydrogen-containing plasma comprise H 2 and a noble gas as a carrier gas.
8. The method of claim 7 , wherein the noble gas is argon or helium.
9. The method of claim 4 , wherein the opening comprises a dual damascene opening.
10. A method for removing polymer as an etching residue, comprising:
providing a substrate formed with a patterned metal hard-mask layer and a damascene opening thereon, wherein a sidewall of the darnascene opening is formed with polymer thereon as an etching residue of a dry etching step for forming the damascene opening, and the dry etching step uses an etching gas containing fluorine;
using hydrogen-containing plasma to treat the substrate; and
performing a wet clean step to remove the polymer from the substrate.
11. The method of claim 10 , wherein the hydrogen-containing plasma treatment is conducted in situ in an etching chamber of the dry etching step.
12. The method of claim 10 , wherein the damascene opening comprises a dual damascene opening.
13. The method of claim 10 , wherein the damascene opening is formed in a silicon oxide layer or a silicon-based low-k material layer.
14. The method of claim 10 , wherein the wet clean step uses an aqueous solution containing quartemary ammonium salt to remove the polymer.
15. The method of claim 10 , wherein gases for producing the hydrogen-containing plasma comprise H 2 and N 2 .
16. The method of claim 15 , wherein in the hydrogen-containing plasma treatment, H 2 is supplied in a flow rate of 50–800 sccm, N 2 is supplied in a flow rate of 10–500 sccm, and a power of 50–200 W and a pressure of 30 mTorr to 1 Torr are applied.
17. The method of claim 10 , wherein gases for producing the hydrogen-containing plasma comprise H 2 and a noble gas as a carrier gas.
18. The method of claim 17 , wherein the noble gas is argon or helium.
19. The method of claim 17 , wherein in the hydrogen-containing plasma treatment, H 2 is supplied in a flow rate of 50–800 sccm, and a power of 50–2000 W and a pressure of 30 mTorr to 1 Torr are applied.