Methods of forming metal lines in semiconductor devices
View Patent ↗Methods for forming metal lines in semiconductor devices are disclosed. One example method may include forming a lower adhesive layer on a semiconductor substrate; forming a metal layer including aluminum on the lower adhesive layer; forming an anti-reflection layer on the metal layer; forming a photomask on the anti-reflection layer; performing an initial etching, a main etching and an over-etching for the anti-reflection layer, the metal layer and the lower adhesive layer, respectively, in a region which is not protected by the photomask, using C 3 F 8 as a main etching gas; and removing the photomask residual on the anti-reflection layer.
1. A method for forming a metal line in a semiconductor device, the method comprising:
forming a lower adhesive layer on a semiconductor substrate;
forming a metal layer including aluminum on the lower adhesive layer;
forming an anti-reflection layer on the metal layer;
forming a photomask on the anti-reflection layer;
performing an initial etching, a main etching and an over-etching for the anti-reflection layer, the metal layer and the lower adhesive layer, respectively, in a region which is not protected by the photomask, using C 3 F 8 as a main etching gas, wherein the main etching of the metal layer is performed using a reactive gas including C 3 F 8 ,NF 3 and N 2 ; and
removing the photomask residual on the anti-reflection layer.
2. A method as defined by claim 1 , wherein, when the main etching is performed, C 3 F 8 is injected at 1 to 200 sccm, NF 3 is injected at 1 to 100 sccm, and N 2 injected at 1 to 100 sccm.
3. A method as defined by claim 1 , wherein, when the main etching is performed, C 3 F 8 is injected at 90 sccm, NF 3 is injected at 50 sccm, and N 2 is injected at 10 sccm.
4. A method as defined by claim 3 , wherein, as process conditions for the main etching, a pressure of 12 mT, a source power of 1,000 W and a bias power of 100 W are used.
5. A method as defined by claim 4 , wherein the metal layer is deposited at a thickness of 4,000 to 6,000 Å.
6. A method as defined by claim 1 , wherein the initial etching for etching the anti-reflection layer is performed using a reactive gas including C 3 F 8 , BCl 3 and Ar.
7. A method as defined by claim 6 , wherein, when the initial etching is performed, C 3 F 8 is injected at 1 to 200 sccm, BCl 3 is injected at 1 to 100 sccm, and Ar is injected at 1 to 100 sccm.
8. A method as defined by claim 6 , wherein, when the initial etching is performed, C 3 F 8 is injected at 60 sccm, BCl 3 is injected at 50 sccm, and Ar is injected at 30 sccm.
9. A method as defined by claim 8 , wherein, as process conditions for the initial etching, a pressure of 12 mT, a source power of 1,200 W and a bias power of 130 W are used.
10. A method as defined by claim 1 , wherein the over-etching for etching the lower adhesive layer is performed using a reactive gas including C 3 F 8 , NF 3 and N 2 .
11. The method of claim 10 , wherein, when the over-etching is performed, C 3 F 8 is injected at 1 to 200 sccm, NF 3 is injected at 1 to 100 sccm, and N 2 is injected at 1 to 100 sccm.
12. A method as defined by claim 10 , wherein, when the over-etching is performed, C 3 F 8 is injected at 80 sccm, NF 3 is injected at 50 sccm, and N 2 is injected at 50 sccm.
13. A method as defined by claim 12 , wherein, as process conditions for the over-etching, a pressure of 12 mT, a source power of 1,000 W and a bias power of 80 W are used.