Method for forming dual damascene with improved etch profiles
View Patent ↗A method for forming a dual damascene with improved profiles including providing a semiconductor process wafer including a dielectric insulating layer and an overlying hardmask layer; forming an uppermost layer of amorphous carbon substantially conformally over the hardmask layer; forming a trench line opening through at least the thickness of the amorphous carbon layer; forming a dual damascene opening comprising forming the trench line opening overlying a via opening pattern through a thickness of the hardmask layer and partially through a thickness of the dielectric insulating layer; and, filling the dual damascene opening with metal.
1. A method for forming a dual damascene with improved profiles comprising the steps of:
providing a semiconductor process wafer comprising a dielectric insulating layer and an overlying hardmask layer;
forming a via opening extending through a thickness of the hardmask layer and dielectric insulating layer;
forming an uppermost layer of amorphous carbon substantially conformally over the hardmask layer following the step of forming the via opening by filling said via opening;
forming a trench line opening through at least the thickness of the amorphous carbon layer;
forming a dual damascene opening comprising forming the trench line opening overlying the via opening pattern through a thickness of the hardmask layer and partially through a thickness of the dielectric insulating layer; and
filling the dual damascene opening with metal.
2. The method of claim 1 , wherein removing comprises a plasma ashing process comprising an O 2 and H 2 plasma source gases.
3. The method of claim 1 further comprising removing an etch stop layer at the bottom of the via opening.
4. The method of claim 1 , wherein the hardmask layer is selected from the group consisting of silicon nitride, silicon oxynitride, silicon carbide, and silicon oxycarbide.
5. The method of claim 1 , wherein the dielectric insulating layer comprises a low-K dielectric insulating layer selected from the group consisting of carbon doped silicon oxide, organo-silicate glass (OSG), and fluorinated silicate glass (FSG).
6. The method of claim 5 , wherein the low-K dielectric insulating layer has a dielectric constant is less than about 3.0.
7. A method for forming a dual damascene with improved profiles comprising the steps of:
providing a semiconductor process wafer comprising a via opening extending through a dielectric insulating layer thickness and an overlying hardmask layer;
forming a layer of amorphous carbon substantially conformally over the hardmask layer to include filling the via opening;
patterning a photoresist layer comprising a trench line opening pattern over the amorphous carbon layer overlying the via opening;
forming a dual damascene opening according to a dry etching process comprising forming the trench line opening through a thickness portion of the dielectric insulating layer; and,
backfilling the dual damascene opening with metal.
8. The method of claim 7 , wherein the step of forming a dual damascene opening further comprises removing the amorphous carbon layer from the via opening bottom portion.
9. The method of claim 8 , wherein removing comprises a plasma ashing process comprising an O 2 and H 2 plasma source gases.
10. The method of claim 8 , further comprising removing an etch stop layer at the bottom of the via opening.
11. The method of claim 10 , wherein the etch stop layer comprises silicon carbide.
12. The method of claim 7 , wherein the hardmask layer is selected from the group consisting of silicon nitride, silicon oxynitride, silicon carbide, and silicon oxycarbide.
13. The method of claim 7 , wherein the amorphous carbon layer is formed by a PECVD process at a temperature of about 300° C. to about 450° C.
14. The method of claim 7 , wherein the dielectric insulating layer comprises a low-K dielectric insulating layer selected from the group consisting of carbon doped silicon oxide, and organosilicate glass (OSG).
15. The method of claim 7 , wherein the dielectric insulating layer comprises a low-K dielectric insulating layer having a dielectric constant is less than about 3.0.
16. A method for forming a dual damascene with improved profiles comprising the steps of:
providing a semiconductor process wafer comprising a dielectric insulating layer and an overlying hardmask layer;
forming a via opening extending through a thickness of the hardmask layer and dielectric insulating layer;
forming an uppermost layer of amorphous carbon substantially conformally over the hardmask layer following the step of forming the via opening by filling said via opening;
forming a trench line opening through at least the thickness of the amorphous carbon layer;
forming a dual damascene opening comprising forming the trench line opening overlying the via opening pattern through a thickness of the hardmnask layer and partially through a thickness of the dielectric insulating layer; and removing the amorphous carbon layer from the via opening;
filling the dual damascene opening with metal.
17. The method of claim 16 , wherein removing comprises a plasma ashing process comprising an O 2 and H 2 plasma source gases.
18. The method of claim 16 further comprising removing an etch stop layer at the bottom of the via opening.
19. The method of claim 16 , wherein the hardmask layer is selected from the group consisting of silicon nitride, silicon oxynitride, silicon carbide, and silicon oxycarbide.
20. The method of claim 16 , wherein the dielectric insulating layer comprises a low-K dielectric insulating layer selected from the group consisting of carbon doped silicon oxide, organo-silicate glass (OSG), and fluorinated silicate glass (FSG).
21. The method of claim 16 , wherein the low-K dielectric insulating layer has a dielectric constant is less than about 3.0.