Title :
Supercritical CO2 for ULK/Cu integration
Author :
Danel, A. ; Millet, C. ; Perrut, V. ; Daviot, J. ; Jousseaume, V. ; Louveau, O. ; Louis, D.
Author_Institution :
DRT, CEA, Grenoble, France
Abstract :
Supercritical CO2 (SC CO2) processing was investigated for porous ultra low-k dielectric (ULK) and copper for successful Back End Of Line (BEOL) integration. The introduction of specific additives into a SC CO2 and careful control of the process parameters lends this technique to a wide range of applications: 1. Stripping: Potentially able to replace both dry ash and wet clean steps to give a single fully compatible process for ULK/Cu. The main current limitation is the removal of resins hardened during dielectric etch. 2. Cleaning: SC CO2 is a unique candidate for a dry-in/dry-out process able to clean surface and pores of ULK materials. The removal of Cu rich residues was demonstrated with a chelating agent dissolved in SC CO2. 3. Curing of ULK: Contamination by water and organics can significantly damaged ULK material and these can be eliminated by processing in SC CO2. Furthermore, by introducing a suitable additive, hexamethyldisilazane (HMDS), subsequent uptake of water was prevented.
Keywords :
carbon compounds; copper; curing; dielectric materials; etching; integrated circuit interconnections; porous materials; silicon compounds; surface contamination; surface hardening; BEOL integration; Back End Of Line integration; CO2; Cu-SiO2; chelating agent; contamination; copper; curing; dielectric etching; hexamethyldisilazane; organic material; porous ultra low-k dielectrics; resin hardening; stripping; supercritical CO2; water; Additives; Ash; Cleaning; Copper; Dielectrics; Dry etching; Process control; Resins; Water pollution; Wet etching;
Conference_Titel :
Interconnect Technology Conference, 2003. Proceedings of the IEEE 2003 International
Print_ISBN :
0-7803-7797-4
DOI :
10.1109/IITC.2003.1219767
