Title :
PVD aluminum dual damascene interconnection: yield comparison between counterbore and self aligned approaches
Author :
Blosse, A. ; Raghuram, U. ; Thekdi, S. ; Koutny, B. ; Lau, G. ; Koh, S.L. ; Goodenough, C. ; Pouëdras, T. ; Sethuraman, A. ; Geha, S. ; Chowdhury, T. ; Guggilla, S. ; Krishna, N. ; Su, J. ; Cha, C. ; Yao, G. ; Price, J.B.
Author_Institution :
Cypress Semicond., San Jose, CA, USA
Abstract :
A comparative study of the counterbore dual damascene (CBDD) and self-aligned dual damascene (SADD) approaches with aluminum interconnects was carried out for application to 0.18 μm ULSI multilevel interconnects. It is shown that the defect density is lower with the SADD approach. Yield degradation with the CBDD approach is explained by photoresist residues in the bottom of vias, which are difficult to remove due to the high aspect ratio of the holes. The Al-CMP process was optimized by introducing dummy structures to reduce Al dishing on wide interconnect lines. Equivalent yield was demonstrated with the SADD approach in comparison with the standard subtractive aluminum etch process on 0.25 μm SRAM technology
Keywords :
SRAM chips; ULSI; aluminium; chemical mechanical polishing; etching; integrated circuit interconnections; integrated circuit metallisation; integrated circuit yield; photoresists; sputter deposition; surface contamination; 0.18 micron; 0.25 micron; Al; Al dishing; Al-CMP process optimization; PVD aluminum dual damascene interconnection; SRAM technology; ULSI multilevel interconnects; aluminum interconnects; counterbore dual damascene; defect density; dummy structures; interconnect yield; photoresist residues; self-aligned dual damascene; subtractive aluminum etch process; via hole aspect ratio; vias; wide interconnect lines; yield degradation; Aluminum; Atherosclerosis; Costs; Etching; Filling; Manufacturing; Random access memory; Resists; Tin; Ultra large scale integration;
Conference_Titel :
Interconnect Technology, 1999. IEEE International Conference
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-5174-6
DOI :
10.1109/IITC.1999.787126
