Title :
Robustness of self-aligned titanium silicide process: Improvement in yield of silicided devices with APM cleaning step
Author :
Lim, C.W. ; Lee, H. ; Pey, K.L. ; Gong, H. ; Bourdillon, A.J. ; Lahiri, S.K.
Author_Institution :
Nat. Univ. of Singapore, Singapore
Abstract :
An additional cleaning technique is implemented in the self-aligned silicide (salicide) process. We discover that logic device yield improves significantly with the additional ammonium peroxide mixture cleaning (APM-clean). This significant improvement is believed to be due to the reduction and tighter distribution achieved in both gate to source/drain leakage and junction leakage. In order to incorporate APM-clean in the salicide process, the stability of both C49 and C54 phase TiSi2 in APM solution is studied. We found that C54 phase TiSi2 shows good stability in APM solution. On the other hand, C49 phase TiSi2 exhibits an interesting line-width dependent etch-rate (⩾1.38 Å/sec), which resulted in higher sheet resistance
Keywords :
ammonium compounds; electric resistance; etching; integrated circuit interconnections; integrated circuit metallisation; integrated circuit testing; integrated circuit yield; leakage currents; surface cleaning; titanium compounds; APM cleaning; APM solution; APM-clean; C49 phase TiSi2 stability; C54 phase TiSi2 stability; TiSi2; ammonium peroxide mixture cleaning; cleaning technique; gate to source/drain leakage; junction leakage; line-width dependent etch-rate; logic device yield; process robustness; salicide process; self-aligned silicide process; self-aligned titanium silicide process; sheet resistance; silicided device yield; Chemicals; Cleaning; Electrical resistance measurement; Fabrication; Logic devices; Robustness; Silicides; Spraying; Stability; Titanium;
Conference_Titel :
Interconnect Technology Conference, 1998. Proceedings of the IEEE 1998 International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-4285-2
DOI :
10.1109/IITC.1998.704787
