TY - GEN
T1 - Evaluation of copper oxide to copper selectivity of chemical systems for BEOL cleaning through electrochemical investigations
AU - Venkataraman, Nandini
AU - Muthukumaran, Ashok Kumar
AU - Raghavan, Srini
PY - 2007
Y1 - 2007
N2 - Back End of Line (BEOL) cleaning of copper based structures requires chemical formulations that can remove copper oxide selectively without corroding copper and etching the dielectric. Many commercially available semi-aqueous and all aqueous formulations claim to meet these criteria. These include semi-aqueous fluoride strippers (SAF) and all- aqueous ammonium phosphate based chemical systems. This paper will report the results from a fundamental study undertaken to evaluate the performance of a semi-aqueous fluoride formulation in removing copper oxide films of controlled thickness grown on copper. The thickness and composition of the oxide films were determined electrochemically using cathodic reduction technique. Electrochemical Impedance spectra of samples immersed in the formulation have been measured as a function of time to follow copper oxide dissolution and the data have been analyzed to detect the transition of copper oxide to copper.
AB - Back End of Line (BEOL) cleaning of copper based structures requires chemical formulations that can remove copper oxide selectively without corroding copper and etching the dielectric. Many commercially available semi-aqueous and all aqueous formulations claim to meet these criteria. These include semi-aqueous fluoride strippers (SAF) and all- aqueous ammonium phosphate based chemical systems. This paper will report the results from a fundamental study undertaken to evaluate the performance of a semi-aqueous fluoride formulation in removing copper oxide films of controlled thickness grown on copper. The thickness and composition of the oxide films were determined electrochemically using cathodic reduction technique. Electrochemical Impedance spectra of samples immersed in the formulation have been measured as a function of time to follow copper oxide dissolution and the data have been analyzed to detect the transition of copper oxide to copper.
KW - BEOL cleaning
KW - Copper oxide removal
KW - Electrochemical impedance spectroscopy
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U2 - 10.1557/proc-0990-b08-25
DO - 10.1557/proc-0990-b08-25
M3 - Conference contribution
AN - SCOPUS:41549159487
SN - 9781558999503
T3 - Materials Research Society Symposium Proceedings
SP - 197
EP - 202
BT - Materials, Processes, Integration and Reliability in Advanced Interconnects for Micro- and Nanoelectronics
PB - Materials Research Society
T2 - 2007 MRS Spring Meeting
Y2 - 9 April 2007 through 13 April 2007
ER -