Integration and characterization of gas cluster processing for copper interconnects electromigration improvement

Measured optical constants of copper from 10 nm to 35 nm

“…Copper recently replaced aluminum as the material of choice for on-chip interconnections [1][2][3][4] because of its low resistivity, ease of deposition, high thermal conductivity, and high electromigration resistance [1,2,5]. This transition has increased the need to accurately characterize the material properties of copper [6][7][8]. In particular, with the push to move to extreme ultraviolet (EUV) wavelengths for lithography [9][10][11], it is desirable to have an accurate characterization of the optical properties of copper in the EUV for the sake of lithographic image modeling.…”