摘要 |
A back end of line cleaning process is performed using a liquid mixture containing at least two benign chemicals that can form a eutectic. In one embodiment, liquid mixtures of urea and choline chloride, at a molar ratio of 2:1, in the temperature range of 40° C. to 70° C. are used to remove etch residues on copper interconnects and dielectric layers created by g-line and DUV resists. In certain embodiments, eutectic, hypereutectic, and hypoeutectic compositions of the at least two benign chemicals are used. |