Investigation of BEOL post etch wet cleaning for 40nm node and beyond

Wet cleaning is very critical for technology nodes below 40&28nm in ULSI manufacturing. Better clean efficiency and less film damage becomes the main challenge for WET clean processes in advanced technology development. New chemicals were used in this article to study BEOL post Etch WET cleaning for 40nm node and beyond. We compared the cleaning performance of chemcial A and chemical B through CD enlargement, kink profile, Cu loss, inline defect and WAT. Experimental results indicated that the copper loss and kink performance of chemical A were better than that of chemical B, even though inline defect, CD enlargement and WAT were comparable.