A liquid mixture formed from two benign chemicals, urea and choline chloride, in the molar ratio of 2:1 has been evaluated for post etch residue (PER) removal from copper surface. Residue films were prepared by etching DUV photoresist films coated on copper in CF 4 /O 2 plasma. Film removal was evaluated under immersion cleaning conditions using X-ray photoelectron spectroscopy and scanning electron microscopy and verified using electrochemical impedance spectroscopy measurements. The residue film was effectively removed in the temperature range of 40–70°C. The results of this study show that choline chloride and urea based DES system has the potential to function as a back end of line cleaning formulation.
No takes yet. Share an insight, caveat, or question.
Thanu et al. (2011) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: