Post-etch residue removal using choline chloride-malonic acid deep eutectic solvent (DES)

作者：Taubert Jenny; Keswani Manish; Raghavan Srini^*

来源：Microelectronic Engineering, 2013, 102: 81-86.

DOI：10.1016/j.mee.2011.11.014

• BEOL cleaning
• Post-etch residue removal
• Deep eutectic solvent
• Electrochemical impedance spectroscopy

Eutectic mixture of choline chloride (CC) and malonic acid (MA) in a molar ratio of 1:1 has been evaluated as a potential chemical system for the removal of residues produced by CF4/O-2 plasma etching of copper coated with DUV photoresist. Immersion cleaning was performed in the liquid at the eutectic composition at 40 and 70 degrees C. Residue removal rate was screened using scanning electron microscopy and verified using X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy measurements. The results presented in this paper show that choline chloride-malonic acid eutectic is effective in removing post-etch residues and has the potential to function as a back end of line cleaning formulation.

• 出版日期2013-2