Title :
Effect of Water Addition to Choline Chloride–Urea Deep Eutectic Solvent (DES) on the Removal of Post-Etch Resid ues Formed on Copper
Author :
Thanu, Dinesh Padmanabhan Ramalekshmi ; Raghavan, Srini ; Keswani, Manish
Author_Institution :
Intel Corp., Chandler, AZ, USA
Abstract :
Feasibility of dissolution of post-etch residues (PERs) formed on copper in formulations containing a mixture of urea (U)-choline chloride (CC) deep eutectic solvent (DES) and water (W) has been investigated. PER films were formed on copper surface by spin coating deep ultraviolet photoresist film, followed by CF4/O2 plasma etching. The residue removal process was characterized using X-ray photoelectron spectroscopy and scanning electron microscopy techniques. Effective removal of PER was obtained in water-DES solutions containing as high as 90% water in the temperature range of 20-40 °C. Additionally, the etch rates of copper and siloxane-based low-k dielectric material in water-DES solutions were found to be lower than that in deaerated 250:1 [H2O: hydrofluoric acid (HF) (49%) volume ratio] dilute HF solutions.
Keywords :
X-ray photoelectron spectra; copper; dissolving; low-k dielectric thin films; photoresists; scanning electron microscopy; solvent effects; spin coating; sputter etching; ultraviolet lithography; water; CF4-O2 plasma etching; Cu; PER films; X-ray photoelectron spectroscopy; choline chloride-urea deep eutectic solvent; post-etch residue dissolution; residue removal process; scanning electron microscopy techniques; siloxane-based low-k dielectric material; spin coating deep ultraviolet photoresist film; temperature 20 degC to 40 degC; water addition effect; water-DES solutions; Cleaning; Copper; Corrosion; Films; Scanning electron microscopy; Solvents; Viscosity; ${bf CF}_{4}/{bf O}_{2}$ plasma; copper corrosion; deep eutectic solvents; post-etch residues; siloxane-based low-k;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on
DOI :
10.1109/TSM.2012.2190998
