Compositions useful in microelectronic device manufacturing for surface preparation and/or cleaning of wafer substrates such as microelectronic device precursor structures. The compositions can be employed for processing of wafers that have, or are intended to be further processed to include, copper metallization, e.g., in operations such as surface preparation, pre-plating cleaning, post-etching cleaning, and post-chemical mechanical polishing cleaning of microelectronic device wafers. The compositions contain (i) alkanolamine, (ii) quaternary ammonium hydroxide and (iii) a complexing agent, and are storage-stable, as well as non-darkening and degradation-resistant in exposure to oxygen.