A method is provided for treating a plurality of semiconductor substrates using the same aqueous SC-1 solution which solution removes and/or inhibits contamination of the semiconductor surfaces by metallic ions present in the solution or on the substrate surface comprising a basic solution containing hydrogen peroxide and an oxidation-resistant chelating additive such as CDTA in an amount effective to provide the desired treatment results. The SC-1 solution may be the conventional 5:1:1 (water:NH4OH:H2O2) solution or a dilute solution such as a 5:x:1 to 200:x:l solution wherein x is 0.025 to 2.