Patent ID: 7018482

Claim:
A method of manufacturing electronic devices in which method, wafers, which are provided at a surface with a material to be removed, are subjected, while being divided into successive batches, to a wet treatment in a bath containing a solution of an acid or base in a solvent, during which wet treatment the successive batches of wafers are immersed in the solution at first, second, and third time intervals, wherein each time interval consists of a processing period during which the material is removed from the surface of the wafers, thereby forming ionic components, and a waiting period following the removal of the wafers from the bath at the end of the processing period, during which wet treatment of the successive batches the conductivity of the solution is monitored, which monitored conductivity is brought to approximately a first desired conductivity at the second time interval during the wet treatment of the successive batches by adding at least one of either the acid, base, or the solvent to the solution inside the bath to compensate for a change in concentration of the solvent, wherein at the third time interval during the wet treatment of the successive batches, a second desired conductivity is determined on the basis of an amount of the ionic components formed as a result of the removal of the material from the wafers, and wherein the solvent comprises H 2 O, H 2 O 2 or a combination of H 2 O and H 2 O 2 .