Embodiments of the invention provide a processing system and a method for processing with a heated etching solution. In one example, tight control over temperature and hydration level of an acidic etching solution is provided. According to one embodiment, the method includes forming the heated etching solution in a first circulation loop, providing the heated etching solution in the process chamber for treating a substrate, forming an additional heated etching solution in a second circulation loop, and supplying the additional heated etching solution to the first circulation loop. According to one embodiment, the processing system includes a process chamber for treating the substrate with the heated etching solution, a first circulation loop for providing the heated etching solution into the process chamber, and a second circulation loop for forming an additional heated etching solution and supplying the additional heated etching solution to the first circulation loop.