Abstract: Vertical spray etch reactor and method in which a nitric acid etching solution is sprayed onto an upright workpiece in the form of low impact, large drops to produce a gentle sheeting flow of the etching solution down the workpiece. The solution is sprayed in a generally trapezoidal pattern with the greater portion of solution being sprayed onto the upper portion of the workpiece. The etching solution is delivered to the spray nozzles by a low shear positive displacement pump. As the workpiece leaves the etch chamber, it is sprayed with a solution to remove the etching solution and dissolved copper and to adsorb gaseous by-products from the etching reaction. The rinsing solution is collected and utilized to replenish the etching solution. The workpiece receives additional rinsing in a third chamber, and gases are exhausted from the system through an exhaust vent in the third chamber. Air is introduced into the etch chamber to move the gaseous by-products toward the exhaust vent.