Vertical spray etch reactor and method

In a reactor for removing copper from a generally planar workpiece with an etching solution containing nitric acid, a polymer and a surfactant:

• an etch chamber, means for conveying the workpiece through the chamber in a generally upright position, a plurality of low impact, large drop producing nozzles arranged in a pattern with a greater number of nozzles toward the upper edge of the workpiece for directing the etching solution onto the workpiece to provide a gentle sheeting flow of the etching solution down the workpiece as the workpiece passes through the etch chamber, and a low shear positive displacement pump for delivering the etching solution to the nozzles.

In a reactor for removing metal from a generally planar workpiece by reaction with a liquid etching solution:

• means for conveying the workpiece in a generally upright position, an etch chamber with means for spraying the workpiece with the etching solution as the workpiece travels through the chamber, a first rinsing chamber having means for spraying a workpiece emerging from the etch chamber with a rinsing solution to remove etching solution and dissolved metal from the workpiece and to adsorb by-product gases from the etching reaction, a second rinsing chamber through which the workpiece travels for further rinsing after leaving the first rinsing chamber, and an exhaust outlet in the second rinsing chamber for exhausting gases from the reactor after said gases have passed through the first rinsing chamber and the second rinsing chamber.

In a process for removing copper from a generally planar workpiece by reaction with an etching solution containing nitric acid, a polymer and a surfactant, the steps of:

• conveying the workpiece in a generally upright position successively through an etch chamber and first and second rinsing chambers, effecting a gentle sheeting flow of the etching solution down the workpiece as the workpiece passes through the etch chamber, spraying the workpiece in the first rinsing chamber with a rinsing solution to remove etching solution and dissolved copper from the workpiece and to adsorb by-product gases from the etching reaction, effecting further rinsing of the workpiece in the second rinsing chamber, and exhausting gases from the second rinsing chamber after said gases have passed through the first rinsing chamber and the second rinsing chamber.

In a process for removing copper from a generally planar workpiece with an etching solution containing nitric acid, a polymer and a surfactant, the steps of:

• conveying the workpiece in a generally upright position through an etch chamber, and effecting a gentle sheeting flow of the etching solution down the workpiece as the workpiece passes through the chamber.

In a process for removing metal from a generally planar workpiece by reaction with a liquid etching solution, the steps of:

• conveying the workpiece in a generally upright position successively through an etch chamber and first and second rinsing chambers, spraying the workpiece with the etching solution as the workpiece travels through the etch chamber, spraying the workpiece emerging from the etch chamber with a rinsing solution in the first rinsing chamber to remove etching solution and dissolved metal from the workpiece and to adsorb by-product gases from the etching reaction, rinsing the workpiece further in the second rinsing chamber, and exhausting gases from the second rinsing chamber after said gases have passed through the first rinsing chamber and the second rinsing chamber.