Stabilized etching solutions for cu and cu/ni layers

A stabilized etch solution for etching copper layers and nickel layers, or layers of corresponding alloys, comprising nitric acid (HNO3), in an amount of 5% to 50% by weight, based on the overall composition, and hydrogen peroxide in an amount of 1% to 10% by weight, based on the overall composition, citric acid, and water.

The etch solution according to claim 1, comprising citric acid in an amount of 0.5% to 10% by weight, based on the overall composition.

The etch solution according to claim 1, comprising nitric acid (HNO3) in an amount of 15% to 35% by weight, based on the overall composition, hydrogen peroxide (H2O2) in an amount of 2% to 6% by weight, based on the overall composition, and citric acid in an amount of 2.5% to 6.5% by weight, based on the overall composition.

The etch solution according to, claim 1, comprising additives selected from the group consisting of wetting agents and/or surfactants.

An etch solution in semiconductor technology comprising the etch solution according to claim 1.

A process for etching successive copper layers and nickel layers in semiconductor technology, which comprises immersing semiconductor elements having corresponding layers in an etch solution according to claim 1 for a sufficiently long time and, after the metal layers have been etched away in a single step, removing the semiconductor elements from the etch solution, washing them with water, and drying them.