DUAL-LAYER ETCH PROCESS

摘要

A method is disclosed for wet etching selectively a seed layer and an adhesion layer from the underlayer of a thin film head wafer. A first etch solution, which selectively etches the seed layer while not significantly etching the adhesion layer and the underlayer, is applied to the surface of the seed layer on the underlayer for a sufficient period of time to remove the seed layer that is exposed to the etch solution, thereby significantly etching the exposed surface of the seed layer while not significantly etching the adhesion layer. A second etch solution, which selectively etches the adhesion layer while not significantly etching the seed layer and the underlayer, is applied to the surface of the adhesion layer on the underlayer for a sufficient period of time to remove the adhesion layer that is exposed to the second etch solution, thereby significantly etching the exposed surface of the adhesion layer while not significantly etching the seed layer and the underlayer.