Semiconductor device with catalytic conductive layer and method for fabricating the same

A method for fabricating a semiconductor device, comprising:

• providing a substrate;
• forming a catalytic conductive layer on a top surface of the substrate;
• forming a mask layer structure, having a mask opening, on the catalytic conductive layer, wherein the catalytic conductive layer is located between the mask layer structure and the substrate;
• patterning the catalytic conductive layer to form an opening exposing an exposed portion of the top surface of the substrate, while leaving a covered portion of the top surface of the substrate covered by the catalytic conductive layer, wherein the mask opening of the mask layer structure is extended through the catalytic conductive layer to form the opening of the catalytic conductive layer;
• removing the mask layer structure on the catalytic conductive layer;
• performing a trench-etching process to recess the covered portion of the top surface of the substrate, resulting in a first trench;
• removing the catalytic conductive layer;
• and
• forming an isolation layer in the first trench;
• wherein performing the trench-etching process comprises applying an etchant solution to the catalytic conductive layer and the substrate.