Silver patterning and interconnect processes

A method for forming a semiconductor device, comprising:

• depositing a hard mask layer over a substrate;
• depositing a silver precursor layer over the hard mask layer;
• patterning the silver precursor layer to form a plurality of silver seed structures having a top surface and two opposing sidewall surfaces;
• depositing silver on the top surface and the sidewall surfaces of the plurality of silver seed structures, thereby forming a plurality of patterned silver structures;
• etching the hard mask layer and the substrate to remove portions of the hard mask layer and the substrate not covered by the plurality of patterned silver structures, thereby forming a plurality of hard mask structures and a plurality of semiconductor fins protruding from a base portion of the substrate;
• and
• removing the plurality of patterned silver structures and the plurality of hard mask structures from the plurality of semiconductor fins.

A method for forming a semiconductor device, comprising:

• forming a hard mask layer over a semiconductor substrate;
• depositing a silver precursor layer over the hard mask layer, wherein the silver precursor layer comprises a silver salt;
• irradiating portions of the silver precursor layer to reduce silver ions in the silver salt, thereby forming a plurality of silver seed structures comprising silver metal;
• removing non-irradiated portions of the silver precursor layer;
• depositing silver over top and sidewall surfaces of the plurality of silver seed structures to form a plurality of patterned silver structures, the plurality of patterned silver structures having a dimension greater than a dimension of the plurality of silver seed structures;
• etching the hard mask layer to form a plurality of hard mask structures using the plurality of patterned silver structures as an etch mask;
• and
• etching the semiconductor substrate to form a plurality of semiconductor fins using the plurality of the patterned silver structures as an etch mask.