Silicon nitride layer under a copper pad

A package comprising:

• a die;
• a substrate with a first side and a second side opposite the first side, the die physically and electrically coupled with the second side of the substrate, the substrate further comprising:
• a copper pad on the first side of the substrate;
• an electrically conductive feature electrically coupled with the copper pad;
• an electrically conductive routing electrically coupled with the electrically conductive feature;
• and
• a layer that includes silicon and nitrogen adjacent to the copper pad, wherein the layer that includes silicon and nitrogen is at least partially between the copper pad and the first side of the substrate, the layer in direct contact with the electrical routing.

A method comprising:

• providing a substrate;
• placing a layer that includes silicon and nitrogen on a side of the substrate;
• drilling a via through the layer that includes silicon and nitrogen into the substrate, wherein the via extends to a routing within the substrate;
• filling the via with a material that includes copper;
• and
• forming a pad that includes copper on the layer that includes silicon and nitrogen, wherein the pad is physically and electrically coupled with the filled via, wherein the layer that includes silicon and nitrogen extends beyond an edge of the pad, and wherein the layer that includes silicon and nitrogen is in direct contact with the routing and in direct contact with the pad.