The invention provides improved techniques for bonding devices using copper-to-copper or other types of bonds. A substrate is cleaned to remove surface oxides and contaminants and then rinsed. The rinsed substrate is provided to coating unit where a protective coating is applied to the substrate. The protective coating may be applied by immersing the substrate in a bath or via chemical vapor deposition. In an aspect, the protective coating may be copper selective so that the protective coating is only applied to copper features of the substrate. The protective coating minimizes formation of oxides and other bond weakening forces that may form during bonding processes, such as bonding a copper wire to a copper bond pad of the substrate. In an aspect, an annealing process is used to cure the protective coating and remove small imperfections and other abnormalities in the protective coating prior to the bonding process.

There is provided a bonding wire for semiconductor devices that exhibits a favorable bondability even when being applied to wedge bonding at the room temperature, and also achieves an excellent bond reliability. The bonding wire includes a core material of Cu or Cu alloy (hereinafter referred to as a Cu core material), and a coating containing a noble metal formed on a surface of the Cu core material. A concentration of Cu at a surface of the wire is 30 to 80 at %.

A described example includes: a semiconductor die having a device side surface and an opposing backside surface, the backside surface mounted to a die pad of a lead frame, the lead frame comprising conductive leads spaced from the die pad; a conductor layer overlying the device side surface; bond pads including bond pad conductors formed in the conductor layer, a nickel layer over the bond pad conductors, and a palladium or gold layer over the nickel layer; conductor traces formed in the conductor layer, the conductor traces free from the nickel layer and the palladium or gold layer; bond wires bonded to the bond pads electrically coupling the bond pads to conductive leads; and mold compound covering the semiconductor die, the bond pads, the bond wires, and portions of the lead frame, wherein portions of the conductive leads are exposed from the mold compound to form terminals.

According to one embodiment, a semiconductor device includes a wiring substrate having a first surface, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface. A first electrode is on the first surface. A semiconductor element is on the wiring substrate and electrically connected to the first electrode. A resin layer covers the semiconductor element and the first surface from a first direction orthogonal to the first surface. A portion of the resin layer contacts the side surface of the wiring substrate from a second direction parallel to the first surface. The resin layer has an outside side surface that is substantially parallel to the first direction.