Semiconductor device

摘要

A semiconductor device includes a semiconductor chip, a wiring on the chip, an insulating film coating the wiring and having an opening partially exposing the wiring, a Ti/W film on a portion of the wiring facing the opening, a Cu layer on the Ti/W film and the wiring's exposed portion, and having a peripheral edge protruding away from the opening more than Ti/W film's peripheral edge in parallel to an insulating film surface, and a solder ball bonded to the Cu layer. The protrusion of the Cu layer's peripheral edge with respect to the Ti/W film's peripheral edge is greater than the Ti/W film's thickness. The Ti/W film's surface doesn't vertically surpass the Cu layer's upper surface in the opening's center. A Cu layer/solder ball interface is arc-shaped on both sides of the Cu layer's upper surface in a cross section taken perpendicularly to the Cu layer's upper surface.

主权项

1. A semiconductor device comprising:
a semiconductor chip; a wiring formed on the semiconductor chip; an insulating film, coating the wiring and having an opening for partially exposing the wiring from the insulating film; a first film made of Ti and W, formed on a portion of the wiring facing the opening; a Cu layer, formed by plating on the first film and on a portion of the wiring exposed through the insulating film such that an upper surface of the Cu layer is a uniform distance from an upper surface of the wiring, and having a peripheral edge portion thereof protruding away from the opening more than a peripheral edge of the first film in a direction parallel to a surface of the insulating film; and a solder ball bonded to the Cu layer, wherein a distance between the surface of the insulating film and the Cu layer is fixed, a protrusion amount of the peripheral edge portion of the Cu layer with respect to the peripheral edge of the first film is greater than a thickness of the first film, the Cu layer is stacked high enough that a surface of the first film does not vertically surpass the upper surface of the Cu layer in the center of the opening, and an interface between the Cu layer and the solder ball is arc-shaped on both sides of the upper surface of the Cu layer in a cross section taken perpendicularly to the upper surface of the Cu layer.