SEMICONDUCTOR DEVICE HAVING BUCKET-SHAPED UNDER-BUMP METALLIZATION AND METHOD OF FORMING SAME

摘要

An embodiment of a method of forming a semiconductor device that includes a substrate (202) having an active layer (204) and interconnect (206) formed on the active layer is described. The method includes: forming a dielectric layer (210) above the interconnect (206) having a tapered via (604) exposing at least a portion of a first metal layer (216); forming an under-bump metallization (UBM) layer (218) over the tapered via and the first metal layer to form a UBM bucket (606); and forming a dielectric cap layer (212) over the dielectric layer and a portion of the UBM layer. The UBM bucket is configured to support a solder ball (214) and can advantageously block all alpha particles emitted by the solder ball having a relevant angle of incidence from reaching the active semiconductor regions of the IC. Thus, soft errors, such as single event upsets in memory cells, are reduced or eliminated.