I/C chip suitable for wire bonding
View Patent ↗A method of forming wire bonds in (I/C) chips comprising: providing an I/C chip having a conductive pad for a wire bond with at least one layer of dielectric material overlying the pad; forming an opening through the dielectric material exposing a portion of said pad. Forming at least a first conductive layer on the exposed surface of the pad and on the surface of the opening. Forming a seed layer on the first conductive layer; applying a photoresist over the seed layer; exposing and developing the photoresist revealing the surface of the seed layer surrounding the opening; removing the exposed seed layer; removing the photoresist material in the opening revealing the seed layer. Plating at least one second layer of conductive material on the seed layer in the opening, and removing the first conductive layer on the dielectric layer around the opening. The invention also includes the resulting structure.
1. An I/C chip suitable for wire bonding comprising:
at least one conductive bond pad;
at least one layer of dielectric material overlying said conductive bond pad;
a surface defining an opening in said layer of dielectric material exposing said conductive bond pad;
an intermediate conductive layer of TaN/Ta disposed in said opening overlying said conductive bond pad and in contact therewith and in contact with the entire surface of said opening and a top surface of said layer of dielectric material;
a conductive seed layer disposed in said opening, overlying said intermediate conductive layer and in contact therewith and overlying said top surface of said layer of dielectric material, said conductive seed layer having exposed edges;
two layers of Ni and Au plated on said conductive seed layer in said opening, overlying said conductive seed layer and completely covering said conductive seed layer including all exposed edges, said two layers of Ni and Au define walls in said opening in which a ball bond and wire is wholly disposed.
2. The I/C chip as defined in claim 1 wherein the conductive bond pad in the I/C chip is Al.
3. The I/C chip as defined in claim 1 wherein the ball bond is Au.