After finishing of the front side CMOS manufacturing process, the silicon wafer is permanently bonded with its front side onto a carrier wafer. The carrier wafer is a high resistivity silicon wafer or a wafer of a dielectric or of a ceramic material. The silicon substrate of the device wafer is thinned from the back side such that the remaining silicon thickness is only a few micrometers. In the area dedicated to a spiral inductor, the substrate material is entirely removed by a masked etching process and the resulting gap is filled with a dielectric material. A spiral inductor coil is formed on the backside of the wafer on top of the dielectric material. The inductor coil is connected to the CMOS circuits on the front side by through-silicon vias.

After finishing of the front side CMOS manufacturing process, the silicon wafer is permanently bonded with its front side onto a carrier wafer. The carrier wafer is a high resistivity silicon wafer or a wafer of a dielectric or of a ceramic material. The silicon substrate of the device wafer is thinned from the back side such that the remaining silicon thickness is only a few micrometers. In the area dedicated to a spiral inductor, the substrate material is entirely removed by a masked etching process and the resulting gap is filled with a dielectric material. A spiral inductor coil is formed on the backside of the wafer on top of the dielectric material. The inductor coil is connected to the CMOS circuits on the front side by through-silicon vias.

In some embodiments, the present disclosure relates to a package assembly having a bump on a first substrate. A molding compound is on the first substrate and contacts sidewalls of the bump. A no-flow underfill layer is on a conductive region of a second substrate. The no-flow underfill layer and the conductive region contact the bump. A mask layer is arranged on the second substrate and laterally surrounds the no-flow underfill layer. The no-flow underfill layer contacts the substrate between the conductive region and the mask layer.

In some embodiments, the present disclosure relates to a package assembly having a bump on a first substrate. A molding compound is on the first substrate and contacts sidewalls of the bump. A no-flow underfill layer is on a conductive region of a second substrate. The no-flow underfill layer and the conductive region contact the bump. A mask layer is arranged on the second substrate and laterally surrounds the no-flow underfill layer. The no-flow underfill layer contacts the substrate between the conductive region and the mask layer.

Representative implementations of techniques and devices are used to reduce or prevent conductive material diffusion into insulating or dielectric material of bonded substrates. Misaligned conductive structures can come into direct contact with a dielectric portion of the substrates due to overlap, especially while employing direct bonding techniques. A barrier interface that can inhibit the diffusion is disposed generally between the conductive material and the dielectric at the overlap.

Representative implementations of techniques and devices are used to reduce or prevent conductive material diffusion into insulating or dielectric material of bonded substrates. Misaligned conductive structures can come into direct contact with a dielectric portion of the substrates due to overlap, especially while employing direct bonding techniques. A barrier interface that can inhibit the diffusion is disposed generally between the conductive material and the dielectric at the overlap.

The present disclosure provides an integrated circuit (IC) structure. The IC structure includes a semiconductor substrate; an interconnection structure formed on the semiconductor substrate; and a redistribution layer (RDL) metallic feature formed on the interconnection structure. The RDL metallic feature further includes a barrier layer disposed on the interconnection structure; a diffusion layer disposed on the barrier layer, wherein the diffusion layer includes metal and oxygen; and a metallic layer disposed on the diffusion layer.

A semiconductor structure includes a conductive line, a pad layer, and a barrier layer. The conductive line is embedded in a multi-level interconnect structure. The pad layer is over the conductive line. The barrier layer is between the conductive line and the pad layer. The pad layer is electrically connected to the conductive line through the barrier layer, and the barrier layer includes a first poly-crystalline layer and a second poly-crystalline layer. A boundary is between the first poly-crystalline layer and the second poly-crystalline layer.

A semiconductor structure includes a conductive line, a pad layer, and a barrier layer. The conductive line is embedded in a multi-level interconnect structure. The pad layer is over the conductive line. The barrier layer is between the conductive line and the pad layer. The pad layer is electrically connected to the conductive line through the barrier layer, and the barrier layer includes a first poly-crystalline layer and a second poly-crystalline layer. A boundary is between the first poly-crystalline layer and the second poly-crystalline layer.

A semiconductor package includes a first semiconductor chip having a first substrate, a first insulating layer on the first substrate, and a plurality of first bonding pads on the first insulating layer, and having a flat upper surface by an upper surface of the first insulating layer and upper surfaces of the plurality of first bonding pads; and a second semiconductor chip on the upper surface of the first semiconductor chip and having a second substrate, a second insulating layer below the second substrate and in contact with the first insulating layer, and a plurality of second bonding pads on the second insulating layer and in contact with the first bonding pads, respectively, wherein the first insulating layer includes an insulating interfacial layer in contact with the second insulating layer, embedded in the first insulating layer, and spaced apart from the plurality of first bonding pads.