A device includes a semiconductor die including a via, a layer of titanium tungsten (TiW) in contact with the via, and a copper pillar including a top portion and a bottom portion. The bottom portion is in contact with the layer of TiW. The copper pillar includes interdiffused zinc within the bottom portion.

During electro-oxidative metal removal on a semiconductor substrate, the substrate having a metal layer is anodically biased and the metal is electrochemically dissolved into an electrolyte. Metal particles (e.g., copper particles when the dissolved metal is copper) can inadvertently form on the surface of the substrate during electrochemical metal removal and cause defects during subsequent semiconductor processing. Contamination with such particles can be mitigated by preventing particle formation and/or by dissolution of particles. In one implementation, mitigation involves using an electrolyte that includes an oxidizer, such as hydrogen peroxide, during the electrochemical metal removal. An electrochemical metal removal apparatus in one embodiment has a conduit for introducing an oxidizer to the electrolyte and a sensor for monitoring the concentration of the oxidizer in the electrolyte.

During electro-oxidative metal removal on a semiconductor substrate, the substrate having a metal layer is anodically biased and the metal is electrochemically dissolved into an electrolyte. Metal particles (e.g., copper particles when the dissolved metal is copper) can inadvertently form on the surface of the substrate during electrochemical metal removal and cause defects during subsequent semiconductor processing. Contamination with such particles can be mitigated by preventing particle formation and/or by dissolution of particles. In one implementation, mitigation involves using an electrolyte that includes an oxidizer, such as hydrogen peroxide, during the electrochemical metal removal. An electrochemical metal removal apparatus in one embodiment has a conduit for introducing an oxidizer to the electrolyte and a sensor for monitoring the concentration of the oxidizer in the electrolyte.

Disclosed are examples of integrated circuit (IC) structures and techniques to fabricate IC structures. Each IC package may include a die (e.g., a flip-chip (FC) die) and one or more die interconnects to electrically couple the die to a substrate. The die interconnect may include a pillar, a wetting barrier on the pillar, and a solder cap on the wetting barrier. The wetting barrier may be wider than the pillar. The die interconnect may also include a low wetting layer formed on the wetting barrier.

Disclosed are examples of integrated circuit (IC) structures and techniques to fabricate IC structures. Each IC package may include a die (e.g., a flip-chip (FC) die) and one or more die interconnects to electrically couple the die to a substrate. The die interconnect may include a pillar, a wetting barrier on the pillar, and a solder cap on the wetting barrier. The wetting barrier may be wider than the pillar. The die interconnect may also include a low wetting layer formed on the wetting barrier.

A semiconductor device includes a substrate having a plurality of pads on a surface of the substrate, a semiconductor chip that includes a plurality of metal bumps connected to corresponding pads on the substrate, a first resin layer between the surface of the substrate and the semiconductor chip, a second resin layer between the substrate and the semiconductor chip and between the first resin layer and at least one of the metal bumps, and a third resin layer on the substrate and above the semiconductor chip.

The present disclosure relates to the technical field of semiconductor packaging, and discloses a semiconductor structure and a method for forming the same. The method includes: providing a chip, the chip having interconnect structures on its surface, the top of the interconnect structures having an exposed fusible portion; providing a substrate, the substrate having conductive structures on its surface; patterning the conductive structures so that edges of the conductive structures have protrusions; combining the chip with the substrate. The new structure design avoids the product failure of the chip and the semiconductor substrate in the molding stage, and also strengthens the weld metal bonding force between the conductive structures and the substrate.

A system and method for etching a die in a tin (Sn) electrolyte. The die includes a silicon wafer and a diffusion barrier disposed on the silicon wafer. A copper seed layer disposed on the diffusion barrier and at least one copper bump bond is disposed on a portion of the copper seed layer. A tin layer is disposed on side walls of the at least one copper bump bond. The tin layer inhibits etching of the side walls of the at least one copper bump bond during an etching process to the copper seed layer to remove exposed portions of the copper seed layer.

A chip structure is provided. The chip structure includes a substrate. The chip structure includes an interconnect layer over the substrate. The chip structure includes a conductive pad over the interconnect layer. The chip structure includes a conductive bump over the conductive pad. The conductive bump has a first portion, a second portion, and a neck portion between the first portion and the second portion. The first portion is between the neck portion and the conductive pad. The neck portion is narrower than the first portion and narrower than the second portion.

A method for forming a package structure includes forming an under bump metallization (UBM) layer over a metal pad and forming a photoresist layer over the UBM layer. The method further includes patterning the photoresist layer to form an opening in the photoresist layer. The method also includes forming a first bump structure over the first portion of the UBM layer. The first bump structure includes a first barrier layer over a first pillar layer. The method includes placing a second bump structure over the first bump structure. The second bump structure includes a second barrier layer over a second pillar layer. The method further includes reflowing the first bump structure and the second bump structure to form a solder joint between a first inter intermetallic compound (IMC) and a second IMC.