A tin plating solution and a method for fabricating a semiconductor device are provided. The tin plating solution comprises tin ions supplied from a soluble tin electrode, an aliphatic sulfonic acid having a carbon number of 1 to 10, an anti-oxidant, a wetting agent, and a grain refiner that is an aromatic carbonyl compound.

A semiconductor structure including an integrated circuit die and conductive bumps is provided. The integrated circuit die includes bump pads. The conductive bumps are disposed on the bump pads. Each of the conductive bumps includes a first pillar portion disposed on one of the bump pads and a second pillar portion disposed on the first pillar portion. The second pillar portion is electrically connected to one of the bump pads through the first pillar portion, wherein a first width of the first pillar portion is greater than a second width of the second pillar portion. A package structure including the above-mentioned semiconductor structure is also provided.

A package component includes a dielectric layer and a metal pad over the dielectric layer. A plurality of openings is disposed in the metal pad. The first plurality of openings is separated from each other by portions of the metal pad, with the portions of the metal pad interconnected to form a continuous metal region.

Various semiconductor chips and packages are disclosed. In one aspect, an apparatus is provided that includes a semiconductor chip that has a side, and plural conductive pillars on the side. Each of the conductive pillars includes a pillar portion that has an exposed shoulder facing away from the semiconductor chip. The shoulder provides a wetting surface to attract melted solder. The pillar portion has a first lateral dimension at the shoulder. A solder cap is positioned on the pillar portion. The solder cap has a second lateral dimension smaller than the first lateral dimension.

Package structures and methods for manufacturing the same are provided. The package structure includes a first bump structure formed over a first substrate. The first bump structure includes a first pillar layer formed over the first substrate and a first barrier layer formed over the first pillar layer. In addition, the first barrier layer has a first protruding portion laterally extending outside a first edge of the first pillar layer. The package structure further includes a second bump structure bonded to the first bump structure through a solder joint. In addition, the second bump structure includes a second pillar layer formed over a second substrate and a second barrier layer formed over the second pillar layer. The first protruding portion of the first barrier layer is spaced apart from the solder joint.

A method includes performing a first laser shot on a first portion of a top surface of a first package component. The first package component is over a second package component, and a first solder region between the first package component and the second package component is reflowed by the first laser shot. After the first laser shot, a second laser shot is performed on a second portion of the top surface of the first package component. A second solder region between the first package component and the second package component is reflowed by the second laser shot.

A method includes forming a metal bump on a top surface of a first package component, forming a solder region on a top surface of the metal bump, forming a protection layer extending on a sidewall of the metal bump, reflowing the solder region to bond the first package component to a second package component, and dispensing an underfill between the first package component and the second package component. The underfill is in contact with the protection layer.

In order to manufacture an alloy bump, a resist pattern having openings which expose a substrate is formed on the substrate, an under-bump metal is formed on the substrate inside the openings, a first plating film is formed on the under-bump metal by electroplating, a second plating film containing no metal components which are contained in the first plating film is formed on the first plating film by electroplating, the resist pattern is removed, and the alloy bump is formed by heat treating the substrate to thereby alloy the first plating film and the second plating film.

In order to manufacture an alloy bump, a resist pattern having openings which expose a substrate is formed on the substrate, an under-bump metal is formed on the substrate inside the openings, a first plating film is formed on the under-bump metal by electroplating, a second plating film containing no metal components which are contained in the first plating film is formed on the first plating film by electroplating, the resist pattern is removed, and the alloy bump is formed by heat treating the substrate to thereby alloy the first plating film and the second plating film.

Sequential electrodeposition of metals into through-mask features on a semiconductor substrate is conducted such as to reduce the deleterious consequences of lipseal's pressure onto the mask material. In a first electroplating step, a first metal (e.g., nickel) is electrodeposited using a lipseal that has an innermost point of contact with the semiconductor substrate at a first distance from the edge of the substrate. In a second electroplating step, a second metal (e.g., tin) is electrodeposited using a lipseal that has an innermost point of contact with the semiconductor substrate at a greater distance from the edge of the substrate than the first distance. This allows to at least partially shift the lipseal pressure from a point that could have been damaged during the first electrodeposition step and to shield from electrolyte any cracks that might have formed in the mask material during the first electroplating step.