A cryogenic under bump metallization (UBM) stack includes an adhesion and barrier layer and a conductive pillar on the adhesion and barrier layer. The conductive pillar functions as a solder wetting layer of the UBM stack and has a thickness. An indium superconducting solder bump is on the conductive pillar. The thickness of the conductive pillar is sufficient to prevent intermetallic regions, which form in the conductive pillar at room temperature due to interdiffusion, from extending through the entire thickness of the conductive pillar to maintain the structural integrity of the UBM stack. The indium (In) solder bump may be formed through electroplating, with the conductive pillar being copper (Cu) and the adhesion and barrier layer being titanium tungsten (TiW) and a thin seed layer of copper (Cu), or a layer of titanium (Ti). The UBM stack eliminates the need for magnetic materials such as nickel (Ni) in the stack, making the stack suitable for cryogenic applications.

Disclosed is a method for manufacturing a flip chip, in which a gold typically used in a flip chip manufacturing is adhered by conductive adhesives, wherein the method comprises steps of depositing a metal seed layer on a substrate; applying and patterning a photoresist or a dry film; forming a gold bump by electroplating; patterning the seed layer; forming an insulating layer on the seed layer and upper end of the gold bump; and patterning an insulating layer. Accordingly, it is possible to manufacture a flip chip, in which electrical function between bumps can be evaluated, with less cost.

A method for fabricating a semiconductor structure is provided. The method includes: providing a semiconductor chip comprising an active surface; forming a conductive bump over the active surface of the semiconductor chip; and coupling the conductive bump to a substrate. The conductive bump includes a plurality of bump segments including a first group of bump segments and a second group of bump segments. Each bump segment has a same segment thickness in a direction orthogonal to the active surface of the semiconductor chip, and each bump segment has a volume defined by a multiplication of the same segment thickness with an average cross-sectional area of the bump segment in a plane parallel to the active surface of the semiconductor chip. A ratio of a total volume of the first group of bump segments to a total volume of the second group of bump segments is between 0.03 and 0.8.

Methods and apparatus to reduce defects in interconnects between semiconductor dies and package substrates are disclosed. An apparatus includes a substrate and a semiconductor die mounted to the substrate. The apparatus further includes bumps to electrically couple the die to the substrate. Ones of the bumps have corresponding bases. The bases have a shape that is non-circular.

Methods and apparatus to reduce defects in interconnects between semiconductor dies and package substrates are disclosed. An apparatus includes a substrate and a semiconductor die mounted to the substrate. The apparatus further includes bumps to electrically couple the die to the substrate. Ones of the bumps have corresponding bases. The bases have a shape that is non-circular.

A hybrid wafer bonding method includes providing a first semiconductor structure and providing a second semiconductor structure. The first semiconductor structure includes a first via structure in a first dielectric layer, the first via structure including a first contact via surface. The second semiconductor structure includes a second via structure in a second dielectric layer, the second via structure including a second contact via surface. The first contact via surface is bonded with the second contact via surface. A barrier structure is formed surrounding the second contact via surface along a lateral direction and extending into each of the first contact via surface and the second dielectric layer in a vertical direction. The first via structure includes first metal impurities doped in a bulk region of the first via structure, and the second via structure includes second metal impurities doped in a bulk region of the second via structure.

Embodiments of mechanisms for testing a die package with multiple packaged dies on a package substrate use an interconnect substrate to provide electrical connections between dies and the package substrate and to provide probing structures (or pads). Testing structures, including daisy-chain structures, with metal lines to connect bonding structures connected to signals, power source, and/or grounding structures are connected to probing structures on the interconnect substrate. The testing structures enable determining the quality of bonding and/or functionalities of packaged dies bonded. After electrical testing is completed, the metal lines connecting the probing structures and the bonding structures are severed to allow proper function of devices in the die package. The mechanisms for forming test structures with probing pads on interconnect substrate and severing connecting metal lines after testing could reduce manufacturing cost.

A semiconductor device includes a semiconductor element, an internal electrode connected to the semiconductor element, a sealing resin covering the semiconductor element and a portion of the internal electrode, and an external electrode exposed from the sealing resin and connected to the internal electrode. The internal electrode includes a wiring layer and a columnar portion, where the wiring layer has a wiring layer front surface facing the back surface of the semiconductor element and a wiring layer back surface facing opposite from the wiring layer front surface in the thickness direction. The columnar portion protrudes in the thickness direction from the wiring layer front surface. The columnar portion has an exposed side surface facing in a direction perpendicular to the thickness direction. The external electrode includes a first cover portion covering the exposed side surface.

A semiconductor device includes a semiconductor element, an internal electrode connected to the semiconductor element, a sealing resin covering the semiconductor element and a portion of the internal electrode, and an external electrode exposed from the sealing resin and connected to the internal electrode. The internal electrode includes a wiring layer and a columnar portion, where the wiring layer has a wiring layer front surface facing the back surface of the semiconductor element and a wiring layer back surface facing opposite from the wiring layer front surface in the thickness direction. The columnar portion protrudes in the thickness direction from the wiring layer front surface. The columnar portion has an exposed side surface facing in a direction perpendicular to the thickness direction. The external electrode includes a first cover portion covering the exposed side surface.

A semiconductor device includes a semiconductor substrate divided into a pad region and a cell region and having an active surface and an inactive surface opposite to the active surface, a plurality of metal lines on the active surface of the semiconductor substrate, passivation layers on the active surface of the semiconductor substrate, and a plurality of bumps in the cell region. The passivation layers include a first passivation layer covering the plurality of metal lines and having a non-planarized top surface along an arrangement profile of the plurality of metal lines, and a second passivation layer on the non-planarized top surface of the first passivation layer and having a planarized top surface on which the plurality of bumps are disposed.