A solder connection may be surrounded by a solder locking layer (1210, 2210) and may be recessed in a hole (1230) in that layer. The recess may be obtained by evaporating a vaporizable portion (1250) of the solder connection. Other features are also provided.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A semiconductor die includes a substrate including a semiconductor surface including circuitry electrically connected to die bond pads that include a first die bond pad exposed by a passivation layer, a top dielectric layer over the passivation layer, and a metal layer electrically connected to the first die bond pad. A pillar is on the metal layer over the first die bond pad, and a solder cap is on a top side of the pillar. The solder cap includes an essentially vertical sidewall portion generally beginning at a top corner edge of the pillar.

Superconducting solder bumps are produced on a qubit substrate by electrodeposition. The substrate comprises qubit areas, and superconducting contact pads connected to the qubit areas. First a protection layer is formed on the substrate, and patterned so as to cover at least the qubit areas. Then one or more thin layers are deposited conformally on the patterned protection layer, the thin layers comprising at least a non-superconducting layer suitable for acting as a seed layer for the electrodeposition of the solder bumps. The seed layer is removed locally in areas which lie within the surface area of respective contact pads. This is done by producing and patterning a mask layer, so that openings are formed therein, and by removing the seed layer from the bottom of the openings. The solder bumps are formed by electrodeposition of the solder material on the bottom of the openings. After the formation of the solder bumps, the seed layer and the protection layer are removed.

Methods and semiconductor devices for bonding a first semiconductor device to a second semiconductor device include forming metal pads including a textured microstructure having a columnar grain structure at substantially the same angular direction from the top surface to the bottom surface. The textured crystalline microstructures enables the use of low temperatures and low pressures to effect bonding of the metal pads. Also described are methods of packaging and semiconductor devices.

Methods and semiconductor devices for bonding a first semiconductor device to a second semiconductor device include forming metal pads including a textured microstructure having a columnar grain structure at substantially the same angular direction from the top surface to the bottom surface. The textured crystalline microstructures enables the use of low temperatures and low pressures to effect bonding of the metal pads. Also described are methods of packaging and semiconductor devices.

In some embodiments, to increase the height-to-pitch ratio of a solder connection that connects different structures with one or more solder balls, only a portion of a solder ball's surface is melted when the connection is formed on one structure and/or when the connection is being attached to another structure. In some embodiments, non-solder balls are joined by an intermediate solder ball (140i). A solder connection may be surrounded by a solder locking layer (1210) and may be recessed in a hole (1230) in that layer. Other features are also provided.

The present disclosure provides a semiconductor device including: a substrate including, in a central portion the substrate, n first element formation regions having a rectangular shape and are arrayed along a first direction, and n+m second element formation regions arrayed along the first direction adjacent to the first element formation regions; plural projecting electrodes formed at each of the first and the second element formation regions; and plural dummy projecting electrodes formed, at a peripheral portion, overlapping a triangle defined by a first edge of the first element formation region that forms a boundary between the first element formation region and the peripheral portion, and a second edge of the second element formation region that is adjacent to a corner of the first edge and that forms a boundary between the second element formation region and the peripheral portion.

A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

The invention relates to a ball-limiting metallurgy stack for an electrical device that contains at least one copper layer disposed upon a Ti adhesion metal layer. The ball-limiting metallurgy stack resists Sn migration toward the upper metallization of the device.