A semiconductor structure includes a wafer having a wafer outer surface; a semiconductor chip; and a plurality of copper pillars on the semiconductor chip. The pillars have curved end portions and pillar outside surfaces. Also included are a plurality of copper pads on the wafer. The pads have end portions aligned with the curved end portions of the plurality of copper pillars on the semiconductor chip, and the curved end portions of the plurality of copper pillars and the end portions of the plurality of copper pads define a plurality of bonding material receiving regions. The pads have pad outside surfaces. A copper bonding layer is on the pillar outside surfaces, the pad outside surfaces, the bonding material receiving regions, and portions of the outer surface of the wafer. The portions have an annular shape about the copper pads when viewed in plan.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 μm or more, diameters of 10 μm or below, and inter-pillar spacing below 20 μm. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 μm or more, diameters of 10 μm or below, and inter-pillar spacing below 20 μm. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

Solder-pinning metal pads for electronic components and techniques for use thereof to mitigate de-wetting are provided. In one aspect, a structure includes: a substrate; and a solder pad on the substrate, wherein the solder pad has sidewalls extending up from a surface thereof. For instance, the sidewalls can be present at edges of the solder pad, or inset from the edges of the solder pad. The sidewalls can be vertical or extend up from the solder pad at an angle. The sidewalls can be formed from the same material or a different material as the solder pad. A method is also provided that includes forming a solder pad on a substrate, the solder pad comprising sidewalls extending up from a surface thereof.

Solder-pinning metal pads for electronic components and techniques for use thereof to mitigate de-wetting are provided. In one aspect, a structure includes: a substrate; and a solder pad on the substrate, wherein the solder pad has sidewalls extending up from a surface thereof. For instance, the sidewalls can be present at edges of the solder pad, or inset from the edges of the solder pad. The sidewalls can be vertical or extend up from the solder pad at an angle. The sidewalls can be formed from the same material or a different material as the solder pad. A method is also provided that includes forming a solder pad on a substrate, the solder pad comprising sidewalls extending up from a surface thereof.

A semiconductor device includes a first semiconductor structure including a first high electron mobility transistor (HEMT) device, wherein the first HEMT device includes a first gate, a first source, and a first drain; and a second semiconductor structure stacked above and bonded to the first semiconductor structure, wherein the second semiconductor structure includes a second HEMT device and a third HEMT device, wherein the second HEMT device includes a second gate, a second source, and a second drain that is electrically connected to the first source, wherein the third HEMT device includes a third gate, a third source, and a third drain that is electrically connected to the first gate.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 μm or more, diameters of 10 μm or below, and inter-pillar spacing below 20 μm. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 μm or more, diameters of 10 μm or below, and inter-pillar spacing below 20 μm. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

A microelectronic device has a pillar connected to an external terminal by an intermetallic joint. Either the pillar or the external terminal, or both, include copper in direct contact with the intermetallic joint. The intermetallic joint includes at least 90 weight percent of at least one copper-tin intermetallic compound. The intermetallic joint is free of voids having a combined volume greater than 10 percent of a volume of the intermetallic joint; and free of a void having a volume greater than 5 percent of the volume of the intermetallic joint. The microelectronic device may be formed using solder which includes at least 93 weight percent tin, 0.5 weight percent to 5.0 weight percent silver, and 0.4 weight percent to 1.0 weight percent copper, to form a solder joint between the pillar and the external terminal, followed by thermal aging to convert the solder joint to the intermetallic joint.

The present application discloses a semiconductor device and a method for fabricating the semiconductor device. The semiconductor device includes an active interposer including a programmable unit, a first memory die positioned above the active interposer and including a storage unit, and a first logic die positioned below the active interposer. The active interposer, the first memory die, and the first logic die are electrically coupled.