Disclosed are techniques for selectively boosting conductive pillar bumps. In an aspect, an apparatus includes a plurality of metal pads, a first set of boosting pads attached to a first set of the plurality of metal pads, a first set of conductive pillar bumps attached to the first set of boosting pads, a second set of conductive pillar bumps attached to a second set of the plurality of metal pads, wherein heights of the first set of conductive pillar bumps are shorter than heights of the second set of conductive pillar bumps, and wherein heights of the first set of boosting pads plus the heights of the first set of conductive pillar bumps are within a tolerance threshold of the heights of the second set of conductive pillar bumps, and solder attached to the first set of conductive pillar bumps and the second set of conductive pillar bumps.

A multi-layer semiconductor structure includes a first semiconductor structure and a second semiconductor structure, with at least one of the first and second semiconductor structures provided as a superconducting semiconductor structure. The multi-layer semiconductor structure also includes one or more interconnect structures. Each of the interconnect structures is disposed between the first and second semiconductor structures and coupled to respective ones of interconnect pads provided on the first and second semiconductor structures. Additionally, each of the interconnect structures includes a plurality of interconnect sections. At least one of the interconnect sections includes at least one superconducting and/or a partially superconducting material.

A cryogenic electronic package includes at least two superconducting and/or conventional metal semiconductor structures. Each of the semiconductor structures includes a substrate and a superconducting trace. Additionally, each of the semiconductor structures includes a passivation layer and one or more under bump metal (UBM) structures. The cryogenic electronic package also includes one or more superconducting and/or conventional metal interconnect structures disposed between selected ones of the at least two superconducting semiconductor structures. The interconnect structures are electrically coupled to respective ones of the UBM structures of the semiconductor structures to form one or more electrical connections between the semiconductor structures. A method of fabricating a cryogenic electronic package is also provided.

Described are concepts, systems, circuits and techniques related to shielded through via structures and methods for fabricating such shielded through via structures. The described shielded through via structures and techniques allow for assembly of multi-layer semiconductor structures including one or more superconducting semiconductor structures (or integrated circuits).

An integrated circuit structure includes a substrate, a PPI over the substrate, a solder region over and electrically coupled to a portion of the PPI, and a molding compound molding a lower portion of the solder region therein. A top surface of the molding compound is level with or lower than a maximum-diameter plane, wherein the maximum-diameter plane is parallel to a major surface of the substrate, and the maximum-diameter of the solder region is in the maximum-diameter plane.

An integrated circuit structure includes a substrate, a PPI over the substrate, a solder region over and electrically coupled to a portion of the PPI, and a molding compound molding a lower portion of the solder region therein. A top surface of the molding compound is level with or lower than a maximum-diameter plane, wherein the maximum-diameter plane is parallel to a major surface of the substrate, and the maximum-diameter of the solder region is in the maximum-diameter plane.

A method of fabricating an interconnect structure includes providing a semiconductor structure and performing a first spin resist and bake cycle. The first spin resist and bake cycle includes applying a first predetermined amount of a resist material over one or more portions of the semiconductor structure and baking the semiconductor structure to form a first resist layer portion of a resist layer. The method also includes performing a next spin resist and bake cycle. The next spin resist and bake cycle includes applying a next predetermined amount of the resist material and baking the semiconductor structure to form a next resist layer portion of the resist layer. The method additionally includes depositing a conductive material in an opening formed in the resist layer and forming a conductive structure from the conductive material. An interconnect structure is also provided.

Disclosed is a semiconductor device suppressed in decrease of reliability. The semiconductor device comprises an electrode pad portion (2) formed on the upper surface of a semiconductor substrate (1), a passivation layer (3) so formed on the upper surface of the semiconductor substrate (1) as to overlap a part of the electrode pad portion (2) and having a first opening portion (3a) where the upper surface of the electrode pad portion (2) is exposed, a barrier metal layer (5) formed on the electrode pad portion (2), and a solder bump (6) formed on the barrier metal layer (5). The barrier metal layer (5) is formed such that an outer peripheral end (5b) lies within the first opening portion (3a) of the passivation layer (3) when viewed in plan.

Disclosed is a semiconductor device suppressed in decrease of reliability. The semiconductor device comprises an electrode pad portion (2) formed on the upper surface of a semiconductor substrate (1), a passivation layer (3) so formed on the upper surface of the semiconductor substrate (1) as to overlap a part of the electrode pad portion (2) and having a first opening portion (3a) where the upper surface of the electrode pad portion (2) is exposed, a barrier metal layer (5) formed on the electrode pad portion (2), and a solder bump (6) formed on the barrier metal layer (5). The barrier metal layer (5) is formed such that an outer peripheral end (5b) lies within the first opening portion (3a) of the passivation layer (3) when viewed in plan.

A technique is disclosed for causing the top surfaces of solder bumps on a chip to be in the same plane to ensure a more reliable bond between the chip and a substrate. The chip is provided with solder pads that may have different heights. A dielectric layer is formed between the solder pads. A relatively thick metal layer is plated over the solder pads. The metal layer is planarized to cause the top surfaces of the metal layer portions over the solder pads to be in the same plane and above the dielectric layer. A substantially uniformly thin layer of solder is deposited over the planarized metal layer portions so that the top surfaces of the solder bumps are substantially in the same plane. The chip is then positioned over a substrate having corresponding metal pads, and the solder is reflowed or ultrasonically bonded to the substrate pads.