A semiconductor device includes a pad, a diffusion layer, and a melting layer. The pad included by the semiconductor device includes a concave portion on a surface at which solder connection is to be performed. The diffusion layer included by the semiconductor device is disposed at the concave portion and constituted with a metal which remains on the surface of the pad while diffusing into solder upon the solder connection. The melting layer included by the semiconductor device is disposed adjacent to the diffusion layer and constituted with a metal which diffuses and melts into the solder upon the solder connection.

A semiconductor device assembly, comprising a first semiconductor device including a first substrate with a frontside surface, a plurality of solder bumps located on the frontside surface of the first substrate, and a first polymer layer on the frontside surface. The semiconductor device assembly also comprises a second semiconductor device including a second substrate with a backside surface, a plurality of TSVs protruding from the backside surface of the second substrate, and a second polymer layer on the backside surface of the first substrate, the second polymer layer having a plurality of openings corresponding to the plurality of TSVs. The first and second semiconductor devices are bonded such that the first polymer layer contacts the second polymer layer and each of the plurality of solder bumps extends into a corresponding one of the plurality of openings and contacts a corresponding one of the plurality of TSVs.

A semiconductor device includes a conductive component on a substrate, a passivation layer on the substrate and including an opening that exposes at least a portion of the conductive component, and a pad structure in the opening and located on the passivation layer, the pad structure being electrically connected to the conductive component. The pad structure includes a lower conductive layer conformally extending on an inner sidewall of the opening, the lower conductive layer including a conductive barrier layer, a first seed layer, an etch stop layer, and a second seed layer that are sequentially stacked, a first pad layer on the lower conductive layer and at least partially filling the opening, and a second pad layer on the first pad layer and being in contact with a peripheral portion of the lower conductive layer located on the top surface of the passivation layer.

Various chip stacks and methods and structures of interconnecting the same are disclosed. In one aspect, an apparatus is provided that includes a first semiconductor chip that has a first glass layer and plural first groups of plural conductor pads in the first glass layer. Each of the plural first groups of conductor pads is configured to bumplessly connect to a corresponding second group of plural conductor pads of a second semiconductor chip to make up a first interconnect of a plurality interconnects that connect the first semiconductor chip to the second semiconductor chip. The first glass layer is configured to bond to a second glass layer of the second semiconductor chip.

Various chip stacks and methods and structures of interconnecting the same are disclosed. In one aspect, an apparatus is provided that includes a first semiconductor chip that has a first glass layer and plural first groups of plural conductor pads in the first glass layer. Each of the plural first groups of conductor pads is configured to bumplessly connect to a corresponding second group of plural conductor pads of a second semiconductor chip to make up a first interconnect of a plurality interconnects that connect the first semiconductor chip to the second semiconductor chip. The first glass layer is configured to bond to a second glass layer of the second semiconductor chip.

A semiconductor device assembly, comprising a first semiconductor device including a first substrate with a frontside surface, a plurality of solder bumps located on the frontside surface of the first substrate, and a first polymer layer on the frontside surface. The semiconductor device assembly also comprises a second semiconductor device including a second substrate with a backside surface, a plurality of TSVs protruding from the backside surface of the second substrate, and a second polymer layer on the backside surface of the first substrate, the second polymer layer having a plurality of openings corresponding to the plurality of TSVs. The first and second semiconductor devices are bonded such that the first polymer layer contacts the second polymer layer and each of the plurality of solder bumps extends into a corresponding one of the plurality of openings and contacts a corresponding one of the plurality of TSVs.

A semiconductor structure includes a first semiconductor layer and a second semiconductor layer bonded to each other. The first semiconductor layer includes a first redistribution line, and the first redistribution line has a first projection length on a bonding surface of the first semiconductor layer and the second semiconductor layer. The second semiconductor layer includes a second redistribution line, and the second redistribution line has a second projection length on the bonding surface. The first projection length is different from the second projection length. The first redistribution line is electrically connected to the second redistribution line. A method for forming the same is also provided.

A bonded assembly of a first semiconductor die and a second semiconductor die includes first and second semiconductor dies. The first semiconductor die includes first semiconductor devices, first metal interconnect structures embedded in first dielectric material layers, and first metal bonding pads laterally surrounded by a semiconductor material layer. The second semiconductor die includes second semiconductor devices, second metal interconnect structures embedded in second dielectric material layers, and second metal bonding pads that include primary metal bonding pads and auxiliary metal bonding pads. The auxiliary metal bonding pads are bonded to the semiconductor material layer through metal-semiconductor compound portions formed by reaction of surface portions of the semiconductor material layer and an auxiliary metal bonding pad. The primary metal bonding pads are bonded to the first metal bonding pads by metal-to-metal bonding.

The present application discloses a method for fabricating a semiconductor device. The method includes providing a first semiconductor structure; and forming a first connecting structure comprising a first connecting insulating layer on the first semiconductor structure, two first conductive layers in the first connecting insulating layer, and a first porous layer between the two first conductive layers; wherein a porosity of the first porous layer is between about 25% and about 100%.

The present application discloses a method for fabricating a semiconductor device. The method includes providing a first semiconductor structure; and forming a first connecting structure comprising a first connecting insulating layer on the first semiconductor structure, two first conductive layers in the first connecting insulating layer, and a first porous layer between the two first conductive layers; wherein a porosity of the first porous layer is between about 25% and about 100%.