A method for forming a through-substrate via structure includes providing a substrate and providing a conductive via structure adjacent to a first surface of the substrate. The method includes providing a recessed region on an opposite surface of the substrate towards the conductive via structure. The method includes providing an insulator in the recessed region and providing a conductive region extending along a first sidewall surface of the recessed region in the cross-sectional view. In some examples, the first conductive region is provided to be coupled to the conductive via structure and to be further along at least a portion of the opposite surface of the substrate outside of the recessed region. The method includes providing a protective structure within the recessed region over a first portion of the first conductive region but not over a second portion of the first conductive region that is outside of the recessed region. The method includes attaching a conductive bump to the second portion of the first conductive region.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin. An indium preform is placed between the second adhesion layer and the lid and the indium preform is reflowed.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin. An indium preform is placed between the second adhesion layer and the lid and the indium preform is reflowed.

A semiconductor device includes: a semiconductor die having a metal region; a substrate having a metal region; and a soldered joint between the metal region of the semiconductor die and the metal region of the substrate. One or more intermetallic phases are present throughout the entire soldered joint, each of the one or more intermetallic phases formed from a solder preform diffused into the metal region of the semiconductor die and the metal region of the substrate. The soldered joint has the same length-to-width aspect ratio as the semiconductor die.

A semiconductor device includes: a semiconductor die having a metal region; a substrate having a metal region; and a soldered joint between the metal region of the semiconductor die and the metal region of the substrate. One or more intermetallic phases are present throughout the entire soldered joint, each of the one or more intermetallic phases formed from a solder preform diffused into the metal region of the semiconductor die and the metal region of the substrate. The soldered joint has the same length-to-width aspect ratio as the semiconductor die.

There is provided semiconductor devices and methods of forming the same, the semiconductor devices including: a first semiconductor element having a first electrode; a second semiconductor element having a second electrode; a Sn-based micro-solder bump formed on the second electrode; and a concave bump pad including the first electrode opposite to the micro-solder bump, where the first electrode is connected to the second electrode via the micro-solder bump and the concave bump pad.

A method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

A method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

The present application discloses a method for fabricating a semiconductor device with a connection structure. The method includes providing a first semiconductor structure comprising a plurality of first conductive features adjacent to a top surface of the first semiconductor structure; forming a connection structure comprising a connection insulating layer on the top surface of the first semiconductor structure, a connection layer in the connection insulating layer, and a plurality of first porous interlayers on the plurality of first conductive features and in the connection insulating layer; and forming a second semiconductor structure comprising a plurality of second conductive features on the plurality of first porous interlayers.

The present application discloses a method for fabricating a semiconductor device with a connection structure. The method includes providing a first semiconductor structure comprising a plurality of first conductive features adjacent to a top surface of the first semiconductor structure; forming a connection structure comprising a connection insulating layer on the top surface of the first semiconductor structure, a connection layer in the connection insulating layer, and a plurality of first porous interlayers on the plurality of first conductive features and in the connection insulating layer; and forming a second semiconductor structure comprising a plurality of second conductive features on the plurality of first porous interlayers.