An integrated circuit (IC) die structure comprises a substrate material comprising silicon. Integrated circuitry is over a first side of the substrate material. A composite layer is in direct contact with a second side of the substrate material. The second side is opposite the first side. The composite layer comprises a first constituent material associated with a first linear coefficient of thermal expansion (CTE), and a first thermal conductivity exceeding that of the substrate. The composite layer also comprises a second constituent material associated with a second CTE that is lower than the first, and a second thermal conductivity exceeding that of the substrate.

An integrated circuit (IC) die structure comprises a substrate material comprising silicon. Integrated circuitry is over a first side of the substrate material. A composite layer is in direct contact with a second side of the substrate material. The second side is opposite the first side. The composite layer comprises a first constituent material associated with a first linear coefficient of thermal expansion (CTE), and a first thermal conductivity exceeding that of the substrate. The composite layer also comprises a second constituent material associated with a second CTE that is lower than the first, and a second thermal conductivity exceeding that of the substrate.

A method of forming a semiconductor package. Implementations include forming on a die backside an intermediate metal layer having multiple sublayers, each including a metal selected from the group consisting of titanium, nickel, copper, silver, and combinations thereof. A tin layer is deposited onto the intermediate metal layer and is then reflowed with a silver layer of a substrate to form an intermetallic layer having a melting temperature above 260 degrees Celsius and including an intermetallic consisting of silver and tin and/or an intermetallic consisting of copper and tin. Another method of forming a semiconductor package includes forming a bump on each of a plurality of exposed pads of a top side of a die, each exposed pad surrounded by a passivation layer, each bump including an intermediate metal layer as described above and a tin layer coupled to the intermediate metal layer is reflowed to form an intermetallic layer.

A method of forming a semiconductor package. Implementations include forming on a die backside an intermediate metal layer having multiple sublayers, each including a metal selected from the group consisting of titanium, nickel, copper, silver, and combinations thereof. A tin layer is deposited onto the intermediate metal layer and is then reflowed with a silver layer of a substrate to form an intermetallic layer having a melting temperature above 260 degrees Celsius and including an intermetallic consisting of silver and tin and/or an intermetallic consisting of copper and tin. Another method of forming a semiconductor package includes forming a bump on each of a plurality of exposed pads of a top side of a die, each exposed pad surrounded by a passivation layer, each bump including an intermediate metal layer as described above and a tin layer coupled to the intermediate metal layer is reflowed to form an intermetallic layer.

A 3D IC package includes a bottom die having a back interconnect side opposing a front device side, the back interconnect side having a plurality of bottom die interconnects extending thereto. A top die has a front device side opposing a back side, the front device side having a plurality of top die interconnects. An interposer includes a redistribution layer (RDL) between the bottom die and the top die, the RDL including a plurality of wiring layers extending from back side RDL interconnects thereof to front side RDL interconnects thereof. An under bump metallization (UBM) couples the back side RDL interconnects to the plurality of top die interconnects at a first location, and the front side RDL interconnects are coupled to the plurality of bottom die interconnects at a second location. The first location and second location may not overlap.

A 3D IC package includes a bottom die having a back interconnect side opposing a front device side, the back interconnect side having a plurality of bottom die interconnects extending thereto. A top die has a front device side opposing a back side, the front device side having a plurality of top die interconnects. An interposer includes a redistribution layer (RDL) between the bottom die and the top die, the RDL including a plurality of wiring layers extending from back side RDL interconnects thereof to front side RDL interconnects thereof. An under bump metallization (UBM) couples the back side RDL interconnects to the plurality of top die interconnects at a first location, and the front side RDL interconnects are coupled to the plurality of bottom die interconnects at a second location. The first location and second location may not overlap.

A ring-like sealing frame (3) and a bump (4) are simultaneously formed on a main surface of a first substrate (1) by patterning a metal paste. A ring-like protrusion (8) having a smaller width than a width of the sealing frame (3) is formed on a main surface of a second substrate (5). The main surface of the first substrate (1) and the main surface of the second substrate (5) are aligned to face each other. The sealing frame (3) is bonded to the protrusion (8), and the bump (4) is electrically bonded to the second substrate (5). A height of the protrusion (8) is 0.4 to 0.7 times a distance between the first substrate (1) and the second substrate (2) after bonding.

A semiconductor device is disclosed including an integrated memory module. The integrated memory module may include a pair of semiconductor die, which together, operate as a single, integrated flash memory. In one example, the first die may include the memory cell array and the second die may include the logic circuit such as CMOS integrated circuits. In one example, the second die may be flip-chip bonded to the first die. The flip-chip bond pads on the first and second dies may be made small, with a small pitch, to allow a large number of electrical interconnections between the first and second semiconductor dies.

A ring-like sealing frame (3) and a bump (4) are simultaneously formed on a main surface of a first substrate (1) by patterning a metal paste. A ring-like protrusion (8) having a smaller width than a width of the sealing frame (3) is formed on a main surface of a second substrate (5). The main surface of the first substrate (1) and the main surface of the second substrate (5) are aligned to face each other. The sealing flame (3) is bonded to the protrusion (8), and the bump (4) is electrically bonded to the second substrate (5). A height of the protrusion (8) is 0.4 to 0.7 times a distance between the first substrate (1) and the second substrate (2) after bonding.

A semiconductor device is disclosed including an integrated memory module. The integrated memory module may include a pair of semiconductor die, which together, operate as a single, integrated flash memory. In one example, the first die may include the memory cell array and the second die may include the logic circuit such as CMOS integrated circuits. In one example, the second die may be flip-chip bonded to the first die. The flip-chip bond pads on the first and second dies may be made small, with a small pitch, to allow a large number of electrical interconnections between the first and second semiconductor dies.