Substrates that are bonding targets are bonded in ambient atmosphere via bonding films, including oxides, formed on bonding faces of the substrates. The bonding films, which are metal or semiconductor thin films formed by vacuum film deposition and at least the surfaces of which are oxidized, are formed into the respective smooth faces of two substrates having the smooth faces that serve as the bonding faces. The bonding films are exposed to a space that contains moisture, and the two substrates are overlapped in the ambient atmosphere such that the surfaces of the bonding films are made to be hydrophilic and the surfaces of the bonding films contact one another. Through this, a chemical bond is generated at the bonded interface, and thereby the two substrates are bonded together in the ambient atmosphere. The bonding strength γ can be improved by heating the bonded substrates at a temperature.

A heat spreading material is integrated into a composite die structure including a first IC die having a first dielectric material and a first electrical interconnect structure, and a second IC die having a second dielectric material and a second electrical interconnect structure. The composite die structure may include a composite electrical interconnect structure comprising the first interconnect structure in direct contact with the second interconnect structure at a bond interface. The heat spreading material may be within at least a portion of a dielectric area through which the bond interface extends. The heat spreading material may be located within one or more dielectric materials surrounding the composite interconnect structure, and direct a flow of heat generated by one or more of the first and second IC dies.

A heat spreading material is integrated into a composite die structure including a first IC die having a first dielectric material and a first electrical interconnect structure, and a second IC die having a second dielectric material and a second electrical interconnect structure. The composite die structure may include a composite electrical interconnect structure comprising the first interconnect structure in direct contact with the second interconnect structure at a bond interface. The heat spreading material may be within at least a portion of a dielectric area through which the bond interface extends. The heat spreading material may be located within one or more dielectric materials surrounding the composite interconnect structure, and direct a flow of heat generated by one or more of the first and second IC dies.

A multi-chip unit suitable for chip-level packaging may include multiple IC chips that are interconnected through a metal redistribution structure, and that are directly bonded to an integrated heat spreader. Bonding of the integrated heat spreader to the multiple IC chips may be direct so that no thermal interface material (TIM) is needed, resulting in a reduced bond line thickness (BLT) and lower thermal resistance. The integrated heat spreader may further serve as a structural member of the multi-chip unit, allowing a second side of the redistribution structure to be further interconnected to a host by solder interconnects. The redistribution structure may be fabricated on a sacrificial interposer that may facilitate planarizing IC chips of differing thickness prior to bonding the heat spreader. The sacrificial interposer may be removed to expose the RDL for further interconnection to a substrate without the use of through-substrate vias.

A multi-chip unit suitable for chip-level packaging may include multiple IC chips that are interconnected through a metal redistribution structure, and that are directly bonded to an integrated heat spreader. Bonding of the integrated heat spreader to the multiple IC chips may be direct so that no thermal interface material (TIM) is needed, resulting in a reduced bond line thickness (BLT) and lower thermal resistance. The integrated heat spreader may further serve as a structural member of the multi-chip unit, allowing a second side of the redistribution structure to be further interconnected to a host by solder interconnects. The redistribution structure may be fabricated on a sacrificial interposer that may facilitate planarizing IC chips of differing thickness prior to bonding the heat spreader. The sacrificial interposer may be removed to expose the RDL for further interconnection to a substrate without the use of through-substrate vias.

After finishing of the front side CMOS manufacturing process, the silicon wafer is permanently bonded with its front side onto a carrier wafer. The carrier wafer is a high resistivity silicon wafer or a wafer of a dielectric or of a ceramic material. The silicon substrate of the device wafer is thinned from the back side such that the remaining silicon thickness is only a few micrometers. In the area dedicated to a spiral inductor, the substrate material is entirely removed by a masked etching process and the resulting gap is filled with a dielectric material. A spiral inductor coil is formed on the backside of the wafer on top of the dielectric material. The inductor coil is connected to the CMOS circuits on the front side by through-silicon vias.

After finishing of the front side CMOS manufacturing process, the silicon wafer is permanently bonded with its front side onto a carrier wafer. The carrier wafer is a high resistivity silicon wafer or a wafer of a dielectric or of a ceramic material. The silicon substrate of the device wafer is thinned from the back side such that the remaining silicon thickness is only a few micrometers. In the area dedicated to a spiral inductor, the substrate material is entirely removed by a masked etching process and the resulting gap is filled with a dielectric material. A spiral inductor coil is formed on the backside of the wafer on top of the dielectric material. The inductor coil is connected to the CMOS circuits on the front side by through-silicon vias.

An anisotropic conductive film can reduce the conduction resistance of an anisotropic conductively connected connection structure, and can reliably suppress the occurrence of short-circuits. The film has a structure wherein insulating particle-including conductive particles, wherein insulating particles adhere to the surfaces of conductive particles, are distributed throughout an insulating resin layer. In the insulating particle-including conductive particles, a number of insulating particles in contact with the conductive particles with respect to a film thickness direction is lower than with respect to a film planar direction. Preferably, a number of the insulating particles overlapping with the conductive particles when one of a front and rear film surface of the anisotropic conductive film is viewed in plan view is lower than a number of the insulating particles overlapping with the conductive particles when the other of the film surfaces is viewed in plan view.

An anisotropic conductive film can reduce the conduction resistance of an anisotropic conductively connected connection structure, and can reliably suppress the occurrence of short-circuits. The film has a structure wherein insulating particle-including conductive particles, wherein insulating particles adhere to the surfaces of conductive particles, are distributed throughout an insulating resin layer. In the insulating particle-including conductive particles, a number of insulating particles in contact with the conductive particles with respect to a film thickness direction is lower than with respect to a film planar direction. Preferably, a number of the insulating particles overlapping with the conductive particles when one of a front and rear film surface of the anisotropic conductive film is viewed in plan view is lower than a number of the insulating particles overlapping with the conductive particles when the other of the film surfaces is viewed in plan view.

In one example, a semiconductor device can comprise (a) an electronic device comprising a device top side, a device bottom side opposite the device top side, and a device sidewall between the device top side and the device bottom side, (b) a first conductor comprising, a first conductor side section on the device sidewall, a first conductor top section on the device top side and coupled to the first conductor side section, and a first conductor bottom section coupled to the first conductor side section, and (c) a protective material covering the first conductor and the electronic device. A lower surface of the first conductor top section can be higher than the device top side, and an upper surface of the first conductor bottom section can be lower than the device top side. Other examples and related methods are also disclosed herein.