Disclosed is a semiconductor device including a conductive pattern on a substrate, a passivation layer on the substrate and including an opening that partially exposes the conductive pattern, and a pad structure in the opening of the passivation layer and connected to the conductive pattern. The pad structure includes a first metal layer that fills the opening of the passivation layer and has a width greater than that of the opening, and a second metal layer on the first metal layer. The first metal layer has a first thickness at an outer wall of the first metal layer, a second thickness on a top surface of the passivation layer, and a third thickness on a top surface of the conductive pattern. The second thickness is greater than the first thickness, and the third thickness is greater than the second thickness.

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.

A display device includes a substrate including a display area in which pixels are located, and a non-display area, first and second electrodes in the display area and spaced from each other, light emitting elements between the first and second electrodes, connection electrodes electrically connected to the light emitting elements, a fan-out line electrically connected to the pixels in the non-display area, a first pad electrode on the fan-out line, a pad connection electrode on the fan-out line and the first pad electrode, and electrically connecting the fan-out line and the first pad electrode, and a second pad electrode at a same layer as at least one of the connection electrodes, and contacting the first pad electrode.

A lead-free solder ball is provided which suppresses interfacial peeling in a bonding interface of a solder ball, fusion defects which develop between the solder ball and solder paste, and which can be used both with Ni electrodes plated with Au or the like and Cu electrodes having a water-soluble preflux applied atop Cu. The lead-free solder ball for electrodes of BGAs or CSPs consists of 1.6-2.9 mass % of Ag, 0.7-0.8 mass % of Cu, 0.05-0.08 mass % of Ni, and a remainder of Sn. It has excellent resistance to thermal fatigue and to drop impacts regardless of the type of electrodes of a printed circuit board to which it is bonded, which are Cu electrodes or Ni electrodes having Au plating or Au/Pd plating as surface treatment.

A method of forming semiconductor devices includes providing a wafer having a first side and second side, electrically conductive pads at the second side, and an electrically insulative layer at the second side with openings to the pads. The first side of the wafer is background to a desired thickness and an electrically conductive layer is deposited thereon. Nickel layers are simultaneously electrolessly deposited over the electrically conductive layer and over the pads, and diffusion barrier layers are then simultaneously deposited over the nickel layers. Another method of forming semiconductor devices includes depositing backmetal (BM) layers on the electrically conductive layer including a titanium layer, a nickel layer, and/or a silver layer. The BM layers are covered with a protective coating and a nickel layer is electrolessly deposited over the pads. A diffusion barrier layer is deposited over the nickel layer over the pads, and the protective coating is removed.

A method of forming semiconductor devices includes providing a wafer having a first side and second side, electrically conductive pads at the second side, and an electrically insulative layer at the second side with openings to the pads. The first side of the wafer is background to a desired thickness and an electrically conductive layer is deposited thereon. Nickel layers are simultaneously electrolessly deposited over the electrically conductive layer and over the pads, and diffusion barrier layers are then simultaneously deposited over the nickel layers. Another method of forming semiconductor devices includes depositing backmetal (BM) layers on the electrically conductive layer including a titanium layer, a nickel layer, and/or a silver layer. The BM layers are covered with a protective coating and a nickel layer is electrolessly deposited over the pads. A diffusion barrier layer is deposited over the nickel layer over the pads, and the protective coating is removed.

A method for bonding two superconducting integrated circuits (“chips”), such that the bonds electrically interconnect the chips. A plurality of indium-coated metallic posts may be deposited on each chip. The indium bumps are aligned and compressed with moderate pressure at a temperature at which the indium is deformable but not molten, forming fully superconducting connections between the two chips when the indium is cooled down to the superconducting state. An anti-diffusion layer may be applied below the indium bumps to block reaction with underlying layers. The method is scalable to a large number of small contacts on the wafer scale, and may be used to manufacture a multi-chip module comprising a plurality of chips on a common carrier. Superconducting classical and quantum computers and superconducting sensor arrays may be packaged.

A manufacturing method of a metal bump structure is provided. A driving base is provided. At least one pad and an insulating layer are formed on the driving base. The pad is formed on an arrangement surface of the driving base and has an upper surface. The insulating layer covers the arrangement surface of the driving base and the pad, and exposes a part of the upper surface of the pad. A patterned metal layer is formed on the upper surface of the pad exposed by the insulating layer, and extends to cover a part of the insulating layer. An electro-less plating process is performed to form at least one metal bump on the patterned metal layer. A first extension direction of the metal bump is perpendicular to a second extension direction of the driving base.

A method of treatment of an electronic circuit including at a location at least one electrically-conductive test pad having a first exposed surface. The method includes the at least partial etching of the test pad from the first surface, and the forming on the electronic circuit of an interconnection level covering said location and including, on the side opposite to said location, a second planar surface adapted for the performing of a hybrid molecular bonding.