A display device includes a substrate, a first metal layer on the substrate, a first barrier insulating layer on the first metal layer, an etching control layer on the first barrier insulating layer, a first contact hole passing through the substrate, the first barrier insulating layer, and the etching control layer, a second barrier insulating layer on the etching control layer and including a second contact hole, a fan-out line on the second barrier insulating layer and included in a second metal layer, a pad part inserted into the second contact hole and included in the second metal layer, the pad part integral with the fan-out line, a display layer on the fan-out line, and a flexible film under the substrate and inserted into the first contact hole to be electrically connected to the pad part. The first metal layer includes an etching mark adjacent to the first contact hole.

An embodiment is a package including a first package structure. The first package structure includes a first integrated circuit die having an active side and a back-side, the active side comprising die connectors, a first electrical connector adjacent the first integrated circuit die, an encapsulant laterally encapsulating the first integrated circuit die and the first electrical connector, a first redistribution structure on and electrically connected to the die connectors of the first integrated circuit die and the first electrical connector, and thermal elements on the back-side of the first integrated circuit die. The package further includes a second package structure bonded to the first electrical connector and the thermal elements with a first set of conductive connectors.

An embodiment is a package including a first package structure. The first package structure includes a first integrated circuit die having an active side and a back-side, the active side comprising die connectors, a first electrical connector adjacent the first integrated circuit die, an encapsulant laterally encapsulating the first integrated circuit die and the first electrical connector, a first redistribution structure on and electrically connected to the die connectors of the first integrated circuit die and the first electrical connector, and thermal elements on the back-side of the first integrated circuit die. The package further includes a second package structure bonded to the first electrical connector and the thermal elements with a first set of conductive connectors.

Even in a case where a pad becomes smaller, solder connection strength is improved. 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.

Various embodiments of the present disclosure are directed towards an integrated circuit (IC) chip comprising a semiconductor device that is inverted and that overlies a dielectric region inset into a top of a semiconductor substrate. An interconnect structure overlies the semiconductor substrate and the dielectric region and further comprises an intermetal dielectric (IMD) layer. The IMD layer is bonded to the top of the semiconductor substrate and accommodates a pad. A semiconductor layer overlies the interconnect structure, and the semiconductor device is in the semiconductor layer, between the semiconductor layer and the interconnect structure. The semiconductor device comprises a first source/drain electrode overlying the dielectric region and further overlying and electrically coupled to the pad. The dielectric region reduces substrate capacitance to decrease substrate power loss and may, for example, be a cavity or a dielectric layer. A contact extends through the semiconductor layer to the pad.

Various embodiments of the present disclosure are directed towards an integrated circuit (IC) chip comprising a semiconductor device that is inverted and that overlies a dielectric region inset into a top of a semiconductor substrate. An interconnect structure overlies the semiconductor substrate and the dielectric region and further comprises an intermetal dielectric (IMD) layer. The IMD layer is bonded to the top of the semiconductor substrate and accommodates a pad. A semiconductor layer overlies the interconnect structure, and the semiconductor device is in the semiconductor layer, between the semiconductor layer and the interconnect structure. The semiconductor device comprises a first source/drain electrode overlying the dielectric region and further overlying and electrically coupled to the pad. The dielectric region reduces substrate capacitance to decrease substrate power loss and may, for example, be a cavity or a dielectric layer. A contact extends through the semiconductor layer to the pad.

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 method includes forming a conductive pad over an interconnect structure of a wafer, forming a capping layer over the conductive pad, forming a dielectric layer covering the capping layer, and etching the dielectric layer to form an opening in the dielectric layer. The capping layer is exposed to the opening. A wet-cleaning process is then performed on the wafer. During the wet-cleaning process, a top surface of the capping layer is exposed to a chemical solution used for performing the wet-cleaning process. The method further includes depositing a conductive diffusion barrier extending into the opening, and depositing a conductive material over the conductive diffusion barrier.

An integrated circuit includes a first chip bonded to a second chip. The first chip includes gate all around transistors on a substrate. The first chip includes backside conductive vias extending through the substrate to the gate all around transistors. The second chip includes electronic circuitry electrically connected to the transistors by the backside conductive vias.

An integrated circuit includes a first chip bonded to a second chip. The first chip includes gate all around transistors on a substrate. The first chip includes backside conductive vias extending through the substrate to the gate all around transistors. The second chip includes electronic circuitry electrically connected to the transistors by the backside conductive vias.