Microelectronic assemblies fabricated using hybrid manufacturing with modified via-last process are disclosed. The fabrication approach is based on using hybrid manufacturing to bond first and second IC structures originally provided on different dies but filling at least portions of vias that are supposed to couple across a bonding interface between the first and second IC structures with electrically conductive materials after the IC structures have been bonded. A resulting microelectronic assembly that includes the first and second IC structures bonded together may have vias extending through all of the first IC structure and into the second IC structure, thus providing electrical coupling between one or more components of the first IC structure and those of the second IC structure, where an electrically conductive material in the individual vias is continuous through the first IC structure and at least a portion of the second IC structure.

A bonded assembly includes a first semiconductor die that includes first semiconductor devices, and a first pad-level dielectric layer and embedding first bonding pads; and a second semiconductor die that includes second semiconductor devices, and a second pad-level dielectric layer embedding second bonding pads that includes a respective second pad base portion. Each of the first bonding pads includes a respective first pad base portion and a respective first metal alloy material portion having a higher coefficient of thermal expansion (CTE) than the respective first pad base portion. Each of the second bonding pads is bonded to a respective one of the first bonding pads.

A bonded assembly includes a first semiconductor die that includes first semiconductor devices, and a first pad-level dielectric layer and embedding first bonding pads; and a second semiconductor die that includes second semiconductor devices, and a second pad-level dielectric layer embedding second bonding pads that includes a respective second pad base portion. Each of the first bonding pads includes a respective first pad base portion and a respective first metal alloy material portion having a higher coefficient of thermal expansion (CTE) than the respective first pad base portion. Each of the second bonding pads is bonded to a respective one of the first bonding pads.

A semiconductor package includes a semiconductor substrate, a conductive pad on the semiconductor substrate, a redistribution line conductor, a coating insulator, and an aluminum oxide layer. The redistribution line conductor is electrically connected to the conductive pad. The coating insulator covers the redistribution line conductor and partially exposes the redistribution line conductor. The aluminum oxide layer is provided below the coating insulator and extends along a top surface of the redistribution line conductor, and the aluminum oxide layer is in contact with the redistribution line conductor.

A semiconductor package includes a semiconductor substrate, a conductive pad on the semiconductor substrate, a redistribution line conductor, a coating insulator, and an aluminum oxide layer. The redistribution line conductor is electrically connected to the conductive pad. The coating insulator covers the redistribution line conductor and partially exposes the redistribution line conductor. The aluminum oxide layer is provided below the coating insulator and extends along a top surface of the redistribution line conductor, and the aluminum oxide layer is in contact with the redistribution line conductor.

A cobalt electroplating composition may include (a) cobalt ions; and (b) an ammonium compound of formula (NR.sup.1R.sup.2R.sup.3H.sup.+).sub.nX.sup.n−, wherein R.sup.1, R.sup.2, R.sup.3 are independently H or linear or branched C.sub.1 to C.sub.6 alkyl, X is one or more n valent inorganic or organic counter ion(s), and n is an integer from 1, 2, or 3.

A cobalt electroplating composition may include (a) cobalt ions; and (b) an ammonium compound of formula (NR.sup.1R.sup.2R.sup.3H.sup.+).sub.nX.sup.n−, wherein R.sup.1, R.sup.2, R.sup.3 are independently H or linear or branched C.sub.1 to C.sub.6 alkyl, X is one or more n valent inorganic or organic counter ion(s), and n is an integer from 1, 2, or 3.

A semiconductor device and a semiconductor package including the same are provided. The semiconductor device includes a semiconductor element; a protective layer disposed adjacent to the surface of the semiconductor element, the protective layer defining an opening to expose the semiconductor element; a first bump disposed on the semiconductor element; and a second bump disposed onto the surface of the protective layer. The first bump has a larger cross-section surface area than the second bump.

A semiconductor device and a semiconductor package including the same are provided. The semiconductor device includes a semiconductor element; a protective layer disposed adjacent to the surface of the semiconductor element, the protective layer defining an opening to expose the semiconductor element; a first bump disposed on the semiconductor element; and a second bump disposed onto the surface of the protective layer. The first bump has a larger cross-section surface area than the second bump.

A bonded assembly includes a first semiconductor die that includes first metallic bonding structures embedded within a first bonding-level dielectric layer, and a second semiconductor die that includes second metallic bonding structures embedded within a second bonding-level dielectric layer and bonded to the first metallic bonding structures by metal-to-metal bonding. One of the first metallic bonding structures a pad portion, and a via portion located between the pad portion and the first semiconductor device, the via portion having second tapered sidewalls.