A semiconductor device includes a silicon layer, a metal silicide layer arranged directly on the silicon layer, and a solder layer arranged directly on the metal silicide layer.

A method for forming a three-dimensional memory device includes forming, on a first side of a first substrate, a peripheral circuitry including first and second peripheral devices, a first interconnect layer, and a shallow trench isolation (STI) structure between the first and second peripheral devices, and forming, on a second substrate, a memory array including a plurality of memory cells and a second interconnect layer. The method includes bonding the first and second interconnect layers and forming an isolation trench through the first substrate and exposing a portion of the STI structure. The isolation trench is formed through a second side of the first substrate that is opposite to the first side. The method includes disposing an isolation material to form an isolation structure in the isolation trench and performing a planarization process to remove portions of the isolation material disposed on the second side of the first substrate.

A method for forming a three-dimensional memory device includes forming, on a first side of a first substrate, a peripheral circuitry including first and second peripheral devices, a first interconnect layer, and a shallow trench isolation (STI) structure between the first and second peripheral devices, and forming, on a second substrate, a memory array including a plurality of memory cells and a second interconnect layer. The method includes bonding the first and second interconnect layers and forming an isolation trench through the first substrate and exposing a portion of the STI structure. The isolation trench is formed through a second side of the first substrate that is opposite to the first side. The method includes disposing an isolation material to form an isolation structure in the isolation trench and performing a planarization process to remove portions of the isolation material disposed on the second side of the first substrate.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a method for forming a semiconductor device is disclosed. A first device layer is formed above a first substrate. A first bonding layer including a first bonding contact is formed above the first device layer. The first bonding contact is made of a first indiffusible conductive material. A second device layer is formed above a second substrate. A second bonding layer including a second bonding contact is formed above the second device layer. The first substrate and the second substrate are bonded in a face-to-face manner, such that the first bonding contact is in contact with the second bonding contact at a bonding interface.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a method for forming a semiconductor device is disclosed. A first device layer is formed above a first substrate. A first bonding layer including a first bonding contact is formed above the first device layer. The first bonding contact is made of a first indiffusible conductive material. A second device layer is formed above a second substrate. A second bonding layer including a second bonding contact is formed above the second device layer. The first substrate and the second substrate are bonded in a face-to-face manner, such that the first bonding contact is in contact with the second bonding contact at a bonding interface.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a semiconductor device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a substrate, a first device layer disposed on the substrate, and a first bonding layer disposed above the first device layer and including a first bonding contact. The second semiconductor structure includes a second device layer and a second bonding layer disposed below the second device layer and including a second bonding contact. The first bonding contact is in contact with the second bonding contact at the bonding interface. At least one of the first bonding contact or the second bonding contact is made of an indiffusible conductive material.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a semiconductor device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a substrate, a first device layer disposed on the substrate, and a first bonding layer disposed above the first device layer and including a first bonding contact. The second semiconductor structure includes a second device layer and a second bonding layer disposed below the second device layer and including a second bonding contact. The first bonding contact is in contact with the second bonding contact at the bonding interface. At least one of the first bonding contact or the second bonding contact is made of an indiffusible conductive material.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a semiconductor device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a substrate, a first device layer disposed on the substrate, and a first bonding layer disposed above the first device layer and including a first bonding contact. The second semiconductor structure includes a second device layer and a second bonding layer disposed below the second device layer and including a second bonding contact. The first bonding contact is in contact with the second bonding contact at the bonding interface. At least one of the first bonding contact or the second bonding contact is made of an indiffusible conductive material.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a semiconductor device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a substrate, a first device layer disposed on the substrate, and a first bonding layer disposed above the first device layer and including a first bonding contact. The second semiconductor structure includes a second device layer and a second bonding layer disposed below the second device layer and including a second bonding contact. The first bonding contact is in contact with the second bonding contact at the bonding interface. At least one of the first bonding contact or the second bonding contact is made of an indiffusible conductive material.

A semiconductor element includes a semiconductor substrate; a collector layer on the semiconductor substrate; a base layer on the collector layer; an emitter layer on the base layer; emitter wiring electrically coupled to the emitter layer; a top metal layer on the emitter wiring; a first protective film covering the emitter wiring and the top metal layer, the first protective film having a first opening that overlaps at least the collector layer; and a bump including an under-bump metal layer electrically coupled to the emitter wiring via the first opening, the under-bump metal layer being larger than the first opening in plan-view area. The first protective film has an inner edge around the first opening, and the inner edge is on the top metal layer.