A method includes bonding a first device die with a second device die. The second device die is over the first device die. A passive device is formed in a combined structure including the first and the second device dies. The passive device includes a first and a second end. A gap-filling material is formed over the first device die, with the gap-filling material including portions on opposite sides of the second device die. The method further includes performing a planarization to reveal the second device die, with a remaining portion of the gap-filling material forming an isolation region, forming a first and a second through-vias penetrating through the isolation region to electrically couple to the first device die, and forming a first and a second electrical connectors electrically coupling to the first end and the second end of the passive device.

A semiconductor package includes a base including a first bonding structure; and a first semiconductor chip, including a second bonding structure, the second bonding structure being coupled to the first bonding structure of the base, wherein the first bonding structure includes: a test pad; a first pad being electrically connected to the test pad; and a first insulating layer, wherein the second bonding structure includes: a second pad being electrically connected to the first pad; and a second insulating layer being in contact with the first insulating layer, and wherein at least a portion of the test pad is in contact with the second insulating layer.

A semiconductor package includes a base including a first bonding structure; and a first semiconductor chip, including a second bonding structure, the second bonding structure being coupled to the first bonding structure of the base, wherein the first bonding structure includes: a test pad; a first pad being electrically connected to the test pad; and a first insulating layer, wherein the second bonding structure includes: a second pad being electrically connected to the first pad; and a second insulating layer being in contact with the first insulating layer, and wherein at least a portion of the test pad is in contact with the second insulating layer.

Methods for bonding substrates used, for example, in substrate-level packaging, are provided herein. In some embodiments, a method for bonding substrates includes: performing electrochemical deposition (ECD) to deposit at least one material on each of a first substrate and a second substrate, performing chemical mechanical polishing (CMP) on the first substrate and the second substrate to form a bonding interface on each of the first substrate and the second substrate, positioning the first substrate on the second substrate so that the bonding interface on the first substrate aligns with the bonding interface on the second substrate, and bonding the first substrate to the second substrate using the bonding interface on the first substrate and the bonding interface on the second substrate.

Methods for bonding substrates used, for example, in substrate-level packaging, are provided herein. In some embodiments, a method for bonding substrates includes: performing electrochemical deposition (ECD) to deposit at least one material on each of a first substrate and a second substrate, performing chemical mechanical polishing (CMP) on the first substrate and the second substrate to form a bonding interface on each of the first substrate and the second substrate, positioning the first substrate on the second substrate so that the bonding interface on the first substrate aligns with the bonding interface on the second substrate, and bonding the first substrate to the second substrate using the bonding interface on the first substrate and the bonding interface on the second substrate.

Embodiments of three-dimensional (3D) memory devices and methods for forming the 3D memory devices are disclosed. In an example, a method for forming a 3D memory device is disclosed. A memory stack including interleaved sacrificial layers and dielectric layers is formed above a first substrate. A channel structure extending vertically through the memory stack is formed. A single-crystal silicon layer is formed in a second substrate. An interconnect layer including a bit line is formed on the single-crystal silicon layer above the second substrate. The single-crystal silicon layer and the interconnect layer formed thereon are transferred from the second substrate onto the memory stack above the first substrate, such that the bit line in the interconnect layer is electrically connected to the channel structure.

Embodiments of three-dimensional (3D) memory devices and methods for forming the 3D memory devices are disclosed. In an example, a method for forming a 3D memory device is disclosed. A memory stack including interleaved sacrificial layers and dielectric layers is formed above a first substrate. A channel structure extending vertically through the memory stack is formed. A single-crystal silicon layer is formed in a second substrate. An interconnect layer including a bit line is formed on the single-crystal silicon layer above the second substrate. The single-crystal silicon layer and the interconnect layer formed thereon are transferred from the second substrate onto the memory stack above the first substrate, such that the bit line in the interconnect layer is electrically connected to the channel structure.

A wafer-to-wafer semiconductor device includes a first wafer substrate having a first bonding layer formed on a first bulk substrate layer. A second wafer substrate includes a second bonding layer formed on a second bulk substrate layer. The second bonding layer is bonded to the first bonding layer to define a bonding interface. At least one of the first wafer substrate and the second wafer substrate includes a crack-arresting film layer configured to increase a bonding energy of the bonding interface.

A wafer-to-wafer semiconductor device includes a first wafer substrate having a first bonding layer formed on a first bulk substrate layer. A second wafer substrate includes a second bonding layer formed on a second bulk substrate layer. The second bonding layer is bonded to the first bonding layer to define a bonding interface. At least one of the first wafer substrate and the second wafer substrate includes a crack-arresting film layer configured to increase a bonding energy of the bonding interface.

A method includes patterning a cavity through a first passivation layer of a first package component, the first package component comprising a first semiconductor substrate and bonding the first package component to a second package component. The second package component comprises a second semiconductor substrate and a second passivation layer. Bonding the first package component to the second package component comprises directly bonding the first passivation layer to the second passivation layer; and reflowing a solder region of a conductive connector disposed in the cavity to electrically connect the first package component to the second package component.