In an embodiment, a method includes: bonding a back side of a first memory device to a front side of a second memory device with dielectric-to-dielectric bonds and with metal-to-metal bonds; after the bonding, forming first conductive bumps through a first dielectric layer at a front side of the first memory device, the first conductive bumps raised from a major surface of the first dielectric layer; testing the first memory device and the second memory device using the first conductive bumps; and after the testing, attaching a logic device to the first conductive bumps with reflowable connectors.

A structure includes a first die and a second die. The first die includes a first bonding layer having a first plurality of bond pads disposed therein and a first seal ring disposed in the first bonding layer. The first bonding layer extends over the first seal ring. The second die includes a second bonding layer having a second plurality of bond pads disposed therein. The first plurality of bond pads is bonded to the second plurality of bond pads. The first bonding layer is bonded to the second bonding layer. An area interposed between the first seal ring and the second bonding layer is free of bond pads.

A structure includes a first die and a second die. The first die includes a first bonding layer having a first plurality of bond pads disposed therein and a first seal ring disposed in the first bonding layer. The first bonding layer extends over the first seal ring. The second die includes a second bonding layer having a second plurality of bond pads disposed therein. The first plurality of bond pads is bonded to the second plurality of bond pads. The first bonding layer is bonded to the second bonding layer. An area interposed between the first seal ring and the second bonding layer is free of bond pads.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

A semiconductor device includes a first interconnect structure over first substrate, a first bonding layer over the first interconnect structure, multiple first bonding pads disposed in a first region of the first bonding layer, the first bonding pads having a first pitch, and multiple second bonding pads disposed in a second region of the first bonding layer, the second region extending between a first edge of the first bonding layer and the first region, the second bonding pads having the first pitch, the multiple second bonding pads including multiple pairs of adjacent second bonding pads, wherein the second bonding pads of each respective pair are connected by a first metal line.

Embodiments include a wafer-on-wafer bonding where each wafer includes a seal ring structure around die areas defined in the wafer. Embodiments provide a further seal ring spanning the interface between the wafers. Embodiments may extend the existing seal rings of the wafers, provide an extended seal ring structure separate from the existing seal rings of the wafers, or combinations thereof.

The disclosed technology generally relates to semiconductor wafer bonding, and more particularly to direct bonding by contacting surfaces of the semiconductor wafers. In one aspect, a method for bonding a first semiconductor substrate to a second semiconductor substrate by direct bonding is described. The substrates are both provided on their contact surfaces with a dielectric layer, followed by a CMP step for reducing the roughness of the dielectric layer. Then a layer of SiCN is deposited onto the dielectric layer, followed by a CMP step which reduces the roughness of the SiCN layer to the order of 1 tenth of a nanometer. Then the substrates are subjected to a pre-bond annealing step and then bonded by direct bonding, possibly preceded by one or more pre-treatments of the contact surfaces, and followed by a post-bond annealing step, at a temperature of less than or equal to 250° C. It has been found that the bond strength is excellent, even at the above named annealing temperatures, which are lower than presently known in the art.

The disclosed technology generally relates to semiconductor wafer bonding, and more particularly to direct bonding by contacting surfaces of the semiconductor wafers. In one aspect, a method for bonding a first semiconductor substrate to a second semiconductor substrate by direct bonding is described. The substrates are both provided on their contact surfaces with a dielectric layer, followed by a CMP step for reducing the roughness of the dielectric layer. Then a layer of SiCN is deposited onto the dielectric layer, followed by a CMP step which reduces the roughness of the SiCN layer to the order of 1 tenth of a nanometer. Then the substrates are subjected to a pre-bond annealing step and then bonded by direct bonding, possibly preceded by one or more pre-treatments of the contact surfaces, and followed by a post-bond annealing step, at a temperature of less than or equal to 250° C. It has been found that the bond strength is excellent, even at the above named annealing temperatures, which are lower than presently known in the art.

A semiconductor device includes: a first semiconductor substrate and a logic circuit provided on the first semiconductor substrate; a memory cell provided above the logic circuit and a second semiconductor substrate provided above the memory cell; a bonding pad provided above the second semiconductor substrate and electrically connected to the logic circuit; and a wiring provided above the second semiconductor substrate. The wiring is electrically connected to the memory cell, and includes at least one of a data signal line, a control voltage line, and a power supply line.

A semiconductor device includes: a first semiconductor substrate and a logic circuit provided on the first semiconductor substrate; a memory cell provided above the logic circuit and a second semiconductor substrate provided above the memory cell; a bonding pad provided above the second semiconductor substrate and electrically connected to the logic circuit; and a wiring provided above the second semiconductor substrate. The wiring is electrically connected to the memory cell, and includes at least one of a data signal line, a control voltage line, and a power supply line.